Multiscale Modeling of Radiation Hardening in RPV and Austenitic Stainless Steels: from the Atomic to the Continuum Scale

Abstract

Given the nanometric size of radiation defects, Radiation Induced Hardening (RIH) is a textbook case of multiscale physical phenomena. On the one hand, pure atomic features that cannot be described by elasticity contribute strongly to the dislocation interaction. Individual interactions – depending on temperature, dislocation velocity, defect nature and size – can be characterized only when these feature are fully identified and quantified. On the other hand, RIH is usually observed at the macroscopic scale, where its technological impact is the deepest. Physically based modeling of RIH must thus integrate materials properties from the atomic level. Since explicit and direct integration is not possible, investigations at intermediate scales associated with appropriate transition methods are thus necessary. Pertinent links are known to be the intragranular and the crystalline aggregate scales. The first one provides constitutive equations controlling plastic flow, including RIH, and the second one delivers the homogenized mechanical behavior.