| 摘要 |
PROBLEM TO BE SOLVED: To provide a hot rolled steel plate minimal in anisotropy and having high average r-value exceeding 1.0, and to provide the manufacturing method therefor. SOLUTION: A steel, having a composition consisting of, by weight, 0.01-0.06% C, 0.1-0.5% Mn, <=0.3% Si, <=0.05 P, <=0.02% S, <=0.1% Al, <=0.01% N, 0.005-0.05% Nb, and the balance Fe with inevitable impurities, is heated to >=1150 deg.C, and roughing is finished at >=1000 deg.C. Finish continuous rolling is started at 900-950 deg.C, and rooling is performed at a rolling temperature between Ar3 and Ar3+30 deg.C while regulating drafts at the final two passes to 10-40%, respectively, followed by coiling at >=550 deg.C. By this method, the hot rolled steel plate, having ferrite grain size No.11-13 and also having <=2.0 X-ray plane intensity ratio of 111} plane, 112} plane, and 100} plane, can be obtained.
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