Study of radiation effects in FeCr alloys for fusion applications using computer simulation

It has been shown that the primary damage state is not affected by the presence of Cr. While the effective migration energy and the diffusion coefficient of the interstitial defects are essentially lower in Fe-Cr alloys than in pure Fe. With the increase of the Cr concentration, the diffusivity of 1D migrating interstitial clusters drops, reaches a minimum and then rises again. An explanation for the origin of the experimental measured swelling vs Cr concentration is proposed, relying on the non-monotonic dependence of interstitial cluster mobility on Cr content and the interaction between Cr-rich precipitates and interstitial clusters. The defect annealing stages in Fe and Fe Cr have been estimated by applying rate equation (RE) methods, using the molecular dynamics results for the parameterization of RE. The calculation of the defect recovery in Fe-Cr alloys has shown that reasonable agreement for stage I, II and III is obtained, assuming the presence of traps for interstitial defects. The concentration of traps and their trapping energies depend on the Cr content in the alloy.