Types of finished steel products and their terminologies:

Types of finished steel products and their terminologies:

Steel is not a single product. There are currently more than 3,500 different grades of steel with many different properties - physical, chemical, environmental, 75% of which have been developed in the last 20 years. If the Eiffel Tower were to be rebuilt today the engineers would only need one-third of the amount of steel, modern cars have new steels with higher strength reducing the overall shell weight by 25%. Some of the finished steel terminologies have been discussed below:

(1) Annealing: Annealing is a heat treatment process. With this, steel products are reheated to a suitable temperature to remove stresses, resulting from previous processing and to soften them and/or improve their machinability and cold forming properties.

(2) Billet: Billet is a semi-finished steel product with a square cross section up to 155mm x 155mm. This product is either rolled or continuously cast and is further processed by rolling to produce finished products like wire rods, merchant bars and other sections. The range of semi-finished products above 155 mm x 155 mm is called blooms.

(3) Carbon Steel: A type of steel generally having no specified minimum quantity of any alloying element and containing only an incidental amount of any element other than carbon, silicon, manganese, copper, sulfur and phosphorus.

(4) Coated Steel (Galvanized & Color coated): Steel sheet coated through a heat process or through electrolysis with a layer of substance to protect the base metal (substrate) against corrosion. The most commonly used material is zinc which can be applied either using the heat process (hot-dip galvanizing) or using electrolysis (electro-galvanizing). An organic coating (paint, plastic) can also be deposited on the layer of zinc. The zinc-coated steel is often referred to as "galvanized steel".

(5) Electric Sheets: These sheets are produced from steel alloyed with silicon (up to 3.5%) and are used in the manufacture of alternators, transformers and motors. Grain oriented electrical sheets have a high silicon content and are used for the manufacture of large transformers. Non-oriented products are used in electric motors and small transformers.

(6) Flat Steel Products: A flat steel product is a plate product or a (hot or cold) rolled strip product. Typically steel is rolled between sets of rollers to produce the final thickness. Plate products vary in dimensions from 10 mm to 200 mm and thin flat rolled products from 1 mm to 10 mm. Plate products are used for ship building, construction, large diameter welded pipes and boiler applications. Thin flat products find end use applications in automotive body panels, domestic 'white goods' products, 'tin cans' and whole host of other products from office furniture to heart pacemakers.

(7) Long Steel Products: A long product is a rod, a bar or a section - typical rod products are the reinforcing rods for concrete, engineering products, gears, tools etc. are typical of bar products and sections are the large rolled steel joists (RSJ) that are used in building construction projects. Wire-drawn products and seamless pipes are also part of the long products group.

(8) Refining Stand: A stage in the process of making crude steel, during which the crude steel is further refined (i.e., most residual impurities are removed) and additions of other metals may be made before it is cast.

(9) Semi-finished Products: Steel products such as billet, blooms and slabs. These products can be made by direct continuous casting of hot steel or by pouring the liquid steel into ingots, which are then hot rolled into semi-finished products.

(10) Slab: A semi-finished steel product obtained by rolling ingots on a rolling mill or processed through a continuous caster and cut into various lengths. The slab has a rectangular cross section and is used as a starting material in the production process of flat products, i.e., hot rolled coils.

(11) Strip: Flat steel coil products, with widths of less than 600mm for hot rolled products and less than 500mm for cold rolled products.

(12) Thin Strip Continuous Casting: Casting technology that takes liquid steel and casts it into solid strip in one step, thereby eliminating the need for a continuous slab caster and hot strip mill.