| 摘要 |
PROBLEM TO BE SOLVED: To provide a cold rolled steel sheet not only excellent in deep drawability but also excellent in ridging resistance and secondary working brittleness resistance. SOLUTION: A steel slab whose componential composition and slab temperature are controlled to prescribed ones is subjected to hot rolling under the conditions in which the total draft in a ferritic region is 30 to 80%, and finishing temperature is 800 deg.C to the Ar3 point, within 0.5 sec after the completion of the hot rolling, cooling is started, and cooled at a rate of 50 deg.C/s or more, coiled at 400 deg.C or less, thereafter subjected to cold rolling at a draft of 50 to 80% and then subjected to finish annealing at 850 deg.C or more.
|
