There are two types of radiation-induced phase instabilities that AISI 304 is prone to develop at temperatures in the 400–550°C range at dpa rates typical of fast reactors, and there is some concern that these instabilities may shift to lower temperatures (≥400°C) at lower dpa rates typical of pressurized water reactors.

One of these instabilities, the void-induced γ→α transformation, is investigated in this study at dpa rates typical of both types of reactors. The mode of nickel segregation shifts somewhat at PWR-relevant conditions, but the γ→α transformation has not yet been observed in the range 380–400°C for swelling levels less than 2%.