US 12,252,802 B2
Surface-treated steel sheet
Kosuke Kawamoto, Tokyo (JP); Yasuto Goto, Tokyo (JP); Yuta Dairokuno, Tokyo (JP); and Koki Shimada, Tokyo (JP)
Assigned to NIPPON STEEL CORPORATION, Tokyo (JP)
Appl. No. 18/036,877
Filed by NIPPON STEEL CORPORATION, Tokyo (JP)
PCT Filed Nov. 29, 2021, PCT No. PCT/JP2021/043528
§ 371(c)(1), (2) Date May 13, 2023,
PCT Pub. No. WO2022/118770, PCT Pub. Date Jun. 9, 2022.
Claims priority of application No. 2020-200746 (JP), filed on Dec. 3, 2020.
Prior Publication US 2023/0407509 A1, Dec. 21, 2023
Int. Cl. C25D 5/12 (2006.01); C21D 9/46 (2006.01); C25D 3/12 (2006.01); C25D 5/36 (2006.01); C25D 5/50 (2006.01)
CPC C25D 5/12 (2013.01) [C21D 9/46 (2013.01); C25D 3/12 (2013.01); C25D 5/36 (2013.01); C25D 5/50 (2013.01); Y10T 428/12472 (2015.01); Y10T 428/12993 (2015.01)] 3 Claims
OG exemplary drawing
 
1. A surface-treated steel sheet, comprising:
a steel sheet, and
an alloy layer containing Ni and Co on a surface of the steel sheet,
wherein:
a surface roughness Ra1 of a surface of the alloy layer over a sampling length of 5.0 mm in a width direction of the steel sheet is 2.0 μm or less, the surface roughness Ra1 being as defined by JIS B0601 (2013) and measured using a stylus-type surface roughness meter; and
Ra2 that denotes an arithmetic mean height of a roughness curve of the surface of the alloy layer over a sampling length of 10 μm in the width direction of the steel sheet is 20 nm or less, and RSm that denotes a mean length of roughness curve elements of the surface of the alloy layer over a sampling length of 10 μm in the width direction of the steel sheet is 700 nm or more, Ra2 and RSm being measured using an atomic force microscope.