Early corrosion behaviour of irradiated FeCrAl alloy in a simulated pressurized water reactor environment

[Display omitted] •Early corrosion behavior promoted by ion irradiation in FeCrAl alloys was studied.•Morphology and phases, cross-sectional microstructure and weight gain were analyzed.•Fe+ irradiation resulted in the formation of thin Cr-rich oxide layer.•Irradiated alloy showed a low corrosion rate at the initial corrosion stage.•Irradiation and corrosion induced a duplex-layer oxide structure. The early corrosion behaviour of an irradiated FeCrAl alloy in a simulated pressurized water reactor environment was investigated. The irradiated alloy showed a Cr-rich oxide layer, which was not observed in the as-received alloy. The corrosion induced the formation of a duplex-layer oxide structure consisting of an outer hematite α-Fe2O3 layer and an inner spinel Cr-rich oxide layer. In the initial corrosion stage, the smooth surface formed by ion sputtering and the formation of the Cr-rich oxide layer suppressed the corrosion. However, in the later corrosion stage, the irradiated alloys exhibited severe corrosion because of the presence of irradiation-induced defects.