Multiscale modeling of crystal plasticity in Reactor Pressure Vesselsteels: Prediction of irradiation hardening

The plastic behavior of irradiated Reactor Pressure Vessel (RPV) steels is described by constitutiveequations capturing the temperature and strain rate sensitivities. Theflow stress is decomposed into itsfundamental components associated with the microstructure features peculiar to RPV steels, such ascarbides, dislocation network and deformation confinement inside grains. Dislocations are assumed tomove on the {110} and {112} crystallographic planes and a simplified interaction matrix is proposed. Thepredicted yield stress is obtained without adjustable parameters and found in close agreement with alarge number of experimental results over a large temperature range. Finally, the contribution of radi-ation defects is accounted for using atomistic and dislocation dynamics results. The effect of solutecluster is analyzed in details in terms of the cluster size and density and strength. Results are discussedand compared with an experimental database on neutron-irradiated RPV steels.