An object kinetic Monte Carlo model for the microstructure evolution of neutron-irradiated reactor pressure vessel steels

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Authors

Institutes & Expert groups

  • KTH - Royal Institute of Technology
  • Université de Lille - Unite Materiaux et Transformations (UMET) - France

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DOI

Abstract

This work presents a full object kinetic Monte Carlo framework for the simulation of the microstructure evolution of reactor pressure vessel (RPV) steels. The model pursues a “gray-alloy” approach, where the effect of solute atoms is seen exclusively as a reduction of the mobility of defect clusters. The same set of parameters yields a satisfactory evolution for two different types of alloys, in very different irradiation conditions: an Fe–C–MnNi model alloy (high flux) and a high-Mn, high-Ni RPV steel (low flux). A satisfactory match with the experimental characterizations is obtained only if assuming a substantial immobilization of vacancy clusters due to solute atoms, which is here verified by means of independent atomistic kinetic Monte Carlo simulations. The microstructure evolution of the two alloys is strongly affected by the dose rate; a predominance of single defects and small defect clusters is observed at low dose rates, whereas larger defect clusters appear at high dose rates. In both cases, the predicted density of interstitial loops matches the experimental solute-cluster density, suggesting that the MnNi-rich nanofeatures might form as a consequence of solute enrichment on immobilized small interstitial loops, which are invisible to the electron microscope.

Details

Original languageEnglish
Title of host publicationPHYSICA STATUS SOLIDI A-APPLICATIONS AND MATERIALS SCIENCE
Subtitle of host publicationConference on Advances in Materials and Processing Technologies (AMPT)
Pages2974-2980
Number of pages7
Volume213
Edition11
DOIs
Publication statusPublished - 13 Sep 2016

Publication series

NamePhysica Status Solidi (A)
PublisherWiley - John Wiley & Sons, Ltd
ISSN (Print)1862-6319

Keywords

  • crystal defects impurities, ferritic alloys, kinetic Monte Carlo simulations, neutron irradiation

ID: 6770949