STAINLESS STEEL FOR FUEL CELL SEPARATOR AND FUEL CELL SEPARATOR

• Main Authors: TARUYA YOSHIO, ADACHI KAZUHIKO, IMAMURA JUNKO, HAMADA RYUJI, YAZAWA TAKEO
• Format: Patent
• Language: English
• Published: 18.02.2010
• Subjects: ALLOYS; BASIC ELECTRIC ELEMENTS; CHEMISTRY; ELECTRICITY; FERROUS OR NON-FERROUS ALLOYS; METALLURGY; PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSIONOF CHEMICAL INTO ELECTRICAL ENERGY; TREATMENT OF ALLOYS OR NON-FERROUS METALS

PROBLEM TO BE SOLVED: To provide a fuel cell separator which has a low contact electric resistance and ensures less energy loss, and to provide an austenitic stainless steel which has high strength and excellent formability and a method for manufacturing the same. SOLUTION: A surface part of the stainless steel has a chemical composition which consists of, by mass, ≤0.03% C, 0.01-1.5% Si, 0.01-2.5% Mn, ≤0.035% P, ≤0.01% S, 16.0-30.0% Cr, 12.0-50.0% Ni, 0.4-3.5% B, 0.001-0.2% Al, 0.01-0.1% N, ≤7.0% Mo, ≤5.0% Cu and the balance Fe with impurities and satisfies the expression: 17.0≤Cr+3Mo-2.5B, wherein borides are dispersed in the surface part. A central part in the thickness direction has a chemical composition in which 6.0-30.0% Ni, ≤0.01% B and 0.06-0.3% N are contained and other element has the same chemical composition as the surface part, and the central part has 0.2% proof stress YS of ≥300 N/mm2and a total elongation El of ≥40%. COPYRIGHT: (C)2010,JPO&INPIT