Studies on oxidation and deuterium permeation behavior of a low temperature α-Al2O3-forming FeCrAl ferritic steel

To evaluate the capability of FeCrAl ferritic steels as tritium permeation barrier in fusion systems, the oxidation behavior together with the permeation behavior of a FeCrAl steel was investigated. Gas driven permeation experiments were performed. The permeability of the oxidized FeCrAl steel was obtained and a reduced activation ferritic/martensitic steel CLF-1 was used as a comparison. In order to characterize the oxide layer, SEM, XPS, TEM, HRTEM were used. Al2O3 was detected in the oxide film by XPS, and HRTEM showed that Al2O3 in the α phase was found. The formation of α-Al2O3 layer at a relatively low temperature may result from the formation of Cr2O3 nuclei.