Technology

RAK Steel manufactures rebars using QST (Quenching and Self Tempering) process technology. RAK Steel has set up a new mill with 18 stands and roughing stands with horizontal vertical configuration. The mill has series of zero tension loopers and a fully automatic bar bundling system. Spacious yard for cast – wise stacking of billets, 12 meter reheating pusher furnace and finishing mill cold shear for cutting of bars.

RAK Steel rebars are hot rolled from steel billets and processed through PLC controlled on line thermo mechanical treatment in 3 successive stages

a) Quenching – The hot rolled bar leaving the final mill stand is rapidly quenched by a special water spray system. This hardens the surface of the bars to a depth optimised for each section through formation of martensitic rim while the core remains hot and austenite.

b) Self Tempering – when the bar leaves the quenching box, the core remains hot compared to the surface causing tempering of the outer martensitic layer into a structure called Tempered Martensite. The core remains austenitic at this stage.

c) Atmospheric cooling – This takes place on the 66 meter cooling bed where austenitic core is transformed into ductile ferrite pearlite structure. Thus the final structure consists of an optimum combination of strong outer layer (tempered martensite) with ductile core (ferrite pearlite). This gives RAK Steel rebars its superior combination of higher strength and ductility.