Kiyotomo Nakata1, Toshimi Yoshida1, Isao Masaoka1, Takashi Saito2, A.~J. Jacobs3, G.~P. Wozadlo3 and W.~J.~S. Yang3
1Hitachi Research Laboratory, Hitachi Ltd., Hitachi
Austenitic stainless steels of Types 316 and 304 were neutron-irradiated up to 2.5×1025 n/m2 (>1 MeV) at 560 K, and the tensile test was performed at 561 K. An increase in yield strength and a decrease in both elongation and work-hardening rate were observed with irradiation dose in the solution-annealed specimens. These mechanical property changes in Type 316 steels were smaller than those in Type 304 steels. The addition of nitrogen to the steels was beneficial for suppression of radiation embrittlement, because the smallest reduction of elongation with irradiation occurred in the specimens with nitrogen of about 0.1%. On the contrary, a large reduction of elongation occurred in the specimens with a remarkably small amount of Si and other impurities. Smaller irradiation-induced changes in tensile properties were observed in the 20% cold-worked specimens than in the solution-annealed ones, and the effects of solute atoms were not observed clearly. The responce of the low-temperature sensitized specimens was similar to that of the solution-annealed ones.
austenitic stainless steel, neutron irradiation, tensile test at intermediate temperature, mechanical property, radiation-induced defect cluster
Please do not copy without permission.