Austenitic stainless steel having superior resistance to irradiation-induced segregation

摘要

There is provided an austenitic stainless steel which is corrosion-resistant in an environment of neutron irradiation, and can suppress stress corrosion cracking and embrittlement. At least one kind of additive selected from Ti more than 0.2 % by weight up to 0.6 %, Zr more than 0.2 % up to 1.14%, Hf more than 0.2% up to 2.24 %, V more than 0.2 % up to 0.64 %, Nb more than 0.5 % up to 1.17 % and Ta more than 0.5 % up to 2.27 % is added to austenitic stainless steel containing Cr, Ni and so on, and said at least one additive exists in a solid-solution state. Further, the steel has a wholly austenitic structure substantially free of carbide. In order to maintain the irradiation-induced segregation prevention effected by the addition element, the C content is limited to 0.01 to 0.008 %, and the N content is limited to 0.001 to 0.1 %. The irradiation-induced segregation of the constituent elements, such as Cr and Ni, occurring in a grain boundary under irradiation, and the deterioration of the corrosion resistance of the material, as well as the embrittlement, can be prevented.