| 摘要 |
A high-strength steel sheet including specific amounts of each of C, Si, Mn, and Al, the remainder being iron and unavoidable impurities, polygonal ferrite, tempered martensite, bainitic ferrite, a mixed structure (MA) of fresh martensite and residual austenite, and the total of polygonal ferrite and bainitic ferrite being specific area ratios, and the Mn concentration in the MA being at least 1.2 times the Mn content of the steel sheet as a whole. |
