US 12,187,009 B2
Surface-treated steel sheet
Kosuke Kawamoto, Tokyo (JP); and Yasuto Goto, Tokyo (JP)
Assigned to NIPPON STEEL CORPORATION, Tokyo (JP)
Appl. No. 18/035,988
Filed by NIPPON STEEL CORPORATION, Tokyo (JP)
PCT Filed Nov. 29, 2021, PCT No. PCT/JP2021/043527
§ 371(c)(1), (2) Date May 9, 2023,
PCT Pub. No. WO2022/118769, PCT Pub. Date Jun. 9, 2022.
Claims priority of application No. 2020-200745 (JP), filed on Dec. 3, 2020.
Prior Publication US 2023/0415453 A1, Dec. 28, 2023
Int. Cl. B32B 15/01 (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); C23C 18/32 (2006.01); C25D 3/12 (2006.01)
CPC B32B 15/015 (2013.01) [C21D 1/74 (2013.01); C21D 6/005 (2013.01); C21D 6/008 (2013.01); C21D 8/0205 (2013.01); C21D 8/0226 (2013.01); C21D 8/0247 (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); C23C 18/32 (2013.01); C25D 3/12 (2013.01)] 6 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
in a case where, in a cross section obtained by cutting the alloy layer in a thickness direction, a range having a width of 2000 nm and extending from a surface of the alloy layer to a depth of 100 nm is partitioned into regions each having a width of 100 nm and a depth of 100 nm, within the range the alloy layer includes:
a plurality of high Co concentration regions in each of which a ratio of a Co concentration to a sum of the Co concentration and a Ni concentration within the partitioned region based on the measurement results obtained by aberration correction function-equipped transmission electron microscope with energy dispersive X-ray spectroscopy is 0.8 or more, and
a plurality of alloyed regions in each of which a ratio of the Co concentration to a sum of the Co concentration and the Ni concentration within the partitioned region based on the measurement results obtained by aberration correction function-equipped transmission electron microscope with energy dispersive X-ray spectroscopy is less than 0.8, the plurality of alloyed regions being arranged alternately with the high Co concentration regions.