Impact of neutron irradiation on the tensile properties of advanced EUROFER97-type steels

Abstract

Tensile properties (strength and ductility) of three different experimental EUROFER97 variants and two standard EUROFER97 products were investigated before and after neutron irradiation performed in the temperature range 275–300 °C up to ∼3 dpa, i.e a damage dose comparable to the end-of-life of ITER operation. The grades with the chemical compositions within and outside the specifications of EUROFER97 steel followed alternative thermo-mechanical treatments (TMT) as compared to the reference EUROFER97. Mechanical properties were assessed with hardness and tensile tests, while fracture surface was investigated by scanning electron microscopy. Post irradiation examination was conducted to evaluate the hardening behavior, change in ductility and fracture surface after irradiation. Furthermore, Ductile-to-Brittle Transition Temperature (DBTT) shift due to neutron irradiation was estimated based on the correlation formerly established for EUROFER97 at the studied irradiation temperature.