Effect of Cr content on the nanostructural evolution of irradiated ferritic/martensitic alloys: An object kinetic Monte Carlo model

摘要: Abstract Self-interstitial cluster diffusivity in Fe–Cr alloys, model materials for high-Cr ferritic/martensitic steels, is known to be reduced a non-monotonic way as function of Cr concentration: it first decreases, then increases. This behaviour caused by relatively long-ranged attractive interaction between atoms and crowdions correlates well with the experimentally observed swelling these alloys under neutron irradiation, also seen decrease increase increasing content, comparable irradiation conditions. Moreover, recent studies reveal that C dispersed Fe matrix form complexes vacancies which, turn, act trap one-dimensionally migrating self-interstitial clusters. The mobility one-dimensional clusters considered key determine susceptibility. However, no has ever been built quantitatively describes dependence on allowing presence matrix. In this work we developed physically-based sets parameters object kinetic Monte Carlo (OKMC) simulations intended study nanostructure evolution Fe–Cr–C alloys. nanostructural Fe–C four (containing 2.5, 5, 9 12 wt.% Cr) irradiated up ∼0.6 dpa at 563 K was simulated according reference experiments were reproduced. Our shows SIA major influence evolution: increases number vacancy-SIA recombinations thus leads suppression voids formation. provides clear framework interpret versus content. suggests amount an equally important role: high amounts may counteract beneficial effect reducing swelling.