| 摘要 |
PROBLEM TO BE SOLVED: To provide a method of stable manufacture of a hot rolled steel plate having high workability by a low temperature heating -low temperature finish hot rolling process. SOLUTION: A steel, having a composition which consists of, by weight, 0.01-0.05% C, <=0.5% Si, 0.05-1.00% Mn, <=0.100% P, <=0.03% S, 0.005-0.07% Al, 0.0025-0.0100% N, 0.0015-0.0070% B, 0.001-0.04% Ti, and the balance iron with inevitable impurities and in which the above B, Ti, and N are contained in amounts in the ranges satisfying ln (B wt.%×N wt.%)>-12.2, B wt.%/N wt.%<1.2, and ln (Ti wt.%×N wt.%)>-11.2, is heated to 950 to <1,120 deg.C and then hot rolled at 750 to 835 deg.C finishing temperature.
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