A comparison between different oxide dispersion strengthened ferritic steel ongoing in situ oxide dissolution in High Voltage Electron Microscope

ODS materials are considered for nuclear applications but previous experimental studies have shown a partial dissolution of some oxides under neutron irradiation.In this work, electron irradiations were used to evaluate the stability of the oxides depending on the chemical composition of the oxide dispersion. Four ferritic steels based on EM10 (Fe–9Cr–1Mo) and reinforced respectively by Al2O3, MgO, MgAl2O4 and Y2O3, were studied. These materials were irradiated with 1 MeV or 1.2 MeV electrons in a High Voltage Electron Microscope. This technique allows to follow one single oxide and to determine the evolution of its size during the irradiation. In situ HVEM observations indicate that the dissolution rate depends on the chemical composition of the oxide, on the temperature and on the irradiation dose.