| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a high strength steel sheet, having effectively reduced variations in hardness in the sheet thickness direction and the sheet width direction of a steel sheet, and thereby having improved material uniformity in the steel sheet. <P>SOLUTION: A high strength steel sheet comprises a composition containing, by mass%, 0.02 to 0.15% C, 0.01 to 1.5% Si and 0.1 to 2.5% Mn, with the balance of Fe and unavoidable impurities. In the high strength steel sheet, a steel structure is a bainitic structure, and each of variations in hardness in the sheet thickness direction and the sheet width direction is 50 or less in Vickers hardness ΔHV. <P>COPYRIGHT: (C)2012,JPO&INPIT |
