SMALL-PUNCH TECHNIQUE FOR MEASUREMENT OF MATERIAL DEGRADATION OF IRRADIATED FERRITIC ALLOYS

The yield stress and fracture strain of irradiated ferritic alloys were measured using a small-punch test. The characteristics of hardening and intergranular embrittlement induced during neutron irradiation (0.94 x 10(23) n m-2) at 395-degrees-C in ferritic alloys doped with Cu, P and/or C were investigated. The effect of neutron irradiation on hardening was found to be greater in alloys doped with Cu and/or P than in C-containing alloys. The neutron irradiation produced a more substantial increase in the ductile-brittle transition temperature in the Cu-doped alloy compared with the other alloys and cause a significant decrease in the ductility of the Cu-doped alloy. Intergranular and transgranular fracture occurred in the alloys doped without and with C, respectively. The neutron irradiation did not alter the fracture mode.