| 摘要 |
PURPOSE: To obtain a cold-rolled steel sheet for deep drawing having various kinds of anisotropies in the surface according to use by selecting the specific condition, treating an extra-low carbon steel to hot-rolling, cold-rolling and continuous annealing, in order to control the structure. CONSTITUTION: In the steel sheet having <=0.004wt.% C, in the case of the shape A:|(rC-rQ)/(rL-rQ)|>=2 of the anisotropy, when the finish temp. T of the hot-rolling is >=Ar3 transformation point and cold rolling ratio R of the cold rolling is 65-85%, the temp. raising speed V is made to be <10 deg.C/sec, and when V is >=10 deg.C/sec, R is made to be 75-85%. In the case of the shape B:|(rC-rQ)/(rL- rQ)|<2 of the anisotropy, T>=Ar3 transformation point, R=60-74% and V>=10 deg.C/ sec. In the case of the shape C, D:|(rQ-rL)/(rQ-rC)|>=2 and <2, in the shape C, T<Ar3 transformation point, R=74-90% V>=10 deg.C/sec and in the shape D, only R in the case of the shape C is made to be 74-90%. Wherein, (r) values of L (0 deg.C), Q (45 deg.C) and C (90 deg.C) directions to the rolling direction are made to be rL, rQ and rC, respectively.
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