| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for mass-producing a hot press-formed part, at a low cost, in which even in the case, as the working stock for hot press forming, any of a steel sheet or a plated steel sheet is used, oxidation of the surface caused by heating to high temperature upon hot press forming can be prevented even without controlling heating atmosphere, has satisfactory dimensional precision even when a shape is complicated and has high strength. SOLUTION: A steel sheet or a plated steel sheet is dipped into a salt bath in which the viscosity of a molten salt is≤30 mPa s so as to be made almost vertical to the bath face of the salt bath, is heated, is then conveyed to a press forming machine, and during a period when the temperature lies in the quenchable temperature of the steel sheet or the plated steel sheet, is press-formed so as to be a formed article. Then, the formed article is rapidly cooled in a state of being constrained by the press die of the press forming machine, and further, upon the rapid cooling or after the rapid cooling, a cleaning medium is sprayed on the formed part, and salt stuck to the formed part is removed so as to produce a press-formed article. Further, on and after the formed article is lifted up from the pressed die in press forming, a cleaning medium is sprayed on the press die so as to remove the salt stuck to the press die. COPYRIGHT: (C)2010,JPO&INPIT |
