The dominant mechanisms for the formation of solute-rich clusters in low-Cu steels under irradiation

Research output: Contribution to journalArticlepeer-review


Institutes & Expert groups

  • CIEMAT - Centro de Investigaciones Energéticas, Medioambientales y Tecnológicas
  • HZDR - Helmholtz,Zentrum Dresden, Rossendorf
  • EDF - Electricité de France
  • CCFE - Culham Centre for Fusion Energy
  • University of Oxford
  • CEA Saclay - Commissariat à l'énergie atomique
  • KTH - Royal Institute of Technology
  • CNRS - Centre national de la recherche scientifique

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The formation of nano-sized, coherent, solute-rich clusters (NSRC) is known to be an important factor causing the degradation of the macroscopic properties of steels under irradiation. The mechanisms driving their formation are still debated. This work focuses on low-Cu reactor pressure vessel (RPV) steels, where solute species are generally not expected to precipitate. We rationalize the processes that take place at the nanometre scale under irradiation, relying on the latest theoretical and experimental evidence on atomic-level diffusion and transport processes. These are compiled in a new model, based on the object kinetic Monte Carlo (OKMC) technique. We evaluate the relevance of the underlying physical assumptions by applying the model to a large variety of irradiation experiments. Our model predictions are compared with new experimental data obtained with atom probe tomography and small angle neutron scattering, complemented with information from the literature. The results of this study reveal that the role of immobilized self-interstitial atoms (SIA) loops dominates the nucleation process of NSRC.


Original languageEnglish
Article number100472
JournalMaterials Today Energy
Publication statusPublished - 3 Jul 2020


  • Solutes precipitation, Kinetic Monte Carlo, Atom probe tomography, Hardening and embrittlement, Reactor pressure vessel steel

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