| 摘要 |
A high-strength hot-rolled steel sheet containing by mass 0.05-0.12% C, 0.05-1.0% Si, 0.5-1.8% Mn, at most 0.04% P, at most 0.0030% S, 0.005-0.07% Al, at most 0.006% N, and 0.05-0.15% Ti, the remainder having a component composition comprising Fe and unavoidable impurities, the amount (Ti*) of the Ti content [Ti] present as a precipitate in a position from 1/8 to 3/8 of the sheet thickness being from 0.3×[Ti] to 0.6×[Ti]; and having a microstructure in which an area ratio accounting for the entire structure of a bainite phase exceeds 95%. |
