Void swelling behavior in electron irradiated Fe-Cr-Ni model alloys under temperature variation

We examined the effect of short HVEM pre-irradiation at lower or higher temperature on void swelling behavior in electron irradiated austenitic model alloys, Fe-15Cr-xNi (x = 15, 20, 25 or 30 wt%). By 6 dpa irradiation at constant temperature, voids were formed at 200-400 °C in 15, 20, and 25Ni alloys but did not form above 350 °C in the 30Ni alloy. In the temperature variation irradiation, an initial 0.6 dpa irradiation at 200-500 °C was followed by irradiation of 5.4 dpa at 400 °C. The effect of pre-irradiation at lower temperature was a slight increase in the void number density, and that at higher temperature was a suppression of void formation. SFT induced by irradiation at lower temperature were not effective void nuclei in the subsequent irradiation at higher temperature.