Modeling of irradiation hardening of polycrystalline materials

High energy particle irradiation of structural polycrystalline materials usually produces irradiation hardening and embrittlement. The development of predictive capability for the influence of irradiation on mechanical behavior is very important in materials design for next-generation reactors. A multiscale approach was implemented in this work to predict irradiation hardening of iron based structural materials. In the microscale, dislocation dynamics models were used to predict the critical resolved shear stress from the evolution of local dislocation and defects. In the macroscale, a viscoplastic self-consistent model was applied to predict the irradiation hardening in samples with changes in texture. The effects of defect density and texture were investigated. Simulated evolution of yield strength with irradiation agrees well with the experimental data of irradiation strengthening of stainless steel 304L, 316L and T91. This multiscale modeling can provide a guidance tool in performance evaluation of structural materials for next-generation nuclear reactors.

Predicted increase of yield strength with defect density from irradiation by bridging dislocation dynamics model and crystal viscoplasticity model, validated by experimental results of irradiation hardening in stainless steels.Figure optionsDownload as PowerPoint slideHighlights
► Prediction of irradiation hardening by multiscale modeling.
► Bridging dislocation dynamics model and viscoplasticity self-consistent model.
► Simulation results on irradiation hardening agree well with experimental data.