| 摘要 |
　A hot-rolled steel sheet comprises, in mass%, 0.030-0.120% of C, at most 1.20% of Si, 1.00-3.00% of Mn, 0.01-0.70% of Al, 0.05-0.20% of Ti, 0.01-0.10% of Nb, at most 0.020% of P, at most 0.010% of S, and at most 0.005% of N, with the remainder consisting of Fe and impurities, wherein: 0.106≥(C%-Ti%*12/48-Nb%*12/93)≥0.012; the {112}(110) pole density is at most 5.7 at a depth of 1/4 of the thickness of the steel sheet; the aspect ratio (long axis/short axis) of prior austenite grains is 5.3 or less; the deposition density of (Ti, Nb) C having a size of 20nm or less is at least 109 pieces/mm3; the yield ratio (YR), which is the ratio of the tensile strength to the yield stress, is at least 0.80; and the tensile strength is at least 590Mpa. |
