The effect of pre-heat treatment of AluChrom 318 on the corrosion behaviour and Cr evaporation in SOFC Cathode Air Pre-heater

An extremely low Cr evaporation rate was confirmed for the alumina-forming alloy (AluChrom 318) used in an SOFC Cathode Air Pre-Heater application in our previous work. In the current study, a pre-heat treatment was applied on the AluChrom 318 in order to achieve the formation of a protective alumina scale prior to SOFC application, further decreasing the oxidation rate and Cr evaporation. To examine this further, the effect of pre-heat treatment on the AluChrom 318 was investigated with two variables, namely; temperature (800 to 1100 °C) and dwelling time (0.5 to 4 hours). The results in this study show that the AluChrom 318 pre-treated at 1100 °C for 1 hour will form an α-Al₂O₃ scale leading to a 98% reduction of oxidation rate and 90% reduction of Cr evaporation compared to the non-treated AluChrom 318 under simulated SOFC cathode conditions.