US 12,129,568 B2
Surface-treated steel sheet
Yasuto Goto, Tokyo (JP); Kosuke Kawamoto, Tokyo (JP); Yuta Dairokuno, Tokyo (JP); Yuji Kajii, Tokyo (JP); and Koki Shimada, Tokyo (JP)
Assigned to NIPPON STEEL CORPORATION, Tokyo (JP)
Appl. No. 18/035,745
Filed by NIPPON STEEL CORPORATION, Tokyo (JP)
PCT Filed Nov. 29, 2021, PCT No. PCT/JP2021/043526
§ 371(c)(1), (2) Date May 7, 2023,
PCT Pub. No. WO2022/118768, PCT Pub. Date Jun. 9, 2022.
Claims priority of application No. 2020-200744 (JP), filed on Dec. 3, 2020.
Prior Publication US 2023/0407510 A1, Dec. 21, 2023
Int. Cl. C25D 5/50 (2006.01); C21D 1/74 (2006.01); C21D 6/00 (2006.01); C21D 8/02 (2006.01); C21D 9/46 (2006.01); C22C 38/00 (2006.01); C22C 38/02 (2006.01); C22C 38/04 (2006.01); C22C 38/06 (2006.01); C25D 3/12 (2006.01); C25D 3/56 (2006.01); C25D 5/12 (2006.01)
CPC C25D 5/50 (2013.01) [C21D 1/74 (2013.01); C21D 6/005 (2013.01); C21D 6/008 (2013.01); C21D 8/0205 (2013.01); C21D 8/0221 (2013.01); C21D 8/0278 (2013.01); C21D 9/46 (2013.01); C22C 38/001 (2013.01); C22C 38/002 (2013.01); C22C 38/004 (2013.01); C22C 38/02 (2013.01); C22C 38/04 (2013.01); C22C 38/06 (2013.01); C25D 3/12 (2013.01); C25D 3/562 (2013.01); C25D 5/12 (2013.01); C21D 2251/02 (2013.01)] 6 Claims
OG exemplary drawing
 
1. A surface-treated steel sheet, comprising:
a steel sheet, and
an Ni—Co —Fe alloy layer containing Ni, Co, and Fe on the steel sheet surface,
wherein:
in a thickness direction of the Ni—Co —Fe alloy layer, a Co concentration in percent by mass in the Ni—Co —Fe alloy layer is highest at a position which is on an outermost surface side of the Ni—Co —Fe alloy layer relative to a position where an Ni concentration in percent by mass in the Ni—Co —Fe alloy layer is highest, and the Co concentration in percent by mass is highest between the outermost surface of the Ni—Co —Fe alloy layer and a depth of 100 nm from the outermost surface; and
the Ni—Co —Fe alloy layer includes:
an Ni-concentrated region in which the Ni concentration in percent by mass increases toward the outermost surface of the Ni—Co —Fe alloy layer between the outermost surface of the Ni—Co —Fe alloy layer and a position where the Co concentration is highest.