Characterization of dislocation loops and chromium-rich precipitates in ferritic iron–chromium alloys as means of void swelling suppression

We have used both ab initio and empirical potential based molecular dynamics and static calculations to parameterize a model accounting for the mobility of self-interstitial clusters and small dislocation loops in Fe-Cr alloys depending on Cr content. Particularly, we have considered the interval of 5-15% of Cr, corresponding to the typical concentration of Cr in ferritic/martensitic steels. The mobility of self-interstitial clusters and small dislocation loops was found to be strongly reduced in the presence of Cr due to attractive interaction between self-interstitials and Cr atoms, whereas Cr-rich precipitates act as repulsive obstacles. The results obtained allow the experimental trend of swelling measurements in neutron and high-energy electron irradiated Fe-Cr alloys to be interpreted and explained.