| 摘要 |
PROBLEM TO BE SOLVED: To provide a high-strength press part excellent in impact absorption properties and its production method.SOLUTION: A high-strength press part is produced by press-hardening a steel sheet having a composition comprising, by mass%, 0.2-0.6% of C, 0.001-3.0% of Si, 0.5-3.0% of Mn, 0.1% or less of P, 0.07% or less of S, 0.01-0.1% of Al and the balance Fe with inevitable impurities so as to produce a high-strength press part which has a hardness at the sheet thickness center of the press part of Hv 400 or higher, includes surface layers from the front and back surfaces to a depth of 20-200 μm composed of a soft layer of a hardness of Hv 300 or lower and is excellent in impact absorption properties. |
