US 12,344,915 B2
Hot dip galvanized ultra-high strength steel sheets with high flatness
Zhou Wang, Shanghai (CN); Zhisong Chai, Liaoning (CN); Wei Xu, Shenyang (CN); and Jianfeng Wang, Shanghai (CN)
Assigned to GM GLOBAL TECHNOLOGY OPERATIONS LLC, Detroit, MI (US)
Filed by GM GLOBAL TECHNOLOGY OPERATIONS LLC, Detroit, MI (US)
Filed on Aug. 3, 2023, as Appl. No. 18/364,840.
Claims priority of application No. 202310037615.0 (CN), filed on Jan. 10, 2023.
Prior Publication US 2024/0229182 A1, Jul. 11, 2024
Int. Cl. C21D 9/46 (2006.01); B32B 15/01 (2006.01); C21D 1/74 (2006.01); C21D 1/84 (2006.01); C21D 6/00 (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 38/28 (2006.01); C22C 38/38 (2006.01); C22C 38/42 (2006.01); C22C 38/44 (2006.01); C22C 38/46 (2006.01); C22C 38/48 (2006.01); C22C 38/50 (2006.01); C22C 38/58 (2006.01); C23C 2/06 (2006.01); C23C 2/40 (2006.01)
CPC C21D 9/46 (2013.01) [B32B 15/013 (2013.01); C21D 1/74 (2013.01); C21D 1/84 (2013.01); C21D 6/002 (2013.01); C21D 6/004 (2013.01); C21D 6/005 (2013.01); C21D 6/008 (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 38/28 (2013.01); C22C 38/38 (2013.01); C22C 38/42 (2013.01); C22C 38/44 (2013.01); C22C 38/46 (2013.01); C22C 38/48 (2013.01); C22C 38/50 (2013.01); C22C 38/58 (2013.01); C23C 2/06 (2013.01); C23C 2/40 (2013.01); C21D 2211/001 (2013.01); C21D 2211/002 (2013.01); C21D 2211/005 (2013.01); C21D 2211/008 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A coated steel sheet comprising:
a steel sheet comprising iron (Fe), carbon (C) in a range from 0.05% to 0.35 wt. %, manganese (Mn) in a range from 0.1% to less than 2 wt. %, chromium (Cr) in a range from 1.2% to 6.0 wt. %, silicon (Si) in a range from 0.01% to less than 0.6 wt. %, aluminum (Al) in a range from 0.5% to 1.3 wt. %, vanadium (V) in a range from 0.01% to 0.5 wt. %, niobium (Nb) in a range from 0.01% to 0.2 wt. %, and titanium (Ti) in a range from 0.01% to 0.3 wt. %; and
a zinc coating formed on an outer surface of the steel sheet, and
wherein a microstructure of the steel sheet comprises martensite in a range from 70-99 vol. %, austenite in a range from 3-20 vol. %, bainite in a range from 0-20 vol. %, ferrite in a range from 0-10 vol. %, and Cr-enriched carbide in a range from 0.1% to 10 vol. %, and wherein the Cr-enriched carbide includes Cr in a range from 10% to 51 wt. % and carbon (C) in a range from 49 to 90 wt. %.