STRESS-STRAIN RELATIONS OF HFIR-IRRADIATED AUSTENITIC STAINLESS-STEELS

Tensile specimens of austenitic stainless steels were irradiated up to 50 dpa at temperature of 573, 673 and 773 K and HFIR. True stress-strain relation derived from the load-displacement curves were analyzed in terms of induced effective strain and strain hardening behavior. The strain hardening exponent of the material was only slightly affected by irradiation at 573 and 673 K. Irradiation at 773 K changes work hardening characteristics. This might have resulted from fine MC precipitation and/or helium produced during irradiation. Fracture strain decreases with dose, and the dose dependence was pronounced at 773 K. Heat-to-heat variation was not large between two Ti-modified steels.