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Glossary of technical terms for the use of metallurgical engineers Terms starting with alphabet ‘K’ 

• satyendra
• November 8, 2024
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• Glossary of technical terms for the use of metallurgical engineers Terms starting with alphabet ‘K’,

Glossary of technical terms for the use of metallurgical engineers

Terms starting with alphabet ‘K’ 

Kaikaku – It is a critical element within the Lean manufacturing framework representing a profound paradigm shift, embodying the Japanese term for radical change. Distinguished from the incremental nature of continuous improvement, Kaikaku seeks to dismantle and radically overhaul existing processes. This method is particularly invoked when gradual improvements are insufficient to address the evolving challenges or objectives of an organization. Kaikaku is about breaking away from entrenched norms and methodologies to foster significant, comprehensive transformations. By adopting this approach, organizations aim to achieve monumental cost savings, boost efficiency to new heights, and elevate quality standards. The implementation of Kaikaku needs a bold vision and a willingness to re-engineer processes from the ground up, making it a potent tool for the organizations facing the need for drastic operational changes.

Kaizen – It is a concept referring to organizational activities that continuously improve all functions and involve all employees from the top management to the workers at the shop floor. Kaizen also applies to processes, such as marketing, purchasing and logistics, that cross organizational boundaries. Kaizen aims to eliminate waste and redundancies. Kaizen can also be referred to as zero investment improvement (ZII) because of its utilization of existing resources.

Kalman filter – It is an algorithm which uses a series of measurements observed over time, Including statistical noise and other inaccuracies, to produce estimates of unknown variables that tend to be more accurate than those based on a single measurement, by estimating a joint probability distribution over the variables for each time-step. The filter is constructed as a mean squared error minimizer, but an alternative derivation of the filter is also provided showing how the filter relates to maximum likelihood statistics.

Kanban – It is a scheduling system for lean manufacturing. The system takes its name from the cards that track production within a factory. A goal of the kanban system is to limit the buildup of excess inventory at any point in production. Limits on the number of items waiting at supply points are established and then reduced as inefficiencies are identified and removed. Whenever a limit is exceeded, this points to an inefficiency that should be addressed. In Kanban, problem areas are highlighted by measuring lead time and cycle time of the full process and process steps. One of the main benefits of Kanban is to establish an upper limit to work in process (normally referred as ‘WIP’) inventory to avoid overcapacity.

Kaowool – It is a type of high-temperature mineral wool made from the mineral kaolin. It is a type of high-temperature mineral wool. It can withstand temperatures close to 1,650 deg C.

Kapton – It is the trade name for a polyimide film which emits low smoke and flame, resists hydraulic fluids, and has good low-temperature and high-temperature performance.

Karat – It is a unit for designating the fineness of gold in an alloy. In this system, 24 karat (24 k) is 1,000 fine or pure gold. Table 1 gives the most popular jewelry gold qualities.

Karman vortex street – When a body is placed in the middle of a media flow, separation occurs and vortices are formed on both sides if velocity or Reynolds number R is above a certain value. It is interesting to note, that after a vortex has formed on one side a similar vortex forms on the other side which causes the first one to be shed. That periodic vortices are shed from each side alternately was discovered by Karman after whom the vortex street is named. These usually undesirable vortices are utilized as the basis for the measurement in vortex flow meters.

Kata – It means a structured way of doing things or practice, i.e., the form and order of doing things. Obsession with quality and executing processes in the correct and appropriate order is deeply rooted in Japanese culture. Instead of rushing to fix a problem when a person has little to no insight, Kata encourages thinking before doing.

Kawasaki basic oxygen process (K-BOP) – In the operation of this process, 30 % of the oxygen is soft blown from a multi-hole lance set high above the steel bath, with the remainder injected through the base of the vessel using shrouded tuyere technology. This allows low turndown carbons (of the order of 0.02 % carbon to 0.04 % carbon), together with higher scrap-melting capabilities (e.g., 33 % against 30 % of the charge).

Kee Klamp – It is a structural pipe fitting commonly used in the construction of handrails and barriers. Fabricated installations comprise the fittings and separate tubing components, which can be sized on site.

Keel block – It is a standard test casting, for steel and other high-shrinkage alloys, consisting of a rectangular bar which resembles the keel of a boat, attached to the bottom of a large riser, or shrink head. Keel blocks which have only one bar are frequently called Y-blocks. Keel blocks which are having two bars are called double keel blocks. Test samples are machined from the rectangular bar, and the shrink head is discarded.

Kelvin (K) – It is the base unit for temperature in the International System of Units (SI).

Kelvin scale – It is an absolute temperature scale which starts at the lowest possible temperature (absolute zero), taken to be 0 K. By definition, the Celsius scale (symbol degree C) and the Kelvin scale have the exact same magnitude; that is, a rise of 1 K is equal to a rise of 1 deg C and vice versa, and any temperature in degrees Celsius can be converted to kelvin by adding 273.15.

Kelvin-Stokes theorem – It is a theorem in calculus, useful in analytic solutions of problems in electro-magnetism.

Kentledge, kentledge weights – These are slabs or blocks of concrete or iron (normally pig iron, sometimes with a cast-in handle to assist moving). They are used as counterweights in cranes such as tower cranes or swing bridges. On construction sites, prior to the erection of a building, static load testing can use a large number of kentledge stacked onto a platform. This platform is used to drive piles into the ground beneath to test the integrity of the foundation.

Kerf – It is the width of the cut produced during a cutting process. It is the width of a cut made by a saw blade, torch, waterjet, laser beam, and so forth.

Kernel – It is a core component of an operating system and serves as the main interface between the computer’s physical hardware and the processes running on it. The kernel enables multiple applications to share hardware resources by providing access to central processing unit (CPU), memory, disk input/output (I/O), and networking.
Kettle – It is the molten zinc filled tank or pot where the metallurgical bonding of zinc and steel takes place.

Kevlar – It is trade name for an organic polymer composed of aromatic polyamides having a para-type orientation (parallel chain extending bonds from each aromatic nucleus).

Key – It is a machine element which is used to connect a rotating machine element to a shaft. The key prevents relative rotation between the two parts and can enable torque transmission. For a key to function, the shaft and rotating machine element must have a keyway and a keyseat, which is a slot and pocket in which the key fits. The whole system is called a keyed joint. A keyed joint can allow relative axial movement between the parts.

Key brick – It is a brick made so that each narrow side is inclined at the same angle toward the end of the brick.

Keyhole – It is a technique of welding in which a concentrated heat source, such as a plasma arc, penetrates completely through a work-piece forming a hole at the leading edge of the molten weld metal. As the heat source progresses, the molten metal fills in behind the hold to form the weld bead.

Keyhole sample – It is a type of sample containing a hole-and-slot notch, shaped like a keyhole, normally used in impact bend tests.

Keying – It is the deformation of metal particles during compacting to increase interlocking and bonding. In electrical connector, keying is used by electrical connectors to prevent mating in incorrect orientation. In graphics, keying is a technique for compositing two full frame images together.

Key performance indicator (KPI) – A Key performance indicator is a metric for measuring project success. Key performance indicators are established before project execution begins.

Keystone – It is the wedge-shaped stone at the apex of a masonry arch or typically round-shaped one at the apex of a vault. In both cases it is the final piece placed during construction and locks all the stones into position, allowing the arch or vault to bear weight.

K-factor – It is the ratio between the unknown and standard X-ray intensities used in quantitative analyses. It is also the coefficient of thermal conductivity. The quantity of heat which passes through a unit cube of material in a given time when the difference in temperature of two opposite faces is one degree.

Kic – It is the critical stress intensity factor. The critical stress intensity factor for plane strain Kic is measured by bending the sample with artificially created single sharp crack of predefined or measurable size and geometry that is intentionally made larger than any other crack that might be present or developed in the specimen during the load to assure that it is this artificial crack that becomes critical under the load. It is defined as the plane strain fracture toughness. It is a measure of the resistance of a material to crack extension under predominantly linear-elastic conditions (i.e., low toughness conditions when there is little to no plastic deformation occurring at the crack tip).

Kickoff meeting – The first meeting between a project team and stakeholders. It serves to review project expectations and to build enthusiasm for a project.

Kikuchi lines – These are light and dark lines superimposed on the background of a single-crystal electron-diffraction pattern caused by diffraction of diffusely scattered electrons within the crystal. It is the pattern provides information on the structure of the crystal.

Killed steel – It is that steel which is treated with a strong deoxidizing agent such as silicon or aluminum in order to reduce the oxygen content to such a level that no reaction occurs between carbon and oxygen during solidification. Killed steels are made by complete deoxidation of the liquid steel before it is cast so that no gas evolution occurs during solidification. These are the steels to which normally aluminum, silico-manganese, ferro-silicon, or ferro-manganese is added as deoxidizing agents. Properly killed steel is more uniform in analysis and is comparatively free from aging. However, for the same carbon and manganese content killed steels are harder than rimmed steels. Normally, all steels above 0.25 % carbon are killed. Also, all forging grades of steels, structural steels from 0.15 % carbon to 0.25 % carbon and some special steels in the low carbon range are killed. Only killed steels can be cast in continuous casting machines.

Kiln – It is a large furnace which is used for baking, drying, or burning firebrick or refractories, or for calcining ores or other substances.

Kilo – It is a decimal unit prefix in the metric system denoting multiplication by one thousand (1000). It is used in the International System of Units, where it has the symbol ‘k’, in lowercase.

Kilovolt-ampere – It is a unit of measurement of apparent power in an electrical circuit. It is the product of the root mean square voltage (in volts) and the root mean square current (in amperes). Volt-amperes product is equal to the real power, measured in watts. The volt-ampere is dimensionally equivalent to the watt. In SI units, 1 V x A = 1 W. VA rating is most used for generators and transformers, and other power handling equipment, where loads can be reactive (inductive or capacitive).

Kimberlite – It is a variety of peridotite which is the most common host rock of diamonds.

Kinematic analysis – It is an analysis to determine the position, velocity, and acceleration of all bodies in a mechanical system at a sequence of user-specified time steps. This type of analysis is frequently used to check the range of motion and to determine whether the design will allow motion / velocity / acceleration to be in the expected range.

Kinematic determinacy – It is a term used in structural mechanics to describe a structure where material compatibility conditions alone can be used to calculate deflections. A kinematically determinate structure can be defined as a structure where, if it is possible to find nodal displacements compatible with member extensions, those nodal displacements are unique. The structure has no possible mechanisms, i.e. nodal displacements, compatible with zero member extensions, at least to a first-order approximation.

Kinematics – It describes the motion of points, bodies (objects), and systems of bodies (groups of objects) without considering the forces which cause them to move.

Kinematic viscosity – It is defined as the resistance of liquid to flow. It refers to the thickness of the oil and is determined by measuring the amount of time taken for a given oil to pass through an orifice of a specified size. It is the ratio of absolute viscosity to the specific gravity of the oil at the temperature at which the viscosity is measured. Its unit is ‘stokes’. For practical purposes, viscosity of petroleum oils is expressed in time in seconds taken by a given quantity of oil to flow through a standard capillary tube. It is expressed as Saybolt universal seconds at 40 deg C or at 100 deg C.

Kinematic wear marks – In ball bearings, it is a series of short curved marks on the surface of a bearing race because of the kinematic action of imbedded particles or asperities rolling and spinning at the ball or roller contact points. The length and curvature of these marks depend on the degree of spinning and on the distance from the spinning axis of the rolling element.

Kinetic coefficient of friction – It is the coefficient of friction under conditions of macroscopic relative motion between two bodies.

Kinetic energy – The kinetic energy of an object is the energy which it possesses because of its motion. It is calculated by virtue of its mass and velocity and is equal to half its mass times its velocity squared Kinetic energy of atoms or molecules increases with temperature as the heat (energy) transferred into the substance is converted into kinetic energy with resulting increase in the velocities of the particles.

Kinetic friction – It is the friction under conditions of macroscopic relative motion between two bodies. This term is sometimes used as a synonym for kinetic coefficient of friction. However, it can also be used merely to indicate that the type of friction being indicated is associated with macroscopic motion rather than static conditions.

Kingsbury bearing – It is a pad bearing in which the pads are free to take up a position at an angle to the opposing surface according to the hydrodynamic pressure distribution over its surface.

Kink – It features local curvature of the same direction on adjacent sides of the sheet metal.

Kink band (deformation) – In polycrystalline materials, it is a volume of crystal which has rotated physically to accommodate differential deformation between adjoining parts of a grain while the band itself has deformed homogeneously. This occurs by regular bending of the slip lamellae along the boundaries of the band.

Kirchhoff’s circuit laws – These are two equalities that deal with the current and potential difference (normally known as voltage) in the lumped element model of electrical circuits. These are widely used in electrical engineering. They are also called Kirchhoff’s rules or simply Kirchhoff’s laws. These laws can be applied in time and frequency domains and form the basis for network analysis. Both of Kirchhoff’s laws can be understood as corollaries of Maxwell’s equations in the low-frequency limit. They are accurate for direct current circuits, and for alternating current circuits at frequencies where the wave-lengths of electro-magnetic radiation are very large compared to the circuits.

Kirchhoff’s current law – This law states that the current entering any junction is equal to the current leaving that junction, i.e., i1 +i2 + i3 +i4, where ‘i’ is the current. This law, also called Kirchhoff’s first law, or Kirchhoff’s junction rule, states that, for any node (junction) in an electrical circuit, the sum of currents flowing into that node is equal to the sum of currents flowing out of that node, or equivalently the algebraic sum of currents in a network of conductors meeting at a point is zero.

Kirchhoff equations – In fluid dynamics, these equations describe the motion of a rigid body in an ideal fluid.

Kirchhoff’s voltage law – This law states that the sum of all the voltages around a loop is equal to zero, i.e., v1 + v2 + v3 +v4 = 0, where ‘v’ is the voltage. This law, also called Kirchhoff’s second law, or Kirchhoff’s loop rule, states that the directed sum of the potential differences (voltages) around any closed loop is zero.

Kirkendall effect – It is the motion of the interface between two metals which occurs because of the difference in diffusion rates of the metal atoms.

KIscc – It is the threshold stress intensity for stress corrosion cracking. It is abbreviation for the critical value of the plane strain stress-intensity factor which produces crack propagation by stress-corrosion cracking of a given material in a given environment.

Kish – It is the free graphite which forms in molten hyper-eutectic cast iron as it cools. In castings, the kish can segregate toward the cope surface, where it lodges at or immediately beneath the casting surface.

Kiss cut – It is a form of die cutting where the top layer of material is cut without cutting through the bottom attached material.

Kit drawing – It identifies an item or group of items with instructions for their use. It does not necessarily define a complete functional assembly. It is prepared when it is desired to identify all of the items required to perform a specific operation in kit form. It includes (i) a parts list of the contents of the kit including the identification of each item, (ii) documents which are a part of the kit, (iii) pictorial representations, (iv) special tool requirements for installation of the kit, and (v) retest or recalibration requirements.

K-lines – Once the photoelectric effect creates a vacancy in the K-shell, the excited state relaxes by filling the vacancy with an electron from an outer orbital. Only certain transitions are allowed because of quantum mechanical rules called selection rules. The transitions which follow the selection rules are termed allowed (diagram) lines, those that do not are called forbidden, and those that result in atoms with two or more vacancies in inner orbitals at the time of the emission are called satellite (non-diagram) lines. The number of K-lines, and the exact one observed for an element, depends in part on the number of filled orbitals.

Klystron – It is a specialized linear-beam vacuum tube which is used as an amplifier for high radio frequencies, from ultra-high frequency up into the microwave range. It is  an evacuated electron-beam tube in which an initial velocity modulation imparted to electrons in the beam subsequently results in density modulation of the beam. This device is used as an amplifier or oscillator in the microwave region.

Kneading – It is the process of mixing water with blended clay (clay with additional minerals) to make it plastic. Kneading of the brick earth occurs after clay has been weathered, and blended and is the last step in the preparation of brick earth before moulding it into the shape.

Knife coating – It is a method of coating a substrate (normally paper or fabric) in which the substrate, in the form of a continuous moving web, is coated with a material, the thickness of which is controlled by an adjustable knife or bar set at a suitable angle to the substrate.

Knife gate valve – A knife gate valve works by lifting a plate with a planar or ‘knife’ edge from the path of flow which can literally cut through different impediments during closing thereby creating complete closure against a soft sealing surface. This soft sealing surface normally dictates use in rather low-pressure systems and is not designed to handle high pressure. The knife gate valve is primarily designed for isolation or on / off service rather than a throttled or partial-flow application.

Knife-line attack – It is the inter-granular corrosion of an alloy, normally stabilized stainless steel, along a line adjoining or in contact with a weld after heating into the sensitization temperature range.

Knife mark – It is a continuous scratch (which also can be creased) near a slit edge, caused by sheet contacting the slitter knife.

Knitted fabrics – In composites, these are the fabrics produced by inter-looping chains of yarn.

Knock – In a spark ignition engine, It is the uneven burning of the air / fuel charge which causes violent, explosive combustion and an audible metallic hammering noise. Knock results from premature ignition of the last part of the charge to burn.

Knock-down – It consists of a collection of parts / sub-assemblies of an equipment which are required to be assembled at the site where the equipment is to be installed and commissioned. The parts are typically manufactured at the manufacturing plant, and then sent to the erection site for final assembly.

Knockout – It is the removal of sand cores from a casting. It is also the jarring of an investment casting mould to remove the casting and investment from the flask. It is a mechanism for freeing formed parts from a die used for stamping, blanking, drawing, forging, or heading operations. It is also a partially pierced hole in a sheet metal part, where the slug remains in the hole and can be forced out by hand if a hole is needed. Knockout is also means ejecting of a compact from a die cavity.

Knockout mark – It is a small protrusion, such as a button or ring of flash, resulting from depression of the knockout pin from the forging pressure or the entrance of metal between the knockout pin and the die.

Knockout pin – It is a power-operated plunger installed in a die to aid removal of the finished forging.

Knockout punch – It is a punch which is used for the ejection of compacts.

Knoop hardness number (HK) – It is a number related to the applied load and to the projected area of the permanent impression made by a rhombic-based pyramidal diamond indenter having included edge angles of 172-degree 30-minute and 130-degree 0-minute computed from the equation ‘HK = P/0.072089d square’, where ‘P’ is the applied load, kgf, and ‘d’ is the length of the long diagonal of the impression in millimeters. In reporting Knoop hardness numbers, the test load is stated.

Knoop hardness test – It is an indentation hardness test using calibrated machines to force a rhombic-based pyramidal diamond indenter having specified edge angles, under specified conditions, into the surface of the material under test and to measure the long diagonal after removal of the load.

Knowledge – It can be defined as (i) awareness or familiarity gained by experience (of a person, fact, or thing), (ii) a person’s range of information which can be either a theoretical or practical understanding of a subject, language, etc. or the sum of what is known or both, and (iii) true, justified belief which means certain understanding, as opposed to opinion. Knowledge is the key resource, for the organizational strength. It is fundamentally different from the other traditional key resources such as land, labour, and even capital. The organization needs systematic work on the quality of knowledge and the productivity of knowledge. The performance capacity, if not the survival, of the organization in the knowledge society has become increasingly dependent on these two factors related to knowledge.

Knowledge base – It is a collection of formulas, rules, and lessons learned that, when connected to a computerized database and manipulated with artificial intelligence methods, allows decisions to be made which approximate those made by humans, but much faster.

Knowledge integration – It refers to the process of merging two or more originally unrelated knowledge structures into a single structure.

Knowledge management – It is simply defined as doing what is needed to get the most out of knowledge resources. It focuses on organizing and making available important knowledge, wherever and whenever it is needed. It is all about the application of the available knowledge in the organization in different situations faced during its functioning. It is the organizational discipline which promotes an integrated approach to the creation, capture, organization, access and use of the organizational knowledge assets. These assets include structured databases, textual information such as policy and procedure documents, and most importantly, the tacit knowledge and expertise resident in the heads of individual employees. Knowledge management is the systematic management of the organizational knowledge assets for creating value and meeting its tactical and strategic requirements. It consists of the initiatives, processes, strategies, and systems which sustain and enhance the storage, assessment, sharing, refinement, and creation of knowledge. The organization is needed to define knowledge management in terms of its objectives. It is the activity which is being practiced by several organizations all over the world. In the process of knowledge management, the organizations comprehensively gather information by using numerous methods and tools. The gathered information is then organized, stored, shared, and analyzed using defined techniques. The analysis of such information is done based on resources, documents, people, and their skills. Properly analyzed information is then stored as ‘knowledge’ of the organization. This knowledge is later used for activities such as organizational decision making and training new employees etc.

Knowledge-based system (KBS) – It is a computer programme which reasons and uses a knowledge base to solve complex problems. The term can refer to a broad range of systems. However, all knowledge-based systems have two defining components namely (i) an attempt to represent knowledge explicitly, called a knowledge base, and (ii) a reasoning system which allows them to derive new knowledge, known as an inference engine.

Knowledge-based expert systems – These are the most common types of knowledge-based systems. These systems mimic human experts’ decision-making processes, making them helpful for complex analyses, calculations and predictions. In addition to presenting solutions, they provide specific explanations for the problems which they are solving.

Knowledge management cycle – It is a process of transforming information into knowledge within the organization. It constitutes as a continuous cycle of three processes, namely (i) knowledge creation and improvement, (ii) knowledge distribution and circulation, and (iii) knowledge addition and application. The knowledge management cycle explains how knowledge is captured, processed, and distributed in the organization. It is the deliberate and systematic collaboration of the organizational human resource, technologies, and processes. It is styled and structured in order to add value through reuse and innovation.

Knowledge management system – It expresses a deliberate, systematic and synchronized approach to ensure the full utilization of the organizational knowledge base, combined with the potential of employees’ skills, competencies, thoughts, innovations, and ideas to create a more efficient and effective organization. It incorporates both holding and storing of the knowledge perspective, with respect to the intellectual assets. It has four sub-systems consisting of (i) knowledge discovery system, (ii) knowledge capture system, (iii) knowledge sharing system, and (iv) knowledge application system.

Known deposit, known source – It is a deposit or source which has been demonstrated to exist by direct evidence. More detailed specifications can be found in relevant source-specific aligned systems.

Knuckle area – It is the area of transition between sections of different geometry in a filament- wound part, e.g., where the skirt joins the cylinder of the pressure vessel. It is also called Y-joint.

Knuckle joint – It is a mechanical joint that connects two rods or pipes at an angle, allowing limited angular movement and rotation between them. It consists of a spherical ball and socket joint, with a cylindrical extension called the knuckle.

Knuckle-joint press – It is a press whose action is based on a hinged joint and flywheel. This type of press has a relatively long extrusion dwell, particularly useful for preventing the springing back of the surface metal. Knuckle-joint presses are available with press forces from 2,000 kilonewton to 10,000 kilonewton and bolster widths from 1,500 millimeters to 4,000 millimeters, fixed or adjustable stroke.

Knuckle-lever press – It is a heavy short-stroke press in which the slide is directly actuated by a single toggle joint which is opened and closed by a connection and crack. It is used for embossing, coining, sizing, heading, swaging, and extruding.

Knurling – It is impressing a design into a metallic surface, normally by means of small, hard rollers which carry the corresponding design on their surfaces.

K-radiation – It is the characteristics X-rays produced by an atom when a vacancy in the K-shell is filled by one of the outer electrons.

Kraft process – It is a wood-pulping process in which sodium sulphate is used in the caustic soda pulp-digestion liquor. It is also called kraft pulping or sulphate pulping.

Kroll process – It is a process for the production of metallic titanium sponge by the reduction of titanium tetra-chloride with a more active metal, such as magnesium or sodium. The sponge is further processed to granules or powder.

Krypton – It is a chemical element; it has symbol Kr and atomic number 36. It is a colorless, odorless noble gas that occurs in trace quantities in the atmosphere and is frequently used with other rare gases in fluorescent lamps. Krypton is chemically inert. Krypton, like the other noble gases, is used in lighting and photography.

K-series – It is the set of X-ray wave-lengths comprising K-radiation.

K-shell – It is the innermost shell of electrons which surrounds an atomic nucleus and constitutes the lowest available energy level of the electrons. It has electrons which are characterized by the principal quantum number 1.