The effect of irradiation on the mechanical properties of ferritic-martensitic steels

Abstract

Abstract In this article the influence of irradiation on the tensile, toughness and in-pile creep properties of ferritic-martensitic stainless steels is reviewed in view of their possible application as structural materials for fusion reactors. For irradiations below 400°C, rather low doses of 10 to 20 dpa cause already strong hardening and embrittlement as shown by the reduced tensile ductility and impact strength. The static fracture toughness appears to be less degraded. From the known data it cannot be concluded with certainty that saturation has been reached. Helium contents up to 80 appm have shown no effect, neither at low, nor at high temperature. It remains to be demonstrated however that this is also true for contents which are an order of magnitude larger. As for the in-pile creep behaviour it will probably be necessary to limit the stress to some critical value depending on the temperature in order to avoid “break away” creep.