| 摘要 |
PURPOSE:To produce a cold rolled steel plate having excellent aging resistance and deep drawability in the stage of producing said steel plate, by regulating the contents of C and N in steel, cold drafts and annealing temp. to specific values. CONSTITUTION:The steel slab contg. <=0.0030% C, <=0.0020% N, <=0.20% Mn, and 0.020<=sol. Al<=0.070% or contained further with B at 0.0005%<=B<=0.0020% in order to provide an effect of suppressing ferrite transformation is hot-rolled at >=850 deg.C finishing temp. and 500-700 deg.C coiling temp. The hot-rolled steel plate is cold-rolled at >=80% cold draft and is then annealed continuously at >=750 deg.C. The cold-rolled steel plate having excellent aging resistance and deep drawability is obtained. |
