Ni DIFFUSION-PLATED STEEL SHEET AND METHOD FOR MANUFACTURING Ni DIFFUSION-PLATED STEEL SHEET

A Ni diffusion-plated steel sheet of the present invention includes a base steel sheet and a Fe—Ni diffusion alloy-plating layer positioned on at least one surface of the base steel sheet, an Ni coating weight of the Fe—Ni diffusion alloy-plating layer is 9.0 to 20 g/m, a Fe concentration Cs of an outermost layer of the Fe—Ni diffusion alloy-plating layer is 10 to 55 mass %, the base steel sheet has a predetermined chemical composition, and a ferrite grain size number specified by JIS G 0551 (2013) of the base steel sheet is 11.0 or more.