Method to produce stainless steel for fuel cell separators, stainless steel for fuel cell separators, fuel cell separator and fuel cell

摘要

A method of producing stainless steel for use in a fuel cell separator, wherein stainless steel containing 16% by mass or more of Cr is subjected to electrolytic treatment with at least one of an acid-containing solution including 0 , 5% by mass or more of sulfuric acid and / or a solution containing 5% by mass or more of sodium sulfate and then to immersion treatment in a solution containing fluorine, wherein the solution containing fluorine is hydrofluoric acid or a mixture of nitric acid and hydrofluoric acid having a concentration of hydrofluoric acid [HF] (% by mass) and a concentration of nitric acid [HNO3] (% by mass) that satisfy the relationship: [HF] = 0.8 x [HNO3].