Glossary of technical terms for the use of metallurgical engineers Terms starting with alphabet ‘F’
Glossary of technical terms for the use of metallurgical engineers
Terms starting with alphabet ‘F’
Fabric – It is a material made of woven fibers or filaments. It is a planar textile which is also known as cloth.
Fabricated valve – It is a valve in which the body is neither cast nor forged but rather is formed from plate or pipe welded together.
Fabricating (fabrication) – It is the manufacture of products from moulded parts, rods, tubes, sheeting, extrusions, or other form by appropriate operations, such as punching, cutting, drilling, and tapping. Fabrication includes fastening parts together or to other parts by mechanical devices, adhesives, heat sealing, welding, or other means.
Fabric fill face – It is that side of the woven fabric where the highest number of the yarns are perpendicular to the selvage.
Fabric, non-woven – It is a planar textile structure produced by loosely compressing together fibres, yarns, rovings, and so on, with or without a scrim cloth carrier. It is accomplished by mechanical, chemical, thermal, or solvent means, and combinations thereof.
Fabric prepreg batch – It consists of prepreg containing fabric from one fabric batch, impregnated with one batch of resin in one continuous operation.
Fabric warp face – It is that side of the woven fabric where the highest number of the yarns are parallel to the selvage.
Fabric, woven – It is a material (normally a planar structure) constructed by interlacing yarns, fibres, or filaments to form such fabric patterns as plain, harness satin, or leno weaves.
Fabricate – It means to work a material into a finished state by machining, forming, or joining.
Fabricator – Fabricator is a producer of intermediate products that does not also produce primary metal. For example, a reinforcement bar fabricator processes the material to the specifications of a particular construction project.
Fabrication – Metal fabrication is the creation of metal structures by cutting, bending and assembling processes. It is a value-added process involving the creation of machines, parts, and structures from different raw materials.
Facade engineering – It is the art and science of resolving aesthetic, environmental and structural issues to achieve the effective enclosure of buildings.
Face – In a lathe tool, it is the surface against which the chips bear as they are formed. In mining, it is the end of a drift, cross-cut or stope in which work is taking place.
Face-centered – It consists of having atoms or groups of atoms separated by translations of (i)1/2, 1/2, 0, (ii) 1/2, 0, 1/2 and (iii) 0, 1/2, 1/2 from a similar atom or group of atoms. The number of atoms in a face-centered cell is to be a multiple of 4.
Face centred cubic (FCC) – It is a type of atomic arrangement and is relatively ‘tightly packed (atomic packing factor = 0.74). Face centred cubic is formally defined as a cubic lattice with the face positions fully equivalent to each of the eight corners. A Face centred cubic unit cell contains atoms at all the corners of the crystal lattice and at the centre of all the faces of the cube. The atom present at the face-centered is shared between 2 adjacent unit cells and only 1/2 of each atom belongs to an individual cell.
Face (crystal) – It is an idiomorphic plane surface on a crystal.
Face milling – It consists of milling a surface which is perpendicular to the cutter axis.
Face pressure – It is the face load divided by the contacting area of the sealing lip. The face load is the sum of the pneumatic or hydraulic force and the spring force. For lip seals and packings, the face load also includes the interference load.
Face reinforcement – It is the weld reinforcement at the side of the joint from which welding has been done.
Face seal – It is a device which prevents the leakage of fluids along rotating shafts. Sealing is accomplished by a stationary primary-seal ring bearing against the face of a mating ring mounted on a shaft. Axial pressure maintains the contact between seal ring and mating ring.
Face-to-face, valve – It is the overall dimension from the inlet face to the outlet face of the valve (one end to the other). This dimension is governed by the standards, to ensure that such valves are mutually interchangeable regardless of the manufacturer.
Face-type cutters – These are the cutters which can be mounted directly on and driven from the machine spindle nose.
Facing – In machining, it consists of generating a surface on a rotating work-piece by the traverse of a tool perpendicular to the axis of rotation. In foundry practice, it is a material which is applied in a wet or dry condition to the face of a mould or core for improving the surface of the casting. For abrasion resistance, the preferred term is hard-facing which is the application of a hard, wear-resistant material to the surface of a component by welding, spraying, or allied welding processes for reducing wear or loss of material by abrasion, impact, erosion, galling, and cavitation. In case of pipe fittings, facing is the finishing of the contact surface of flanged fittings.
Facings – These are skins and doublers in any lay-up. Facings is also the outermost layer or composite component of a sandwich construction, normally thin and of high density, which resists most of the edgewise loads and flatwise bending moments, It is synonymous with face, skin, and face sheet.
Facility – It consists of land, buildings, and other structures, their functional systems and equipment, and other fixed systems and equipment installed therein, including site development features outside the plant, such as landscaping, roads, walks, and parking areas, outside lighting and communication systems, central utility plants, utilities supply and distribution systems, and other physical plant features. Facility consists of the equipment, structure, system, process, or activity which fulfills a specific purpose.
Factor analysis – It is a statistical method for reducing a set of variables to a smaller number of factors or basic components in a scale or instrument being analyzed. Two main forms are exploratory factor analysis (EFA) and confirmatory factor analysis (CFA).
Factor of safety – It is the ratio of the material strength to the computed stress. The factor of safety can vary from around 1.3, where component performance is well known and material properties show little variability, to 3 or 4 for an untried material or where stresses or environment are uncertain.
Fail action – It is a term used to describe the desired failure position of a control valve. It can be fail-closed, fail-open, or fail-in-place. With a spring-return actuator fail-in-place action normally needs the use of a lock-up valve.
Fail-closed – It is a condition wherein the valve closure member moves to a closed position when the actuating energy source fails.
Fail-open – It is a condition wherein the valve closure member moves to an open position when the actuating energy source fails.
Fail-safe – It is a characteristic of a valve and its actuator, which upon loss of actuating energy supply, causes a valve closure member to be fully closed, fully open, or remain in the last position, whichever position is defined as necessary to protect the process and equipment. Action can involve the use of auxiliary controls connected to the actuator.
Fail-safe design – It is a design which seeks to ensure that a failure is not going to affect the product or change it to a state in which injury or damage occurs.
Fail-safe valve – In a face-safe valve, when there is a failure in the pipeline system, the actuated valve is designed to automatically either open or close the valve.
Failure – It is a general term which is used to imply that a part in service (i) has become completely inoperable, (ii) is still operable but incapable of satisfactorily performing its intended function, or (iii) has deteriorated seriously, to the point that it has become unreliable or unsafe for continued use. The term failure is also normally applied to the manufacturing processes which produce products that do not meet specifications.
Failure analysis – It is a process of collecting and analyzing data and it is carried out to determine the causes or factors that have led to the undesired loss of functionality or failures of equipment components and assemblies, or structures. It is a multi-level process that includes physical investigation. The normal scope of a failure analysis is to find the failure mechanism and the most probable cause of the failure. The term failure mechanism is normally described as the metallurgical, chemical, mechanical, or tribological process leading to a particular failure mode.
Failure mechanism – It is a structural or chemical process, such as corrosion or fatigue, which is the cause of failure.
Failure mode and effect analysis (FMEA) – It is a systematic, detailed method of analysis of the malfunctions or defects which can be produced in the components of an engineering system. The analysis examines each potential failure mode to assess the reliability of the system elements and to ascertain the consequences of the failure upon the entire system. It is a ‘bottom up’ hazard identification technique. It considers the individual elements of a system, determines how each element can fail, and explores the effects of each such element failure on the operation of the system as a whole. This technique can also be used to quantify the failure rate of the total system by counting the contribution of each individual element.
Failure mode, effect, and criticality analysis (FMECA) – It is an extension of failure mode and effect analysis in which the criticality of each assembly is examined and the components and assemblies to which special attention are required to be given are identified.
Fairing – It is a member or structure, the primary function of which is to stream-line the flow of a fluid by producing a smooth outline and to reduce drag, as in aircraft frames and boat hulls.
Falcon concentrators – These are enhanced gravity separators (EGS) consisting of a fast-spinning bowl. The bowl is fed from its bottom and uses centrifugal force to drain the slurry in a thin flowing film at its wall. The Falcon concentrator is basically a combination of a sluice and a continuously operating centrifuge. It is capable of operating at a high speed of rotation and hence gravity force enables fine particles of different specific gravity to be separated. The shape of the spinning bowl is such that as the feed slurry moves up the bowl the heavier particles react more than the lighter particles to the forces acting upon them. This results in migration of the heavier particles within the slurry stream to the surface in contact with the bowl, while the lighter particles tend to move to the top of the slurry with the water. Separation then takes place by removal of the lower (higher specific gravity) portion of the slurry through a collection lip/slot, the flow through which is regulated by a number of orifices which open and close in a controlled manner, removing the concentrate from the main stream, which discharges to tailings.
False bottom – It is an insert put in either member of a die set to increase the strength and improve the life of the die.
False brinelling -It is the damage to a solid bearing surface characterized by indentations not caused by plastic deformation resulting from overload, but thought to be because of other causes such as fretting corrosion. It is also the local spots appearing when the protective film on a metal is broken continually by repeated impacts, normally in the presence of corrosive agents. The appearance is normally similar to that produced by brinelling but corrosion products are normally visible. It can result from fretting corrosion. This term is to be avoided when a more precise description is possible. False brinelling (race fretting) can be distinguished from true brinelling since in false brinelling, surface material is removed so that original finishing marks are removed. The borders of a false brinell mark are sharply defined, whereas a dent caused by a rolling element does not have sharp edges and the finishing marks are visible in the bottom of the dent.
False precision – It occurs when numerical data are presented in a manner which implies better precision than is justified. Since precision is a limit to accuracy, this frequently leads to over-confidence in the accuracy, which is named precision bias.
Fans – Fans are normally identified as machines with relatively low pressure rises which move air, gases, or vapours by means of rotating blades or impellers and change the rotating mechanical energy into pressure or work on the gas or vapour. The result of this work on the fluid is in the form of pressure energy or velocity energy, or some combination of both. Fans are widely used in industrial and commercial applications. Fans are critical for process support and human health from shop ventilation to material handling to boiler applications. There are two primary types of fans namely (i) centrifugal fans, and (ii) axial fans. These types are characterized by the path of the airflow through the fan. Centrifugal fans use a rotating impeller to move the air stream. As the air moves from the impeller hub to the blade tips, it gains kinetic energy. This kinetic energy is then converted to a static pressure increase as the air slows before entering the discharge. Axial fans move the air stream along the axis of the fan. Fan and blower selection depends on the volume flow rate, pressure, type of material handled, space limitations, and efficiency. Fan efficiencies differ from design to design and also by types.
Fans, industrial – Industrial fans are machines, whose primary function is to provide a large flow of air or gas to various processes. This is achieved by rotating a number of blades, connected to a hub and shaft, and driven by a motor or turbine. The flow rates of these fans range from around 5.7 cubic meter perm minute to 57,000 cubic meter per minute. A blower is another name for a fan which operates where the resistance to the flow is primarily on the downstream side of the fan.
Fan performance curves – Fan performance is typically defined by a plot of developed pressure and power needed over a range of fan-generated air flow. Understanding this relationship is necessary for designing, sourcing, and operating a fan system and is the key to optimum fan selection.
Fan systems – These are necessary to keep manufacturing processes working. A fan system consists of a fan, an electric motor, a drive system, ducts or piping, flow control devices, and air conditioning equipment (filters, cooling coils, and heat exchangers, etc.).
Farad – It is the SI (The International System of Units) unit of capacitance.
Faraday constant (F) – It is a unit of electric charge widely used in electro-chemistry equal to the negative of the molar charge (electric charge per mole) of electrons. It is equal to approximately 96,500 coulombs per mole.
Faraday–Lenz law – It is one of Maxwell’s equations, describing the relation between a changing magnetic field and production of an electro-motive force.
Faraday shield – It is a solid conductive shield around a volume, which blocks electromagnetic fields.
Faraday’s law – It says that the quantity of any substance dissolved or deposited in electrolysis is proportional to the total electric charge passed. It also says that the quantities of different substances dissolved or deposited by the passage of the same electric charge are proportional to their equivalent weights.
Faraday’s law of induction – It is the relation between a changing magnetic field and the resulting voltage produced in a closed path.
Far-infrared radiation – It is the infrared radiation in the wave-length range of 30 micrometers to 300 micrometers.
Fast breeder – It is a reactor type which is driven by the use of fast neutrons and which exploits the ‘plutonium economy’ fuel cycle by utilizing natural / depleted uranium after an initial fuel charge of plutonium. The fast neutrons (as opposed to the thermal neutrons used in conventional pressurized water reactor, PWR and boiling water reactor, BWR designs) react with the uranium-238 (U-238) to produce plutonium-239 (Pu-239).
Fastener – It is a hardware device which mechanically joins or affixes two or more objects together. Fastener can be easily installed and removed with hand tool or power tool. Common fasteners include screws, bolts, nuts and rivets. In general, fasteners are used to create non-permanent joints, i.e., joints which can be removed or dismantled without damaging the joining components. Steel fasteners are normally made of stainless steel, carbon steel, or alloy steel.
Fast Fourier transform – It is a digital algorithm to analyze a time series of sampled data into a set of sine and cosine frequency components.
FASTMET process – It is a coal-based process of ironmaking. It enables the conversion of metallic oxides from either iron ore fines or steel plant metallurgical waste, into metalized iron. FASTMET is a unique process uses a rotary hearth furnace (RHF) to reduce agglomerates containing coal with a high reduction ratio and high productivity. The FASTMET process converts iron ore pellet feed, iron ore fines and / or steel plant metallurgical waste into direct reduced iron (DRI) using pulverized non-coking coal as a reductant. The end product DRI can be either hot briquetted to produce hot briquetted iron (HBI), or discharged as hot DRI into transfer containers, or cooled if cold DRI is needed.
FASTMELT process – It is the FASTMET process with the addition of an ‘electric iron melting furnace’ (EIF) to produce liquid iron or hot metal.
Fast neutron – It is a neutron which has not been slowed down (or ‘moderated’) by a moderator material, typically water or graphite. The slower neutrons are referred to as thermal neutrons, meaning they have the sort of energy associated with ‘normal’ levels of heat.
Fast tracking – It is a schedule compression technique or duration compression technique in which the duration of a critical path is shortened by performing sections of some critical path activities concurrently instead of consecutively.
Fat – It is an organic ester, the product of a reaction between a fatty acid and glycerol. Fat can be of animal or vegetable materials or can be made synthetically.
Fatal injury – It is industrial accident resulting in a fatal injury to either the organization’s employees, contractor’s employee undertaking work for the organization or other persons where these result from an industrial accident arising from the organization’s activities. Death is to be certified by a medical professional. Fatality does not include fatalities involving voluntary social activities even if they are sponsored by the organization.
Fatal occupational injury – It is the occupational accident or injury leading to the death of a worker.
Fatality – It is the death resulting from an accident.
Fatality frequency rate (FFR) – It is calculated on the number of fatalities per million-man hours.
Fatigue – It is the phenomenon leading to fracture under repeated or fluctuating stresses having a maximum value less than the ultimate tensile strength of the material. Fatigue failure normally occurs at loads which applied statically produces little perceptible effect. Fatigue fractures are progressive, beginning as minute cracks which grow under the action of the fluctuating stress.
Fatigue assessment – It consists of fatigue resistance verification of a component subjected to a number of design / operating cycles.
Fatigue cracks – When the material is subjected to fatigue stress (cyclically applied stress), fatigue cracks can develop and grow and this eventually leads to failure. Fatigue cracks can happen even if the magnitude of the stress is smaller than the ultimate strength of the material. Fatigue cracks normally originate at the surface but in some cases can also initiate below the surface. Fatigue cracks initiate at location with high stresses such as discontinuities (hole, notch, scratch, sharp corner, porosity, crack, or inclusions etc.) and can also initiate at surfaces having rough surface finish or due to the presence of tensile residual stresses.
Fatigue crack growth rate (da/dN) – It is the rate of crack extension caused by constant-amplitude fatigue loading, expressed in terms of crack extension per cycle of load application, and plotted logarithmically against the stress-intensity factor range, ‘K’.
Fatigue failure – It is the failure which occurs when a sample undergoing fatigue completely fractures into two parts or has softened or been otherwise considerably reduced in stiffness by thermal heating or cracking.
Fatigue life (N) – It is (i) the number of cycles of stress or strain of a specified character which a given sample sustains before failure of a specified nature occurs, (ii) the number of cycles of deformation needed to bring about failure of a test sample under a given set of oscillating conditions (stresses or strains).
Fatigue life for ‘p’ % survival – It is an estimate of the fatigue life which ‘p’ % of the population is going to attain or exceed at a given stress level. The observed value of the median fatigue life estimates the fatigue life for 50 % survival. Fatigue life for ‘p’ % survival values, where ‘p’ is any number, such as 95, 90, etc., can also be estimated from the individual fatigue life values.
Fatigue limit – It is the maximum stress which presumably leads to fatigue fracture in a specified number of stress cycles. The value of the maximum stress and the stress ratio also is to be stated.
Fatigue limit for ‘p’ % survival – It is the limiting value of fatigue strength for ‘p’ % survival as the number of stress cycles becomes very large. ‘p’ cam be any number, such as 95, 90, etc.
Fatigue notch factor (Kf) – It is the ratio of the fatigue strength of an unnotched sample to the fatigue strength of a notched sample of the same material and condition. Both the strengths are determined at the same number of stress cycles.
Fatigue notch sensitivity (q) -It is an estimate of the effect of a notch or hole of a given size and shape on the fatigue properties of a material, measured by ‘q = (Kf -1)/(Kt -1)’, where ‘Kf’ is the fatigue notch factor and ‘Kt’ is the stress-concentration factor. A material is said to be fully notch sensitive if ‘q’ approaches a value of 1, it is not notch sensitive if the ratio approaches 0.
Fatigue ratio – It is the ratio of fatigue strength to tensile strength. Mean stress and alternating stress is to be stated.
Fatigue resistance – It refers to the ability of a material to withstand repeated cycles of stress or strain without experiencing failure. This property is crucial in applications where materials are subjected to fluctuating loads over time, such as in automotive, aerospace, and industrial machinery components.
Fatigue strength – It is the maximum cyclical stress which a material can withstand for a given number of cycles before failure occurs.
Fatigue strength at ‘N’ cycles (SN) – It is a hypothetical value of stress for failure at exactly ‘N’ cycles as determined from an S-N curve. The value of ‘SN’ hence determined is subject to the same conditions as those which apply to the S-N curve. The value of ‘SN’ which is normally found in the literature is the hypothetical value of maximum stress, ‘Smax’, minimum stress ‘Smin’, or stress amplitude, ‘Sa’, at which 50 % of the samples of a given sample can survive ‘N’ stress cycles in which the mean stress Sm = 0. This is also known as the median fatigue strength at ‘N’ cycles.
Fatigue strength for ‘p’ % survival at ‘N’ cycles – It is an estimate of the stress level at which ‘p’ % of the population is going to survive ‘N’ number of cycles. ’p’ can be any number, such as 95, 90, etc. The estimates of the fatigue strengths for ‘p’ % survival values are derived from particular points of the fatigue-life distribution since there is no test procedure by which a frequency distribution of fatigue strengths at ‘N’ cycles can be directly observed.
Fatigue-strength reduction factor – It is the ratio of the fatigue strength of a member or sample with no stress concentration to the fatigue strength with stress concentration. This factor has no meaning unless the stress range and the shape, size, and material of the member or sample are stated.
Fatigue striation – It is a micro-scale fatigue fracture feature sometimes observed which indicates the position of the crack front after each succeeding cycle of stress. The distance between striations indicates the advance of the crack front during one stress cycle, and a line normal to the striation indicates the direction of local crack propagation. It is not to be confused with beach marks, which are much larger (macroscopic) and form differently. It is also not to be confused with other similarly appearing micro-scale features, such as a stretch zone at the tip of a pre-existing crack-like imperfection, a Wallner line, and so on. Fatigue striation is the parallel lines frequently observed in electron microscope fractographs or fatigue fracture surfaces. The lines are transverse to the direction of local crack propagation. The distance between successive lines represents the advance of the crack front during the one cycle of stress variation. In glasses, fatigue striation is a fracture-surface marking consisting of the separation of the advancing crack front into separate fracture planes. It is also known as coarse hackle, step fracture, or lance. Striations can also be called shark’s teeth or whiskers.
Fatigue test – It is a method for determining the range of alternating (fluctuating) stresses a material can withstand without failing.
Fatigue wear – It is the removal of particles detached by fatigue arising from cyclic stress variations. It is also the wear of a solid surface caused by fracture arising from material fatigue. Fatigue wear is essential in periodically loaded dies and tools, such as rolls. In loaded tools, the surface is in compression and shear stresses are generated below the surface. Repeated loading causes generation of micro cracks, usually below the surface, at a point of weakness, such as an inclusion or second phase particle. On subsequent loading and unloading, the micro crack propagates and voids coalesce. When the crack reaches a critical size, it changes direction to emerge the surface and a flat sheet-like particle is detached. This is also known as delamination wear or if the particle is relatively large it is known as spalling. When normal loading is combined with sliding, the location of maximum shear stress moves towards the surface and fatigue cracks may then originate from surface defects.
Fatty acid – It is an organic acid of aliphatic structure originally derived from fats and fatty oils.
Fatty oil – It is a fat (glycerol ester) which is liquid at room temperature.
Fault – It is a break in the earth’s crust which is caused by tectonic forces which have moved the rock on one side with respect to the other.
Fault, electrical – It is a short circuit, open circuit, or other disruption of a power system.
Fault hazard analysis (FHA) – It is a qualitative analysis of design hazards other than malfunctions. Failure mode effect analysis, failure mode effect and criticality analysis, and fault tree analysis consider only malfunctions.
Fault tree – It is the analysis of an event in a top-down manner. The event is analyzed by breaking it down at each successive stage to identify what equipment and operator actions, if failed, would lead to the postulated outcome. The fault tree starts with the top event, as defined within the event tree analysis, and at each stage identifies combinations of precursor event(s) using logical operators such as ‘AND’ and ‘OR’.
Fault tree analysis (FTA) – It is an analysis method which provides a systematic description of the combinations of possible occurrences in a system which can result in failure. It is a graphical representation of the Boolean (a data type which has one of two possible values normally denoted true and false) logic which relates to the output (top) event. It is a graphical method for analyzing how a top event (normally a hazardous event) can be caused by lower-level events combined by logical operators (most frequently ‘AND’ and ‘OR’ gates). The method is useful for identifying single points of failure or limited redundancy in complex systems, and can be used for system reliability and availability calculations.
Fax – It is the facsimile, the transmission of paper images by radio or by wire.
Faying surface – It is the mating surface of a member which is in contact with or in close proximity to another member to which it is to be joined.
Feasibility report – It is a report which evaluates a set of proposed project paths or solutions to determine if they are viable. Persons who prepare the feasibility report evaluate the feasibility of different solutions and then chooses their recommendation for the best solution.
Feasibility mineral resource – Feasibility mineral resource is that part of measured mineral resource, which after feasibility study has been found to be economically not mineable.
Feasibility study – It is a comprehensive technical and economic assessment of the practicality of a project or system. A feasibility study aims to objectively and rationally uncover the strengths and weaknesses of a proposed venture, opportunities and threats present in the natural environment, the resources needed to carry through, and ultimately the prospects for success. In its simplest terms, the two criteria to judge feasibility are cost needed and value to be attained. A well-designed feasibility study is to provide a historical background of the project, a description of the product or service, accounting statements, details of the operations and management, marketing research and policies, financial data, and regulatory requirements. Normally, feasibility studies precede technical development and project implementation. A feasibility study evaluates the project’s potential for success. Hence I is perceived objectivity is an important factor in the credibility of the study for potential investors and lending institutions. It is hence to be conducted with an objective, unbiased approach to provide information upon which decisions can be based.
Feather burr – It is a very fine or thin burr.
Feather edge – It is same as feather burr except that feather edge can also refer to the ends of a lead-in or lead-out thread, which is a very thin machined ridge. It is sometimes called a wire edge or whisker-type burr.
Features – In computer modeling, these are higher level constructs (other than points, curves, and surfaces) which allow designers to work more naturally with geometries such as slots, through holes, and bosses etc. Form features such as these allow designers to add relatively complex yet common shapes without having to apply Boolean (a data type which has one of two possible values normally denoted true and false) operations on blocks and other shapes.
Feed – It is the rate at which a cutting tool or grinding wheel advances along or into the surface of a Work-piece, the direction of advance depending on the type of operation involved.
FEED – This acronym means ‘front-end engineering design’. FEED is the process by which early design and planning of a project is undertaken. The outcomes of front-end engineering design normally provide information for project execution and assist with gaining more certainty on price models and commercial terms for the project.
Feedability – It is the ability of a grease to flow to the suction of a pump.
Feed-back – It is a system which samples part of its output and adds that to its input; feed-back can be either positive or negative, aiding or opposing the initial input signal.
Feed-back amplifier – It is an amplifier which feeds back a small sample of its output to its input, for improving the linearity.
Feed-back control – It is a control mechanism which uses information from measurements to manipulate a variable to achieve the desired result. In feed-back control, the variable being controlled is measured and compared with a target value. This difference between the actual and desired value is called the error. Feed-back control manipulates an input to the system to minimize this error.
Feed-back loop – It is the signal path from the output back to the input to correct for any variation between the output levels from the set level. In other words, the output of a process is being continually monitored, the error between the set point and the output parameter is determined, and a correction signal is then sent back to one of the process inputs to correct for changes in the measured output parameter.
Feeder – It is a device which is mounted at the outlet of storage units such as bins, bunkers, silos or hoppers and which are used to control and meter the flow of bulk materials from the storage unit to meet the specified discharge flow rate. When the feeder stops, material flow ceases and when the feeder is turned on, there is a close correlation between its speed of operation and the rate of discharge of the bulk material.
Feeder (feeder head, feed-head) – In foundry practice, it is a riser which is a reservoir of molten metal connected to a casting to provide additional metal to the casting, needed as the result of shrinkage before and during solidification.
Feed forward – A feed forward is an element or pathway within a control system which passes a controlling signal from a source in its external environment to a load elsewhere in its external environment. This is frequently a command signal from an external operator.
Feed-forward control – It is a control system which adjusts the controlled variable based on a model of the process and measurements of disturbances, instead of feed-back from measurement of the process. It is also called anticipative control. It is a control mechanism which predicts the effects of measured disturbances and takes corrective action to achieve the desired result.
Feed hopper – It is a container which is used for holding the powder prior to compacting in a press.
Feed-in – It is being or belonging to something which feeds material (as into a machine) or to the process of feeding in this way. A feed-in device connects the main source of power to the subsidiary outlets.
Feed-in tariff – It is a premium rate paid to distributed generators to encourage alternative energy sources.
Feeding – In casting, it consists of providing molten metal to a region undergoing solidification, normally at a rate sufficient to fill the mould cavity ahead of the solidification front and to compensate for any shrinkage accompanying solidification. It is also conveying metal stock or work-pieces to a location for use or processing, such as wire to a consumable electrode, strip to a die, or work-pieces to an assembler.
Feed line – In the context of technology, it refers to a transmission line or cable which carries radio frequency (RF) signals between components in a communication system, such as an antenna and transmitter or receiver. Feed lines are made of specialized cables. Each feed line has its own characteristic impedance which is to be matched with that of the antenna to transfer the radio frequency power efficiently.
Feed lines – These are linear marks on a machined or ground surface which are spaced at intervals equal to the feed per revolution or per stroke.
Feed rate – It is the velocity at which the cutter is fed, i.e., advanced against the work-piece. It is expressed in units of distance per revolution for turning and boring (typically in millimeters per revolution).
Feed shoe – It is the part of the powder feed system which delivers the powder into the die cavity.
Feed stock – It is the raw material which goes into a process or plant as input to be converted into a product.
Feed system for gaseous fuels – Gaseous fuels are relatively easy to transport and handle. Any pressure difference causes gas to flow, and most gaseous fuels mix easily with air. Since on-site storage of gaseous fuel is typically not feasible, boilers are to be connected to a fuel source through a gas pipeline. Flow of gaseous fuels to a boiler can be precisely controlled using a variety of control systems. These systems normally include automatic valves which meter through gas flow through a burner and into the boiler based on steam or hot water demand.
Feed system for liquid fuels – Like gaseous fuels, liquid fuels are also relatively easy to transport and handle by using pumps and piping networks which link the boiler to a fuel supply such as a fuel oil storage tank. For promoting complete combustion, liquid fuels are to be atomized to allow thorough mixing with combustion air. Atomization by air, steam, or pressure produces tiny droplets which burn more like gas than liquid. Control of boilers which burns liquid fuels can also be accomplished using a variety of control systems which meter fuel flow.
Feed system for solid fuels – Solid fuels are much more difficult to handle than gaseous and liquid fuels. Preparing the fuel for combustion is normally necessary and can involve techniques such as crushing and / or pulverizing. Before combustion can occur, the individual fuels particles are to be transported from a storage area to the boiler. Mechanical devices such as conveyors, augers, hoppers, slide gates, vibrators, and blowers are frequently used for this purpose. The method selected depends primarily on the size of the individual fuel particles and the properties and characteristics of the fuel. Stokers are commonly used to feed solid fuel particles such as crushed coal, wood chips, and various forms of biomass into boilers
Feed velocity – It is the velocity at which the rolling stock enter the rolling mill. It is expressed in units of distance per minute (typically in metres per minute).
Feed water – It is the water which is used to remove heat from a reactor and produce (‘feed’) steam to drive the turbine generators. In case of a boiler in a power plant, feed water is the water supplied to the boiler which is converted into steam.
Feed-water heater – The purpose of feedwater heater is to preheat the feedwater with the heat energy of the spent steam. This improves the boiler efficiency. Heaters are shell and tube heat exchangers with the feedwater on the tube side (inside) and steam on the shell side (outside). The heater closest to the boiler receives the hottest steam. The condensed steam is recovered in the heater drains and pumped forward to the heater immediately upstream, where its heat value is combined with that of the steam for that heater. Ultimately the condensate is returned to the condensate storage tank or condenser hotwell.
Feldspar – It is a group of common rock-forming minerals which includes microcline, orthoclase, plagioclase and others. It is a group of rock-forming aluminium tectosilicate minerals, also containing other cations such as sodium, calcium, potassium, or barium. The most common members of the feldspar group are the plagioclase (sodium-calcium) feldspars and the alkali (potassium-sodium) feldspars. Feldspars crystallize from magma as both intrusive and extrusive igneous rocks and are also present in several types of metamorphic rock. Rock formed almost entirely of calcic plagioclase feldspar is known as anorthosite. Feldspars are also found in several types of sedimentary rocks.
Felsic – It is the term which is used to describe light-coloured rocks containing feldspar, feldspathoids and silica.
Felt – It is a fibrous material which is made up of interlocked fibres by mechanical or chemical action, moisture, or heat. It is made from fibres such as asbestos, cotton, glass, and so forth.
Female threaded – These pipe fittings have interior threads. They are either screwed on the outside of pipe end of a smaller diameter with external threading or they receive male threaded pipe fittings.
Female slip fit – In these pipe fittings there are no threads. They slip fit into a slightly smaller diameter sleeve.
Ferri-magnetic material – It is a material which macroscopically has properties similar to those of a ferro-magnetic material but that microscopically also resembles an anti-ferro-magnetic material in that some of the elementary magnetic moments are aligned antiparallel. If the moments are of different magnitudes, the material can still have a large resultant magnetization. It is also a material in which unequal magnetic moments are lined up anti-parallel to each other. Permeabilities are of the same order of magnitude as those of ferro-magnetic materials, but are lower than they are to be if all atomic moments are parallel and in the same direction. Under ordinary conditions the magnetic characteristics of ferri-magnetic materials are quite similar to those of ferro-magnetic material.
Ferrite – It is a solid solution of one or more elements in body-centered cubic iron. Unless otherwise designated (for example, as chromium ferrite), the solute is normally assumed to be carbon. On some equilibrium diagrams, there are two ferrite regions separated by an austenite area. The lower area is alpha ferrite, while the upper area is delta ferrite. If there is no designation, ferrite is assumed. Ferrite is also an essentially carbon-free solid solution in which iron is the solvent and which is characterized by a body-centered cubic crystal structure. Fully ferritic steels are only obtained when the carbon content is quite low. The most obvious micro-structural features in such metals are the ferrite grain boundaries.
Ferrite banding – It is parallel bands of free ferrite aligned in the direction of working. Sometimes it is referred to as ferrite streaks.
Ferrite core – It is a magnetic core for an inductor made from a metal oxide compound.
Ferrite magnet – It is a magnet made of a mixture of ferric oxide and a strong basic oxide, e.g., NaFeO2 (sodium ferrate). The oxides are used as compacted powders for rectifiers or permanent magnets or as powder on memory or record tapes.
Ferrite number – It is an arbitrary, standardized value designating the ferrite content of an austenitic stainless steel weld metal. This value directly replaces percent ferrite or volume percent ferrite and is determined by the magnetic test.
Ferrite-pearlite banding – It is inhomogeneous distribution of ferrite and pearlite aligned in filaments or plates parallel to the direction of working.
Ferrite stabilizer – It is an alloying element which, when added to iron, increases the region of the phase diagram in which ferrite is the stable phase. The strongest ferrite stabilizers are silicon, chromium, and molybdenum.
Ferrite streaks – It is parallel bands of free ferrite aligned in the direction of working.
Ferritic bainitic (FB) steels – Ferritic bainitic steels are sometimes called ‘stretch flangeable’ (SF) or ’high hole expansion’ (HHE) steels because of their improved edge stretch capability. Ferritic bainitic steels have a micro-structure of fine ferrite and bainite. Strengthening is obtained by both grain refinement and the second phase hardening with bainite. Ferritic bainitic steels are available as hot-rolled products. The primary advantage of ferritic bainitic steels over high strength low alloy steels and dual face steels is the improved stretchability of sheared edges as measured by the hole expansion test. Compared to high strength low alloy steels with the same level of strength, ferritic bainitic steels also have a higher strain hardening exponent and increased total elongation. Because of their good weldability, ferritic bainitic steels are considered for tailored blank applications. These steels are characterized by both good crash performances and good fatigue properties.
Ferritic grain size – It is the grain size of the ferritic matrix of a steel.
Ferritic malleable – It is a cast iron made by prolonged annealing of white iron in which decarburization, graphitization, or both take place to eliminate some or all of the cementite. The graphite is in the form of temper carbon. If decarburization is the predominant reaction, the product shows a light fracture surface, hence white-heart malleable. Otherwise, the fracture surface is dark, hence black-heart malleable. Ferritic malleable has a predominantly ferritic matrix.
Ferritic stainless-steels – These steels with body centered cubic crystal structures are a family of utility stainless steels which offer considerable better atmospheric corrosion resistance than carbon steels, as well as having good ductility, formability and impact resistance. Ferritic grades, containing only chromium and possibly other elements such as molybdenum, titanium, aluminum, and niobium etc., are well known as cost savings materials since majority of them have no expensive nickel additions. Also, the chromium content can be optimized ranging from 10.5 % to 29 % taking into account a very wide range of applications. The ferritic stainless steels are ferro-magnetic. They can have good ductility and formability, but high-temperature strengths are relatively poor compared to the austenitic grades. Toughness can be somewhat limited at low temperatures and in heavy sections.
Ferritic steel – It is a type of steel which is composed of less than 0.1 % carbon. It is magnetic and not capable of hardening through heating and quenching.
Ferritizing anneal – It is a treatment given as-cast gray or ductile (nodular) iron to produce an essentially ferritic matrix. For the term to be meaningful, the final micro-structure desired or the time-temperature cycle used is to be specified.
Ferro-alloys – Ferroalloys are a group of materials which are alloys of iron that contain a high percentage of one or more non-ferrous metals as alloying elements. These alloys are used for the addition of these other elements into liquid metal. They are normally used as addition agents. More than 85 % of ferroalloys produced are used primarily in the manufacture of steel.
Ferro-aluminum – It is a ferro-alloy composed of iron and aluminum with the content of the aluminum ranging from 30 % to 75 %. It is primarily used as a deoxidation agent for steel, as well as for moulding in combination with scrap copper and carbon steel. Ferro-aluminum as ferro-aluminum thermite (FAT) is an agent, which when ignited and mixed, can give off super extreme quantities of heat. Although this reactant is stable at room temperature, it burns through an extremely intense exothermic reaction.
Ferro-boron – It is a noble ferro-alloy which is mainly used as an additive in steelmaking to increase the hardenability, creep resistance and hot workability since steels alloyed with boron are oxidation resistant up to 900 deg C. The raw materials needed to produce ferro-boron are boric oxides and boric acid. Carbon (charcoal) and aluminum or magnesium is used as a reducing agent. The alloys can be produced by carbo-thermic or metallo-thermic reduction processes.
Ferro-chrome – Ferro-chrome is an alloy of chromium and iron containing between 45 % and 70 % of chromium. It also contains varying amounts of iron, carbon and other alloying elements. Ferro chrome with chrome content below 56 % is known as ‘charge chrome’. Ferro chrome is the major alloying element in the production of stainless steel. The use of ferro chrome depends widely on the carbon content. Ferro chrome can hence be classified as (i) high carbon ferro chrome with 4 % to 12 % C, (ii) medium carbon ferro chrome with 0.5 % to 4 % C, and low carbon ferro chrome with 0.1 % to 0.5 % C.
Ferro-electric – It is a crystalline material which shows spontaneous electrical polarization, hysteresis, and piezoelectric properties.
Ferro-electric effect – It is the phenomenon whereby certain crystals can shows a spontaneous dipole moment (which is called ferro-electric by analogy with ferro-magnetism showing a permanent magnetic moment). Ferro-electric crystals frequently show several Curie points, domain structures, and hysteresis, much as do ferro-magnetic crystals.
Ferro-electricity – It is the property of materials which spontaneously maintain an electrical polarization, as a ferro-magnetic material maintains magnetic polarization.
Ferro-graph – It is an instrument which is used to determine the size distribution of wear particles in lubricating oils of mechanical systems. The technique relies on the debris being capable of being attracted to a magnet.
Ferro-magnetic material – It is a material which in general shows the phenomena of hysteresis and saturation, and whose permeability is dependent on the magnetizing force. Microscopically, the elementary magnets are aligned parallel in volumes called domains. The unmagnetized condition of a ferro-magnetic material results from the overall neutralization of the magnetization of the domains to produce zero external magnetization.
Ferro-magnetic resonance – It is the magnetic resonance of a ferro-magnetic material.
Ferro-magnetism – It is a property shown by certain metals, alloys, and compounds of the transition (iron group), rare-earth, and actinide elements in which, below a certain temperature termed the Curie temperature, the atomic magnetic moments tend to line up in a common direction. Ferro-magnetism is characterized by the strong attraction of one magnetized body for another. Ferro-magnetism is a physical phenomenon (long-range ordering), in which certain materials like iron strongly attract each other. It is one of the common phenomena which are responsible for magnetism in the magnets. One of the vital requirements of ferro-magnetic material is that ions and atoms are to possess permanent magnetic moments. Some ions and atoms consist of the permanent magnetic moment which can be considered as a dipole that comprises a north pole separated from a south pole. Ferro-magnetism is caused in ferromagnets and the ferromagnets need to have net angular momentum which is got either through the orbital component of the spin component. In electro-magnetism, permeability is the measure of magnetization which a material obtains in response to an applied magnetic field.
Ferro-manganese (Fe-Mn) – It is a bulk ferroalloy of great importance, mainly in the steel and stainless-steel industries. Initially employed as a deoxidizing and desulphurizing agent, ferro manganese is mostly being used today for improving the hardness and wear resistance of steels. Ferro manganese is produced as three types of products namely (i) high carbon ferro manganese, (ii) medium carbon ferro manganese, and (iii) low carbon ferro manganese. High carbon ferro manganese has manganese in the range of 72 % to 82 %, carbon in the range of 6 % to 8 % and silicon in the range of around 1.5 %. Medium carbon ferro manganese has manganese in the range of 74 % to 82 %, carbon in the range of 1 % to 3 % and silicon in the range of around 1.5 %. Low carbon ferro manganese has manganese in the range of 80 % to 85 %, carbon in the range of 0.1 % to 0.7 % and silicon in the range of 1 % to 2 %.
Ferro-molybdenum (Fe-Mo) – It is an important noble ferro alloy. It is used in the production of different alloy steels. Commercial grade ferro-molybdenum contains between 60 % and 70 %. Ferro-molybdenum is a molybdenum based ferro-alloy, produced by alumino / silico thermic reduction from technical grade molybdenum trioxide (MoO3) or in induction / electric arc furnaces from molybdenum containing scraps.
Ferro-nickel (Fe-Ni) – It is a noble ferro-alloy. It is used for alloying in the production of stainless and construction steels. It is produced in reduction furnaces from nickel concentrates. It can contain up to 97.6 % nickel and be with high / low iron content.
Ferro-niobium – It is a niobium based ferro-alloy. It contains niobium in range of 60 % to 70 %. It is used as alloying additive in heat resistant and stainless steels to improve their corrosion resistance, plasticity and welding properties. It is also used for preventing the inter-crystalline corrosion of stainless chrome nickel steel. Its addition to construction steels prevents welded joint from corrosion. It is also used for micro-alloying in high strength low alloy steels. It is used in specialty alloyed steels. Vacuum grade ferro-niobium is used for super alloys additions in turbine blade applications in jet engines and land-based turbines, inconel family of alloys, and super alloys for the aerospace industry. The raw materials needed to produce ferro-niobium are ores and concentrates which contain niobium and iron oxide. Basic raw material for producing ferro niobium is pyrochlore ore. From this ore niobium penta-oxide (Nb2O5) is produced. Niobium penta-oxide is mixed with iron oxide and aluminum and is then reduced by alumino-thermic reaction to produce ferro niobium.
Ferro-silicon (Fe-Si) – Ferro-silicon contains 65 % to 90 % of silicon and minor amounts of iron, aluminum and carbon. Ferro-silicon increases the strength of steel and is therefore used in those steels which are needed for producing wire cords for tyres and ball bearings. Ferro-silicon is also used for deoxidation during steel making. The other major applications of ferro-silicon are in electrical steels used for transformers and dynamos, alloy steels for tools and automobile valves, and in iron castings.
Ferro-titanium – It is produced in two grades containing titanium in the range of 25 % to 35 % and 65 % to 75 %. This alloy is used for production of construction and stainless steels, and welding electrodes. Ferro-titanium when added to steel, increases yield strength of steel and reduces its cracking tendency. In the production of stainless steel with a high chrome and nickel content, it is used to bond the sulphur. Ferro-titanium is manufactured from various raw materials such as titanium scrap, ilemenite sand, rutile and titanium sponge. It is produced either from primary or secondary raw materials. The primary raw materials are minerals that contain titanium oxide, such as ilmenite. The reduction is normally carried out by the metallo-thermic process since the carbo-thermic reduction produces a ferro-alloy which contains too much carbon and hence not of much use in steel making. The production takes place as a batch process in a refractory lined crucible or in an electric furnace, depending on the process variation.
Ferro-tungsten – It is a tungsten based ferro-alloy which is used for the production of special steels. It is produced from different raw materials which contain tungsten oxides, e.g. wolframite, scheelite and hubnerite. The reduction of these minerals is done either by carbo-thermic or metallo-thermic reduction as well as by a combination of both. The tungsten trioxide in these ores is reduced by silicon and / or aluminum. Ferro tungsten contains 75 % to 85 % tungsten. Fe-W has a steel grey appearance and a fine-grained structure consisting of FeW and Fe2W.
Ferrous – This term is used for metallic materials in which the main component is iron.
Ferrous scrap – It is also referred to as, iron and steel scrap, or simply scrap comes from end-of-life products (old or obsolete scrap) as well as scrap generated from the manufacturing process (new, prime or prompt scrap). It is metal that contains iron. Iron and steel scrap can be processed and re-melted repeatedly to form new products. Due to the value of metal in the ferrous scrap, it is recycled or reused wherever it is possible. In fact, ferrous scrap is being recycled long before current awareness of environmental concerns started. Ferrous scrap is generated during the production of iron and steel, fabrication or manufacture of iron and steel products, or when the product made of iron and steel reaches its end of life. Because of the high value of the metal, the ferrous scrap is largely being recovered.
Ferrous scrap recycling – It consists of collection, sorting, shredding and / or sizing, and final melting at the steel plants.
Ferro-vanadium – It is vanadium based ferro-alloy which is used for the modification of the micro-structure of steel and for increasing the tensile strength, hardness, and high temperature strength. It is used in the high-speed steels. Vanadium content in ferro-vanadium ranges from 35 % to 80 %. Ferro-vanadium is produced by a carbo-thermic or a metallo-thermic (alumino thermic) reduction of vanadium oxides, assisted by the presence of iron. Since carbon is used in a carbo-thermic reduction, the carbon content of the ferro-alloy is normally high. Hence the process cannot be used if there is a requirement for low carbon content. Low carbon ferro-vanadium is normally produced by an alumino thermic reduction.
Fettling mixes – These are also granular refractory materials, with function similar to gunning mixes, but are applied by shoveling into the furnace needing patching.
Fibre – It is the characteristic of wrought metal which indicates directional properties and is revealed by etching of a longitudinal section or is manifested by the fibrous or woody appearance of a fracture. It is caused mainly by extension of the constituents of the metal, both metallic and non-metallic, in the direction of working during rolling, extrusion, or other solid-state processes, or by crystallographic alignment of the matrix phase itself. It is also the pattern of preferred orientation of metal crystals after a given deformation process, normally wire-drawing. In composites, fibre is a general term used to refer to filamentary materials. Frequently, fibre is used synonymously with filament. It is a general term for a filament with a finite length that is at least 100 times its diameter, which is typically 0.1 millimeter to 0.13 millimeter. In majority of the cases, it is prepared by drawing from a molten bath, spinning, or deposition on a substrate. A whisker, on the other hand, is a short, single- crystal fibre or filament made from a wide variety of materials, with diameters ranging from 1 micrometer to 25 micrometer and aspect ratios (a measure of length) between 100 and 15,000. Fibres can be continuous or specific short lengths (discontinuous), normally no less than 3.2 millimeters.
Fibre content – It is the quantity of fibre present in a composite. This is normally expressed as a percentage volume fraction or weight fraction of the composite.
Fibre count – It is the number of fibres per unit width of ply present in a specified section of a composite.
Fibre diameter – It is the measurement (expressed in hundred thousandths) of the diameter of individual filaments.
Fibre direction – It is the orientation or alignment of the longitudinal axis of the fibre with respect to a stated reference axis.
Fibre-glass – It is an individual filament made by drawing molten glass. A continuous filament is a glass fibre of great or indefinite length. A staple fibre is a glass fibre of relatively short length, normally less than 430 millimeters, the length related to the forming or spinning process used.
Fibre-glass reinforcement – It is the major material which is used to reinforce plastic. It is available as mat, roving, fabric, and so forth. It is incorporated into both thermosets and thermoplastics.
Fibre grease – It is a type of grease having a pronounced fibrous structure.
Fibering – It is the elongation and alignment of internal boundaries, second phases, and inclusions in particular directions corresponding to the direction of metal flow during deformation processing.
Fibre metallurgy – It is the technology of producing solid bodies from fibres or chopped filaments, with or without a metal matrix. The fibres can consist of such non-metals as graphite or aluminum oxide, or of such metals as tungsten or boron.
Fibre-optic cable – It is a transmission medium which uses infra-red energy or light to transmit information down a long thin transparent filament such as glass.
Fibre pattern – It consists of visible fibres on the surface of laminates or moulding. It is the thread size and weave of glass cloth.
Fibre placement – It is the continuous process for fabricating composite shapes with complex contours and / or cutouts by means of a device which lays pre-impregnated fibres (in tow form) onto a non-uniform mandrel or tool. It differs from filament winding in several ways. There is no limit on fibre angles. Compaction takes place on-line through heat, pressure, or both, and fibres can be added and dropped as necessary. The process produces more complex shapes and permits a faster put-down rate than filament winding.
Fibre-reinforced composite – It is a composite building material which consists of three components namely the fibres as the discontinuous or dispersed phase, the matrix as the continuous phase, and the fine inter-phase region, also known as the interface. The term is generic for composite materials and applies to metal and non-metal reinforcements. The metallic component can be made by powder metallurgy techniques.
Fibre-reinforced plastic (FRP) – It is a general term for a composite which is reinforced with cloth, mat, strands, or any other fibre form. It is a composite material made of a polymer matrix reinforced with fibres. The fibres are usually glass, carbon, aramid, or basalt. Rarely, other fibres such as paper, wood, boron, or asbestos have been used.
Fibre ropes – These ropes are made from a range of materials in a wide variety of constructions for a great diversity of uses, from the purely decorative to demanding engineering. fibre ropes are split into two categories namely (i) natural fibre rope such as manila, sisal, jute and cotton etc. and (ii) synthetic or man-made fibre rope such as polyester, polypropylene and nylon etc. Each type has its own range of characteristics and benefits but also some drawbacks.
Fibre show– It consists of strands or bundles of fibres which are not covered by plastic and which are at or above the surface of a composite.
Fibre stress – It is the local stress through a small area (a point or line) on a section where the stress is not uniform, as in a beam under a bending load.
Fibre texture – It is a texture characterized by having only one preferred crystallographic direction.
Fibre wash – It is the splaying out of woven or non-woven fibres from the normal reinforcement direction. Fibres are carried along with bleeding resin during cure.
Fibrous fracture – It is a gray and amorphous fracture which results when a metal is sufficiently ductile for the crystals to elongate before fracture occurs. When a fibrous fracture is got in an impact test, it can be regarded as definite evidence of toughness of the metal.
Fibrous structure – In forgings, it is a structure revealed as laminations, not necessarily detrimental, on an etched section or as a ropy appearance on a fracture. It is not to be confused with silky or ductile fracture of a clean metal. In wrought iron, it is a structure consisting of slag fibres embedded in ferrite. In rolled steel plate stock, it is a uniform, fine-grained structure on a fractured surface, free of laminations or shale-type discontinuities.
Fidelity – It is the degree to which an instrument indicates the measure variable without dynamic error.
Fieldbus – It is a digital, serial, two-way communications system which interconnects measurement and control devices such as sensors, actuators and controllers. Additional intelligence can be embedded in field devices which can allow calibration and diagnostics and decentralized control. A fieldbus is a member of a family of industrial digital communication networks used for real-time distributed control. Fieldbus profiles are standardized by the International Electrotechnical Commission as IEC 61784/61158.
Field coil – It is an electro-magnet used to generate a magnetic field in an electro-magnetic machine, typically a rotating electrical machine such as a motor or generator. It consists of a coil of wire through which a current flows.
Field devices – These are equipments which are connected to the field side on the integrated circuits. Types of field devices include remote thermal units (RTUs), programmable logic controller (PLCs), actuators, sensors, HMIs, and associated communications.
Field effect transistor – It is a transistor which relies on modulation of conductivity of a channel instead of injection of minority carriers as does a bipolar transistor.
Field-emission microscopy (FEM) – It is an image-forming analytical technique in which a strong electro-static field causes emission of electrons from a sharply rounded point or from a sample which has been placed on that point. The electrons are accelerated to a phosphorescent screen, or photographic film, producing a visible picture of the variation of emission over the specimen surface.
Field ion microscopy (FIM) – It is an analytical technique in which atoms are ionized by an electric field near a sharp specimen tip, the field then forces the ions to a fluorescent screen, which shows an enlarged image of the tip, and individual atoms are made visible. It can be used to resolve the individual atoms on the surface of a solid. It can also be used to study the three-dimensional structure of a material since successive atom layers can be ionized and removed from the surface by field evaporation. The ions removed from the surface by field evaporation can be analyzed chemically by coupling to the microscope a time-of-flight mass spectrometer of single-particle sensitivity, known as an atom probe (AP). The range of applications of the field ion microscopy / atom probe technique has extended rapidly, and virtually all metals and semi-conductors can now be studied. Whenever atomic-scale information on the structure or composition of a material is necessary, this approach is required to be considered.
Field ionization – It is the ionization of gaseous atoms and molecules by an intense electric field, frequently at the surface of a solid.
Field-oriented control – It is a control strategy for variable frequency drives which models the magnetic field of the motor to control it.
Field performance – It means performance of a device / equipment in its actual use.
Field serviceable – An equipment is field serviceable when normal repair or replacement of operating parts can be accomplished in the field without returning to the manufacturer.
Field winding – It is the insulated current-carrying coils on a field magnet which produce the magnetic field needed to excite a generator or motor.
FIFO – It means ‘first in first out’. It is an inventory method which assumes the first goods produced / purchased are the first goods sold. It is an asset management and valuation method in which older inventory is moved out before new inventory comes in. The first goods to be sold are the first goods produced / purchased.
Filament – It is a small, thin wire with two bigger wires holding it up in an incandescent light bulb. The filament is the part of the light bulb which produces light. Filaments are made of tungsten. Whenever an electric current goes through the filament, the filament glows. It is also known as the electron emitting element in a vacuum tube. To make the bulb produce more light, the filament is normally made of coils of fine wire, also known as the coiled coil. In case of composites, filament is the smallest unit of a fibrous material. It consists of the basic units formed during drawing and spinning, which are gathered into strands of fibre for use in composites. Filaments normally are of extreme length and very small diameter, normally less than 25 micrometers. Normally, filaments are not used individually. Some textile filaments can function as a yarn when they are of sufficient strength and flexibility.
Filamentary composite – It is a major form of advanced composite in which the fibre constituent consists of continuous filaments. Specifically, a filamentary composite is a laminate comprised of a number of laminae, each of which consists of a non-woven, parallel, uniaxial, planar array of filaments (or filament yarns) embedded in the selected matrix material. Individual laminae are directionally oriented and combined into specific multi-axial laminates for application to specific envelopes of strength and stiffness requirements.
Filamentary shrinkage – It is a fine network of shrinkage cavities, occasionally found in steel castings, which produces a radiographic image resembling lace.
Filament winding – It is a process for fabricating a reinforced plastic or composite structure in which continuous reinforcements (filament, wire, yarn, tape, and the like), either previously impregnated with a matrix material or impregnated during the winding, are placed over a rotating and removable form or mandrel in a prescribed way to meet certain stress conditions. Normally, the shape is a surface of revolution and may or may not include end closures. When the needed number of layers is applied, the wound form is cured and the mandrel is removed.
Filar eyepiece – It is an eyepiece having in its focal plane a fiducial line which can be moved using a calibrated micrometer screw. It is useful for accurate determination of linear dimensions. It is also termed filar micrometer.
File hardness – It is the hardness as determined by the use of a steel file of standardized hardness on the assumption that a material that cannot be cut with the file is as hard as, or harder than, the file. Files covering a range of hardnesses can be used. The most common are files heat treated to around 67 HRC (Rockwell C hardness) to 70 HRC.
Filiform corrosion – It is the corrosion which occurs under some coatings in the form of randomly distributed thread-like filaments.
Fill – It is the yarn oriented at right angles to the warp in a woven fabric.
Fill density – It is the weight of a unit volume of powder, normally expressed as grams per cubic centimeter, determined by a specified method.
Fill depth – It is synonymous with fill height.
Filled-system thermometer – It consists of a hollow metal bulb connected by a capillary tube to a device which responds to volume or pressure changes. The system is partially or completely filled with a liquid which expands with heat and contracts when cooled.
Filled thermal system – It is a thermal system filled with a gas and operating on the principle of pressure change with temperature change. The system is normally compensated.
Filler – In lubrication, it is a substance such as lime, talc, mica, and other powders, added to a grease to increase its consistency or to an oil to increase its viscosity. In composites, filler is a relatively inert substance which is added to a material to alter its physical, mechanical, thermal, electrical, and other properties, or to lower cost or density. Sometimes the term is used specifically to mean particulate additives.
Filler metal – It is the metal added in making a brazed, soldered, or welded joint.
Filler wire – It is a non-standard term for welding wire.
Fillet – It is a concave corner piece which is normally used at the intersection of casting sections. It is also the radius of metal at such junctions as opposed to an abrupt angular junction. Fillet is also a radius (curvature) imparted to inside meeting surfaces. In composites, fillet is a rounded filling or adhesive which fills the corner or angle where two adherends are joined.
Fillet radius – It is the blend radius between two abutting walls.
Fillet weld – It is a weld of approximately triangular cross section joining two surfaces approximately at right angles to each other in a lap joint, T-joint, or corner joint.
Fillet weld break test – It is a test in which the sample is loaded so that the weld root is in tension.
Fillet weld leg – It is the distance from the joint root to the toe of the fillet weld.
Fillet weld size – For equal leg fillet welds, it is the leg lengths of the largest isosceles right triangle which can be inscribed within the fillet weld cross section. For unequal leg fillets, it is the leg lengths of the largest right triangle which can be inscribed within the fillet weld cross section.
Fillet weld throat – It is the minimum distance minus any convexity between the weld root and the face of a fillet weld.
Fill factor – It is the quotient of the fill volume of a powder over the volume of a green compact after ejection from the die. It is the same as the quotient of the powder fill height of the compact over the height of the compact. It is the inverse parameter of compression ratio.
Fill height – It is the distance between the lower punch face and the top plane of the die body in the fill position of the press tool.
Filling yarn – It is the transverse threads or fibers in a woven fabric. Those fibers running perpendicular to the warp. It is also called weft.
Fill position – It is the position of the press tool which enables the filling of the desired quantity of powder into the die cavity.
Fill ratio – It is the ratio of the volume of loose powder in a die to the volume of the compact made from it.
Fill shoe – It is the part of the powder feed system which delivers the powder into the die cavity.
Fill volume – It the volume which a powder fills after flowing loosely into a space which is open at the top, such as a die cavity or a measuring receptacle.
Film – It is a thin, not necessarily visible, layer of material.
Film adhesive – It is a synthetic resin adhesive, normally of the thermosetting type, in the form of a thin, dry film of resin with or without a paper or glass carrier.
Film badge – This photographic film is a type of dosimeter used for the measurement of ionizing radiation exposure for personnel monitoring purposes. The film badge can contain two or three films of differing sensitivities, and it can also contain a filter which shields part of the film from certain types of radiation.
Film resistance – It is the electrical resistance which results from films at contacting surfaces, such as oxides and contaminants, which prevent pure metallic contact.
Film strength – It is the relative resistance of a bisque to mechanical damage. It is an imprecise term denoting ability of a surface film to resist rupture by the penetration of asperities during sliding or rolling. A high film strength is mainly inferred from a high load-carrying capacity and is seldom directly measured.
Film thickness – In a dynamic seal, it is the distance separating the two surfaces which form the main seal.
FILO principle – It means ’First In, Last Out’ i.e., the first object or item in a stack is the last object or item to leave the stack. It is a storage method in which the most recently received stock is used first. This means that the newest products are sold or consumed first, while the older stock remains in the warehouse for longer.
Filter – It a substance with pores through which a gas or liquid is passed to separate out floating matter. It is also a device containing a filter. In photography, it is a transparent material (as coloured glass) which absorbs light of some wave-lengths and is used to change light. In electrical engineering, it is a circuit which selectively alters a signal based on its frequency components. In powder metallurgy, metal filters are porous products made either from wires and fibres or from sintered powders. In microscopy, filter is a semi-transparent optical element which is capable of absorbing unwanted electro-magnetic radiation and transmitting the remainder. A neutral density filter attenuates relatively uniformly from the ultra-violet to the infra-red, but in several applications highly wave-length-selective filters are used.
Filter capacitor – In a power supply, it is a capacitor which smooths the direct current voltage produced by a rectifier stage.
Filters (bag houses) – Fabric filters are also known as bag houses. They use filtration to separate dust particulates from dusty gases. They are one of the most efficient and cost -types of dust collectors available. Dust-laden gases enter the fabric filter and pass-through fabric bags which act as filters. The bags can be of woven or felted cotton, synthetic, or glass-fibre material in either a tube or envelope shape. The high efficiency of these filters is due to the dust cake formed on the surfaces of the bags. The fabric filters mainly provide a surface on which dust particulates collect.
Filtration – It is a physical separation process that separates solid matter and fluid from a mixture using a filter medium which has a complex structure through which only the fluid can pass. It removes coarse suspended matter and sludge from coagulation or from water softening systems. Gravel beds and anthracite coal are common materials used for filter beds. Softening is the treatment of water to remove dissolved mineral salts such as calcium and magnesium, known as hardness, in boiler feedwater. Softening methods include the addition of calcium carbonate (lime soda), phosphate, and / or zeolites (crystalline mineral compounds).
Filtration of particles from gas streams – A major class of particulate air pollution control devices relies on the filtration of particles from gas streams. A variety of filter media is employed, including fibrous beds, packed beds, and fabrics. Fibrous beds used to collect airborne particles are typically quite sparsely packed, usually only around 10 % of the bed volume being fibers. Packed bed filters consist of solid packing normally in a tube and tend to have higher packing densities than do fibrous filters. Both fibrous and packed beds are widely used in the ventilation systems. Fabric filters are frequently used to remove solid particles from industrial gases, whereby the dusty gas flows through fabric bags and the particles accumulate on the cloth. The physical mechanisms by which the filtration is accomplished vary depending on the mode of filtration.
Fin – It is the thin projection formed on a forging by trimming or when metal is forced under pressure into hair-line cracks or die interfaces.
Final annealing – It is an imprecise term used to denote the last anneal given to a non-ferrous alloy prior to shipment.
Final density – In powder metallurgy, it is the density of a sintered product.
Final polishing – It is a polishing process in which the primary objective is to produce a final surface suitable for microscopic examination.
Fine gold – It is the fineness which is the proportion of pure gold in jewelry or bullion expressed in parts per thousand. Hence, 925 fine gold indicates 925 parts out of 1,000, or 92.5 % is pure gold.
Fine grinding – It is precision grinding process which uses extremely fine abrasive (50 micrometers and finer).
Fineness – It is a measure of the purity of gold or silver expressed in parts per thousand.
Fineness of enamel – It is a measurement of the degree to which a frit has been milled in wet or dry form. It is normally expressed in grams residue retained on a certain type of mesh screen from a 50 cubic meters sample or a 100 grams sample.
Fines – It is the product which passes through the finest screen in sorting crushed or ground material. It is also the sand grains which are substantially smaller than the predominating size in a batch or lot of foundry sand. It is also the portion of a powder composed of particles smaller than a specified size, normally 44 micrometers.
FINEX process – It is a smelting-reduction process for the production of hot metal (HM). This process is based on the direct use of non-coking coal. The FINEX process can directly use iron ore fines without any kind of agglomeration. In the FINEX process, fine iron ore is preheated and reduced to fine direct reduced iron (DRI) in three stage fluidized bed reactor system with reduction gas produced from melter gasifier. The fluidized bed reactors enable the FINEX process to use fine ores instead of lump ore or pellets. The FINEX process uses high purity oxygen, resulting in an export gas with only low quantities of nitrogen. As its net calorific value is more than two times of the blast furnace top gas, it can be partially recycled for reduction work or can be used for heat or energy generation.
Fine silver – It is the silver with a fineness of three nines (999), which is equivalent to a minimum content of 99.9 % silver (Ag) with the remaining content unrestricted.
Finish – It is the surface condition, quality, or appearance of a metal. It is the stock on a forging or casting to be removed in finish machining. It is the forging operation in which the part is forged into its final shape in the finish die. If only one finish operation is scheduled to be performed in the finish die, this operation is to be identified simply as finish, normally first, second, or third finish designations are so termed when one or more finish operations are to be performed in the same finish die. In composites, It is the chemical finish applied to glass and other fibres, after sizing has been removed, to facilitate resin wetting, resin bonding, and good environmental performance of the cured laminate.
Finish allowance – It is the quantity of excess metal surrounding the intended final configuration of a formed part. It is sometimes called forging envelope, machining allowance, or cleanup allowance.
Finish annealing – It is a sub-critical annealing treatment applied to cold-worked low-carbon or medium-carbon steel. Finish annealing, which is a compromise treatment, lowers residual stresses, hence minimizes the risk of distortion in machining while retaining majority of the benefits to machinability contributed by cold working.
Finished rolled products – These are the products which have been manufactured by rolling and which are normally not further hot worked in the steel plant. The cross-section is uniform over the whole length. These are normally defined by a standard, which fixes the normal size ranges and the tolerances on shape and dimension. The surface is normally smooth, but reinforcing bars or floor plates, for example, can have a regularly raised or indented pattern.
Finished steel – It is the steel which is ready for the market and has been processed beyond the stages of billets, blooms, and slabs. These steel products can be broadly divided into four categories namely (i) bar, rod, and sectional products, (ii) plate and sheet products, (iii) coated steel products, and (iv) pipe and tube products.
Finished stock – It means stock which has been manufactured and which is ready for packing, shipment or sale.
Finisher (finishing impression) – It is the die impression which imparts the final shape to a forged part.
Finish grinding – It is the final grinding action on a work-piece, of which the objectives are surface finish and dimensional accuracy.
Finishing – It is the final stages of inspection and preparation of the galvanized steel so that it complies with the specification.
Finishing block – It is also known as no-twist block or no-twist mill. In wire rod mills, it represents one of the key elements. Only through this development, it has become possible to safely roll thin wire rods at speed of over 120 metres per second. The finishing block can be of 4, 6, 8, and 10 roll stands for twist free rolling. A primary gearbox drives the roll units through two common shafts. Finishing blocks having two different sizes of roll units are available, with 170/150 millimeters diameter rolls and 225/200 millimeters diameter rolls. All roll units are identical and inter-changeable.
Finishing die – It is the die set which is used in the last forging step.
Finishing drawing – The finishing drawing has a close relationship with the elevation drawings as it also talks about the smaller details of a facility. This drawing is important for maintaining the aesthetic value of the structure.
Finishing facilities – It is that portion of the plant complex which processes semi-finished products (slabs or billets) into saleable products. Finishing operations can include rolling mills, pickle lines, tandem mills, annealing facilities, temper mills, and coating lines.
Finishing mill – It is that rolling mill which produces saleable products.
Finishing stand – It is the last stand in a rolling mill, which determines the surface finish and final gauge.
Finishing temperature – It is the temperature at which hot working is completed.
Finish machining – It is a machining process which is analogous to finish grinding.
Finish-to-finish – In a finish-to-finish relationship, a successor activity cannot finish until a predecessor activity has finished.
Finish-to-start – In a finish-to-start relationship, a successor activity cannot start until a predecessor activity has finished.
Finish trim – It is the flash removal from a forging. It is normally performed by trimming, but sometimes by band sawing or similar techniques.
Finite element analysis (FEA), Finite element modeling (FEM) – These are numerical techniques in which the analysis of a complex part is represented by a mesh of elements inter-connected at node points. The coordinates of the nodes are combined with the elastic properties of the material to produce a stiffness matrix, and this matrix is combined with the applied loads to determine the deflections at the nodes, and hence, the stresses. All of the above is done with special analysis /modeling software. These approaches also can be used to solve other field problems in heat transfer, fluid flow, and acoustics etc.
Finite impulse response – It is a class of digital filters whose response to an impulse return to zero in finite time.
Finmet process – It is the process which reduces iron ore fines with gas in a descending series of fluidized bed reactors. The reduced iron is hot briquetted.
Finned tubes – They are tubes where fins have been added on the outside to increase the contact area with the outside fluid, to exchange heat and between the fluid inside the tube and the fluid outside the tube. These tubes are the main components of heat exchangers.
Finned tube heat exchanger or economizer – Finned tube heat exchanger is used to recover heat from low to medium temperature exhaust gases for heating liquids. Applications include boiler feed water preheating and air preheating etc. The finned tube consists of a round tube with attached fins which maximize surface area and heat transfer rates. Liquid or air flows through the tubes and receives heat from hot exhaust gases flowing across the tubes. A finned tube exchanger where boiler exhaust gases are used for feed water preheating is generally referred to as a boiler economizer.
Finstock – It is narrow strip in the thickness range 0.2 millimeters to 0.4 millimeters used for finning of heat exchanger tubes in applications such as air conditioning.
Fire assay – It is an assaying method normally used for the determination of precious metal content.
Fire-brick – It is a refractory brick, frequently made from fireclay, which is able to withstand high temperature (1,500 deg C to 1,600 deg C) and is used to line furnaces, ladles, or other molten metal containment components.
Firebrick, insulating – It is a refractory brick which is characterized by low thermal conductivity and low heat capacity.
Fire-clay – It is a mineral aggregate which has as its essential constituent the hydrous silicates of aluminum with or without free silica. It is used in commercial refractory products.
Fireclay, nodular – It is a rock containing aluminous or ferruginous nodules, or both, bonded by fireclay.
Fireclay, plastic or bond – It is a fireclay of sufficient natural plasticity to bond non-plastic materials.
Fireclay plastic refractory -It is a fireclay material tempered with water and suitable for ramming into place to form a monolithic furnace lining which attains satisfactory physical properties when subjected to the heat of furnace operation.
Fire-clay refractory bricks – These bricks are manufactured from unfired refractory bond clay and fireclays (chamotte), fired refractory clay or similar grog materials. Fireclay refractory bricks have two main components namely 18 % to 44 % of alumina (Al2O3) and 50 % to 80 % of silica (SiO2). The variety of clays and manufacturing techniques allows the production of several brick types appropriate to particular applications. The usefulness of fireclay refractory bricks is largely because of the presence of mineral mullite, which forms during firing and is characterized by high refractoriness and low thermal expansion. There are five standard classes of fireclay bricks namely (i) super duty, (ii) high duty, (iii) medium duty, (iv) low duty, and (v) semi silica.
Fire cracks – Fire cracks are thermo-shock cracks which form under a very sharp cooling rate on the roll surface. When the heated roll surface with a thermal gradient perpendicular to the roll surface during the revolution of the roll is quenched by the cooling water, surface tensile stress is built up. When the tensile stress reaches the tensile strength of the roll material, then cracks (fire cracks) are initiated. These cracks are only formed under tensile stress.
Fire-cracker welding – It is a variation of the shielded metal arc welding process in which a length of covered electrode is placed along the joint in contact with the work-pieces. During the welding operation, the stationary electrode is consumed as the arc travels the length of the electrode.
Fire crack transfer marks – Fire crack transfer marks are patterns of elevations which recur periodically and run at right angle to the direction of rolling. They can be easily detected with naked eye or with low magnification because of their characteristics. During hot rolling, the surface of the rolls is subjected to continuous heating and quenching. With inadequate cooling and the use of unsuitable roll material, stress cracks can occur in the roll grooves. These crack depressions in the roll surface leads to elevations on the rolled product. Although fire crack transfer marks are smoothed in subsequent passes, they can lead to other surface defects such as cracks and laps.
Fired mould – It is a shell mould or solid mould which has been heated to a high temperature and is ready for casting.
Fire-fighting – Fire is one of the major hazards present in a steel plant. A well-planned fire-fighting system is necessary for combating the fires.
Fire-fighting drawing – This drawing is drawn before the construction of a facility. The drawing shows the pattern of the placement of the fire hoses, points, water outlets, and everything connected with fire-fighting. The drawing also lays out the fire protection plan and safety systems which are to be set in place.
Fire hazard analysis – It is an assessment of the risks from fire within an individual fire area in a facility analyzing the relationship to existing or proposed fire protection. This includes an assessment of the consequences of fire on safety systems and the capability to safely operate a facility during and after a fire.
Fire protection engineering – It is the application of science and engineering principles to protect people, property, and their environments from the harmful and destructive effects of fire and smoke. It encompasses engineering which focuses on fire detection, suppression and mitigation and fire safety engineering which focuses on human behaviour and maintaining a tenable environment for evacuation from a fire. Fire protection engineering frequently includes fire safety engineering.
Firing – It is the controlled heat treatment of ceramic ware in a kiln or furnace to develop the desired final properties.
Firing time – It is the period during which the ceramic ware remains in the firing zone of the furnace to mature a ceramic or porcelain enamel coating.
Fire loss – It is the monetary cost of restoring damaged property to its pre-fire condition. When determining the loss, the estimated damage to the facility and contents is to include replacement cost, less salvage value.
Fire point – Fire point is the temperature at which a fluid gives off vapour in sufficient quantity to ignite and continue to burn when exposed to a spark or flame. Like flash point, a high fire point is required of desirable hydraulic fluids.
Fire prevention – It is the concept of preventing outbreaks of fire, of reducing the risk of fire spreading and of avoiding danger to persons and property from fire.
Fire protection – It is a broad term which encompasses all aspects of fire safety, including building construction and fixed building fire features, fire suppression and detection systems, fire water systems, emergency process safety control systems, emergency fire-fighting organizations (fire departments, fire brigades, etc.), fire protection engineering, and fire prevention. Fire protection is concerned with preventing or minimizing the direct and indirect consequences of the fire.
Fire protection system – It is the system designed to detect and contain or extinguish a fire, as well as limit the extent of fire damage and enhance life safety.
Fire-refined copper – It is the copper which has been refined by the use of a furnace process only, including refinery shapes, and by extension, as well as the fabricators’ products made therefrom. Normally, when this term is used alone it refers to fire-refined tough pitch copper without elements other than oxygen being present in considerable quantities.
Fire resistant hydraulic fluids – These fluids generate less heat when burnt than those of mineral oil-based fluids. These fluids are mainly used in situations where there are chances of fire hazards. These fluids are made of lower heat value compared to those of mineral oil-based fluids, such as water-glycol, phosphate ester, and polyol esters. International Organization for Standardization (ISO) have classified these fluids as HFAE (soluble oils), HFAS (high water-based fluids), HFB (invert emulsions), HFC (water glycols), HFDR (phosphate ester), and HRDU (polyol esters).
Fire resistant steels – These steels have been developed for construction applications where increased high temperature strength provides improved protection to a building structure during a fire. Improved fire protection, in turn, helps to prevent building collapse caused by reduced load carrying capability of steel structures at high temperature, or provides the building occupants higher time to escape the building in the event of such a collapse.
Fire-safe – This is a term used to describe the fire resistance ability of a valve when exposed to fire. In order to qualify for this certification, a valve is required to be exposed to fire for a 30-minute period. Once acceptable leakage (through the test valve and also external leakage) has been confirmed, the valve is considered to be fire-safe.
Fire safety – It is a risk-based approach to fire safety.
Fire-tube boiler – Fire tube boiler consists of numbers of tubes through which hot gasses are passed. These hot gas tubes are immersed into water, in a closed vessel. In this boiler one closed vessel or shell contains water, through which hot gas tubes are passed. These hot gas tubes heat up the water and convert the water into steam and the steam remains in same vessel.
Firmware – It is the software of a computer which is never or rarely altered during its working life, e.g., the control computer programme for an automotive ignition system.
First aid – It is the skilled application of accepted principles of treatment on the occurrence of an accident or in the case of sudden illness, using facilities or materials available at the time. It is the immediate care given to a person who is injured.
First angle projection – In the first angle projection, the front view is the basis (reference) and the other views are drawn as ‘shadows’ of that view. That is, the left- hand side view for example is drawn on the right side of the front view. Similarly, the top view (plan) is drawn at the bottom of the front view etc.
First block, second block, and finish – It is the forging operation in which the part to be forged is passed in progressive order through three tools mounted in one forging machine. Only one heat is involved for all three operations.
First-order transition – It is a change of state associated with crystallization or melting in a polymer.
Fir-tree crystal – It is a type of dendrite crystal.
Fish bone diagrams – These are casual diagrams which show the causes of a specific event. Common uses of these diagrams are (i) product design and quality defect prevention, and (ii) to identify potential factors causing an overall effect. Each cause or reason for imperfection is a source of variation. These diagrams are also known as cause-and-effect analysis diagrams.
Fisher’s exact test – It is a non-parametric statistical significance test used in the analysis of contingency tables where sample sizes are small. The test is useful for categorical data which result from classifying objects in two different ways. It is used to examine the significance of the association (contingency) between two kinds of classifications.
Fish-eye – It is an area on a steel fracture surface which is having a characteristic white crystalline appearance.
Fish-eye (weld defect) – It is a discontinuity found on the fracture surface of a weld in steel which consists of a small pore or inclusion surrounded by an approximately round, bright area.
Fish-mouth fracture – It is the macroscale appearance of a longitudinal fracture in an internally pressurized pipe, tube, or pressure vessel.
Fish-mouthing – It is the pronounced wide cracking over the entire surface of a coating having the appearance of alligator hide. It is also the longitudinal splitting of flat slabs in a plane parallel to the rolled surface.
Fish-scale – It is a scaly appearance in a porcelain enamel coating in which the evolution of hydrogen from the base metal (iron or steel) causes loss of adhesion between the enamel and the base metal. The scales are somewhat like blisters that have cracked partway around the perimeter but still remain attached to the coating around the rest of the perimeter.
Fish-tail – In roll forging, it is the excess trailing end of a forging. It is frequently used, before being trimmed off, as a tong hold for a subsequent forging operation. In hot rolling or extrusion, it is the imperfectly shaped trailing end of a bar or special section which is to be cut off and discarded as mill scrap.
Fissile material – It is the material which is fissionable by thermal (slow) neutrons. The three main fissile materials are uranium-233 (U-235), and plutonium-239 (Pu-239). Although this term has sometimes been used as a synonym for fissionable material, it has now acquired this more restrictive meaning.
Fission – Fission creates the release of energy where heavy element atoms are split up into smaller atoms, producing free neutrons and large quantities of energy. The energy is derived from small changes in mass which is converted to energy (E = mc2).
Fission products – These are the smaller atoms produced when a large atom undergoes fission, frequently extremely radioactive
Fissure – It is a small crack-like weld discontinuity with only slight separation (opening displacement) of the fracture surfaces. The prefixes macro or micro indicate relative size. In mining, it is an extensive crack, break, or fracture in rocks.
Fitness for purpose – It is one of the objectives of standards. Standards help in identifying the optimum parameters for the performance of a process, product, or services and the method for evaluating product conformity. Standards also lay down conditions for using the process, product, or service, as otherwise any failure of the process, product, or service because of improper use can be attributed by the user to a deficiency or lack of quality of the process, product, or service.
Fitting – It is a device which is used for connecting elements in fluid lines e.g., elbows, tees, nipples, unions, and flanges etc.
Five-number summary – It is the summary for a numeric variable, the least value (minimum), the lower quartile, the median, the upper quartile, and the greatest value (maximum), in that order. These are shown graphically in a boxplot.
Fixed assets – These are possessions such as buildings, machinery, and land which are unlikely to be converted into cash during the normal business cycle.
Fixed automation – It is normally custom-engineered, special-purpose equipment to automate a fixed sequence of operations. It is used in high volume production with dedicated equipment, which has a fixed set of operation and designed to be efficient for this set. Continuous flow and discrete mass production systems use this automation. Fixed automation is normally associated with high production rates and inflexible design of the product.
Fixed costs – These are those costs which do not increase with the volume of production, e.g., the depreciation, interest on capital, and overhead labour costs etc.
Fixed duration – It is a task in which the time required for completion is fixed.
Fixed effect – It is an unobserved characteristic of subjects which is both a predictor of the study endpoint and correlated with one or more explanatory variables in a regression model. Left unaddressed, it leads to biased regression estimates.
Fixed-feed grinding – It is the grinding in which the wheel is fed into the work, or vice versa, by given increments or at a given rate.
Fixed-land bearing – It is an axial-load or radial-load bearing equipped with fixed pads, the surfaces of which are contoured to promote hydrodynamic lubrication.
Fixed-load or fixed-displacement crack-extension-force curves – These are the curves got from a fracture mechanics analysis for the test configuration, assuming a fixed applied load or displacement and generating a curve of crack-extension force against the effective crack size as the independent variable.
Fixed mandrel – It is a device for producing hollow extrusions of regular cross section. The tapered mandrel is attached to the main extrusion ram and passes through the hollow billet. As the ram moves forward the mandrel passes, with the billet, through the die giving a product, slightly tapering in wall thickness along its length. The mandrel is tapered to facilitate its removal when extrusion is complete.
Fixed oil – It is an imprecise term denoting an oil which is difficult to distill without decomposition.
Fixed-pad bearing – It is an axial-load or radial-load bearing equipped with fixed pads, the surfaces of which are contoured to promote hydrodynamic lubrication.
Fixed position welding – It is the welding in which the work is held in a stationary position.
Fixed price contract (FPC) – A fixed price contract pays an agreed-upon fee and does not incorporate other variables, such as time and cost.
Fixture – It is a device which is designed to hold parts to be joined in proper relation to each other.
Fixturing – It is the placing of parts to be heat treated in a constraining or semi constraining apparatus to avoid heat-related distortions.
Flag – It is a marker inserted adjacent to the edge at a splice or lap in a roll or foil.
Flake – It is a short, discontinuous internal crack in ferrous metals which is attributed to stresses produced by the localized transformation and hydrogen-solubility effects during cooling after hot working. In fracture surfaces, flakes appear as bright, silvery areas with a coarse texture. In deep acid-etched transverse sections, they appear as discontinuities which are normally in the midway to centre location of the section. It is also termed hairline cracks and shatter cracks.
Flake graphite – It is the graphitic carbon, in the form of platelets, which is occurring in the micro-structure of gray iron.
Flaking – It is the removal of material from a surface in the form of flakes or scale-like particles. It is also a form of pitting resulting from fatigue.
Flake powder – It is flat or scale-like particles whose thickness is small compared to other dimensions.
Flame – It is the product of a highly exothermic reaction and can be regarded as a body of gaseous material consisting of reacting gases and finely dispersed carbonaceous particles (soot). Flames are of two types based on their shape. They are (i) round flame, and (ii) flat or rectangular flame. These are the two most common flame shapes produced by the burners. Also, flames can be luminous or non-luminous.
Flame and plasma guniting mixes – These are guniting mixes which make use of oxy-gas, oxy-acetylene, and oxy-hydrogen torches or plasma torch for flame spraying and flame-plating of refractory compounds. The plasma torch can double to triple the gas temperature of fuel torches, but at such increased cost that it might be economically impractical for refurbishing furnace refractories.
Flame annealing – It is the annealing in which the heat is applied directly by a flame.
Flame cleaning – It is the cleaning metal surfaces of scale, rust, dirt, and moisture by use of a gas flame.
Flame cutting – The preferred term is oxygen cutting which is a group of cutting processes used to sever or remove metals by means of the chemical reaction between oxygen and the base metal at high temperatures. In the case of oxidation-resistant metals, the reaction is facilitated by the use of a chemical flux or metal powder.
Flame detector – It is a device which indicates if a fuel (liquid, gaseous, or pulverized) is burning, or if ignition has been lost. The indication can be transmitted to a signal or to a control system.
Flame failure devices -These are also known as photo-cells or magic eyes. These devices are used to prevent dangerous occurrences whereby fuel continues to enter the furnace in the event when the flame unexpectedly goes out during normal operation. Modern devices detect a specific frequency within the electro-magnetic spectrum which is emitted by a flame. When activated, they force a shut down and lock out of the burner requiring manual reset. As with level limiters, they are to be fail safe, of high integrity, and self-monitoring.
Flame hardening – It is a process for hardening the surfaces of hardenable ferrous alloys in which an intense flame is used to heat the surface layers above the upper transformation temperature, where upon the work-piece is immediately quenched.
Flame ionization detector – It is a scientific instrument that measures analytes in a gas stream. It is frequently used as a detector in gas chromatography. The measurement of ions per unit time makes this a mass sensitive instrument.
Flame propagation rate – It is the speed of travel of ignition through a combustible mixture.
Flame resistance – It is the ability of a material to extinguish flame once the source of heat is removed.
Flame retardants – These are certain chemicals which are used to reduce or eliminate the tendency of a resin to burn.
Flame safeguard – It is a control which sequences the burner through several stages of operation to provide proper air purge, ignition, normal operation, and shutdown for safe operation.
Flame scanner – Flame scanner is a device used to observe the flame in a boiler. If the flame is extinguished for any reason, the flame scanner sends a signal to close the fuel supply valve to prevent a possible explosion.
Flame spraying – It is a thermal spraying process in which an oxy-fuel gas flame is the source of heat for melting the surfacing material. Compressed gas may or may not be used for atomizing and propelling the surfacing material to the substrate.
Flame straightening – It is the correcting distortion in metal structures by localized heating with a gas flame.
Flammability – It is susceptibility to combustion.
Flange – It is a formed pipe fitting consisting of a projecting radial collar with bolt holes to provide a means of attachment to piping components having a similar fitting. It is the end piece of flanged-end valves.
Flange coupling – It is a very widely used rigid coupling and consists of two flanges keyed to the shafts and bolted. The main features of the design are essentially (i) design of bolts, (ii) design of hub, and (iii) overall design and dimensions.
Flange end valve – In flange end valve, there is a raised area of a flange face which affords a seal with a mating flange face by means of a flat gasket of the same diameter as the raised face. Raised face flanges seal with a flat gasket made of materials designed for installation between the raised faces of two mating flanges (both with raised faces). The raised faces have a prescribed texture to increase their gripping and retaining force on this flat gasket. Some users of raised face flanges specify the use of spiral wound gaskets.
Flanging -It is bending a sheet along a curved line.
Flangeless valve – It is valve style common to rotary control valves. Flangeless valves are held between the flanges by long through-bolts (sometimes also called wafer-style valve bodies).
Flange load – it is the total force compressing the gasket to create a seal. It is the effective pressure resulting from the bolt loading.
Flange weld – It is a weld which is made on the edges of two or more members to be joined, normally light gauge metal, at least one of the members being flanged.
Flange weld size – It is the weld metal thickness which is measured at the weld root.
Flank – It is the end surface of a tool which is adjacent to the cutting edge and below it when the tool is in a horizontal position, as for turning.
Flank wear – It is the loss of relief on the flank of the tool behind the cutting edge because of the rubbing contact between the work and the tool during cutting. It is measured in terms of linear dimension behind the original cutting edge.
Flare-bevel-groove weld – It is a weld in a groove which is formed by a member with a curved surface in contact with a planar member.
Flare-V-groove weld – It is a weld in a groove which is formed by two members with curved surfaces.
Flare stack – an elevated vertical pipe which is used so that ignition and combustion of the discharge takes place at a considerable height. A flare stack is a part of a flare system in an industrial plant where all over-pressurized gases and liquids are released by a pressure safety valve and burnt to prevent over-pressurizing some of the equipment and facilities in a plant.
Flare test – It is a test applied to tubing, involving tapered expansion over a cone. It is similar to the pin expansion test.
Flaring – It consists of forming an outward acute-angle flange on a tubular part. It is also forming a flange by using the head of a hydraulic press.
Flash – In forging, it is the metal in excess of which is needed to fill the blocking or finishing forging impression of a set of dies completely. Flash extends out from the body of the forging as a thin plate at the line where the dies meet and is subsequently removed by trimming. Since it cools faster than the body of the component during forging, flash can serve to restrict metal flow at the line where dies meet, hence ensuring complete filling of the impression. In casting, it is a fin of metal which results from leakage between mating mould surfaces. In welding, it is the material which is expelled or squeezed out of a weld joint and that forms around the weld. In powder metallurgy, flash is the excess metal forced out between the punched and the die cavity wall during compacting or coining. In composites, a flash is that portion of the charge which flows from or is extruded from the mould cavity during the moulding. It is extra plastic attached to a moulding along the parting line, which is to be removed before the part is considered finished.
Flash annealing – It consists of annealing of a work-piece by rapid heating and a short dwell time at the appropriate temperature.
Flash-back – It is a recession of the welding or cutting torch flame into or back of the mixing chamber of the torch.
Flash butt welding – It is a non-standard term for flash welding.
Flash coat – It is a thin metallic coating normally less than 0.05 millimeters in thickness.
Flash extension – It is that portion of flash which is remaining on a forged part after trimming. It is normally included in the normal forging tolerances.
Flashing – It is the phenomenon by which a fluid vapourizes because of sudden pressure drop across a valve. Particularly, it occurs when the downstream pressure is below the upstream vapour pressure value. Beside physical damages, the occurrence of flashing within a control valve results in a decreased ability of the valve to convert pressure drop across it into mass flow rate. In flash welding, it is the heating portion of the cycle, consisting of a series of rapidly recurring localized short circuits followed by molten metal expulsions, during which time the surfaces to be welded are moved one toward the other at a pre-determined speed.
Flash ironmaking technology (FIT) using hydrogen – This technology is based on the direct gaseous reduction of iron oxide concentrate in a flash reduction process. It has the potential to reduce energy consumption by 32 % to 57 % and lower carbon di-oxide emissions by 61 % to 96 % compared with the average present blast furnace-based operation. This technology reduces iron ore concentrate in a flash reactor with a suitable reductant gas such as hydrogen or natural gas, and possibly bio / coal gas or a combination thereof. This technology is suitable for an industrial operation which converts iron ore concentrate (less than 100 micrometers) to metal without further treatment. This transformative technology produces iron while bypassing palletization or sintering as well as coke making steps. Further, the process is intensive because of the fact that the fine particles of the concentrate are reduced at a fast rate at 1,150 deg C to 1,350 deg C. Hence, the needed residence times in this process is of the order of seconds rather than the minutes and hours needed for pellets and even iron ore fines. 90 % – 99 % reductions take place in 2 seconds to 7 seconds at 1,200 deg C to 1,500 deg C. The residence time is a combination of speed of reaction because of the temperature, size of the feed material and quantity of excess gas / distance from equilibrium line. The energy need of the process with hydrogen as reduction gas is 5.7 giga joules per ton of liquid iron. The heating portion of the reactor is where the induction heating coil heats up the graphite susceptor. The susceptor heats up refractory wall by radiation. Both susceptor and refractory heat up the gas and particle by convection and radiation. After being heat up to the temperature, gas and particles enter the reaction zone, where good insulation is assumed so wall condition is set to be adiabatic. After the reaction zone, there is a cooling zone with cooling panel to cool gas and particles.
Flash land -It is the configuration in the blocking or finishing impression of forging dies which is designed to restrict or to encourage the growth of flash at the parting line, whichever can be needed in a particular case to ensure complete filling of the impression.
Flash line – It is the line left on a forging after the flash has been trimmed off.
Flash pan – It is the machined-out portion of a forging die that permits the flow through of excess metal.
Flash plate – It is a very thin final electro-deposited film of metal (less than 2.5 micrometers thick).
Flash point – Flash point is the minimum temperature at which the lubricant’s vapours ignite when tiny flame is brought near. Fire point is the minimum temperature at which the lubricant’s vapours burn constantly for 5 seconds when tiny flame is brought near. Both flash point and the fire point are to be higher than the maximum achievable ambient temperatures.
Flash steam – When hot condensate under pressure is released to lower pressure, part of it is re-evaporated, becoming what is known as flash steam. The term is traditionally used to describe steam issuing from condensate receiver vents and open-ended condensate discharge lines from steam traps.
Flash temperature – It is the maximum local temperature generated at some point in a sliding contact. The flash temperature occurs at areas of real contact because of the frictional heat dissipated at these areas. The duration of the flash temperature is frequently of the order of a micro-second. The term flash temperature can also mean the average temperature over a restricted contact area, e.g., between gear teeth.
Flash time – It is the time between paint application and baking. Normally a considerable quantity of solvent is lost during this interval, and this solvent loss prevents popping problems in the oven.
Flash welding – It is a resistance welding process which produces coalescence at the faying surfaces of abutting members by a flashing action and by the application of pressure after heating is substantially completed. The flashing action, caused by the very high current densities at small contacts between the parts, forcibly expels the material from the joint as the parts are slowly moved together. The weld is completed by a rapid upsetting of the work-pieces.
Flask – It is a metal or wood frame which is used for making and holding a sand mould. The upper part is called the cope, while the lower part is called the drag. Flask is also a vessel or container, most commonly a type of glassware, widely used in laboratories for a variety of purposes, such as preparing, holding, containing, collecting, or volumetrically measuring chemicals, samples, or solutions, or as a chamber in which a chemical reaction occurs. Flasks come in a number of shapes and sizes but are typically characterized by a wider vessel ‘body’ and one or more narrower tubular sections with an opening at the top.
Flat belt conveyor – The active side of belt in this conveyor, remains flat supported by cylindrical rollers or flat slider bed. The conveyor is normally short in length and suitable for conveying unit loads like crates, boxes, packages, and bundles etc. in manufacturing, shipping, warehousing, and assembly operations. Flat belts are used conveniently for conveying parts between work-stations or in an assembly line in mass production of goods.
Flat-die forging – It consists of forging of the metal between flat or simple-contour dies by repeated strokes and manipulation of the work-piece. It is also known as open-die forging, hand forging, or smith forging.
Flat drill – It is a rotary end-cutting tool constructed from a flat piece of material. It is provided with suitable cutting lips at the cutting end.
Flat edge trimmer – It is a machine for trimming notched edges on shells. The slide is cam driven so as to get a brief dwell at the bottom of the stroke, at which time the die, sometimes called a shimmy die, oscillates to trim the part.
Flat face, flange – Typically flat face is used on pump facings or on fibre-glass flanges where the torque of compressing the gasket can damage the flange body. Their principal use is to make connections with cast iron flanges. They are mainly used for rubber lined equipments of chemical plants. They are also used for equipments operating under low pressure. Since the width of the gasket is more, the gasket seating force is more.
Flat flame burner – It is a burner which gives a flat flame. It transfers heat to the surrounding refractory wall or roof by highly turbulent convection. The refractory then radiates heat uniformly to the load. Minimum forward velocity results in uniform radiant heating with no flame impingement. It converts the refractory expanse of a furnace wall or roof into a uniform-heat, radiating surface which is capable of high rates of radiant heat transfer over wide areas. The burners’ flames scrub adjacent refractory and have little f It’s simply the amount of space between the plate and a perfectly flat surface.
Flat honing – It is a low-velocity abrading process, similar to honing, which uses a large, flat honing surface to simultaneously finish a large number of flat parts.
Flatness – It is simply the amount of space between the plate and a perfectly flat surface. It is a measure the form of a surface, which indicates whether all of the points along the surface lie in the same plane. It is symbolized in Geometric Dimensioning and Tolerancing (GD&T) by a parallelogram, flatness and is particularly useful when two surfaces are to be assembled together to form a tight seal. Flatness of rolled steel sheets depends on the roll deflection.
Flatness tolerance – It consists of a three-dimensional geometric tolerance which controls how much a product surface can deviate from a flat plane. The permitted deviation depends upon the thickness of the sheet or plate varying between 0.2 % and 0.5 % of its width and length, normally measured over a 1 metre length.
Flat position – It is the welding position which is used to weld from the upper side of the joint. The face of the weld is approximately horizontal.
Flat-position welding – It consists of welding from the upper side, the face of the weld being horizontal. It is also called down hand welding.
Flat products – These products refer to the products which consist of strips, sheets and plates. These are finished steel products which are produced from slabs / thin slabs in rolling mills using flat rolls.
Flat return idlers – The flat return idler consists of a long single roll, fitted at each end with a mounting bracket. Idler roll length, bracket design, and mounting-hole spacing allow for adequate transverse belt movement without permitting the belt edges to contact any stationary part of the conveyor or its frame.
Flat rolled steels – These are the steel produced in flat rolling mills utilizing relatively smooth and cylindrical rolls. The width to thickness ratio of flat rolled products is normally fairly large. Examples of flat rolled steel are hot rolled plates, sheets and coils, cold rolled sheets and coils, and coated sheets and coils, and tin mill products etc.
Flat rolling – Rolling of strips and plates is normally referred to as flat rolling. The objectives of the process are reducing of the thickness of the work-piece, and increasing its length and thereby changing its mechanical and metallurgical attributes.
Flat rolling mills – These are those rolling mills which roll flat products.
Flat springs – These springs are made from flat strips of material (normally metal) which store and release energy when deflected by an external load. Unlike helical springs, which are typically made from coiled wire, flat springs are cut or pressed from sheet metal. These springs are used in several applications and are ideally suited for applications where space is limited or where the spring can be used as part of mounting assembly. The flat spring design allows forming of specific features and profiles for a unique application and mounting location.
Flatteners – They are also known as levellers or straighteners. They carryout shape corrections of the strip to ensure flatness before further processing during the unwinding of a coil. It is the first operation during the unwinding a coil. The process consists of bending the unwound strip back and forth over a series of work rolls to alternately stretch and compress the upper and lower surfaces. The process removes the coil set. Removing coil set needs permanent yielding in the outer 20 % of the top and bottom surfaces of the steel. The central 80 % of the thickness remains unchanged. Flatteners are appropriate for this type of shape correction. Only end bearings support the simplest flatteners, with no backup rolls used. Closing the entry roll gap risks deflection of the unsupported centre, potentially leading to creating edge waves in the coil.
Flattening – It is a preliminary operation performed on forging stock to position the metal for a subsequent forging operation. It also consists of the removal of irregularities or distortion in sheets or plates by a method such as roller leveling or stretcher leveling.
Flattening dies – These are the dies used to flatten sheet metal hems, i.e., dies which can flatten a bend by closing it. These dies consist of a top and bottom die with a flat surface which can close one section (flange) to another (hem, seam).
Flattening test – It is a quality test for tubing in which a sample is flattened to a specified height between parallel plates.
Flat-top chain conveyor – It consists of a particular group of carrier chain conveyors, which can be rolling or sliding type, with specially designed chain links or with flat plate attached to the chain links so as to provide a continuous, smooth, level top surface to carry small articles like bottles, and cans, etc. at a high speed. These conveyors are widely used in canning and bottling plants. Different types of chains and / or attachments are used such as hinged-joint continuous flat top sliding type, plate-top sliding or rolling type, crescent-shaped plate top type. The crescent plate design is particularly suitable for carousel-type operation to turn in a horizontal curve, a typical example being the baggage handling conveyors in the arrival section of an airport.
Flat-top chains – These are intended only for conveying. They can replace conveyor belts and belt drives as the material can be carried directly on its links. An individual link is normally made out of a steel plate with barrel-shaped hollow protrusions on its bottom side. The links are connected to preceding and succeeding links by passing a pin through these protrusions underneath the links. The nature of these joints allows movement only in one direction. These chains are used almost exclusively on conveyors. In practice, the flat-top chains are basically special types of slat conveyors. Wear is the most important parameter in the design of the flat-top chains. Joint wear and top plate and track wears are of the greatest concerns. Top plate and sprocket wears are also of some concern.
Flat type wire rope – In flat type wire rope, the strands are combined in such a way that the outer circumference of the rope is flat in shape. This rope has a smooth surface and hence the surface pressure due to coming into contact with the groove of the drum and the sheave is smaller than that of ordinary ropes. It is also superior in its wear resistance nature. In general, the triangular strand and the shell strand are used the most. The flat strand is also being used at certain places.
Flat wire – It is a roughly rectangular or square mill product, narrower than strip, in which all surfaces are rolled or drawn without any previous slitting, shearing, or sawing.
Flaw – It is a near synonym for discontinuity but with an undesirable connotation. It is a non-specific term frequently used to imply a crack-like discontinuity. The preferred terms are discontinuity and defect.
Fleissner process – This is a very old process for drying low-rank coals. This process is based on the principle that uneven shrinking of the coal and consequent disintegration can be prevented by controlled removal of the water. The saturated steam atmosphere prevents evaporation until the lump is heated, and then loss of water can be controlled by gradual reduction of the steam pressure. It is a thermal drying process, in which the action of high-pressure steam on a lump of lignite produces these effects. As the temperature rises and the pressure increases part of the colloidal water is expelled from the lump as a liquid. The lump shrinks as water leaves and the cells collapse, and when the pressure is lowered, more water leaves by evaporation caused by the sensible heat stored in the lump. When the pressure is lowered further by vacuum, additional moisture is evaporated, which cools the lump. Many methods of drying are based on Fleissner process.
Fleming’s left-hand rule for motors – It is a mnemonic to recall the relative orientation of current, magnetic field and resulting force for electric motors.
Fleming’s right-hand rule for generators – It is a mnemonic to recall the relative orientation of current, magnetic field and resulting force for electric generators.
Fleming valve – It is the first important vacuum tube device, used as a radio detector.
Flexible automation – This type of automation has the flexibility and is used to manufacture a variety of products. In this automation system operators give high-level commands in the form of codes entered into computer identifying product and its location in the sequence and the lower level changes are done automatically. Each production machine receives settings / instructions from computer. The machines automatically load / unload required tools and carries out their processing instructions. After processing, products are automatically transferred to next machine. It is typically used in job shops and batch processes where product varieties are high and job volumes are medium to low. However, this type of automation is associated with lower production rates and products which needs frequent changing due to their dependence on the demand.
Flexible cam – It is an adjustable pressure-control cam of spring steel strips which is used to get varying pressure during a forming cycle.
Flexible couplings – These couplings are normally used to transmit driving torque between a prime mover and a rotating element of the equipment. Although designed to accommodate misalignment, normally it is desired not to use a flexible coupling to compensate for misalignment of the rotating element of the equipment and driver shafts. The purpose of the flexible coupling is to compensate for temperature changes in the couplings and shafts, and to permit axial movement of the shafts without interference with each other while power is transmitted from the driver to the rotating element of the equipment.
Flexible hinge, flexure pivot bearing – It is a type of bearing guiding the moving parts by flexure of an elastic member or members rather than by rolling or sliding. However, it is to be noted that only limited movement is possible with a flexure pivot.
Flexible manufacturing system (FMS) – It is a manufacturing system in which there is some quantity of flexibility which allows the system to react in case of changes, whether predicted or unpredicted. This flexibility is normally considered to fall into two categories, which both contain numerous sub-categories. The first category is called routing flexibility, which covers the system’s ability to be changed to produce new product types, and the ability to change the order of operations executed on a part. The second category is called machine flexibility, which consists of the ability to use multiple machines to perform the same operation on a part, as well as the system’s ability to absorb large-scale changes, such as in volume, capacity, or capability.
Flexible moulds – These are moulds made of rubber or elastomeric plastics, used for casting plastics. They can be stretched to remove cured pieces with undercuts.
Flexible reduction sizing (FRS) block – This block has been developed for rolling higher grades and simultaneously improving the metallurgical properties of the rolled product. This is a four-strand block with speed shift gear boxes. It is installed down line of a no-twist wire rod block. On the flexible reduction sizing block all dimensions can be finish rolled with the advantage of one family rolling, which means that only one pass size is used in each stand over the whole size range. Due to the cooling section in between the no-twist block and flexible reduction sizing block, thermo-mechanical rolling becomes feasible. There are several good design features in this block.
Flexible tube valve – It is a special valve using a flexible sleeve or tube which acts as the closure element. Pressure applied to the jacket space surrounding the outside of the tube controls the opening and closing of the valve.
Flexibility – It is the quality or state of a material which allows it to be flexed or bent repeatedly without undergoing rupture.
Flexibility principle – This principle states that all other things being equal, a good layout is one which provides flexibility. Flexibility factor includes consideration because of changes in material, equipment, process, man, supporting activities, and installation limitations etc. It means easy changing to new arrangements or it includes flexibility and expendability of layouts.
Flexibility, wire rope – The flexibility of a wire rope is a measure of how easily the rope allows itself to bend around a given diameter. The flexibility of the wire rope is among other things dependent on the line pull. The flexibility of an unloaded rope can be measured by the sag of a rope under its own weight. The flexibility of a steel wire rope typically increases with an increasing number of strands and wires in the rope. The flexibility is also influenced by the lay lengths of the strands, of the rope core and the rope, as well as by the gaps between wires and strands.
Flex roll – It is a movable jump roll designed to push up against a metal sheet as it passes through a roller leveler. The flex roll can be adjusted to deflect the sheet any quantity up to the roll diameter.
Flex rolling – It consists of passing metal sheets through a flex roll unit to minimize yield-point elongation in order to reduce the tendency for stretcher strains to appear during forming.
Flexural bearing – A flexural bearing is a bearing which allows motion by bending a load element. A typical flexure bearing is just one part, joining two other parts. For example, a hinge can be made by attaching a long strip of a flexible element to a door and to the door frame. Another example is a rope swing, where the rope is tied to a tree branch.
Flexural modulus – Within the elastic limit, it is the ratio of the applied stress on a test sample in flexure to the corresponding strain in the outermost fibre of the sample. Flexural modulus is the measure of relative stiffness.
Flexural strength – It is a property of solid material which indicates its ability to withstand a flexural or transverse load. It is the maximum stress which can be borne by the surface fibres in a beam in bending. The flexural strength is the unit resistance to the maximum load before failure by bending, normally expressed in force per unit area.
Flexure – It is a term used in the study of strength of materials to indicate the property of a body, normally a rod or beam, to bend without fracture.
Flight conveyor – it is a conveyor comprising of one or more endless strands of chain with spaced transverse flights or scrapers attached which push granular bulk material along a shaped trough. The material can be loaded at any point into the trough and discharge can also be affected at various points through openings in the trough floor, closed by sliding gates. Both upper and lower strand can be used for transporting materials in opposite directions. These conveyors normally work at speed range of 30 metres per minute to 50 metres per minute to handle free flowing materials of small to moderate size to move them in both the directions. These are used for handling coal, ashes, sand, gravel, ore, wood chips, saw dust, chemicals, grains, and cereals etc., normally for loading bunkers and bins and also used under floor for removal of metal chips / cut pieces. One flight conveyor can handle two or more materials simultaneously by making two or more material flow troughs / channels side by side and designing the flights to match individual troughs. These conveyors are built rugged for long life and low maintenance.
Flights – Flights or lifters are most commonly seen in rotary dryers. They are, however, sometimes utilized in low temperature kilns in order to shower the material and increase heat transfer efficiency.
Flint fireclay – It is a hard or flint-like fireclay occurring as an unstratified massive rock, practically devoid of natural plasticity and showing a conchoidal fracture.
Float – It is the pieces of rock which have been broken off and moved from their original location by natural forces such as frost or glacial action. In networking, float of an activity represents the excess of available time over its duration. Total float is the amount of time by which the completion of an activity can be delayed beyond the earliest expected completion time without affecting the overall project duration. Free float is the time by which the completion of an activity can be delayed beyond the earliest finish time without affecting the earliest start of subsequent (succeeding) activities.
Floating bearing – It is a bearing which is designed or mounted to permit axial displacement between shaft and housing.
Floating ball valve – It is a ball valve having a non-trunnion-mounted ball. The ball is free to float between the seat rings and hence causes higher torques.
Floating crane – These cranes are used mainly in the constructions of bridges and ports. They are also used for occasional loading and unloading of especially heavy or awkward loads on and off the ships. Some floating cranes are mounted on a pontoon; others are specialized crane barges with a lifting capacity sometimes exceeding 9,000 tons. These cranes are used to transport entire bridge sections. Floating cranes are also used to salvage sunken ships.
Floating die – In metal forming, it is a die which is mounted in a die holder or a punch which is mounted in its holder such that a slight quantity of motion compensates for tolerance in the die parts, the work, or the press. It is also a die mounted on heavy springs to allow vertical motion in some trimming, shearing, and forming operations. In powder metallurgy, it is a die body which is suspended on springs or an air cushion which causes the die to move together with the upper punch over a stationary punch. The rate of die movement is lower than that of the upper punch and is a function of friction coefficient of the powder in relation to the wall of the die cavity.
Floating die pressing – It is the compaction of a powder in a floating die, resulting in densification at opposite ends of the compact. It is analogous to double action pressing.
Floating mandrel – It is a tapered mandrel which is inserted into the hollow extrusion billet. It is not attached to the extrusion ram so is left free to centre itself in a hollow billet as it moves forward through the die as the ram advances and extrusion proceeds. The resulting product tapers slightly in wall thickness along the length.
Floating plug – In tube drawing, it is an unsupported mandrel which locates itself at the die inside the tube, causing a reduction in wall thickness while the die is reducing the outside diameter of the tube.
Float measurement – It is a method of measuring flow in an open channel. The water level is sampled by a float whose elevation is mechanically transmitted to a non-linear scale or is electrically linearized and converted to a standardized output signal. Contamination, fouling, mechanical abrasion, and frost can affect the float and transmitting element, and since these affect the flow profile, they are responsible for errors. Possibly the float has to be installed in a separate float chamber. Additionally, increased maintenance expenditures are to be expected. These are the reasons that a float measurement is seldom used in these applications.
Flocculate – It means to aggregate into larger particles, i.e., to increase in size to the point where precipitation occurs.
Flocculation – It is a physico-chemical process which helps to encourage the aggregation of viscous colloidal and delicately separated suspended matters by mixing physically and by aiding chemical coagulant. This process consists of a rapid mixing tank and a flocculation tank. The wastewater stream mixes with the coagulants in a rapid mix tank and is then passed through the flocculation basin and in the flocculation basin a slow mixing of waste occurs which allows the particles to be collected in the form of more settleable and heavier solids. A better mixing is facilitated with the help of a diffused air or the mechanical paddles. The natural organic polymers, inorganic electrolytes, and synthetic poly-electrolytes are the various different types of chemicals used for the coagulation. Depending upon the characteristics and the chemical properties of the contaminants, the specific chemicals are selected.
Flocculating – In porcelain enameling, it is the thickening the consistency of a slip by adding a suitable electrolyte.
Flocking – It is a method of coating by spraying finely dispersed textile powders or fibres.
Flock point – It is a measure of the tendency of a lubricant to precipitate wax or other solids from solution. It is to be noted that depending on the test used, the flock point is the temperature needed for precipitation, or the time needed at a given temperature for precipitation.
Flood lubrication – It is a system of lubrication in which the lubricant is supplied in a continuous stream at low pressure and subsequently drains away. It is also known as bath lubrication.
Floor moulding – It consists of making sand moulds from loose or production patterns of such size that they cannot be satisfactorily handled on a bench or moulding machine, the equipment being located on the floor during the entire operation of making the mould.
Floor plan drawing – This drawing is in-depth version of the floor layout. Civil floor plans are made irrespective of the fact that they are to be utilized during the construction of a building, or production shop. Applications include an understanding of the dimensions and different kinds of installment. This helps in getting an idea about the usage of the limited room space. Floor plans are normally very useful, and they are the most used location drawings. They are really the sectional plans since they show the view obtained by cutting horizontally through a building at some point above the floor level. It is assumed that one move away the top part of the building and look down at the plan of the remaining bottom part. This plan view not only shows the arrangement of the rooms and spaces and their shapes, but also shows the thickness of all the external and internal walls. Floor plans are a form of orthographic projection which can be used to show the layout of floors within buildings. They can be prepared as part of the design process, or to provide instructions for construction, frequently associated with other drawings, schedules, and specifications.
Floppers – · On metals, these are lines or ridges which are transverse to the direction of rolling and normally confined to the section midway between the edges of a coil as rolled.
Flop forging – It is a forging in which the top and bottom die impressions are identical, permitting the forging to be turned upside down during the forging operation.
Flo-spinning – It is forming cylindrical, conical and curvilinear shaped parts by power spinning over a rotating mandrel.
Flotation – It is the concentration of valuable minerals from ores by agitation of the ground material with water, oil, and flotation chemicals. The valuable minerals are normally wetted by the oil, lifted to the surface by clinging air bubbles, and then floated off. It is also a milling process in which valuable mineral particles are induced to become attached to bubbles and float as others sink.
Flotation process – The principle of the flotation process is based on the differences in the chemical properties of the mineral surface (hydrophilic, flowability). The flotation agent is used to selectively attach useful minerals or useless impurities to the bubbles for the purpose of separation. This method is also called chemical beneficiation. A standard flotation circuit starts by separating the scrubbed ore into a coarse portion (e.g., +20 mesh), and a fine portion (e.g., -20 mesh). For designing optimum flotation circuits, it is necessary to understand the processing needs, and the technical and mineralogical characteristics of the ore. Successful flotation involves proper liberation, adding the proper reagents to induce selected minerals to become hydrophobic (water repelling) or hydrophilic (water attracting). Aeration (bubbles) is added through spargers at the bottom of the flotation cell. The bubbles attract and then float the hydrophilic minerals, leaving the hydrophobic component in the underflow as tailings. The flotation circuit then concentrates and separates the desired minerals.
Flow – It is the movement (slipping or sliding) of essentially parallel planes within an element of a material in parallel directions. It occurs under the action of shear stress. Continuous action in this manner, at constant volume and without disintegration of the material, is termed yield, creep, or plastic deformation.
Flowability – Flowability is the ability of a material to flow, high flowability indicates that the material can flow easily and quickly, while a high viscosity indicates that the material is more resistant to flow. In casting, it is a characteristic of a foundry sand mixture which enables it to move under pressure or vibration so that it makes intimate contact with all surfaces of the pattern or core box. In welding, brazing, or soldering, it is the ability of molten filler metal to flow or spread over a metal surface.
Flow brightening – It is the melting of an electro-deposit, followed by solidification, especially of tin plate. It is the fusion of a metallic coating on a base metal. It is also fusion (melting) of a chemically or mechanically deposited metallic coating on a substrate, particularly as it pertains to soldering.
Flow cavitation – It is the cavitation caused by a decrease in static pressure induced by changes in the velocity of a flowing liquid. Typically, this can be caused by flow around an obstacle or through a constriction, or relative to a blade or foil.
Flow characteristics – The term refers to the properties and behaviour of the flow, such as velocity, pressure, and temperature, which are obtained through mathematical equations and operational data. These characteristics demonstrate the correlation between different variables and validate the methodology used in the analysis.
Flow characteristic, valve – It is the relationship between flow through the valve and percent rated travel as the latter is varied from 0 to 100 %. This term is always to be designated as either inherent flow characteristic or installed flow characteristic.
Flow chart – A flowchart is a type of diagram that represents a workflow or process. A flowchart can also be defined as a diagrammatic representation of an algorithm, a step-by-step approach to solving a task. The flowchart shows the steps as boxes of various kinds, and their order by connecting the boxes with arrows. A flowchart shows separate steps of a process in sequential order. It is a generic tool which can be adapted for a wide variety of purposes, and can be used to describe different processes, such as a manufacturing process, an administrative or service process, or a project plan.
Flow coating – It is the process of coating a metal shape by causing the slip to flow over its surface and then allowing the excess slip to drain.
Flow coefficient – It is a constant related to the geometry of a valve, for a given travel, which can be used to establish flow capacity. It is defined as the flow of water in cubic meters per hour at a pressure drop of 0.1 MPa with temperature ranging from 5 deg C to 30 deg C.
Flow control devices – They include inlet dampers on the box, inlet vanes at the inlet to the fan, and outlet dampers at the outlet of the fan.
Flow control valve – A flow control valve regulates the flow or pressure of a fluid. It normally responds to signals generated by independent devices such as flow meter or temperature gauge.
Flow factor – It is the time needed for a standard powder sample of standard weight to flow through an orifice in a standard instrument as per a specified procedure.
Flow lines – These are the lines on the surface of painted sheet, brought about by incomplete leveling of the paint. Flow lines can frequently be revealed by etching the surface or a section of a metal part. In mechanical metallurgy, it is the paths followed by minute volumes of metal during deformation. In composites, flowline is a mark on a moulded piece made by the meeting of two flow fronts during moulding. It is also called striae, weld mark, or weld line.
Flow marks – It is the wavy surface appearance of an object moulded from thermo-plastic resins, caused by improper flow of the resin into the mould.
Flow meters – They measure the flow of a fluid in a pipe. Flow meters measure indirectly by measuring a related property such as a differential pressure across a flow restriction or a fluid velocity in a pipe. Flow meters also use the direct method for measured value acquisition. They measure either the flow velocity or the kinetic energy of the flow. In powder metallurgy, a flow meter is a metal cylinder whose interior is funnel shaped and whose bottom is a calibrated orifice of standard dimensions to permit passage of a powder and determination of the flow rate.
Flow modifying devices (FMDs) – These are the devices which modify the flow of liquid metal in a continuous casting tundish. They assist in the flotation of inclusions, by harnessing the turbulent energy from the ladle shroud. Principal among these flow modifying devices are pour-pads, weirs, dams, baffles with holes and turbulence inhibitors. The turbulence inhibitor controls the degree of splashing of liquid metal during ladle changes or at the beginning of the casting sequences. It is also useful in increasing the plug flow, the residence time, and decreasing the dead volume. Flow modifying devices are typically manufactured by casting shapes with 70 % alumina refractories, through occasionally areas subject to strong erosive flow can necessitate a switch to magnesite-based refractories. Less costly refractory grades, such as 60 % alumina, can be used to manufacture flow modifying device shapes but have shown a propensity for premature failures in field trials when tundishes are used for multiple heat sequences.
Flow patterns – Flow patterns can be considered to be laminar, turbulent, or a combination of both. Osborne Reynolds observed in 1880 that the flow pattern could be predicted from physical properties of the liquid. If the Reynolds number for the flow in a pipe is equal to or less than 2,000 the flow is laminar, from 2,000 to around 5,000 is the intermediate region where the flow can be laminar, turbulent, or a mixture of both, depending upon other factors, and beyond 5,000 the flow is always turbulent.
Flow principle – This principle states that all other things being equal, a good layout is one which provides for smooth and uninterrupted flow of men and materials.
Flow rate – It is the time needed for a standard powder sample of standard weight to flow through an orifice in a standard instrument as per a specified procedure.
Flow sheet – It is an illustration which is showing the sequence of operations, step by step, by which ore is treated in a milling, concentration, or smelting process.
Flow stress – It is the stress needed to produce plastic deformation in a solid metal.
Flow test – it is a standardized test to measure how readily a powder flows.
Flow through – It is a forging defect which is caused by metal flow past the base of a rib with resulting rupture of the grain structure.
Flow transmitter – It is a device which is designed to measure the rate of flow of a fluid (liquid or gas) through a pipeline or conduit. It is an upgraded version of the flow meter. It is a flow meter with an integrated electronic circuit as an operational system. The primary purpose of flow transmitter is to provide accurate and real-time data on the flow rate of a fluid. This information is essential for process control, monitoring, and optimization.
Flue – It is a passage for products of combustion.
Flue gas – It is the gas exiting to the atmosphere through a flue, which is a pipe or channel for conveying exhaust gases, as from a fireplace, oven, furnace, boiler or steam generator. It frequently refers to the exhaust gas of combustion.
Fluid – It is a liquid, gas, or other material which can continuously move and deform (flow) under an applied shear stress, or external force. Fluids have zero shear modulus, or, in simpler terms, are substances which cannot resist any shear force applied to them.
Fluid bearings – Fluid bearings support their loads solely on a thin layer of liquid or gas. They are usually of two types namely (i) hydrostatic bearings where load is supported by high pressure fluid and (ii) hydrodynamic bearings where load is supported by a lubricant film. Hydrostatic bearings are externally pressurized fluid bearings, where the fluid is usually oil, water or air, and the pressurization is done by a pump. Hydrodynamic bearings rely on the high speed of the journal (the part of the shaft resting on the fluid) to pressurize the fluid in a wedge between the faces. Hydrodynamic bearings support a rotating shaft and transmit its axial load to a machine foundation by floating it on a self-renewing film of oil. Fluid bearings are frequently used in high load, high speed or high precision applications where ordinary ball bearings would have short life or cause high noise and vibration. They are also used increasingly to reduce cost. Fluid bearings use a thin layer of liquid or gas fluid between the bearing faces, typically sealed around or under the rotating shaft.
Fluid-cell process – It is a modification of the Guerin process for forming sheet metal. The fluid-cell process uses higher pressure and is mainly designed for forming slightly deeper parts, using a rubber pad as either the die or punch. A flexible hydraulic fluid cell forces an auxiliary rubber pad to follow the contour of the form block and exert a nearly uniform pressure at all points on the work-piece.
Fluid energy mills – The general principle of operation in a fluid energy mill is that the material to be ground is fed into a grinding chamber in a high speed, high pressure and, often, high temperature jet of air (or other gas). The particles collide violently and this causes comminution to take place. Various designs of fluid energy mill exist, the most common being the micronizer. This mill has a shallow circular grinding chamber and a series of peripheral jets set tangentially to a common circle. The turbulence causes bombardment which effects a rapid reduction in particle size. A centrifugal classification system keeps larger particles within the chamber while allowing fine particles to leave. In a well-designed fluid energy mill, there is normally almost no contact between the charge and the mill lining. These mills are suitable for hard or soft materials to be reduced to 0.02 mm or less. This method of milling tends to be energy intensive and slow but is suitable where the product is highly sensitive to heat or contamination from grinding media.
Fluid erosion – It is the progressive loss of original material from a solid surface because of the mechanical interaction between that surface and a fluid, a multi-component fluid, and impinging liquid, or solid particles.
Fluid flow -It is normally the motion of a fluid which is subjected to different unbalanced forces. It is mainly a part of fluid mechanics and fluid flow normally deals with the dynamics of the fluid. The motion of the fluid continues till different unbalanced forces are applied to the fluid.
Fluid flow, pipe – It is the flow of a fluid in a pipe. There are three fluid flow regimes in a pipe namely laminar, turbulent, and a transition region. The conditions which lead to each type of flow behaviour are system-specific. Fluid flow simulations for various Reynolds numbers can be used to clearly identify and quantify when flow gets transition from laminar to turbulent.
Fluid forming – It is a modification of the Guerin process. Fluid forming differs from the fluid-cell process in that the die cavity, called a pressure dome, is not completely filled with rubber, but with hydraulic fluid retained by cup-shaped rubber diaphragm.
Fluid friction – It is the frictional resistance because of the viscous or rheological flow of fluids.
Fluidity – It is the ability of liquid metal to run into and fill a mould cavity.
Fluidized bed – It is a contained mass of a finely divided solid which behaves like a fluid when brought into suspension in a moving gas or liquid.
Fluidized-bed boiler – In modern large-capacity coal-fired boilers, coal is burnt in suspension. Fluidized-bed combustion ensures burning of solid fuel in suspension, in a hot inert solid-bed material of sand, limestone, refractory, or ash, with high heat transfer to the furnace and low combustion temperatures (800 deg C to 950 deg C). The combustor-bed material consists of only 35 % coal. Fluidized-bed combustion is comprised of a mixture of particles suspended in an upwardly flowing gas stream, the combination of which shows fluid-like properties. Fluidized-bed burners are capable of firing a wide range of solid fuels with varying heating value, ash content, and moisture content.
Fluidized-bed coating – It is a method of applying a thermoplastic or thermosetting resin coating to a heated article which is immersed in a dense-phase fluidized bed of powdered resin and thereafter heated in an oven to provide a smooth, pinhole -free coating.
Fluidized bed combustion (FBC) – It is a combustion technology which is used to burn solid fuels. In its most basic form, fuel particles are suspended in a hot, bubbling fluidity bed of ash and other particulate materials (sand, limestone etc.). through which jets of air are blown to provide the oxygen needed for combustion or gasification. The resultant fast and intimate mixing of gas and solids promotes rapid heat transfer and chemical reactions within the bed. Fluidized bed combustion furnaces are capable of burning a variety of low-grade solid fuels, including most types of coal, coal waste and woody biomass, at high efficiency and without the necessity for expensive fuel preparation (e.g., pulverizing). In addition, for any given thermal duty, fluidized bed combustion furnaces are smaller than the equivalent conventional furnace, sand hence offer considerable advantages over the latter in terms of cost and flexibility.
Fluidized-bed heating – It is heating carried out in a medium of solid particles suspended in a flow of gas.
Fluidized bed reduction – In the fluidized bed reduction process, the finely divided solid is a powdered ore or reducible oxide, and the moving gas is reducing. The process operation is carried out at high temperature in a furnace.
Fluidized bed scrubber – It is a type of scrubber which circulates boiler ash and lime between a scrubber and fabric filter, hence also called circulating fluidized bed scrubber (CFBS). Flue gas enters the circulating fluidized bed scrubber (with or without ash) at the bottom of the up-flow vessel, flowing upward through a venturi section that accelerates the gas flow rate, causing turbulent flow. The turbulator wall surface of the vessel causes highly turbulent mixing of the flue gas, solids, and water for 4 to 6 seconds to achieve a high capture efficiency of the vapor phase acid gases and metals contained within the flue gas. The gas and solids mixture then leaves the top of the scrubber.
Fluorescence – It is a type of photo-luminescence in which the time interval between the absorption and re-emission of light is very short.
Fluorescent lamp – It is a type of electric lamp which relies on a phosphor coating to produce visible light from the ultraviolet light generated by a mercury discharge.
Fluorescent magnetic-particle inspection – It is the inspection with either dry magnetic particles or those in a liquid suspension, the particles being coated with a fluorescent substance to increase the visibility of the indications.
Fluorescent penetrant inspection – It is the inspection using a fluorescent liquid which penetrates a surface opening. After the surface has been wiped clean, the location of any surface flaws can be detected by the fluorescence, under ultraviolet light, of back-seepage of the fluid.
Fluorescent yield – An electron is ejected from an atomic orbital by the photoelectric process with two possible results either X-ray photon emission or secondary (Auger) electron ejection. One of these events occurs for each excited atom, but not both. Hence, secondary electron production competes with X-ray photon emission from excited atoms in a sample. The fraction of the excited atoms which emits X-rays is termed the fluorescent yield. This value is a property of the element and the X-ray line under consideration. Low atomic number elements also have low fluorescent yield. Coupled with the high mass absorption coefficients which low-energy X-rays show, the detection and determination of low atomic number elements by X-ray spectrometry is challenging.
Fluoro-carbons – Fluoro-carbons are chemical compounds with carbon-fluorine (C-F) bonds. They are a group of synthetic halogen-substituted methane and ethane derivatives containing atoms of chlorine and fluorine. Compounds which contain several carbon-fluorine bonds frequently have distinctive properties, e.g., improved stability, volatility, and hydrophobicity. Fluoro-carbons which contain chlorine are called chloro-fluoro-carbons (CFCs). Chloro-fluoro-carbons normally known by commercial names such as Freon, Arcton, and Frigen. Because of their unique combination of non-flammability and general inertness, chloro-fluoro-carbons are used as refrigerants, aerosol propellants, foam-blowing agents, solvents, glass chillers, and polymer intermediates, as well as in fire extinguishers and anesthetics.
Fluorometric analysis, fluorimetry – It is a method of chemical analysis which measures the fluorescence intensity of the analyte or a reaction product of the analyte and a chemical reagent.
Fluoroplastic – It is a plastic based on polymers made from monomers containing one or more atoms of fluorine, or copolymers of such monomers with other monomers, the fluorine-containing monomer(s) being in highest quantity by mass.
Fluoroscopy – It is an inspection procedure in which the radiographic image of the subject is viewed on a fluorescent screen. It is normally limited to low-density materials or thin sections of metals because of the low light output of the fluorescent screen at safe levels of radiation.
Fluorspar – It is also called fluorite. It is the mineral form of calcium fluoride (CaF2). It belongs to the halide minerals. It crystallizes in isometric cubic habit, although octahedral and more complex isometric forms are not uncommon. The Mohs scale of mineral hardness, based on scratch hardness comparison, defines value 4 as fluorspar. Pure fluorite is colourless and transparent, both in visible and ultraviolet light, but impurities normally make it a colourful mineral and the stone has ornamental and lapidary uses. Industrially, fluorspar is used as a flux for smelting, and in the production of certain glasses and enamels. The purest grades of fluorite are a source of fluoride for hydrofluoric acid manufacture, which is the intermediate source of the majority of the fluorine-containing fine chemicals.
Flush bottom valves – These valves are generally at the lowest point of a tank or reactor and used to drain out contents. They are unique since it leaves no dead space in the valve when it is closed. This eliminates the problem of product build-up within the valve.
Flushing – It is a procedure for hydraulic systems of cleaning the fluid to a pre-determined standard. In pipelines for flushing, a fluid (normally water) is introduced into the pipes which are to be cleaned. This fluid, with a pressure calibrated according to the result to be achieved, transports the contaminants, cleaning the pipes.
Flute – As applied to drills, reamers, and taps, it is the channels or grooves formed in the body of the tool for providing cutting edges and for permitting passage of cutting fluid and chips. As applied to the milling cutters and hobs, it is the chip space between the back of one tooth and the face of the following tooth.
Fluted bearing – It is a sleeve bearing with oil grooves normally in an axial direction.
Fluted core – It is an integrally woven reinforcement material consisting of ribs between two skins in a unitized sandwich construction.
Fluting – It is forming longitudinal recesses in a cylindrical part, or radial recesses in a conical part. It is also a series of sharp parallel kinks or creases occurring in the arc when sheet metal is roll formed into a cylindrical shape. It also consists of grinding the grooves of a twist drill or tap. In bearings, it is a form of pitting in which the pits occur in a regular pattern so as to form grooves. Ridges can occur with or without burnt craters. The general cause involves vibration together with excessive wear or excessive load. Fluting is also electric discharge pitting in a rolling-contact bearing subject to vibration.
Flutes – These are elongated grooves or voids which connect widely spaced cleavage planes.
Flux – It is a chemical substance which reacts with gangue minerals to form slags, which are liquid at furnace temperature and low enough in density to float on the molten bath of metal or matte. In metal refining, it is a material added to a melt for removing undesirable substances, like sand, ash, or dirt. Fluxing of the melt facilitates the agglomeration and separation of such undesirable constituents from the melt. It is also used as a protective covering for certain molten metal baths. Lime or limestone is normally used to remove sand, as in iron smelting and sand is used to remove iron oxide in copper refining. In brazing, cutting, soldering, or welding, flux is the material used to prevent the formation of, or to dissolve and facilitate removal of, oxides and other undesirable substances. This term flux is also applied to the quantity of particles or energy which crosses a unit area per unit time. The unit of flux is the number of particles or energy, per square centimeter per second. In galvanizing, flux consists of the chemicals used to protect steel from oxidation prior to entering the molten zinc containing pot.
Flux, electric – In electromagnetism, electric flux is the measure of the electric field through a given surface, although an electric field in itself cannot flow. Electric flux is the property of an electric field that may be thought of as the number of electric lines of force (or electric field lines) that intersect a given area. Electric field lines are considered to originate on positive electric charges and to terminate on negative charges.
Flux cored arc welding (FCAW) – It is an arc welding process which joins metal by heating them with an arc between a continuous tubular filler-metal electrode and the work. Shielding is provided by a flux contained within the consumable tubular electrode. Additional shielding may or may not be obtained from an externally supplied gas or gas mixture.
Flux cored electrode – It is a composite filler metal electrode consisting of a metal tube or other hollow configuration containing ingredients to provide such functions as shielding atmosphere, deoxidation, arc stabilization, and slag formation. Minor quantities of alloying materials can be included in the core. External shielding may or may not be used.
Flux cover (metal bath dip brazing and dip soldering) – It is a layer of molten flux over the molten filler metal bath.
Flux density – In magnetism, the number of flux lines per unit area passing through a cross section at right angles. It is given by B = mu H, where ‘mu’ and ‘H’ are permeability and magnetic-field intensity, respectively.
Flux-gate magnetometer – It is an instrument which is used in geophysics to measure total magnetic field.
Flux inclusions – It is the flux carried out onto the steel from the top flux blanket incorporated in the wet process. It occurs only in the wet galvanizing process.
Fluxing – Fluxing is the use of a hot zinc ammonium chloride pre-flux solution to condition the cleaned steel prior to its immersion in the molten zinc. It is the process by which steel is dipped in aqueous zinc ammonium chloride to remove undesirable substances and to protect it from further oxide formation prior to entering the galvanizing bath.
Flux leakage techniques – Magnetic particle inspection system based on flux leakage techniques is a well proven system but only suitable for cold billets. The magnetic sensors are deployed either to scan the surface directly or indirectly where a contacting tape transfers the magnetic image to a separate scanning head. In either case there is a temperature limit imposed on the billet to ensure a satisfactory test. Attempts have been made to utilize this form of inspection on continuous cast billet and the results are very disappointing. Continuous cast defects such as pinholes, transverse cracking and other defects with a transverse component can escape detection and in addition the level of spurious marking is very high. It is important to remember that the level of spurious marking generated by any inspection system is just as significant a feature as its detection efficiency.
Flux lines – These are imaginary lines which are used as a means of explaining the behaviour of magnetic and other fields. Their concept is based on the pattern of lines produced when magnetic particles are sprinkled over a permanent magnet. It is sometimes called magnetic lines of force.
Flux linkage – In a magnetic system, it is that part of the magnetic flux which passes through a given closed path, which can be a winding.
Flux oxygen cutting – It is a non-standard term for chemical flux cutting.
Flux pit – In porcelain enamel, it is a cone-like depression defect in the fired enamel surface, somewhat larger than a pinhole.
Flux staining – It occurs after galvanizing, when the crevices and overlaps, which are not sealed, can show signs of brown staining bleeding out of the crevices. This is the result of iron-rich flux residues being trapped in the crevices absorbing moisture.
Fly ash – It is a by-product which is generated during the burning of pulverized coal in a thermal power plant. Specifically, it is the unburned residue which is carried away from the burning zone in the boiler by the flue gases and then collected by electrostatic separators or by any other means. Fly ash is a pozzolanic material. It is normally finer than Portland cement and consists mostly of small spheres of glass of complex composition involving silica, ferric oxide, and alumina. The composition of fly ashes varies with the source of coal.
Fly-back converter – It is a type of voltage converter which stores energy in an inductor.
Fly-back transformer – It is a type of transformer which recovers energy stored in its own core. Historically it is used in the deflection circuits of cathode ray tube display systems.
Fly cutting – It is the cutting with a single-tooth milling cutter.
Flying shear – It is a machine for cutting continuous rolled products to length which does not need a halt in rolling, but rather moves along the runout table at the same speed as the product while performing the cutting, and then returns to the starting point in time to cut the next piece. It is a standard industrial equipment known for cutting a constant product at a determined length at line speed. Flying shears do not interrupt the primary production, ensuring maximized productivity.
Fly-wheel – It is a mechanical device specifically designed to use the conservation of angular momentum so as to efficiently store rotational energy, which is a form of kinetic energy proportional to the product of its moment of inertia and the square of its rotational speed. In particular, if it is assumed that the flywheel’s moment of inertia is constant (i.e., a flywheel with fixed mass and second moment of area revolving about some fixed axis) then the stored (rotational) energy is directly associated with the square of its rotational speed.
Foam blanket – It is an additive which forms a layer on the surface of electro-plating baths which have poor anode / cathode efficiency and prevents any mist or spray from escaping.
Foamed plastics – These are resins in sponge form, flexible or rigid, with cells closed or inter-connected and density over a range from that of the solid parent resin to 0.03 grams per cubic centimeters. Compressive strength of rigid foams is fair, making them useful as core materials for sandwich constructions. It is also a chemical cellular plastic, the structure of which is produced by gases generated from the chemical interaction of its constituents.
Foaming – It is the continuous formation of bubbles which have sufficiently high surface tension to remain as bubbles beyond the disengaging surface. Foaming is an important phenomenon which is normally encountered when gas is blown through a viscous liquid. It is beneficial in the steelmaking as it assists the refining process in different ways. It provides an increased surface area for the refining reactions and protects the liquid metal bath from the direct contact of the atmosphere. It enhances the kinetics of the reactions, heat transfer, and energy efficiency of the process. It forms the medium for post-combustion and heat transfer. It protects the refractory lining from extreme combustion effects by providing a shield for the refractory and hence extends the life of the refractory lining. It acts as a sink for the oxides of impurities such as manganese, silicon, and phosphorus, which have been oxidized from the liquid bath. In addition, slag foaming prevents the liquid bath from oxidizing and enables control of its composition. It also acts as a thermal insulator between the hot bath and the surroundings and thus prevents major energy losses.
Foaming agent – It consists of chemicals added to plastics and rubbers which generate inert gases on heating, causing the resin to assume a cellular structure.
Foaming index (FI) – It is an important parameter for the slag foaming. It can be viewed as the time for the gas to pass through the slag. It is an indication of the extent of the foaming and is the ratio between the foam height and the superficial gas velocity. Hence, the unit of the foaming index is time which is normally in seconds. Hence, the foaming index can be interpreted as a measure of the time it takes for the process gases to vertically pass through the foam. The foaming index is related to the slag properties such as viscosity. The higher is the viscosity, the higher is the foaming index. The obvious consequence is that an increased viscosity automatically leads to an increased foam height. The foaming index decreases with increasing bubble size.
Foamy slag – It is at the heart of modern steelmaking in electric arc furnace (EAF) process. The foaming helps to shield refractories from arc plasma, stabilizes the arc and helps to increase the power input and energy efficiency, reduces nitrogen pick-up, improves productivity, and chromium recovery in stainless steel melting. Foaming of slag takes place because of carbon mono-oxide bubbles generated by the reaction of bath carbon with the injected oxygen gas.
Foaming slag control system – For automated foaming slag operation, several approaches exist which use sound measurements. Foaming slag control system is a sensor system. It is based on structure-born noise and is an approach to evaluate the quantity of foaming slag in the electric arc furnace. In regards to trends and reproducibility, this method has proved to successfully follow the real foaming slag situation in the arc furnace.
Foam inhibitor – It is a surface-active chemical compound which is used in minute quantities to prevent or reduce foaming. Silicone fluids are frequently used as foam inhibitors.
Foam-in-place – It refers to the deposition of foams when the foaming machine must be brought to the work that is ‘in place’ as opposed to bringing the work to the foaming machine. It is also, foam mixed in a container and poured into a mould, where it rises to fill the cavity.
Focal length – It is the distance from the second principal point to the point on the axis at which parallel rays entering the lens converges or focuses.
Focal spot – It is that area on the target of an x-ray tube which is bombarded by electrons.
Focus – It is a point at which rays originating from a point in the object converge or from which they diverge or appear to diverge under the influence of a lens or diffracting system.
Focused improvement – It is an improvement strategy based on the theory of constraints. Attention is focused on addressing one limiting factor, called a constraint, at a time in order to optimize a system. Each constraint is improved until it no longer limits the system’s performance.
Focusing (x-rays) – It is the operation of producing a convergent beam in which all rays meet in a point or line.
Focusing device (electrons) – It is a device which effectively increases the angular aperture of the electron beam illuminating the object, rendering the focusing more critical.
Fog quenching – It is the quenching in a fine vapour or mist.
Foil – It is metal in sheet form less than 0.15 millimeter thick.
Foil, annealed It is that foil which has been completely softened by thermal treatment.
Foil bearing – It is a bearing in which the housing is replaced by a flexible foil held under tension against a partition of the journal periphery, lubricant being retained between the journal and the foil.
Foil, bright two sides – It is the foil which is having a uniform bright specular finish on both sides.
Foil, chemically cleaned – It is the foil which is chemically washed to remove lubricant and foreign material.
Foil, embossed – It is the foil on which a pattern has been impressed by means of an engraved roll or plate.
Foil, etched – It is the foil which has been roughened chemically or electro-chemically to provide an increased surface area.
Foil, hard – It is the foil which has been fully work hardened by rolling.
Foil, intermediate temper – It is the foil which is intermediate in temper between annealed foil and hard foil.
Foil (film) lamination – It is an industrial process in which decorative foils are bonded to substrate materials in order to improve their appearance and feel.
Foil, matte one side (M1S) – It is the foil with a diffuse reflecting finish on one side and a bright specular finish on the other.
Foil, mechanically grained – It is the foil which has been mechanically roughened for such applications as lithography.
Foil, mill finish (MF) – It is the foil which is having a non-uniform finish which can vary from coil to coil and within a coil.
Foil, scratch brushed – It is the foil which is abraded, normally with wire brushes, to produce a roughened surface.
Foil stock – It is a semi-finished rolled product of rectangular cross section in coiled form suitable for further rolling.
Fold – It is a defect in metal, normally on or near the surface, caused by continued fabrication of overlapping surfaces. It is a forging defect caused by folding metal back onto its own surface during its flow in the die cavity. In mining, fold is the bending or wrinkling of rock strata.
Follow board – In foundry practice, it is a board contoured to a pattern to facilitate the making of a sand mould.
Follow die – It is a progressive die consisting of two or more parts in a single holder. It is used with a separate lower die to perform more than one operation (such as piercing and blanking) on a part in two or more stations.
Follower – It is an extension used between the pile and the hammer which transmits blows to the pile when the pile head is either below the reach of the hammer (below the guides / leads) or under water. A follower is normally a section of pipe or ‘H’ pile with connections which match both the pile hammer and the pile.
Follower plate – It is a plate fitted to the top surface of a grease dispenser.
Foot step bearing – It is also known as pivot bearing. In this bearing the bearing pressure is exerted parallel to the shaft whose axis is vertical. It is to be noted that in this case the end of the shaft rests within the bearing.
Foot switch – It is normally an electrical switch. It is simply a device which opens or closes an electrical circuit. It is operated by an operator by stepping on the actuator, which is typically a push-button or a pedal. The advantage of using a foot switch is simply that it frees up the operator’s hands for other work while still allowing the operator’s full control over switching.
Footwall – It is the rock which is on the underside of a vein or ore structure.
Force – It is an influence which can push or pull an object to change its motion. A force can cause an object with mass to change its velocity (e.g., moving from a state of rest), i.e., to accelerate. A force has both magnitude and direction, making it a vector quantity. It is also the male half of the mould which enters the cavity, exerting pressure on the resin and causing it to flow. It is also called punch.
Forced-air quench – It is a quench utilizing blasts of compressed air against relatively small parts such as a gear.
Forced / assisted circulation boiler – The density difference between the saturated liquid and saturated vapour starts diminishing at 18 MPa or higher fluid pressure, hence, it is difficult to maintain natural circulation of fluid flow in boiler tubes. In such cases fluid flow is ensured with the help of forced / assisted circulation using pumps. The forced / assisted circulation principle applies equally in both super-critical and sub-critical ranges.
Forced circulation – It is the circulation of water in a boiler by mechanical means external to the boiler.
Forced draft fan – It is a fan supplying air under pressure to the fuel burning equipment.
Force-feed lubrication – It is a system of lubrication in which the lubricant is supplied to the bearing under pressure.
Force majeure – It is a common clause in contracts which essentially frees both parties from liability or obligation when an extraordinary event or circumstance beyond the control of the parties, such as a war, strike, riot, crime, epidemic, or sudden legal change prevents one or both parties from fulfilling their obligations under the contract. Force majeure frequently includes events described as an act of God, though such events remain legally distinct from the clause itself. In practice, most force majeure clauses do not entirely excuse a party’s non-performance but suspend it for the duration of the force majeure.
Forecast – It is a prediction or estimation of future product demand in the market based on available information.
Fore-hand welding – It is a welding technique in which the welding torch or gun is directed toward the progress of welding.
Foreign structure – It is a metallic structure which is not intended as part of a cathodic protection system of interest.
Forensic metrology – Forensic metrology is the application of measurements and hence measurement standards to the solution and prevention of crime. It is practiced within the laboratories of law enforcement agencies throughout the world.
Foreseeable future – It is the period of time which a project can make a reasonable projection of the occurrence of future conditions, events, or other factors which determine the environmental-socio-economic viability or technical feasibility of the project.
Forgeability – It is the term used to describe the relative ability of material to deform without fracture. It also describes the resistance to flow from deformation.
Forged roll Scleroscope hardness number (HFRSc or HFRSd) – It is a number related to the height of rebound of a diamond-tipped hammer dropped on a forged steel roll. It is measured on a scale determined by dividing into 100 units the average rebound of a hammer from a forged steel roll of accepted maximum hardness.
Forged steel rolls – These rolls are made by forging. The forged steel rolls contain less carbon compared to cast steel rolls since high carbon content can cause cracks during the forging process. The structure of the forged steel rolls is denser than that of cast steel rolls and hence is tougher and can take more loads. However, because of the lower carbon content the hardness is low and more prone to wear than cast steel rolls. These rolls are primarily used where they have to withstand high loads as in blooming mills or in heavy section mills. Forged and hardened rolls are also used as back-up rolls in 4-high mills although normally alloy cast steel rolls are used for back-up.
Forged structure – It is the macro-structure through a suitable section of a forging which reveals direction of working.
Forge welding (FOW) – It is solid-state welding in which metals are heated in a forge (in air) and then welded together by applying pressure or blows sufficient to cause permanent deformation at the interface.
Forging – It is the process of working metal to a desired shape by impact or pressure in hammers, forging machines (upsetters), presses, rolls, and related forming equipment. Forging hammers, counter-blow equipment, and high-energy-rate forging machines apply impact to the work-piece, while majority of the other types of forging equipment apply squeeze pressure in shaping the stock. Some metals can be forged at room temperature, but majority are made more plastic for forging by heating. Specific forging processes include closed-die forging, high-energy-rate forging, hot upset forging, isothermal forging, open-die forging, powder forging, precision forging, radial forging, ring rolling, roll forging, rotary forging, and rotary swaging. In powder metallurgy, forging is the process of placing a powder in a container, removing the air from the container, and sealing it. This is followed by conventional forging of the powder and container to the desired shape.
Forging billet – It is a wrought metal slug used as forging stock.
Forging, blocker-type – It is a forging made in a single set of impressions to the general contour of a finished part.
Forging, cold-coined – It is a forging which has been restruck cold to get closer dimensions, to sharpen comers or outlines, and in non-heat-treatable alloys, to increase hardness.
Forging dies – These are forms for making forgings. They normally consist of a top and bottom die. The simplest is which forms a completed forging in a single impression. The most complex, consisting of several die inserts, can have a number of impressions for the progressive working of complicated shapes. Forging dies are normally in pairs, with part of the impression in one of the blocks and the rest of the impression in the other block.
Forging, draft-less – It is a forging with zero draft on vertical walls.
Forging envelope – It is the quantity of excess metal surrounding the intended final configuration of a formed part. It is sometimes called forging envelope, machining allowance, or cleanup allowance. It is also the quantity of stock left on the surface of a casting for machining.
Forging, flash-less – It is a closed-die forging made in dies constructed and operated to eliminate, in pre-determined areas, the formation of flash.
Forging, hammer – It is a forging produced by repeated blows in a forging hammer.
Forging, hand – It is a forging which has been worked between flat or simply shaped dies by repeated
Forging ingot – It is a cast metal slug used as forging stock.
Forging, no-draft – It is a forging with zero draft on vertical walls.
Forging machine (upsetter or header) – It is a type of forging equipment, related to the mechanical press, in which the main forming energy is applied horizontally to the work-piece, which is gripped and held by prior action of the dies.
Forging plane – It is a reference plane or planes normal to the direction of applied force from which all draft angles are measured. It is the plane which includes the main die face and which is perpendicular to the direction of ram travel. When parting surfaces of the dies are flat, the forging plane coincides with the parting line.
Forging, precision – It is a forging produced to tolerances closer than standard.
Forging, press – It is a die forging produced by pressure applied in a forging press.
Forging quality – Forging quality of a metal or an alloy means that the metal or alloy has a good ‘forgeability’. The term ‘forgeability’ is defined here as the tolerance of a metal or alloy for deformation without failure, regardless of forging-pressure requirements. Majority of the metals and alloys can be classified into one of three groups namely (i) showing good forgeability, (ii) showing poor forgeability, and (iii) showing variable forgeability. All metals and metal alloys, with very few exceptions, are suitable for forging.
Forging quality steels – These are the type of steels which have a good ‘forgeability’. These are the steels which are used for open forging, die forging and upsetting operations. In these steels, gas content and inclusions are controlled.
Forging range – It is the temperature range in which a metal can be forged successfully.
Forging, rolled ring – It is a cylindrical product of relatively short height, circumferentially rolled from a hollow section.
Forging rolls – These are power-driven rolls which are used in pre-forming bar or billet stock which have shaped contours and notches for introduction of the work.
Forging stock – It is a wrought rod, bar, or other section suitable which is for subsequent change in cross section by forging.
Forging, upset – It is a forging which is having part or all of its cross section higher than that of the stock.
Forklift trucks – These are material handling equipments. They are the most commonly used industrial lift trucks. It is a powered industrial lift truck equipped with lifting media made up of a mast and elevating load carriage. It is a vehicle drawn or propelled by mechanical, or electrical power, designed incorporating a powered lift principally to lift, carry or stack goods by means of (i) a fork consisting of one or more arms which support the load, (ii) a platform, or (iii) any attachment or other mechanism. Forklift truck consists of variety of components needed to handle the task effectively. These components range from truck frame, power source to counterweight and are essential for the forklift to function efficiently. Forklift trucks are the workhorses of material handling because of their flexibility which include (i) indoor / outdoor operation over a variety of different surfaces, (ii) availability with a variety of load capacities, and (iii) availability with a variety of attachments.
Formability – It is the ease with which a metal can be shaped through plastic deformation. Evaluation of the formability of a metal involves measurement of strength, ductility, and the quantity of deformation needed for causing fracture. The term workability is used interchangeably with formability, however, formability refers to the shaping of sheet metal, while workability refers to shaping materials by bulk forming.
Formal standards – These standards are published by the national standardization organizations, regional standardization organizations (e.g. CEN, CENELEC etc.), and international standardization organizations (e.g. ISO, IEC etc.). There are around 160 national standardization organizations which are members of ISO (the International Organization for Standardization).
Form block – It is the tooling, normally the male part, which is used for forming sheet metal contours. It is normally used in rubber-pad forming.
Form cutter – It is a cutter which is profile sharpened or cam relieved, shaped to produce a specified form on the work.
Form defects – These are incomplete / improper macroscopic metal flow leading to improper shape / size of the defects. They are mostly macroscopic with both of process related origin and metallurgical origin.
Form dies – These are dies which are used to change the shape of a sheet metal blank with minimal plastic flow.
Formed refractories – These are those refractories which are manufactured by firing or chemical bonding methods. The fired refractory material is formed by heating the refractory material to a high temperature in a kiln to form a ceramic bond. This process makes the raw material fire-resistant. Chemically bonded refractory bricks are formed with the help of selected additives which solidify at room temperature and provide structural integrity without the need for high-temperature sintering. By eliminating the need for high-temperature processing, considerable energy savings can be achieved. In addition, several methods of changing chemical bonds can develop new compositions to withstand the harsh environments found in several industrial processes.
Form grinding – It is the grinding with a wheel having a contour on its cutting face which is a mating fit to the desired form.
Forming – It is making a change, with the exception of shearing or blanking, in the shape or contour of a metal part without intentionally altering its thickness. It is also the plastic deformation of a billet or a blanked sheet between tools (dies) to get the final configuration. Metal-forming processes are typically classified as bulk forming and sheet forming. It is also being referred to as metal-working. Forming is also a process in which the shape of plastic pieces such as sheets, rods, or tubes is changed to a desired configuration. The use of the term forming in plastics technology does not include such operations as moulding, casting, or extrusion, in which shapes or pieces are made from moulding materials or liquids. In powder metallurgy, forming is a generic term describing the first step in changing a loose powder into a solid of specific configuration.
Forming limit diagram (FLD) – It is a diagram in which the major strains at the onset of necking in sheet metal are plotted vertically and the corresponding minor strains are plotted horizontally. The onset-of-failure line divides all possible strain combinations into two zones namely the safe zone (in which failure during forming is not expected) and the failure zone (in which failure during forming is expected).
Forming processes – Among all manufacturing processes, metal forming processes have a special place since it helps to produce parts of superior mechanical properties with minimum waste of material. In metal forming, the starting material has a relatively simple geometry. The material is plastically deformed in one or more operations into a product of relatively complex configuration. Forming to near-net or to net-shape dimensions drastically reduces metal removal requirements, resulting in considerable material and energy savings. Metal forming processes are normally classified as per two broad categories namely (i) bulk, or massive, forming operations, and (ii) sheet-forming operations. In the broadest and most accepted sense, however, the term forming is used to describe bulk forming as well as sheet-forming processes. In both types of processes, the surfaces of the deforming metal and the tools are in contact, and friction between them can have a major influence on material flow. In bulk forming, the input material is in billet, rod, or slab form, and the surface-to-volume ratio in the formed part increases considerably under the action of largely compressive loading. In sheet forming, on the other hand, a piece of sheet metal is plastically deformed by tensile loads into a three-dimensional shape, frequently without considerably changes in sheet thickness or surface characteristic.
Form-relieved cutter – It is a cutter so relieved that by grinding only the tooth face of the original form is maintained throughout its life.
Form rolling – It is the hot rolling to produce bars having contoured cross sections. It is not to be confused with roll forming of sheet metal or with roll forging.
Form tool – It is a single-edge, non-rotating cutting tool, circular or flat, which produces its inverse or reverse form counter-part upon a work-piece.
Formula weight (FW) – It is a synonym for molar mass and molecular weight, frequently used for non-molecular compounds such as ionic salts.
Formvar – It is a plastic material used for the preparation of replicas or for specimen-supporting membranes.
Formvar replica – It is a reproduction of a surface in a plastic Formvar film (used for the preparation of replicas or for sample-supporting membranes).
Formwork -It consists of moulds into which concrete or similar materials are either precast or cast-in-place. In the context of concrete construction, the falsework supports the shuttering moulds. In specialty applications formwork can be permanently incorporated into the final structure, adding insulation or helping reinforce the finished structure.
Forward contract – The sale or purchase of a commodity for delivery at a specified future date.
Forward converter – It is a type of voltage converter which relies on transformer action to couple energy to its output circuit.
Forward curved fans – These fans are with forward curved blades can move high air volumes against relatively low pressure and are of relatively small size. These fans have low noise level (because of low speed) and are well suited for residential heating, ventilation, and air conditioning (HVAC) applications. They are only suitable for clean service applications but not for high pressure and harsh services. The fan output is difficult to adjust accurately. In these fans, driver is to be selected carefully to avoid motor overload since power curve increases steadily with airflow. These fans have relatively low energy efficiency (55 % to 65 %).
Forward extrusion – It is the extrusion in which the die and ram are at opposite ends of the extrusion stock, and the product and ram travel in the same direction. Also, there is relative motion between the extrusion stock and the die.
Forward integration – It is a form of vertical integration in which the organization moves further in the direction of controlling the distribution of its products or services. In forward integration the organization integrates its operational activities toward the end customer. Forward integration is a strategic process which helps the organization to improve its efficiency and increase profits. By implementing forward integration, the organization gains more control over its product and its delivery to the consumers.
Forward pass – It is the process of moving through the project from start to finish time determining the earliest start and finish times for the activities of the project.
Fossil-fuel phase-out – It is a plan to replace coal, oil, or natural gas fuel with other sources to produce electrical energy.
Fossil-fuel power station – It is a power plant which uses coal, oil, or natural gas fuel.
Fouling – It is an accumulation of deposits. This term includes accumulation and growth of marine organisms on a submerged metal surface and also includes the accumulation of deposits (normally inorganic) on heat exchanger tubing. It is also the accumulation of refuse in gas passages or on heat absorbing surfaces which results in undesirable restriction to the flow of gas or heat.
Fouling organism -It is an aquatic organism with a sessile adult stage which attaches to and fouls under-water structures of ships.
Foundation, equipment – It is a support system for heavy equipments with reciprocating, impacting, or rotating masses. It can resist dynamic forces and the resulting vibrations. When excessive, such vibrations can be detrimental to the equipments, its support system, and any operating personnel subjected to them. The super-structure of vibrating and rotating equipments is known as equipment foundation. It essentially consists of a mass of reinforced concrete. Design of equipment foundation involves consideration of static and dynamic loads.
Foundation analysis and design – Every foundation is analyzed for its dynamic response and checked for strength and stability. Using the equipment, soil and foundation parameters, amplitudes of vibration are computed at the equipment as well as the foundation level. In addition, foundation is designed for its strength and stability to withstand applicable static and dynamic forces. For this, the dynamic forces of the equipment are translated into equivalent static forces on the foundation. Strength check of the foundation is also done for forces because of the environmental effects like wind and earthquake etc. If the strength analysis indicates that there is a need for change in the foundation size, a recheck on the dynamic analysis with the revised foundation size is a necessity. Typical foundation parameters needed for design of equipment foundation system are (i) foundation geometry, (ii) material properties i.e., mass density, dynamic modulus of elasticity, Poisson’s ratio, and coefficient of thermal expansion etc., (iii) strength parameters i.e., yield strength, ultimate tensile strength, allowable strength in compression, tension, bending, and shear etc.
Foundation and equipment load – Foundations supporting different types of equipments are to withstand all the forces which can be imposed on them during their service life. Equipment foundations are unique since they can be subjected to considerable dynamic loads during operation in addition to normal design loads of gravity, wind, and earthquake. The magnitude and the characteristics of the operating loads depend on the type, size, speed, and layout of the equipments. There are two types of loads on the equipment foundations. These are static loads, and dynamic loads. Static loads are (i) dead loads, (ii) live loads, (iii) wind loads, (iv) seismic loads, (v) static operating loads, (vi) special loads for elevated-type foundations, (vii) erection and maintenance loads, and (viii) thermal loads. Dynamic loads are (i) rotating equipment load, (ii) reciprocating equipment load, (iii) impulsive equipment load, (iv) loading conditions, and (v) load combinations.
Foundation design precautions – The precautions needed for foundation design are (i) foundation is to be designed to transmit combined dead load, imposed load, and wind load to the ground, (ii) net loading intensity of pressure coming on the soil is not to exceed the safe bearing capacity, (iii) foundation is to be designed in such a way that settlement to the ground is limited and uniform to avoid damage to the structure, and (iv) design of the foundation, super-structure, and characteristics of the ground are to be studied to get the overall economy.
Foundation plan drawing – A foundation plan drawing shows the top view of the footings or foundation walls, and shows their area and their location by distances between centre-lines and by distances from reference lines or boundary lines. Actually, it is a horizontal section view cut through the walls for the foundation showing beams, girders, piers or columns, and openings, along with dimensions and internal composition. The foundation plan is used primarily by the people who construct the foundation of the proposed structure. A foundation plan drawing
can be made for any floor of a plant facility. The purpose of making this drawing is to convey the dimensions, sizes, shapes, and every single configuration of a floor. Footings are also a necessary part of a foundation plan drawing.
Foundation materials – Plain concrete, brick, reinforced cement concrete (RCC), pre-stressed concrete, and steel are the materials used for the construction of the equipment foundation. Foundations using steel structures have also been used for frame foundations. The sizes of structural members in steel foundations are less than those for reinforced cement concrete foundations and hence the space requirement is much less. As regards vibration, steel structures undoubtedly involve higher risk. Natural frequencies are low and the foundation is deeply under-tuned. The resistance to fire of a steel structure is lower than that of reinforced cement concrete structure. Majority of the high tuned foundations are built of reinforced concrete. Vibration amplitudes are reduced because of the relatively higher damping present in the concrete.
Foundations -They provide support to the structure and transfer the loads from the structure to the soil. But the layer at which the foundation transfers the load is required to have an adequate bearing capacity and suitable settlement characteristics. There are several types of foundations depending on different considerations such as total load from the super-structure, soil conditions, water level, noise and vibrations sensitivity, available resources, time-frame of the project, and cost. Broadly speaking, foundations can be classified as (i) shallow foundations, and (ii) deep foundations.
Foundry – It is a commercial establishment or building where metal castings are produced.
Foundry grade pig iron – This type of pig iron is being used in iron foundries and contains higher silicon. Different standards specify composition limits for silicon and manganese for different grades of this type of pig iron. Silicon content in foundry grade pig iron is much higher and is normally in the range of 1.5 % to 3.5 %. It can be as high as 4.25 %.
Foundry returns – It is the metal in the form of gates, sprues, runners, risers, and scrapped castings of known composition returned to the furnace for remelting.
Four-high mill – It is a type of rolling mill, normally used for flat-rolled mill products, in which two large-diameter backup rolls are used to reinforce two smaller diameter work rolls, which are in contact with the product. Either the work rolls or the back-up rolls can be driven.
Four-high mill roll configuration – In this type of roll configuration, there are four horizontal rolls, mounted in a single vertical plane. Two rolls (inner) are work rolls and two rolls (outer) are back-up rolls. Significance of the back-up rolls consists in a chance of using higher roll forces and decrease in bending (deflection) of work rolls. Small diameters of work roll also permit (except for greater elongation of the rolling stock) a possibility of achieving of more favourable dimensional thickness deviations. The work rolls of the four-high mill are driven while the back-up rolls are normally friction driven. The four-high roll configuration is used for rolling of plates and for hot rolling and cold rolling of steel strip. It is used both in the non-reversing and reversing rolling mills.
Fourier series – It is a set of coefficients of sine and cosine waves. This can represent a time function as a function of frequency.
Fourier transform – It is an algorithm for converting a continuous wave-form in the time domain into an equivalent set of spectral components in the frequency domain.
Fourier transform infrared (FT-IR) spectrometry – It is a form of infra-red spectrometry in which data are obtained as an interferogram, which is then Fourier transformed to get an amplitude against wave-number (or wave-length) spectrum.
Four-point press – It is a press whose slide is actuated by four connections and four cranks, eccentrics, or cylinders, the main merit being to equalize the pressure at the corners of the slides.
FP fibre – It consists of poly-crystalline alumina (Al2O3) fibre. A ceramic fibre useful for high-temperature (1,370 deg C to 1,650 dwg C) composites.
Fraction – It is that portion of a powder sample which lies between two stated particle sizes.
Fractional distillation – It is the fractionation of a mixture of liquids into its component parts, or fractions, by the process of distillation, typically by using a long vertical column attached to the distillation vessel and filled with glass beads. The mixture is heated to a temperature at which one or more of the component compounds vapourizes. The vapour rises up the column until it condenses and runs back into the vessel, creating a temperature and volatility gradient and permitting different fractions to be drawn off at different points along the length of the column. The technique is sensitive enough to separate compounds which have boiling points which differ by less than 25 deg C from each other at standard pressure.
Fractionation – It is a separation process in which a particular quantity of a mixture is divided during a phase transition into a number of smaller quantities, known as fractions, for which the chemical composition varies according to a gradient. Fractionation exploits subtle differences in some specific property (e.g., mass, boiling point, solubility, etc.) between the mixture’s component compounds, making it possible to isolate more than two components of a mixture at the same time. There are several varieties of fractionation employed in many branches of science and technology.
Fractography – It is the descriptive treatment of fracture of materials, with specific reference to photographs of the fracture surface. Macro-fractography involves photographs at low magnification (less than 25×), while the micro-fractography involves photographs at high magnification (higher than 25×).
Fracture – It is the irregular surface produced when a piece of metal is broken. Fracture can be defined as the mechanical separation of a solid owing to the application of stress. In composites, it is the separation of a body, which is defined both as rupture of the surface without complete separation of the laminate and as complete separation of a body because of external or internal forces. Fractures in continuous-fiber-reinforced composites can be divided into three basic fracture types namely intra-laminar, inter-laminar, and trans-laminar. Trans-laminar fractures are those oriented transverse to the laminated plane in which conditions of fibre fracture are generated. Inter-laminar fracture,on the other hand, describes failures oriented between plies, whereas intralaminar fractures are those located internally within a ply. Fractures of engineering materials are broadly categorized as ductile or brittle, and fracture toughness is related to the quantity of energy needed to create fracture surfaces. In mining, fracture is a break in the rock, the opening of which allows mineral-bearing solutions to enter. A ‘cross-fracture’ is a minor break extending at more-or-less right angles to the direction of the main fractures.
Fracture grain size – It is the grain size which is determined by comparing a fracture of a sample with a set of standard fractures. For steel, a fully martensitic sample is normally used, and the depth of hardening and the prior austenitic grain size are determined.
Fracture mechanics – Fracture mechanics is the field of mechanics concerned with the study of the propagation of cracks in materials. It uses methods of analytical solid mechanics to calculate the driving force on a crack and those of experimental solid mechanics to characterize the material’s resistance to fracture. It is a quantitative analysis for evaluating structural behaviour in terms of applied stress, crack length, and sample or machine component geometry.
Fracture resistance – Fracture resistance of a material is characterized by the critical stress intensity factor which can be sustained without fracture.
Fracture strength – It is the normal stress at the beginning of fracture. It is calculated from the load at the beginning of fracture during a tension test and the original cross-sectional area of the sample.
Fracture stress – It is the true, normal stress on the minimum cross-sectional area at the beginning of fracture. The term normally applies to tension tests of unnotched samples.
Fracture surface – It is the irregular surface produced when a piece of metal is broken.
Fracture surface markings – These are fracture surface features which can be used to determine the fracture origin location and the nature of the stress that produced the fracture.
Fracture test – It is the test in which a sample is broken and its fracture surface is examined with the unaided eye or with a low-power microscope to determine such factors as composition, grain size, case depth, or discontinuities.
Fracture toughness – It is a generic term for measures of resistance to extension of a crack. The term is sometimes restricted to results of fracture mechanics tests, which are directly applicable in fracture control. However, the term normally includes results from simple tests of notched or pre-cracked samples not based on fracture mechanics analysis. Results from tests of the latter type are frequently useful for fracture control, based on either service experience or empirical correlations with fracture mechanics tests.
Fragmentation – It is the process of braking a solid into finely divided pieces. It is the sub-division of a grain into small, discrete crystallite outlined by a heavily deformed network of intersecting slip bands as a result of cold working. These small crystals or fragments differ in orientation and tend to rotate to a stable orientation determined by the slip systems.
Fragmented powder – It is a powder obtained by fragmentation and mechanical comminution into fine particles.
Frame – It is the main structure of a press. It is also a list, compiled for sampling purposes, which designates the items(units) of a population or universe to be considered in a study. In valves, a frame is the centre enclosure of the actuator housing the yoke mechanism.
Frame foundation – In frame foundation, equipment is supported on the deck slab. This deck slab in turn is supported on base raft through columns, and base raft rests directly over soil or on group of piles. Size of deck slab, number of columns, height of columns above base raft etc. are primarily dependent on equipment layout. In this case, equipment is treated as non-elastic inertia body whereas deck slab, and columns are considered as elastic inertia bodies and soil is considered as elastic media. In certain specific cases, base raft is also considered as elastic inertia body.
Frame size, electric motor – It defines the geometric values of its physical size, i.e., the outer dimensions of the motor flange and bolt circle. It defines its mechanical interface to attached actuators. Motors of the same frame size can have different power, torque etc. but feature the same geometrical properties. The length of the motor housing is not affected by the frame size.
Framework – It is an organized structure of policies, programmes, and tasks created to achieve a specific outcome. There can be frameworks for broad policies and strategic initiatives at different scales (e.g., operational, financial, marketing, research and development, human resource management and development), programmes and programme delivery, and short-term tasks and projects.
Framing plan drawing – Framing plan drawing is similar to the beam layout. It offers information about the framework, sizes, and positions of the beams. It is helpful since to the site engineers as they can easily understand and layout the plans for the roof, floor, and other such structures which are a necessary part of a building.
Frangible bulb – It is a liquid filled glass device for detecting high temperature. At a pre-determined temperature, the bulb fractures causing the control valve to change state and signal the actuator to close the valve.
Frank-Condon principle – It is the principle which states that the transition from one energy state to another is so rapid that the nuclei of the atoms involved can be considered stationary during the transition.
F-ratio – It is the ratio of two independent unbiased estimates of variance of a normal distribution. It has widespread application in the analysis of variance (ANOVA).
Freckling – It is a type of segregation revealed as dark spots on a macro-etched sample of a consumable electrode vacuum-arc-remelted alloy.
Free Alongside Ship (FAS) – ‘Free Alongside Ship’ means that the seller delivers when the goods are placed alongside the vessel (e.g., on a quay or a barge) nominated by the buyer at the named port of shipment. The risk of loss of or damage to the goods passes when the goods are alongside the ship, and the buyer bears all costs from that moment onwards.
Free ash – It is the ash which is not included in the fixed ash.
Free bend – It is the bend got by applying forces to the ends of a sample without the application of force at the point of maximum bending. In making a free bend, lateral forces first are applied to produce a small quantity of bending at two points. The two bends, each a suitable distance from the centre, are both in the same direction.
Free-board, ladle – It is the measurement of the area between the top edge of the ladle and the surface of the molten metal inside it. Ladle free-board measurement is important for plant safety and efficiency.
Free carbon – It is the part of the total carbon in steel or cast iron which is present in elemental form as graphite or temper carbon.
Free Carrier (FCA) – ‘Free Carrier’ means that the seller delivers the goods to the carrier or another person nominated by the buyer at the seller’s premises or another named place. The parties are well advised to specify as clearly as possible the point within the named place of delivery, as the risk passes to the buyer at that point.
Free corrosion potential – It is the corrosion potential in the absence of net electrical current flowing to or from the metal surface.
Free cutting steels – These steels are those steels which can be machined rapidly (in terms of productivity) by keeping satisfactory tool life, and by avoiding any machining interruption for chips evacuation. This objective is reached economically by using the cheapest routes, such as increasing the sulphur content of the steel and alloying the steel with lead intended to be machined. These two routes have been used for decades, and their cumulative effects have been the heart of development of the low carbon free-cutting steels. Free-cutting steels are used in a broad variety of applications, mainly in the automobile industry. These steels are used in the production of axles, shafts, connection rods, fitting turn-offs, high-pressure fuel injector parts, screws, bolts, and fittings. This group of steels results from the requirement to automated machining, i.e., they are easier to machine than classical steels resulting in higher cutting speed, lower tool wear, better surface finish, better chip breaking, and lower energy consumption of the machines.
Free cyanide – (i) True: It is the actual concentration of cyanide radical, or equivalent alkali cyanide, not combined in complex ions with metals in solution. (ii) Calculated: It is the concentration of cyanide, or alkali cyanide, present in solution in excess of that calculated as necessary to form a specified complex ion with a metal or metals present in solution. (iii) Analytical: It is the free cyanide content of a solution, as determined by a specified analytical method.
Free-energy diagram – It is a graph of the variation with concentration of the Gibbs free energy at constant pressure and temperature.
Free-energy surface – In a ternary or higher order free-energy diagram, it is the locus of points representing the Gibbs free energy as a function of concentration, with pressure and temperature constant.
Free ferrite – It is the ferrite which is formed directly from the decomposition of hypo-eutectoid austenite during cooling, without the simultaneous formation of cementite. It is also the ferrite which is formed into separate grains and not intimately associated with carbides as in pearlite. It is also called pro-eutectoid ferrite.
Free float – It is the quantity of time by which an activity can be postponed without affecting the early start dates of a successor activity.
Free machining – It pertains to the machining characteristics of an alloy to which one or more ingredients have been introduced to produce small broken chips, lower power consumption, better surface finish, and longer tool life. Among such additions are sulphur or lead to steel, lead to brass, lead and bismuth to aluminum, and sulphur or selenium to stainless steel.
Free machining alloy (FMA) – It is an alloy designed to give, when machined, small broken chips, lower power consumption, better surface finish and / or longer tool life. Chemical composition and microstructure both influence this property.
Free milling – It consists of ores of gold or silver from which the precious metals can be recovered by concentrating methods without resorting to pressure leaching or other chemical treatment.
Free moisture content – It is the quantity of easily removable water (unbound water) is known as the free moisture content. It is the unbound water which is associated with a wet solid which exists as a liquid and it exerts its full vapour pressure. It can be removed readily by evaporation.
Free of alloyed steel, scrap – The term free of alloyed steel means that any alloying elements contained in the steel are residual and have not been added for the purpose of making an alloy steel. Ferrous metal scrap is considered free of alloys when the residual alloying elements do not exceed a certain percentage such as nickel – 0.45 %, Molybdenum – 0.10 %, Chromium – 0.20 %, and Manganese – 1.65 %. The combined residuals other than manganese are not to exceed a total of 0.60 %.
Free On Board (FOB) – ‘Free On Board’ means that the seller delivers the goods on board the vessel nominated by the buyer at the named port of shipment or procures the goods already so delivered. The risk of loss of or damage to the goods passes when the goods are on board the vessel, and the buyer bears all costs from that moment onwards.
Free radical – It is a molecule or atom which possesses one unpaired electron. In chemical notation, a free radical is symbolized by a single dot (to denote the odd electron) to the right of the chemical symbol. It is also a type of polymerization in which the propagating species is a long-chain free radical initiated by the introduction of free radicals from thermal or photochemical decomposition.
Free rolling – It is the rolling in which no traction is deliberately applied between a rolling element and another surface.
Free space optical communications – It is the transfer of information from point to point by a beam of light or infrared energy, instead of a wired connection or radio waves.
Free spread – In a bearing, it is the quantity by which the outer circumference of a pair of bearing shells exceeds the inner circumference of the housing.
Free-swelling index (FSI) – It is a measure of the increase in volume of coal when heated under specified conditions. Free-swelling index method is a small-scale test for getting information regarding the free-swelling properties of a coal. The results can be used as an indication of the caking characteristic of the coal when burned as a fuel. The volume increase can be associated with the plastic properties of coal. Coals which do not show plastic properties when heated do not show free swelling. The quantity of swelling depends on the fluidity of the plastic coal, the thickness of bubble walls formed by the gas, and interfacial tension between the fluid and solid particles in the coal. Higher swelling occurs when the above factors cause more gas to be tapped. Free-swelling index increases when the rank for bituminous coals increases, although, for some individual coals, free swelling indices vary. Results for low-rank coals are lower when compared to bituminous coals
Free wall – It is the portion of a honeycomb cell wall that is not connected to another cell.
Freezing – It is a phase transition in which a liquid turns into a solid when its temperature is lowered below its freezing point. For most substances, the melting and freezing points are the same temperature. However, certain substances possess differing solid-liquid transition temperatures. For example, agar displays a hysteresis in its melting point and freezing point. It melts at 85 deg C and solidifies from 32 deg C to 40 deg C.
Freezing point – It is the temperature at which a pure metal, compound, or eutectic changes from liquid to solid. It is the temperature at which the liquid and the solid are at equilibrium.
Freezing-point depression – It is a drop in the maximum temperature at which a substance freezes, caused when a smaller quantity of another, non-volatile substance is added. Examples include adding salt into water, alcohol in water, ethylene or propylene glycol in water, adding copper to molten silver (used to make solder that flows at a lower temperature than the silver pieces being joined).
Freezing range – It is that temperature range between liquidus and solidus temperatures in which molten and solid constituents coexist.
Freon – It is a generic descriptor for a number of halocarbon products. They are stable, non-flammable, low toxicity gases or liquids which have been normally used as refrigerants and as aerosol propellants. These include chloro-fluoro-carbons and hydro-fluoro-carbons, both of which cause ozone depletion (although the latter much less so) and contribute to global warming.
Frequency (symbol f) – It is very frequently measured in hertz (Hz). It is the number of occurrences of a repeating event per unit of time. It is also occasionally referred to as temporal frequency for clarity and to distinguish it from spatial frequency. Frequency is an important parameter used in science and engineering to specify the rate of oscillatory and vibratory phenomena, such as mechanical vibrations, audio signals (sound), radio waves, and light.
Frequency (electrical) – Frequency refers to the number of times the alternating current (AC) switches between positive and negative in 1 second. This switching does not occur in direct currents (DC). The unit of frequency is hertz (Hz).
Frequency (statistics) – In statistics, the frequency or absolute frequency of an event is the number of times the observation has occurred / recorded in an experiment or study. These frequencies are frequently depicted graphically or in tabular form. In statistical analysis, the frequency is the number of times that particular values are obtained in a variable. For example, with the data: dry, rain, dry, dry, dry, rain, rain, dry, the frequency of ‘rain’ is 3 and the frequency of ‘dry’ is 5. The sum of the frequencies is the number of observations, ‘n’, in the variable. In this example, n = 8. The percentage is (100*frequency/n), = 100* 3/8 = 37.5 % for rain, in this example. With as few as 8 values percentages are not normally used, instead state 3 out of the 8 values are rain.
Frequency (x-ray) – It is the number of alternations per second of the electric vector of the x-ray beam. It is equal to the velocity divided by the wave-length.
Frequency changer – It an electric machine which is used to transfer power between two networks with different frequencies, or, an electronic device (normally called a frequency mixer) which changes the frequency of an input signal to some other frequency.
Frequency distribution – It is the way in which the frequencies of occurrence of members of a population, or a sample, are distributed according to the values of the variable under consideration.
Frequency modulation – It is a method of impressing information on a carrier wave by changing its frequency.
Frequency rate – Data on injuries (lost time and / or the total number) is frequently presented in terms of frequencies by relating the absolute numbers to the total number of hours worked. Frequency rate is the number of injuries in the period multiplied by 100,000 total hours worked during the period.
Frequency response – It is the measure of the output of a system in response to an input of varying frequency.
Fresnel fringes – It is a class of diffraction fringes which are formed when the source of illumination and the viewing screen are at a finite distance from a diffracting edge. In the electron microscope, these fringes are best seen when the object is slightly out of focus.
Fretting – It is a type of wear which occurs between tight-fitting surfaces subjected to cyclic relative motion of extremely small amplitude. Normally, fretting is accompanied by corrosion, especially of the very fine wear debris. It is also referred to as fretting corrosion and false brinelling (in rolling-element bearings).
Fretting corrosion – It is the accelerated deterioration at the interface between contacting surfaces as the result of corrosion and slight oscillatory movement between the two surfaces. It is also a form of fretting in which chemical reaction predominates. Fretting corrosion is frequently characterized by the removal of particles and subsequent formation of oxides, which are frequently abrasive and so increase the wear. Fretting corrosion can involve other chemical reaction products, which may not be abrasive.
Fretting fatigue – It is the fatigue fracture which initiates at a surface area where fretting has occurred. It is the progressive damage to a solid surface which arises from fretting. If particles of wear debris are produced, then the term fretting wear can be applied.
Fretting wear – It is the wear arising as a result of fretting.
Friction – It is the resisting force which is tangential to the common boundary between two bodies when, under the action of an external force, one body moves or tends to move relative to the surface of the other. Friction is caused by the interactions at the surfaces of adjoining parts. The frictional forces oppose the relative motion between the moving parts of the machine. Movement of surfaces needs an applied force high enough to overcome microscopic surface interactions. Hence, extra energy is needed to be spent to overcome the friction. The friction between the moving parts of the machine also produces heat which causes damage to the machine. Hence, friction causes wear and tear of the moving parts of the machine in contact and therefore the machine loses its efficiency.
Frictional force – When one surface moves over another surface in a machine, resistance to the relative motion of the surfaces takes place. The solid surface appears smooth to the naked eye, but this smooth surface shows irregularities of projections and cavities when seen under high power microscope. At a microscopic level, all surfaces are rough. When one such surface is placed over another, its projections fall into the cavities of the other and get interlocked. Because of this interlocking, there is resistance to the relative motion of the surfaces. This is called the frictional force or frictional resistance. Surface peaks (asperities) can bond to one another or protrude into adjoining surface. In a rolling mill, frictional force is the force between the entrance plane and the neutral point which act in the direction of the rolling to draw the metal into the roll.
Friction coefficient – It is the dimensionless ratio of the friction force (F) between two bodies to the normal force (N) pressing these bodies together. (mu or f) = (F/N).
Friction drive – In friction drive, the kiln rotation is driven by friction between the rotating support rollers and the kiln tyre. At the same time, a redesigned tyre attachment system allows the kiln shell to expand radially, which means that there is no need for lubrication between the tyre and kiln.
Friction force – Friction force is the positive force resisting the motion when a rolling body (ball, tyre, or wheel) is on a surface. The force is associated with both elastic and nonelastic deformation behaviour of rolling materials, depending on the applied load.
Friction material – It is a sintered material showing a high coefficient of friction designed for use where rubbing or friction wear is encountered.
Friction modifiers – These are mild anti-wear additives used to minimize light surface contact, such as sliding and rolling. These can also be referred to as boundary lubrication additives. These additives are used in lubricants to modify the coefficient of friction, hence the name ‘friction modifiers’.
Friction polymer – It is an amorphous organic deposit which is produced when certain metals are rubbed together in the presence of organic liquids or gases. Friction polymer frequently forms on moving electrical contacts exposed to industrial environments. The varnish like film attenuates or modifies transmitted signals.
Friction scratch – It is a scratch caused by relative motion between two contacting surfaces.
Friction welding (FRW) – It is a solid-state welding process which produces coalescence of materials under compressive force contact of work-pieces rotating or moving relative to one another for producing heat and plastically displacing material from the faying surfaces.
Friedman two-way analysis of variance – It is a non-parametric inferential statistic which is used to compare two or more groups by ranks which are not independent.
Frit – In porcelain enamel, it is the small friable particles which are produced by quenching a molten glassy material.
Frosting – It is a form of ball bearing groove damage, appearing as a frosted area, suggestive that surface distress has occurred.
FSN analysis – This analysis of the inventory is based on consumption figures of the items. Under this analysis, inventory items are classified into three groups namely ‘F’ (fast moving), ‘S’ (slow moving), and ‘N’ (non-moving).
F-test – It is as parametric statistical test of the equality of the means of two or more samples. It compares the means and variances between and within groups over time. It is also called analysis of variance (ANOVA).
Fuel – It is a substance containing combustible used for generating heat.
Fuel-air mixture – It is a mixture of fuel and air.
Fuel-air ratio – It is the ratio of the weight, or volume, of fuel to air.
Fuel assembly – It is the structured collection of fuel rods or elements, the unit of fuel in a reactor.
Fuel cladding – It is the material which I used to construct reactor components and designed to maintain a separation between their contents and the coolant. An example is the cladding of a fuel pin which separates the fuel pellets from the coolant. Zirconium and zirconium alloys (Zircalloy) are common cladding materials.
Fuel cycle – It consists of the sequence of steps involved in supplying, using, and disposing of the fuel used in nuclear reactors. The fuel cycle is ‘closed’ if it includes the reprocessing of spent fuel and recycling of fissile materials resulting from reprocessing. The term ‘open’ or ‘once-through’ cycle means that the fuel is disposed of in a permanent storage site after use in the reactor.
Fuel element debris – It is the material made up of mainly metal components removed from the casing of fuel elements after use.
Fuel-fired furnace – It is that furnace which combust fuel with the purpose of releasing chemical energy as heat. Furnace designs vary as to its function, heating duty, type of fuel and method of introducing combustion air. Heat is generated by mixing fuel with air or oxygen. The residual heat exits the furnace as flue gas.
Fuel gases – These are the gases normally used with oxygen for heating such as acetylene, natural gas, hydrogen, propane, stabilized methyl-acetylene-propadiene, coke oven gas, blast furnace gas, converter gas and other synthetic fuels and hydro-carbons.
Fuel oil – It is any of different fractions obtained from the distillation of petroleum. Such oils include distillates and residues. Fuel oils include heavy fuel oil, marine fuel oil, furnace oil, gas oil, heating oils, diesel fuel, and others.
Fuel reprocessing – It is the method of processing reactor fuel in order to separate the reusable fissionable material from waste material.
Fuel rod (assembly) – It is a long, cylindrical rod, frequently 3.66 metres to 4.27 metres in length, made up of fuel pellets containing enriched uranium in cladding. Fuel rods are bundled into fuel assemblies.
Fuel route – This term is used to refer to the set of processes and areas which the fuel passes through to be brought onto a nuclear licensed site, i.e., prepared prior to use, used for fission, stored on site, undergo its initial on-site treatment, and then be removed from site (as spent fuel) for onward processing.
Fuel-to-steam efficiency – It is the ratio of heat added to boiler feed-water to produce the output steam to the quantity of energy inputted with fuel.
Fugitive binder – It is an organic substance added to a metal powder to improve the bond between the particles during compaction and thereby increase the green strength of the compact, and which decomposes during the early stages of the sintering cycle.
Fugitive emission (FE) test – A fugitive emission is defined as a leak from a fluid (e.g., hydro-carbons, chemical or mixture of chemicals). The fugitive emission test is carried out to evaluate the ability to suppress and / or the performance level of on / off valves and control valves with regards to fugitive emission. The specification for testing describes the type of detection method and test medium to be used and specify the acceptance and rejection criteria.
Full annealing – It is a softening process in which the steel section is heated to a temperature above the austenitic transformation range and after being held for a sufficient time at this temperature, is cooled slowly to a temperature below the transformation range. The steel is generally allowed to cool slowly in the furnace, although it can be removed and cooled in some cooling medium. Since the transformation temperatures are affected by the carbon content of the steel, it is obvious that the high carbon steels can be fully annealed at lower temperatures than the low carbon steels. The microstructure of the hypo-eutectoid steels which result after full annealing consists of ferrite and pearlite. Eutectoid and hyper-eutectoid steels often get spheroidize partially or completely on full annealing.
Full bore, full opening – It describes a valve whose bore (port) is nominally equal to the bore of the connecting pipe.
Full centre – It is the mild waviness down the centre of a metal sheet or strip.
Fuller (fullering impression) – It is the portion of the die used in hammer forging mainly to reduce the cross section and to lengthen a portion of the forging stock. The fullering impression is frequently used in conjunction with an edger (edging impression).
Full-film lubrication – It is a type of lubrication wherein the solid surfaces are separated completely by an elasto-hydro-dynamic fluid film.
Full hard – It is a temper of non-ferrous alloys and some ferrous alloys corresponding approximately to a cold-worked state beyond which the material can no longer be formed by bending. In specifications, a full hard temper is normally defined in terms of minimum hardness or minimum tensile strength (or, alternatively, a range of hardness or strength) corresponding to a specific percentage of cold reduction following a full anneal. For aluminum, a full hard temper is equivalent to a reduction of 75 % from dead soft. For austenitic stainless steels it is a reduction of around 50 % to 55 %.
Full hard cold rolled steel – It is a hot rolled pickled steel which has been cold reduced to a specified thickness and subject to no further processing (not annealed or temper rolled). The product is very stiff. It is not intended for flat work where deformation is very minimal. Full hard temper consists of full hard cold rolled steel produced to a Rockwell hardness of 84 and higher on the ‘B’ scale.
Full heat treatment – For certain alloys, it is the heat treatment cycle consisting of solution treatment followed by artificial age hardening.
Full journal bearing – It is a journal bearing which surrounds the journal by a full 360-degree.
Full load current – It is the current drawn by a motor or other electrical machine at its full rated power and standard voltage.
Full mould – It is a trade name for an expendable pattern casting process in which the polystyrene pattern is vapourized by the molten metal as the mould is poured.
Full penetration weld – It describes the type of weld wherein the weld metal extends across the entire wall thickness of the joint.
Full-wave rectifier – It is a rectifier circuit which converts both positive and negative parts of the input alternating current wave-form into a unidirectional, direct current.
Full width at half maximum (FWHM) – It is a measure of resolution of a spectrum or chromatogram determined by measuring the peak width of a spectral or chromatographic peak at half its maximum height.
Fully-welded ball valve – It refers to a ball valve whereby the body and closure joints are fully welded to complete the valve assembly. This type of valve construction cannot be disassembled nor repaired at site.
Functional block diagram – It depicts the functions of the major elements of a circuit, assembly, and system etc. in simplified form. It is prepared to illustrate the functional relationship of major elements of an assembly, and system etc. It includes major circuit functions depicted by single lines, rectangular blocks, and explanatory notes or text.
Functional decomposition – It is a hierarchical breakdown of a design or product into the basic functions which are to be achieved. This is done by asking the question how? For example, the basic function of a copier is to make copies. Asking how leads to the next level of functions i.e., feed paper, make marks, and handle documents etc. Each function is stated by a verb and a noun.
Functional diagrams – Functional diagrams are a unique form of technical diagram for describing the abstract functions comprising a control system, e.g. proportional integral derivative (PID) controllers, rate limiters, manual loaders. This form of document finds wide application in several industries to document control strategies. Functional diagrams focus on the flow of information within a control system rather than on the process piping or instrument interconnections (wires, tubes, etc.). The general flow of a functional diagram is top-to -bottom, with the process sensing instrument (transmitter) located at the top and the final control element (valve or variable-speed motor) located at the bottom. No attempt is made to arrange symbols in a functional diagram to correspond with actual equipment layout. These diagrams are all about the algorithms used to make control decisions, and nothing more.
Functional group – It is a chemical radical or structure which has characteristic properties. Examples are hydroxyl and carboxyl groups.
Functional requirements – These are those elements of the design which describe its performance behaviour, including its human interface and the environment in which it is required to function.
Functional safety – Functional safety is the property of an engineered system of ensuring safety by virtue of the functions which the system performs and which normally fall into two categories namely (i) control functions to ensure that a piece of equipment remains in a safe state, and (ii) protection functions which put another system into a safe or relative safe state.
Function analysis – It is a technique which is used in the discipline of value analysis that focuses on the reason-for-being of each element of the product.
Fungus resistance – It is the resistance of a material to attack by fungi in conditions promoting their growth.
Furan – It is the resin which is formed from reactions involving furfuryl alcohol alone or in combination with other constituents.
Furnace – It is an enclosed space provided for the combustion of fuel.
Furnace atmosphere control – The purpose of atmosphere control is to maintain consistent levels of the different constituents which make up the atmosphere and to determine if changes in those levels are needed in order to produce a desired result under a given set of conditions. Controls are needed for different heat-treating operations which use a variety of different atmospheres. All methods of atmosphere control can effectively be divided into two groups: those involving control of the atmosphere once it is inside the furnace and those involving control of the atmosphere supply before it is introduced into the furnace. Such control is achieved through the use of atmosphere control devices. Furnace atmosphere control has become increasingly critical to successful heat treating with more precise metallurgical specifications. The prevention of surface oxidation or scaling when metals are exposed to high temperatures remains an important task of the furnace atmosphere. In a more sophisticated view, the atmosphere within the furnace chamber is a full-fledged partner in achieving the chemical reactions that occur during heat treating.
Furnace brazing – It is a mass-production brazing process in which the filler metal is preplaced on the joint, then the entire assembly is heated to brazing temperature in a furnace.
Furnace oil – Furnace oil is a fuel oil which is dark and viscous. It is a residual fuel oil which is obtained by blending residual products from various refining processes with suitable diluent normally middle distillates to get the needed fuel oil grades. It has a flash point above 66 deg C and the calorific value of 44 mega joules per kilograms. The fuel oil grades are similar in nature and are being marketed under different specifications in different countries.
Furnace pad or foundation – It is the civil foundation on which the steel and supporting structure of the blast furnace is erected. This foundation carries the load of the running blast furnace.
Furnace pressure – It is the pressure occurring inside the combustion chamber. It is positive if higher than atmospheric pressure, and negative if lower than atmospheric pressure, and neutral if equal to atmospheric pressure.
Furnace shell – Furnace shell of a blast furnace is made from crack resistant steel and is normally free standing. It is normally designed after comprehensive stress distribution analysis.
Furnace soldering (FS) – It encompasses a group of reflow soldering techniques in which the parts to be joined and preplaced filler metal are put in a furnace and then heated to the soldering temperature. Five reflow technologies are presently certified for use in surface-mount technology (SMT) applications. These are (i) type ‘A’ vapour phase, (ii) type ‘B’ area conduction, i.e., linear conduction, (iii) type ‘C’ hot bar, (iv) type ‘D’ convection and convection /infra-red, and (v) type ‘E’ laser. Of these five methods, three are considered to be mass reflow techniques (Types A, B, and D), since all of the solderable inter-connections on the surface of a printed wiring board (PWB) assembly are brought through the reflow heating cycle simultaneously.
Furnace volume – It is the cubic contents of the furnace or combustion chamber.
Fuse – It is an electrical safety device which operates to provide overcurrent protection of an electrical circuit. Its essential component is a metal wire or strip which melts when too much current flows through it, hence stopping or interrupting the current. It is a circuit protective device.
Fused alumina – It is produced in two forms namely white fused alumina and brown fused alumina. White fused alumina is made from calcined Bayer alumina and different grades are available based on differences in alkali contents. It is used extensively in high-temperature refractory bricks and monolithics.
Fused cast refractories – These are those refractories which are manufactured by melting mixtures of raw material of the desired composition in an electric furnace at a temperature exceeding 2,000 deg C, casting the melt into moulds where it solidifies and cooling the molten refractory material to form a solidified refractory.
Fused coating – It is a metallic coating (normally tin or solder alloy) which has been melted and solidified, forming a metallurgical bond to the base metal.
Fused grain refractory – It is a refractory made predominantly from grain which has solidified from a fused or molten condition.
Fused silica refractory – It is a product composed predominantly of fused, non-crystalline silica.
Fused spray deposit – It is a self-fluxing spray deposit which is deposited by conventional thermal spraying and subsequently fused using either a heating torch or a furnace.
Fused zone – It is the area of base metal melted as determined on the cross section of a weld.
Fusible alloys -It is a group consisting of binary, ternary, quaternary, and quinary alloys which contains bismuth, lead, tin, cadmium, and indium. This term refers to any of more than 100 alloys which melt at relatively low temperatures, i.e., below the melting point of tin-lead solder (183 deg C). The melting points of these alloys range as low as 47 deg C.
Fusible plug – It is a hollowed threaded plug having the hollowed portion filled with a low melting point material.
Fusing – It is the melting of a metallic coating (normally electro-deposited) by means of a heat-transfer medium, followed by solidification.
Fusion – It is the melting together of filler metal and base metal (substrate), or of base metal only, which results in coalescence. In nuclear metallurgy, fusion means thermo-nuclear fusion which is a process in which two or more light nuclei are formed into a heavier nucleus and energy is released.
Fusion bonded epoxy (FBE) coating – Fusion bonded epoxy coating of steel materials is primer less, one-part, heat curable, thermosetting powdered epoxy coating which is designed to provide maximum corrosion protection to the substrate steel. It is a coating of very fast curing, thermosetting protective powder which utilizes heat to melt and adhere the coating material to the steel substrate. It is based on specially selected epoxy resins and hardeners which are in the form of dry powders at normal atmospheric temperature. The epoxy is formulated in order to meet the specifications related to protection of steel as an anti-corrosion coating. Heat cured fusion bonded epoxy coatings are 100 % solids consisting of thermosetting materials which achieve a high bond to metal surface as a result of a heat generated chemical reaction. The fusion bonded epoxy coatings can be applied by fluidized bed, flocking (air spray), or electrostatic spray. Fusion bonded epoxy forms an adherent continuous chemically cross-linked protective film. Fusion-bonded epoxy coating principally protects against corrosion by serving as an electro-chemical and a physical barrier which isolates the steel from the oxygen, moisture, and chloride ions which cause corrosion. Fusion bonded epoxy coating is widely used for coating of reinforcement bars, steel pipes, pipe fittings, pumps, and valves used for the transmission of oil, gas, slurry, and water.
Fusion bonded epoxy coated reinforcement bars – These are reinforcement bars which have fusion bonded epoxy coatings.
Fusion face – It is a surface of the base metal which is to be melted during welding.
Fusion hard-facing – It is a process by which weld materials, with superior properties than the substrate, are applied to the substrate. Frequently two layers total thickness of 3 millimeters to 6 millimeters are applied to reduce the surface hardness dilution of the relatively low-cost steel substrates in the expansive cobalt-based alloys. Hard-facing processes are very useful for improving wear and corrosion resistance to selected areas of mechanical equipment such as cutting edges of earth-moving machinery
or sealing areas of valves. Common hard-facing techniques include arc torch and other processes.
Fusion spray – In thermal spraying, it is the process in which the coating is completely fused to the base metal, resulting in a metallurgically bonded, essentially void-free coating.
Fusion welding – It is any welding process which uses fusion of the base metal to make the weld.
Fusion zone – It is the area of base metal which is melted as determined on the cross section of a weld.
Fuzz– It consists of accumulation of short, broken filaments after passing glass strands, yarns, or rovings over a contact point. Frequently, It is weighted and used as an inverse measure of abrasion resistance.
Fuzzy control – It is a control system which relies on fuzzy logic instead of binary true / false conditions.
Fuzzy logic – It is the use of fuzzy sets in the representation and manipulation of vague information for the purpose of making decisions or taking actions. Fuzzy logic enables computers to make decisions based on information which is not clearly defined.
Leave a Comment