Interatomic potential for studying ageing under irradiation in stainless steels: the FeNiCr model alloy

Abstract

The degradation of austenitic stainless steels in a radiation environment is a\nknown problem for the in-core components of nuclear lightwater reactors. For a\nbetter understanding of the prevailing mechanisms responsible for the materials’ degradation, large-scale atomistic simulations are desirable. In this framework and as a follow-up on Bonny et al (2011 Modelling Simul. Mater. Sci.\nEng. 19 085008), we developed an embedded atom method type interatomic\npotential for the ternary FeNiCr system to model the production and evolution\nof radiation defects. Special attention has been drawn to the Fe10Ni20Cr alloy,\nwhose properties were ensured to be close to those of 316L austenitic stainless\nsteels. The potential is extensively benchmarked against density functional\ntheory calculations and the potential developed in our earlier work. As a\nfirst validation, the potential is used in AKMC simulations to simulate thermal\nannealing experiments in order to determine the self-diffusion coefficients of the\ncomponents in FeNiCr alloys around the Fe10Ni20Cr composition. The results\nfrom these simulations are consistent with experiments, i.e.,DCr > DNi > DFe.