FORMABILITY CHARACTERIZATION OF AISI202 STAINLES STEEL

Abstract

As per the World Steel Association, India was the third largest producer of steel in the world, producing about 89.58 million tonnes of crude steel during the year 2014 - 2015 (WSA, 2015). Out of which about 70% of long steel products are produced from steel rerolling industries, which are mostly small and medium sized enterprises (SMEs). Indian steel rerolling sector comprises of over 1800 SMEs spread across the country. These SMEs are being operated in various clusters located across the country. In one such cluster in Ahmedabad, about 90 small scale stainless steel re-rolling mills are operational in various locations involving Vatva, Odhav, Naroda, Chatral and Kalol industrial areas. This cluster consist of 90 steel re-rolling mills, out of which about 25 mills are doing hot rolling of stainless steel flats and about 65 mills are engaged in cold re-rolling and annealing operations. In simple terms, hot rolling mills symbolize hot rolling of plates while cold rerolling mills symbolizes cold rolling of sheets. In technical terms, hot rolling is the heating the plates at a temperature above 1000-1200 oC in a reheating furnace and rolling the plates in red hot condition to a thickness of approximately 16 gauge. The rerolling process involves reheating the same 16 gauge sheet in a separate reheating furnace to an annealing temperature of around 900 oC. These annealed sheets are then pickled (acid cleaned) through various stages to obtain an intermediate product, free of scales and contamination. These pickled, scale-free sheets are then rolled in cold condition to achieve gauge reduction from 16 to 24 gauge, depending upon the customer requirement.