Depth-dependent nanoindentation hardness of reduced-activation ferritic steels after MeV Fe-ion irradiation

Abstract

The irradiation hardening behavior of F82H reduced-activation ferritic steels after MeV Fe-ion beam irradiation experiments was investigated with a nanoindentation test. Two sets of ion-irradiation experiments were conducted at 270°C with 10.5MeV Fe3+ ions up to 5dpa at a 1000nm depth at TIARA facility and at 290°C with 6.4MeV Fe3+ ions up to 3dpa at a 600nm depth at DuET facility, respectively. The measured nanoindentation hardness was converted to the depth-dependent bulk-equivalent hardness based on a combination of the Nix–Gao model to explain the indentation size effect and the film/substrate model to explain the damage gradient effect in the ion-irradiated region and softer substrate effect of the non-irradiated region beyond the irradiated depth range.