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 alpha' 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. (C) 2009 Elsevier B.V. All rights reserved.