A Brief Review on He Ion Irradiation Research of Steel and Iron-Based Alloys in Nuclear Power Plants

Nuclear power plays a key role as renewable energy in alleviating the worldwide energy shortage. The material degradation caused by high-temperature and high-flux neutron irradiation is the most concerning issue for nuclear reactor safety. A large number of He atoms produced through the ( n , α ) transmutation reaction diffuse and migrate in metals and accumulate to form He bubbles because of the extremely low solubility of He atoms in metal materials. The helium bubbles gather at the grain boundary or grain to cause swelling, hardening, embrittlement, and other damages to the in-core structural components. This paper mainly summarizes the research progress on He irradiation in steel and iron-based alloys, including the diffusion and accumulation of He atoms, the nucleation and growth of He bubbles, and the microstructure and macroscopic degradation of material performance caused by He irradiation. The mechanism of helium irradiation-induced corrosion in steel and iron-based alloys in recent years is reviewed as well. Moreover, the investigations on irradiation performance in additive manufactured stainless steels are summarized, and the mechanism of irradiation resistance is prospected.