Effects of heavy-ion irradiation on solute segregation to dislocations in oxide-dispersion-strengthened Eurofer 97 steel

Interactions of solute atoms with dislocations are known to influence the mechanical properties of metals, and are an important aspect of irradiated materials. Here, atom-probe tomography is used to investigate the segregation of solutes to dislocations in the martensitic/ferritic oxide-dispersion-strengthened Eurofer steel. The material was irradiated with 0.5–2 MeV Fe2+ ions at 400 °C, and the distributions of solutes at dislocations were analysed in the ‘as-received’ condition, after annealing, and after ion implantation. While Mn is randomly distributed in the as-received material, significant segregation of Mn at dislocations and grain boundaries is observed after irradiation. The level of Mn segregation varies depending on the density of oxide particles surrounding the dislocations.