Abstract: The present invention is a stainless steel material having antibacterial properties and antiviral properties, the stainless steel material containing a Cu-rich region 3 in which the concentration of Cu is higher than the average Cu concentration in a matrix along grain boundaries in a surface 1 of the stainless steel material and a surface layer 2 located immediately below the surface of the stainless steel material, wherein the Cu-rich region 3 has Cu grain boundary layers 6 that extend continuously at a depth of 10 ?m to 200 ?m from the surface 1 of the stainless steel material, the average number of the Cu grain boundary layers 6 is 2.0 or more per 100 ?m of a distance parallel to the surface of the stainless steel material in a cross section orthogonal to the surface of the stainless steel material.

Abstract: A stainless steel material has ?-Cu phases exposed on a surface of the stainless steel material. The ?-Cu phases on the surface have an area ratio of 0.1 to 4.0%, an average particle size of 10 to 300 nm, and a maximum interparticle distance of 100 to 1000 nm.

Abstract: A ferritic stainless steel suited for use as a member for heat exchangers to be brazed with Ni-based filler metal or Cu-based filler metal, comprising, on the basis of mass percent, C: 0.03% or less, Si: 3% or less, Mn: 2% or less, P: 0.05% or less, S: 0.03% or less, Cr: from 11 to 30%, Nb: from 0.15 to 0.8%, and N: 0.03% or less, wherein the balance is composed of Fe and incidental impurities, and wherein a value A determined by the following equation is 0.10 or greater: A=Nb?(C×92.9/12+N×92.9/14).

Abstract: A ferritic stainless steel suited for use as a member for heat exchangers to be brazed with Ni-based filler metal or Cu-based filler metal, comprising, on the basis of mass percent, C: 0.03% or less, Si: 3% or less, Mn: 2% or less, P: 0.05% or less, S: 0.03% or less, Cr: from 11 to 30%, Nb: from 0.15 to 0.8%, and N: 0.03% or less, wherein the balance is composed of Fe and incidental impurities, and wherein a value A determined by the following equation is 0.10 or greater: A=Nb?(C×92.9/12+N×92.9/14).