No abstract

No abstract

The effect of fast reactor irradiation on the ductility of annealed AISI Type 316 stainless steel is described in terms of strain rate, temperature, and neutron fluence. Creep and tensile data obtained after EBR-II irradiations are presented and analyzed in terms of controlling deformation mechanisms. The basic nature of each deformation process is used to infer ductility loss trends and to define the environmental conditions where specific ductility-fluence relationships apply. The resulting correlation quantitatively describes ductility to fluences approaching 7 × 1022 n/cm2, strain rates from 10−6/h to 104/h, and temperatures from 370 to 760 C (698 to 1400 F).

The effects of neutron irradiation on the tensile properties of several austenitic stainless steels are considered over a wide fluence and temperature range. At low fluence levels (about 1020 neutrons (n)/cm2, E > 1 MeV), displacement damage results in radiation hardening if the irradiation and test temperatures are below one half the absolute melting temperature (0.5 Tm) of the steel. Above 0.5 Tm, hardening no longer exists, but a ductility loss due to helium embrittlement is observed. The temperature above which radiation hardening is no longer significant increases with increasing fluence. Elevated temperature hardening after fast reactor irradiations is the result of void formation. The hardening observed after thermal reactor irradiations appears to be due to the formation of gas filled bubbles, but the nature of the gas is not clear.

No abstract