The effect of aluminium addition on the high-temperature oxidation behaviour and Cr evaporation of aluminised and alumina-forming alloys for SOFC cathode air pre-heaters

•The oxidation behaviour and Cr evaporation of SS309, aluminised SS309 and AluChrom 318 were studied in air-3% H2O at 850 °C.•Surface aluminising provides the possibility to decrease chromium evaporation from chromia-forming alloys.•Scale spallation found on aluminised SS309 during high temperature exposure.•The AluChrom 318 showed the best Cr retention capability and oxidation resistance among the tested alloys. The corrosion behaviour and Cr retention ability of SS309, aluminised SS309, and AluChrom 318 have been investigated at 850 °C in air with 3 % H2O. The SS309 samples failed the specifications for application as cathode air preheater (CAPH) material due to a high Cr evaporation rate and massive scale spallation. The surface aluminisation dramatically decreased the Cr evaporation rate of SS309, but not in the long-term due to breakaway oxidation induced alumina scale spallation. The AluChrom 318 formed a γ-Al2O3/α-Al2O3 layer scale and demonstrated the highest Cr retention ability and oxidation resistance among the tested alloy samples.