Facilities

Steel Making Process



Steel Making Process

Electrosteel Steels Ltd. has taken lot of technical measures to produce quality product. In the coke ovens, stamp charging technology has been adopted to increase the coke strength. Blast furnaces' operation is fully computer controlled fitted with internal top image camera, temperature flux profile, rope less stock measurement system. To cut down production cost and to enhance higher productivity high temperature stove, coal dust injection system and oxygen enrichment are adopted. To increase metal yield the runners are specially designed and online slag granulation system has been adopted.

Liquid metal from the blast furnace is converted to steel by the LD process, the liquid steel is then taken to a ladle furnace for secondary refining, addition of Ferro-alloys for accurate control of the chemistry, to drive out the non-metallic inclusions and control of temperature for sound casting into billets of size 150x150 mm sq. Electromagnetic starters are being used in the continuous casting machine for getting sound casting. In the rolling mill billets are heated in a computer controlled furnace, having regenerative burners for controlled heating at cheaper cost. The soaked billets are then rolled in bar mill, equipped with alternate horizontal and vertical housing-less stands, for twist free operation and accurate size control. The finished bar then enters the Programmable logic controlled cooling (Quenching) operation, where the bar is subjected to heat treatment in three successive stages. The first stage of quenching begins when the hot rolled bar leaves the final mill stand and is rapidly quenched by special water spray system. This converts the surface layer of the bar to a hardened structure called ‘Martensite’ while the core remains austenitic. The second stage of self-tempering begins when the bar leaves the quenching box with a temperature gradient through its cross section, the temperature of the core being higher than that of the surface. This allows heat to flow from core to the surface, resulting in tempering of the surface, resulting in giving a structure called ‘tempered Martensite’ which is strong and tough. The core is still austenitic at this stage. The third stage of ‘atmospheric cooling’ takes place on the cooling bed, where the austenitic core adjacent to martensitic ring is transformed to a tough banitic structure ring and the core of the bar to ductile pearlite. Thus the final structure consists of a combination of strong outer layer of tempered martensite followed by banite ring and a ductile core of pearlite. This is what gives Electrosteel TMT bar its unique combination of strength and ductility. Bar mill is equipped to produce TMT (size 10mm to 40mm) and rods (size 20mm to 60mm).



In the wire rod mill, coils of TMT (size 8mm to 16mm) and wire rods (size 5.5mm to 16mm) are produced. This mill has fourteen stands of alternate horizontal and vertical housing stands, followed by four numbers, pre finishing mill and then eight numbers no twist block and ultimately four numbers reducing sizing mill, all supplied by Morgan, USA. This mill also has controlled temperature rolling. This total arrangement ensures excellent dimensional tolerance and surface quality free from scratches and other rolling defects.