HIGH-NICKEL AUSTENITIC STAINLESS STEEL RESISTANT TO DEGRADATION CAUSED BY NEUTRON IRRADIATION

摘要

The present invention aims at providing structural materials having resistance to degradation by neutron irradiation, causing no SCC in the environment of light-water reactors even after being subjected to neutron irradiation of approximately at least 1 x 10 <22> n/cm<2> (E > 1 MeV), and having thermal expansion coefficients approximately similar to that of structural materials. High nickel austenitic stainless steels having resistance to degradation by neutron irradiation can be produced by subjecting stainless steels having compositions (by weight %) of 0.005 to 0.08 % of carbon, at most 0.3 % of Mn, at most 0.2 % of (Si + P + S), 25 to 40 % of Ni, 25 to 40 % of Cr, at most 3 % of Mo or at most 5 % of (Mo + W), at most 0.3 % of Nb + Ta, at most 0.3 % of Ti, at most 0.001 % of B and the balance of Fe to a solution-annealing treatment at a temperature of 1000 to 1l50 DEG .