Simulation of nanostructural evolution under irradiation in Fe-9%Cr –C alloys: An object kinetic Monte Carlo study of the effect of temperature and dose-rate

This work explores the effects of both temperature and dose-rate on the nanostructural evolution under irradiation of the Fe-9%Cr –C alloy, model material for high-Cr ferritic/martensitic steels. Starting from an object kinetic Monte Carlo model validated at 563 K, we investigate here the accumulation of radiation damage as a function of temperature and dose-rate, attempting to highlight its connection with low- temperature radiation-induced hardening. The results show that the defect cluster mobility becomes high enough to partially counteract the material hardening process only above ∼290 °C, while high fluxes are responsible for higher densities of defects, so that an increase of the hardening process with increasing dose-rates may be expected.