| 摘要 |
PROBLEM TO BE SOLVED: To provide a hot pressing method by which resistance to hydrogen embrittlement is improved in formed parts for which the hot pressing process of a steel sheet having the tensile strength of≥980 MPa is used. SOLUTION: A dew point inside a heating furnace just before pressing in the hot pressing process is set to -100 to 30°C, the component of the atmosphere inside an annealing furnace is essentially composed of nitrogen or argon, the concentration of hydrogen is set to≤5 mol%, and the steel sheet is heated to 650-1,000°C, and then press forming is performed. COPYRIGHT: (C)2006,JPO&NCIPI
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