Degradation of Ferritic steel interconnects in SOEC environments

Paper in proceeding, 2013

This study investigates the corrosion performance of selected ferritic steels in simulated solid oxide electrolysis cell (SOEC) environments for exposure times up 500 h. Ferritic steels have many properties that are desirable for interconnects but suffer from oxidation and chromium evaporation over time. Four different FeCr alloys have been exposed in different concentrations of dry O2 (anode side) and in 34 % H2O -3 % H2-Ar (cathode side) at 850 °C and gravimetrical measurements have been performed to study oxidation rates. Chromium evaporation has been measured and compared for the oxygen containing environments. Chromium evaporation was found to vary largely with oxygen partial pressure, while the oxidation rate of the steels did not vary substantially in the different oxygen partial pressures. Differences in oxidation behavior of the steels were observed between the exposures in dry O2 and in 34 % H2O -3 % H2 -Ar. Both reduced and increased oxidation rates were observed in the cathode side atmosphere compared to the oxygen side atmosphere for different materials.