Ni-plated steel sheet, and method for producing Ni-plated steel sheet

1. A Ni-plated steel sheet, comprising:

a steel sheet;

a first Ni-plated layer which is formed at least on a one-sided surface of the steel sheet and contains Ni; and

a second Ni-plated layer which is formed on the first Ni-plated layer and contains Ni, wherein an average central-line roughness Ra at an interface between the first Ni-plated layer and the second Ni-plated layer is less than 0.1 μm,

an average central-line roughness Ra of a surface of the second Ni-plated layer is 0.1 μm to 100 μm, and

a coating amount of Ni in an entirety of the first Ni-plated layer and the second Ni-plated layer is 20 mg/m 2 to 2500 mg/m 2 per one-sided surface in terms of metal Ni.

2. The Ni-plated steel sheet according to claim 1 ,

wherein an amount of chlorine in the first Ni-plated layer is 0 ppm to 100 ppm.

3. The Ni-plated steel sheet according to claim 1 or 2 ,

wherein a coating amount of Ni in the first Ni-plated layer is 15 mg/m 2 to 2000 mg/m 2 per one-sided surface in terms of metal Ni, and

a coating amount of Ni in the second Ni-plated layer is 5 mg/m 2 to 500 mg/m 2 per one-sided surface in terms of metal Ni.

4. The Ni-plated steel sheet according to claim 1 or 2 , further comprising:

a chemical conversion treatment film layer, which contains at least one of a chromium oxide, a zirconium compound, a phosphate compound, a titanium oxide, an aluminum oxide, and a manganese oxide, on the second Ni-plated layer.

5. The Ni-plated steel sheet according to claim 1 or 2 ,

wherein the coating amount of Ni is 400 mg/m 2 to 1000 mg/m 2 per one-sided surface in terms of metal Ni.

6. The Ni-plated steel sheet according to claim 1 or 2 ,

wherein the coating amount of Ni in the first Ni-plated layer is 300 mg/m 2 to 800 mg/m 2 per one-sided surface in terms of metal Ni, and

the coating amount of Ni in the second Ni-plated layer is 100 mg/m 2 to 200 mg/m 2 per one-sided surface in terms of metal Ni.

7. The Ni-plated steel sheet according to claim 1 or 2 ,

wherein a surface of the second Ni-plated layer has unevenness in which an average height difference in a thickness direction of the steel sheet is 1 μm to 10 μm.

8. A method for producing the Ni-plated steel sheet according to claim 1 , comprising:

a first plating process of subjecting a steel sheet to an electrolysis treatment in a first Ni-plating bath containing 5 g/L to 60g/L of Ni ions, 20 g/L to 300 g/L of sulfate ions, 10 g/L to 60 g/L of borate ions, and less than 0.5 g/L of chloride ions to form a first Ni-plated layer on the steel sheet; and

a second plating process of subjecting the steel sheet, on which the first Ni-plated layer is formed, to an electrolysis treatment in a second Ni-plating bath containing 5 g/L to 60 g/L of Ni ions, 20 g/L to 300 g/L of sulfate ions, 10 g/L to 60 g/L of borate ions, and 10 g/L to 60 g/L of chloride ions to form a second Ni-plated layer on the first Ni-plated layer,

wherein a temperature of the first Ni-plating bath and a temperature of the second Ni-plating bath are equal to or higher than 10° C. and lower than 90° C., and

in the first plating process and the second plating process, the electrolysis treatment is performed at a current density of 1.0 A/dm 2 to 100 A/dm 2 for an electrolysis treatment time of 0.2 seconds to 150 seconds.

9. The method for producing the Ni-plated steel sheet according to claim 8 ,

wherein a rinsing process is not provided between the first plating process and the second plating process.