| 摘要 |
An object is to provide ferritic stainless steel excellent in corrosion resistance and conductivity that can be ideally used for a separator of a proton-exchange membrane fuel cell, which has low contact resistance and is possible to ensure corrosion resistance in a potential range in which Cr exhibits transpassive dissolution. Specifically, a ferritic stainless steel excellent in corrosion resistance and conductivity and a method for manufacturing the same, the stainless steel having a chemical composition containing, by mass%, C: 0.001% or more and 0.05% or less, Si: 0.001% or more and 0.5% or less, Mn: 0.001% or more and 1.0% or less, Al: 0.001% or more and 0.5% or less, N: 0.001% or more and 0.05% or less, Cr; 17% or more and 23% or less, Mo: 0.1% or less and the balance being Fe and inevitable impurities and a passivation film on the surface of the stainless steel which is obtained by immersing the stainless steel in a solution for an immersion treatment, said solution mainly contains hydrofluoric acid or a liquid mixture of hydrofluoric acid and nitric acid, and in said solution the relationship [HF]‰¥[HNO 3 ] is satisfied, where [HF] denotes the concentration of hydrofluoric acid (mass%) and [HNO 3 ] denotes the concentration of nitric acid (mass%). |
