The study of Oxidation Behavior of AISI 439 Steel at the Presence of Manganese Oxides for the Application in Solid Oxide Fuel Cells

Long–term stability and oxidation resistance of AISI 439 ferritic stainless steel used as interconnects in solid oxide fuel cells can be improved by use of a protective coating. In this study the pack cementation method was employed to coat AISI 439 ferritic stainless steel with manganese. Isothermal oxidation was conducted at 800 ºC for 200 hours in static air to investigate the role of coating against oxidation. Cyclic oxidation was also performed for up to 100 cycles at the oxidation temperature of 800 °C. Formation of manganese oxides (MnFe2O4, Mn3O4 and Mn2O3) during oxidation tests improved oxidation resistance. The coated samples demonstrated lower mass gain in each test, indicating the coating layer could have act as a mass barrier against the outward diffusion of cations specially Cr.