Fusion Bonded Epoxy Coated Reinforcement Bar...

Fusion Bonded Epoxy Coated Reinforcement Bar Fusion bonded epoxy coating, also known as fusion bond epoxy powder coating and commonly referred to as FBE coating, is an epoxy based powder coating that is widely used to protect concrete reinforcement bars from corrosion. FBE coatings are thermoset polymer coatings. The most widely used types include acrylic, vinyl, epoxy, nylon, polyester, and urethane. Most popular for reinforcement bars is epoxy coating. The name fusion bond epoxy is due to resin cross linking and the application method, which is different from a conventional paint. FBE coatings are 100 % solid coatings applied as dry powders and formed into a film by heating. The fusion bonded epoxy coating process for reinforcement bars was developed in United States in 1960s and its use was strongly recommended in coastal areas. Since Its introduction, FBE coating formulations had gone through vast improvements and developments. Today, various types of FBE coatings, which are tailor made to meet various requirements are available. Modern application techniques for applying powders fall into four basic categories. These are (i) fluidized bed process, (ii) electrostatic bed process, (iii) electrostatic spray process, and (iv) plasma spray process. The electrostatic spray process is the most commonly used method of applying powders. In this process, the electrically conductive and grounded object is sprayed with charged, non conducting powder particles. The charged particles are attracted to the substrate and cling to it. The epoxy powder is applied by electrostatic spray on hot steel on preset temperature level. The powder, when in contact with hot bar, melts flows, gels, cures, cools and produces a well adhered continuous corrosion resistant protective coating. The thermosetting of the epoxy is an irreversible process and provides a good protection to reinforcement bars against corrosion. It prevents attack of chloride ion on the metallic surface and the occurrence...

Standardization Process in Steel Industry...

Standardization Process in Steel Industry In a large industry there are a large number of matters as well as items which are apt to become diversified, complicated, and chaotic if not timely controlled. Industrial standardization aims to develop, establish and implement industry level standards, protocols, and conventions as well as national and international level standards for simplification and unification of the working. Standardization can be defined as reducing, simplifying, and organizing matters which are apt to become diversified, complicated, and chaotic if left uncontrolled. It is the process of formulating, issuing, and implementing standards. Standards can be defined as rules specified for standardization.  Standards are documents that provide rules, guidelines or characteristics for activities or their results, for common and repeated use. Standards aim at achieving the optimum degree of order in a given context. The entire industry as well as all the activities of the industry benefit from standardization due to the improved working environment, increased safety, enhanced quality as well as lower transaction costs and prices. There are mandatory standards and voluntary standards, but generally formation and the implementation of the voluntary standards contribute maximum to the process of standardization in the industry. Standards are usually classified in three types namely (i) reference standards, (ii) minimum quality standards, and (iii) compatibility standards. Standardization process is a powerful tool in the hands of management of the organization to simplify the operation and to reduce the inventories of raw materials, in-process materials, finished products, spares, consumables and other store items. It helps to create a strong, open, and well organized technological infrastructure that serve as a foundation for innovation led growth. For organizations of all sizes, effective standardization promotes innovation; enhance productivity and helps in improving the efficiency of man and equipment. It defines...

Basics of Continuous Casting of Steel Jan25

Basics of Continuous Casting of Steel...

Basics of Continuous Casting of Steel Continuous casting is the process whereby liquid steel is solidified into a semi finished product for subsequent rolling in the finish rolling mills. Continuous casting of steel was conceived and patented in 1865 by Sir Henry Bessemer, but it could not be commercialized because of problems related to engineering and equipment. After solving these problems, continuous casting of steel was introduced commercially in 1950s and around 1475 million tons of continuous cast steel was produced globally in 2012. Continuous casting has replaced several steps during steel making process such as ingot casting, mould stripping, heating in soaking pits, and primary rolling with one operation. Continuous casting of steel has helped to achieve improved yield, quality, productivity and cost efficiency. The principle of continuous casting is shown in Fig. 1. Fig 1 Principle of continuous casting Referring to Fig 1, Liquid steel in the steel teeming ladle (1) from the secondary steel making unit is taken to the continuous casting machine. The ladle is raised onto a turret that rotates the ladle into the casting position above the tundish (3). Liquid steel flows out of the ladle into the tundish, and then into a water-cooled copper mould (5). Solidification begins in the mould, and continues through the roll support (6) and the turning zone (7).  The continuous cast strand is then straightened, torch-cut, and then discharged for intermediate storage or hot charged for finished rolling. Depending on the product end use, various shapes are cast. In conventional continuous casting machines these are slabs, blooms or billets. In recent years, the melting, casting, and rolling processes have been linked while casting a shape that substantially conforms to the finished product. These near net shape cast sections are usually applied to beams...

Steel Scrap

Steel Scrap Steel scrap consists of discarded steel or steel products, generally segregated by composition and size or ‘grade’ suitable for melting. There are three main types of scrap which are used by the steel industry as feed stock. These are (i) internal scrap, (ii) prompt scrap, and (iii) obsolete scrap. Internal scrap is also known as revert or home scrap. It refers to the reject metal within the steel plant which gets generated during steel making, steel casting and steel finishing activities within the steel plant. Prompt scrap is also known as process scrap and it is the waste generated during the product manufacturing by the steel plant’s customers i.e. the manufacturing industries. Obsolete scrap consists of that scrap which is recovered from discarded industrial and consumer items i.e. from ships to refrigerators and from construction beams to automobiles. The first two categories of scrap can be returned to the steel making process with little or no pretreatment, obsolete scrap needs to be separated from contaminants, sorted and prepared for steel making. Due to the large improvements which have taken place in the steel manufacturing, steel casting, steel finishing, and product manufacturing technologies in the recent past, the amount of generation of the first two types of scraps have reduced a lot. On the other hand with resources of obsolete scrap are increasing as the world is becoming more industrialized and due to larger quantity of discarded consumer durables and worn out industrial equipment etc. Another way of classifying steel scrap is to classify it according to the products in which the steel was used before it became scrap. The main steel scrap sources in this sense are automobiles, ships, railroads, construction buildings, machinery, white goods, packaging, electric and electronic equipment etc. Steel...

Maintenance Practices for Plant and Equipment...

Maintenance Practices for Plant and Equipment Nothing lasts forever and all the equipment in a plant has associated with it some predefined life expectancy or operational life. Maintenance is the work of keeping the plant and equipment in good condition for operation. It is the action taken to prevent plant and equipment from failing and to repair normal degradation experienced with the operation and to keep it fit for operation. Some organizations do not expend the necessary resources to maintain equipment in proper working order. Instead they wait for equipment failure to occur and then take whatever actions are necessary to repair or replace the equipment. However this fact is to be kept in mind that if there is failure in performing maintenance activities intended by the equipment designer, the life of the operating equipment gets shortened. Adequate maintenance of plant and equipment is necessary to ensure that the plant and equipment is working reliably and effectively. Maintenance can be part of a planned programme or may have to be carried out at short notice after a breakdown. It is carried out to prevent equipment problems and to put fault right. It always involves non-routine activities and can expose those involved and others as well to a range of risks. An effective maintenance programme can result into more reliable plant and equipment. Fewer breakdowns will mean less dangerous contact with machinery is required. It also results into cost benefits because of better productivity and efficiency. Additional hazards can occur when machinery becomes unreliable and develops faults. Maintenance allows these faults to be diagnosed early to manage any risks. However, maintenance needs to be correctly planned and carried out. Unsafe maintenance can cause accidents and serious injuries either during the maintenance or to those using...