Eeffect of fast-neutron irradiation on mechanical properties of iron and some iron binary solid solutions

Abstract

The effect of fast-neutron irradiation on the tensile properties and work hardening behaviour of low-carbon Fe (0.02% C), Fe-4% Cr, Fe-9% Cr and Fe-8% Al were investigated up to a fluence of 1.8 × 10 18 n cm −2 ( E >;1 MeV) at an irradiation temperature of 40°C. The room temperature irradiation-induced increase in yield stress showed a (φt) 1 2 dependence for Fe, Fe-4% Cr and Fe-8% Al in agreement with Seeger's theory. The radiation hardening component, however, decreased with the increase of solute concentration. Fe-9% Cr alloy showed irradiation softening at 1.8 × 10 18 n cm −2 which may be attributed to a irradiation-induced change in the short-range order postulated to exist. Appreciable recovery in the radiation hardening component was observed for Fe and Fe-Cr alloys at 225°C. Fe-8% Al alloy showed recovery at this temperature but to a lesser extent. The work hardening rate decreased with fluence. The decrease was high initially and then tended to saturation. It was also higher in Fe and Fe-4% Cr than in the other alloys.