| 摘要 |
PROBLEM TO BE SOLVED: To provide a method of manufacturing a hot rolled steel plate excel lent in longitudinal crack resistance, and particularly a thick hot rolled steel plate of >=4 mm plate thickness. SOLUTION: At hot finish rolling of a slab of a steel having a composition containing, by weight, 0.001-0.03% C, 0-0.5% Si, 0-2% Mn, <=0.02% P, <=0.02% S, <=0.1% sol. Al and <=0.005% N, rolling is performed under the conditions of: <=95% total finish rolling rate; >=55% total draft at >=2 (Ar3 transformation point + 70 deg.C); and finish rolling temperature between the Ar3 transformation point and (Ar3 transformation point + 40 deg.C).
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