Stainless steel for fuel cell separator with excellent surface hydrophilicity and electrical conductivity, and manufacturing method thereof

Abstract

Disclosed is a stainless steel for a fuel cell separator having excellent surface hydrophilicity and electrical conductivity. According to an embodiment of a stainless steel for a fuel cell separator having excellent surface hydrophilicity and electrical conductivity, the surface oxide element ratio (1) value below may be 0.2 or more and the contact angle may be 80° or less as measured for the surface of a stainless steel containing 15 wt % or more of Cr by X-ray angle-resolved photoemission spectroscopy using an Al-Kα X-ray source under the condition where a take-off angle of photoelectrons is from 120 to 85°. S ⁢ um ⁢ of ⁢ atomic ⁢ concentrations ⁢ ( at ⁢ % ) of ⁢ Cr ⁢ in ⁢ Cr ⁢ oxides ⁢ and ⁢ Cr ⁢ hydroxides Sum ⁢ of ⁢ atomic ⁢ concentrations ⁢ ( at ⁢ % ) ⁢ of metal ⁢ elements ⁢ in ⁢ entire ⁢ oxides ⁢ and ⁢ hydroxides ( 1 ) The Cr oxide represents Cr3O4, Cr2O3, CrO2, or CrO3, and the Cr hydroxide represents CrOOH, Cr(OH)2, or Cr(OH)3. The entire oxides and hydroxides include the Cr oxide, the Cr hydroxide, an Fe oxide, an Fe hydroxide, and a metal oxide (MO), wherein the metal oxide (MO) includes a mixed oxide, M represents an alloying element contained in a matrix other than Cr and Fe, or a combination thereof, and O represents oxygen.

Dependencies are inferred from the claim text.