We exposed coated AISI 441 in a SOFC cathode side atmosphere.
•
The oxidation and chromium volatilization were monitored.
•
RE coated 441 showed improved corrosion resistance and no oxide scale spallation.
•
RE/Co-coated 441 showed superior corrosion behaviour and low chromium evaporation.
Abstract
Reactive Element (RE) and RE/cobalt-coated stainless steel AISI 441 was exposed at Solid Oxide Fuel Cell (SOFC) cathode conditions (850 °C in air with 3% water content) for up to 500 h. The chromium evaporation was measured by applying the denuder technique. Uncoated material exhibited severe spallation which could be successfully prevented by using cerium or lanthanum coatings. By applying double layer coatings of cerium or lanthanum in combination with cobalt the oxidation rate was decreased and the chromium volatilisation was also about 90% lower than the uncoated material.