HT corrosion of a Cr-5 wt % Fe-1 wt % Y2O3 alloy and conductivity of the oxide scale -: Effects of water vapor

Corrosion rates of Cr-5 wt % Fe-1 wt % Y2O3 (Plansee Ducrolloy alloy, PD) were measured by thermogravimetry in air or argon with different water vapor partial pressures at 800, 900, and 950 degreesC. The rates of oxidation and evaporation increased with increasing oxygen and water vapor pressures. A reduction of both rates was achieved by Ce-treatment of the alloy surface. The conductivity measured in the oxide scale after the oxidation increased with increasing water vapor pressure and decreasing temperature used in the oxidation. The oxide scale on the Ce-treated samples had a lower conductivity than similarly grown scales on untreated samples. It is suggested that preoxidation in wet inert gas can help develop adherent, protective, and well-conducting scales on PD interconnect components prior to assembly in fuel cells. (C) 2003 The Electrochemical Society.