| 摘要 |
PROBLEM TO BE SOLVED: To obtain a stainless steel sheet improved in solderability by dispersing and precipitating a Cu-enriched phase and concentrating Cu in a passive layer or in the outermost surface layer. SOLUTION: Stainless steel containing, by mass, >=1.0% Cu, and in which a second phase essentially consisting of Cu is dispersedly precipitated into a matrix in the ratio of >=0.2 vol.% is used as a base material, and the second phase essentially consisting of Cu is exposed to the surface of the base material via a passive film. Stainless steel in which the second phase essentially consisting of Cu is not dispersedly precipitated can also be used, but, in this case, Cu/(Cr+Si), i.e., the concentration ratio between the concentration of Cu to the concentration of Cr and the concentration of Si in the passive film located on the surface of the base material or in the outermost surface layer is controlled to >=0.1. Its solderability moreover improves in the case the precipitation and dispersion of the second phase essentially consisting of Cu and the concentration of Cu into the passive film or the outermost surface layer are combined.
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