Effect of Dynamic Strain Ageing on Environmental Degradation of Fracture Resistance of Low-Alloy RPV Steels in High-Temperature Water Environments

•Elastic plastic fracture mechanics tests on RPV steels with high DSA susceptibility revealed a clear, but moderate reduction of the fracture initiation resistance in high-temperature water.•The reduction of fracture initiation increased with decreasing loading rate in the DSA temperature-strain rate range and was most pronounced in hydrogenated high-temperature water and at 288 °C.•The stronger reduction of fracture resistance in hydrogenated high-temperature water was mainly due to the localization of plastic deformation by interaction between DSA and hydrogen.