Porous polycrystal plasticity modeling of neutron-irradiated austenitic stainless steels

•Stiffness and strength of neutron-irradiated austenitic steels are studied.•Simultaneous influence of irradiation hardening and swelling is studied.•The material is seen as polycrystal with voids due to large irradiation levels.•A micromechanical model is proposed for an elasto-viscoplastic description. v) A decrease of overall elastic properties and strength with porosity is reported.