A study of the oxidation behaviour of FeCrAl-ODS in air and steam environments up to 1400 °C

As a candidate accident tolerant fuel cladding material, the high temperature oxidation behaviour of an Oxygen Dispersion Strengthened (ODS) Fe–12Cr–6Al alloy has been examined in isothermal air and steam environments. While the oxidation behaviour of FeCrAl has been extensively studied, very little has been reported in the literature on FeCrAl-ODS, which is the focus of this manuscript. By conducting Thermogravimetric Analysis (TGA), oxidation experiments were performed on specimens of Fe–12Cr–6Al-ODS at temperatures up to 1400 °C in air and up to 1215 °C in high purity steam. Oxidation kinetics were evaluated by calculating reaction rate constants and activation energies. The formation of an alumina scale was correlated to kinetics results from TGA by coupling Scanning Electron Microscopy (SEM) with Energy Dispersive X-ray Spectroscopy (EDS) line scans to investigate the chemical composition of the primary oxide layer, local oxidation effects, as well as the bulk alloy material. Electron Probe Micro-Analysis (EPMA) point scans were applied to the heavily oxidized specimen to achieve an accurate composition profiling of areas of interest. Finally, thermodynamic calculations were performed to interpret the formation of the complex oxide layer. These experiments support research efforts for the development of accident tolerant fuel technologies at Nippon Nuclear Fuel Development Co., Ltd.