| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a steel sheet for a working stock which has no problems in the reduction of shape fixability and the increase of cost, and can exhibit excellent impact resistance when being used for an automotive structural member, and further, to provide a press-formed member for an automotive structural member having excellent impact resistance. <P>SOLUTION: The partially tempered and softened steel sheet is composed of a high strength steel sheet having a tensile strength of≥980 MPa. The steel sheet has a tempered and softened region wherein tempering treatment is locally performed, and the strength of the tempered and softened region lies in the range of 0.5 to 7 to the strength of the base material. The partially tempered and softened steel sheet comprises, by mass, 0.10 to 0.20% C, 0.5 to 1.5% Si, 1.5 to 3.0% Mn,≤0.05% P,≤0.03% S, 0.01 to 0.1% Al,≤0.01% N and 0.05 to 1.0% Cr, and further comprising one or more selected from Ti, Nb, Mo, V and W in the range of 0 to 0.2% in total, and the balance Fe with inevitable impurities. <P>COPYRIGHT: (C)2011,JPO&INPIT</p> |
