CPC B21D 22/022 (2013.01) [C22C 38/001 (2013.01); C22C 38/002 (2013.01); C22C 38/02 (2013.01); C22C 38/04 (2013.01); C22C 38/06 (2013.01); C22C 38/22 (2013.01); C22C 38/28 (2013.01); C22C 38/32 (2013.01)] | 8 Claims |
1. A method of manufacturing a part to be hot-stamped, the method comprising:
inserting a blank into a heating furnace, wherein the heating furnace includes heating sections and soaking sections;
step heating the blank as the blank passes through the heating sections;
soaking the blank at a temperature of Ac3 to 1,000° C. as the blank passes through the soaking sections;
transferring the soaked blank from the heating furnace to a press mold;
forming a molded body by hot-stamping the transferred blank; and
cooling the formed molded body, wherein, in the step heating of the blank, a temperature condition in the heating furnace satisfies formula:
0<(Tg−Ti)/Lt<0.025° C./mm
wherein Tg denotes a soaking temperature (° C.), Ti denotes an initial temperature (° C.) of the heating furnace, and Lt denotes a total length (mm) of the heating sections,
wherein the soaking is performed in the soaking sections having same temperature range in the heating furnace,
wherein the blank includes a tailor welded blank (TWB) formed by cutting different types of plate materials having different thicknesses into a required shape and welding the cut plate materials to each other.
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