US 12,467,111 B2
Cold-rolled steel plate for hot forming, having excellent corrosion-resistance and spot-weldability, hot-formed member, and method for manufacturing same
Jin-Keun Oh, Gwangyang-si (KR); Yeol-Rae Cho, Gwangyang-si (KR); A-Ra Cho, Incheon (KR); Jin-Ho Cha, Gwangyang-si (KR); Si-Myoung Heo, Gwangyang-si (KR); Jeong-Won Seo, Gwangyang-si (KR); and Seong-Woo Kim, Gwangyang-si (KR)
Assigned to POSCO CO., LTD, Pohang-si (KR)
Filed by POSCO CO., LTD, Pohang-si (KR)
Filed on May 16, 2024, as Appl. No. 18/666,200.
Application 18/242,140 is a division of application No. 18/114,387, filed on Feb. 27, 2023, granted, now 11,788,166, issued on Oct. 17, 2023.
Application 18/114,387 is a division of application No. 17/885,860, filed on Aug. 11, 2022, granted, now 11,624,100, issued on Apr. 11, 2023.
Application 18/666,200 is a continuation of application No. 18/242,140, filed on Sep. 5, 2023, granted, now 12,049,679.
Application 17/885,860 is a continuation of application No. 16/336,645, granted, now 11,441,205, issued on Sep. 13, 2022, previously published as PCT/KR2017/010639, filed on Sep. 26, 2017.
Claims priority of application No. 10-2016-0123273 (KR), filed on Sep. 26, 2016.
Prior Publication US 2024/0301527 A1, Sep. 12, 2024
Int. Cl. C21D 9/46 (2006.01); B21B 3/02 (2006.01); B21D 22/02 (2006.01); C21D 6/00 (2006.01); C21D 8/02 (2006.01); C22C 38/00 (2006.01); C22C 38/02 (2006.01); C22C 38/04 (2006.01); C22C 38/06 (2006.01); C22C 38/20 (2006.01); C22C 38/22 (2006.01); C22C 38/24 (2006.01); C22C 38/26 (2006.01); C22C 38/50 (2006.01); C22C 38/54 (2006.01)
CPC C21D 9/46 (2013.01) [B21B 3/02 (2013.01); B21D 22/022 (2013.01); C21D 6/004 (2013.01); C21D 6/005 (2013.01); C21D 6/008 (2013.01); C21D 8/0205 (2013.01); C21D 8/0226 (2013.01); C21D 8/0236 (2013.01); C21D 8/0247 (2013.01); C22C 38/001 (2013.01); C22C 38/002 (2013.01); C22C 38/008 (2013.01); C22C 38/02 (2013.01); C22C 38/04 (2013.01); C22C 38/06 (2013.01); C22C 38/20 (2013.01); C22C 38/22 (2013.01); C22C 38/24 (2013.01); C22C 38/26 (2013.01); C22C 38/50 (2013.01); C22C 38/54 (2013.01); C21D 2211/003 (2013.01); C21D 2211/005 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A hot-formed product, comprising:
a base steel;
a first oxide layer comprising Si on the base steel; and
a second oxide layer comprising Fe on the first oxide layer;
wherein a first thickness of the first oxide layer is smaller than a first thickness of the second oxide layer.