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

摘要

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