Oxidation Kinetics Of Manganese Cobaltite Spinel Protection Layers On Sanergy Ht For Solid Oxide Fuel Cell Interconnect Applications

Chromia forming ferritic stainless steels (SS) exhibit many desirable qualities for intermediate temperature solid oxide fuel cell interconnect applications. However, with these alloys, there is a need to prevent chromia volatilization and the associated chromium poisoning at the cathode-electrolyte interface, while ensuring low interfacial electrical resistance with the cell electrodes; a need that has generated renewed interest in the development of oxidation resistant, electrically conductive coatings. In the present study, screen printed (Mn,Co)(3)O(4) coatings were applied to a newly developed ferritic SS alloy, Sanergy HT(Cr-21.9%, Ni-0.5%, Mo-0.88%, Nb-0.60%, and Si-0.05%). The oxidation behavior of both the coated alloy and the bare alloy were evaluated at 800 degrees C in air for exposures times up to 1500 h. The oxidation kinetics, investigated using weight gain and scale thickness measurements, exhibited parabolic behavior for the bare alloy. The oxidation behavior of the coated material could not be explained by a single parabolic mechanism. The calculated parabolic thickening rate constants were compared with published data on other ferritic SS alloy compositions.