| 摘要 |
PURPOSE:To manufacture a cold rolled steel sheet having superior deep drawability by regulating the chemical composition of a steel billet, heating the billet to a prescribed temp., finish-rolling it at a prescribed temp., and carrying out continuous annealing at a prescribed temp. CONSTITUTION:The composition of a steel billet is composed of, by weight, <0.01% C, <0.4% Mn, 0.02-0.2% Ti (Ti/C>=4) and the balance Fe with inevitable impurities. The billet is heated to 950-1,100 deg.C, finish-rolled at 700-780 deg.C, and coiled at <=700 deg.C. The resulting hot rolled steel strip of an intermediate thickness is cold rolled to obtain a cold rolled steel strip of the final thickness and this strip is continuously annealed at 700-850 deg.C. |
