Diffusion of 3D-migrating self-interstitial clusters in diluted and concentrated Fe–Cr alloys

We show, using atomic-level simulations, that the mobility of small 3D-migrating self-interstitial atom (SIA) clusters produced in displacement cascades is significantly reduced in concentrated Fe–Cr alloys (up to 15%Cr) as compared to Fe. The presence of α’ precipitates, on the other hand, is only expected to provide scattering centers for interstitial-type defects, whose formation inside the precipitates is energetically unfavorable. The significant reduction in the mobility of 3D-migrating SIA clusters is expected to have an important impact on the microstructure evolution of high-Cr steels, depending on Cr concentration.