PRODUCTION OF COLD ROLLED STEEL SHEET FOR DEEP DRAWING FROM THIN CAST STRIP

摘要

PURPOSE:To produce a steel sheet having excellent deep drawability with conserved energy by forming an extra low C steel having a specific compsn. by continuous casting to a thin cast strip and subjecting the strip to plural passes of hot rolling at specified temps. and drafts, then to cold rolling and continuous annealing. CONSTITUTION:The steel having the compsn. consisting of =0.006wt% C, 0.005-1.00% Si, 0.01-1.00% Mn, 0.001-0.10% P, =0.025% S, =0.005% N, and the balance Fe and unavoidable impurities is continuously cast to form the thin cast strip having 10-50mm thickness. The strip is subjected to high draft rolling at 900-1,100 deg.C and =40% draft in the 1st pass of the subsequent hot rolling and is finished at the Ar3 transformation point or above in the final pass. The steel sheet is next subjected to cold rolling at about =50% draft, then to the continuous annealing. =1 kinds among =0.08% Ti, =0.05% Nb, and 0.003% B are incorporated into the steel having the above-mentioned compsn. at need. The cold rolled steel sheet for deep drawing is obtd. from the thin cast strip with the lessened stages by the above-mentioned method.