Heat resistant steel
AssigneeCeramic Fuel Cells Limited
InventorDonald Jaffrey
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Abstract
A steel composition particularly useful for components of solid oxide fuel cells, for example a connector plate for collecting electrical current from a solid oxide fuel cell, consisting of, in weight percent, 18-28.5 Cr, 0.001-0.20 C, <0.1 Si, 0.005-0.10 Mn, <1.0 Ni, <0.25 N, <0.05 S, <0.08 P, <0.06 Al, <0.25 Additional Defined Metals, and 0.005-0.50 REM, wit the residue iron, excluding incidental impurities, where Additional Defined Metals is the sum of titanium, niobium, vanadium, molybdenum and copper, and REM is one or more of the rare earth metal elements in the group of the lanthanide elements 57 to 71, scandium and yttrium.
Claims7
A steel composition consisting of, in weight percent,
- Chromium 20-27.5 Carbon 0.001-0.20 Silicon <0.1 Manganese 0.005-0.10 Nickel <1.0 Nitrogen <0.25 Sulphur <0.05 Phosphorus <0.08 Aluminium <0.06 Additional Defined Metals <0.25 (total amount) REM 0.005-0.50 (total amount)
- with the residue iron, excluding incidental impurities, where Additional Defined Metals is any titanium, niobium, vanadium, molybdenum and copper present in the steel composition, and REM is any rare earth metal element or elements in the group of the lanthanide elements 57 to 71, scandium and yttrium, said steel having a stable, adherent and very thin layer of chromium oxide which protects the underlying metal from further oxygen induced degradation and provides a superior level of electrical conductivity for use in components of solid oxide fuel cells.
Dependencies are inferred from the claim text.