US 12,330,391 B2
Steel sheet plated with Al—Fe for hot press forming having excellent corrosion resistance and spot weldability, and manufacturing method thereof
Jin-Keun Oh, Gwangyang-si (KR); Seong-Woo Kim, Gwangyang-si (KR); Sang-Heon Kim, Gwangyang-si (KR); and Yeol-Rae Cho, Pohang-si (KR)
Assigned to POSCO, Pohang-si (KR)
Filed by POSCO, Pohang-si (KR)
Filed on Nov. 9, 2022, as Appl. No. 17/983,759.
Application 17/983,759 is a division of application No. 17/297,920, granted, now 11,529,795, previously published as PCT/KR2019/016763, filed on Nov. 29, 2019.
Claims priority of application No. 10-2018-0152572 (KR), filed on Nov. 30, 2018; and application No. 10-2019-0156855 (KR), filed on Nov. 29, 2019.
Prior Publication US 2023/0086620 A1, Mar. 23, 2023
Int. Cl. B32B 15/01 (2006.01); C22C 38/00 (2006.01); C22C 38/02 (2006.01); C22C 38/04 (2006.01); C22C 38/06 (2006.01); C22C 38/28 (2006.01); C22C 38/32 (2006.01); C23C 2/02 (2006.01); C23C 2/12 (2006.01); C23C 2/26 (2006.01); C23C 2/28 (2006.01); C23C 2/40 (2006.01); C23C 24/04 (2006.01); C23C 28/02 (2006.01)
CPC B32B 15/012 (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 38/28 (2013.01); C22C 38/32 (2013.01); C23C 2/02 (2013.01); C23C 2/12 (2013.01); C23C 2/26 (2013.01); C23C 2/28 (2013.01); C23C 2/29 (2022.08); C23C 2/40 (2013.01); C23C 24/04 (2013.01); C23C 28/02 (2013.01)] 11 Claims
 
1. A method of manufacturing an aluminum-iron-based plated steel sheet for hot press forming, the method comprising:
preparing a base steel sheet;
plating the base steel sheet at an plating amount of 40 to 100 g/m2 for each side of the base steel sheet by immersing the base steel sheet in an aluminum plating bath containing, by weight %, silicon (Si): 7 to 15%, magnesium (Mg): 1.1 to 15%, and a balance of aluminum (Al) and inevitable impurities to obtain an aluminum-plated steel sheet;
initial cooling to in a temperature range from 640° C. or more to 680° C. or less at a cooling rate of 0.1 to 5° C./see immediately after completing the immersing the base steel sheet; and
on-line alloying subsequently to the initial cooling, by increasing a temperature of the aluminum-plated steel sheet within a temperature range of 670 to 900° C. for a holding time of 1 to 20 seconds.