Microstructural evolution in proton irradiated NF616 at 773 K to 3 dpa

Ferritic-martensitic (FM) steels have been widely considered as structural materials for future fusion and fission systems due to their excellent swelling resistance and other properties under irradiation. NF616 is a newer generation FM steel that provides higher allowable operating temperatures, but there is limited information on the development of irradiated microstructures or associated mechanical properties in NF616. Studying the irradiation-induced defects as a function of dose could help to better understand the mechanisms of damage evolution. Proton irradiation at 773 K, up to 1, 2 and 3 dpa, was performed on NF616 to investigate damage evolution at different doses. Irradiation-induced defects, such as clusters, loops and dislocations, were investigated.