HOT-ROLLED STEEL PLATE EXCELLENT IN WORKABILITY AND BAKING HARDENABILITY AND ITS PRODUCTION

摘要

PURPOSE:To effectively manufacture a hot-rolled steel plate excellent in workability and baking hardenability, by subjecting a steel stock containing specific percentages of C, Si, Mn, S, solAl, and N to heating, finish rolling, and winding under specific conditions. CONSTITUTION:A steel stock consisting of, by weight ratio, 0.030-0.100% C, =0.10% Si, 0.10-1.00% Mn, =0.015% S, =0.015% SolAl, 0.0010-0.0040% N, and the balance Fe with inevitable impurities is prepared. Subsequently, this steel stock is heated to =1,100 deg.C, and the hot finish rolling of this steel stock is finished at a temp. between the Ar3 transformation point and 950 deg.C, and the resulting hot-rolled plate is wound up at 400-650 deg.C. By this method, the hot-rolled steel plate excellent in ductility, having a BH value of baking hardenability as high as about 10kgf/mm2, and suitable for press forming can be obtained.