| abstract |
A surface-treated steel sheet according to an aspect of the present invention includes: a steel sheet as a base metal and a coating layer, in which the coating layer includes a Ni-Co alloy coating layer, a Ni-Fe alloy layer, and a Ni layer, in the coating layer, a total adhesion amount of Co is 0.2 g/m 2 to 2.3 g/m 2 , and a total adhesion amount of Ni is 8.9 g/m 2 or more, the Ni layer has a thickness of 0.3 µm to 3.0 µm, an atomic concentration of Co on a surface of the Ni-Co alloy coating layer is 20 at% to 70 at%, and a Co concentration gradient y in the coating layer in a depth direction is 50 mass%/µm to 400 mass%/µm. |