US 11,938,530 B2
Method of manufacturing a hot-stamped part
Je Youl Kong, Incheon (KR)
Assigned to Hyundai Steel Company, Incheon (KR)
Filed by Hyundai Steel Company, Incheon (KR)
Filed on Jan. 12, 2023, as Appl. No. 18/153,716.
Application 18/153,716 is a continuation of application No. 17/109,981, filed on Dec. 2, 2020, granted, now 11,583,909.
Claims priority of application No. 10-2019-0171792 (KR), filed on Dec. 20, 2019; and application No. 10-2020-0116097 (KR), filed on Sep. 10, 2020.
Prior Publication US 2023/0143840 A1, May 11, 2023
This patent is subject to a terminal disclaimer.
Int. Cl. B21D 22/02 (2006.01); C22C 38/00 (2006.01); C22C 38/02 (2006.01); C22C 38/04 (2006.01); C22C 38/06 (2006.01); C22C 38/22 (2006.01); C22C 38/28 (2006.01); C22C 38/32 (2006.01)
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
OG exemplary drawing
 
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.