Influence of injected interstitials on α′ precipitation in Fe–Cr alloys under self-ion irradiation

ABSTRACTDepending on the particle used to irradiate Fe–Cr alloys, at the same dose and temperature, α′ precipitation may occur or not. This paper aims at explaining the origin of the absence of α′ precipitation under ion irradiation. A Fe–15at.%Cr alloy was irradiated with 2 MeV Fe2+ ions at 300°C and analysed using atom probe tomography. For the first time to our knowledge, α′ particles were observed under ion irradiation. The characterisation of the α/α′ decomposition with depth showed that injected Fe strongly reduced α′ precipitation. They might have played a major role in the absence of α′ precipitation under ion irradiation.