Tensile properties of EUROFER97-3 after neutron irradiation at 330 °C and 540 °C to damage doses of 19–23 dpa

• For the first time, the tensile properties of EUROFER97-3 steel were investigated after neutron irradiation at high temperature of 540 °C up to damage dose of 20 dpa. • Irradiation at 540 °C causes only minor changes in tensile properties yield strength, ultimate tensile strength, and both uniform and total elongation compared with unirradiated reference data. • Irradiation at 330 °C up to 20 dpa produces strong radiation hardening and embrittlement when uniform elongation is less than 1 %. These results confirm that radiation hardening saturates in dose range of 20–70 dpa.. The reduced activation ferritic-martensitic (RAFM) EUROFER97-3 steel of two heat treatments (EUROFER97-3_1100/700 and EUROFER97-3_980/780) after irradiation in the BOR-60 fast reactor at temperatures of 330 °C and 540 °C, with damage doses ranging from 19.2 to 23.3 dpa exhibited fundamentally different changes in tensile properties depending on the irradiation temperature, regardless of the heat treatment used. Significant radiation hardening and embrittlement were observed after irradiation at 330 °C. In contrast, irradiation at 540 °C resulted in only minor alterations to the tensile properties compared to the unirradiated reference state. These changes can be attributed to the formation of radiation-induced defects and fine precipitates, as well as an evolution in the original phase structure.