Use of a stainless steel sheet having Cu-enriched grains dispersed in its matrix and/or a Cu-condensed layer

摘要

The stainless steel sheet according to the present invention has a stainless steel substrate 1 which contains Cu at a ratio of 1.0 mass % or more and has Cu-enriched grains 2 precipitated at a ratio of 0.2 vol.%. The Cu-enriched grains 2 are exposed outside through pinholes 4 of a passive film 3 generated on the substrate 1. Cu is preferably condensed at a Cu/(Cr+Si) mass ratio of 0.1 or more or a Cu/(Si+Mn) mass ratio of 0.5 or more with respect to Cr, Si and Mn present in the passive film 3 or at an outermost layer of the substrate 1. Precipitation of Cu-enriched grains 2 and condensation of Cu effectively improve solderability and electric conductivity of the stainless steel sheet 1.