Corrosion behavior of a dual-phase FeNiCrCuAl high entropy alloy in supercritical water

High-entropy alloys (HEAs) possess excellent irradiation resistance, however, their corrosion behavior in high temperature water requires further study. The corrosion behavior of a dual-phase FeNiCrCuAl HEA in supercritical water was investigated in this study. The oxidation kinetics follows a parabolic law. An outer FeAl2O4 layer and inner FeCr2O4 layer formed on the FeCr-rich BCC regions after 100 h of exposure. With an increase in the exposure period, the outer and inner layers gradually transformed into γ-Al2O3 and CrAl2O4, respectively. An outer γ-Al2O3 layer and inner NiAl2O4 layer formed on the NiAl-rich BCC regions regardless of the exposure period. Irregular Cu2O particles were deposited on the samples owing to the localized corrosion of the Cu-rich FCC regions.