SANS study of the microstructural evolution of martensitic steels under thermal ageing and neutron irradiation

Abstract : SANS technique has been used to study the microstructural evolution of martensitic steels containing 7-12% Cr, under thermal ageing and neutron irradiation. Some of the investigated alloys are industrial low activation martensitic (LAM) materials, where alloying elements have been substituted by elements with low radiological impact. For materials quenched from the austenitic phase, a direct correlation was found between the hardening and the number density of M2C precipitates induced by thermal ageing at 500 °C. Irradiation-accelerated spinodal decomposition of the B.C.C. ferrite was observed in alloys containing large (= 11%) chromium content.