AUSTENITIC STEEL EXPOSED TO HIGH TEMPERATURE AND HIGH PRESSURE WATER UNDER NEUTRON IRRADIATION

摘要

PURPOSE:To improve the resistance to irradiation brittleness, swelling resistance and stress corrosion resistance in high temp. and high pressure water of apparatus parts to be subjected to neutron irradiation in the core part of a nuclear reactor and a nuclear fusion reactor by manufacturing the apparatus parts with an austenitic stainless steel having specific compsn. CONSTITUTION:The apparatus and structure of the core part subjected to neutron irradiation in a water-boiling reactor, pressurized-water reactor and nuclear fusion reactor are manufactured with a stainless steel having the compsn. contg., by weight, 0.02 to 0.065% C, 1% Si, 10% Mn, 9 to 26% Cr, 8 to 20% Ni, 0.5 to 2.5% Cu and 0.015% B, contg. one or more kinds among 0.8% Nb, 0.8% Ta and 0.6% Ti, contg. at least one one kind among 0.01 to 0.2% Zr, Hf, Y and La and the balance =50% Fe and having the structure constituted of austenite. The stainless steel has =1% tensile elongation at the room temp. after the irradiation of electrons of 5X1022n/cm3 at 300 deg.C, has =3% swelling amt. and has =0.6 ratio of Cr concn. in grain boundary to Cr concn. in a mother phase, by which the service life of the furnace core member can exceedingly be improved.