PRODUCTION OF HIGH-STRENGTH COLD-ROLLED STEEL PLATE FOR DEEP DRAWING HAVING EXCELLENT NONAGING PROPERTY, SECONDARY WORKABILITY AND CURING PERFORMANCE FOR BAKED PAINT

摘要

PURPOSE:To obtain a steel plate having excellent nonaging property, secondary workability, etc. by subjecting an Al killed steel ingot contg. prescribed ratios of C, Si, Mn, P, etc. to prescribed hot working. CONSTITUTION:Al killed steel contg. =0.005% C, =0.8% Si, =1.2% Mn, 0.03- 0.14% P, =0.07% solAl, =0.008% N, 0.8-1.6 B/N and 0.5-6 Nb/C is melted. The Al killed steel ingot obtained by casting said molten metal is hot rolled at 950-1,180 deg.C; thereafter, the rolled plate is cold-rolled and is continuously annealed at temps. higher than the recrystallization temp. and lower than the Ac3 point. Thus, the steel plate having excellent nonaging property, secondary workability, etc. is obtained.