Polarized SANS study of microstructural evolution in a martensitic steel for fusion reactors

The results of a polarized SANS study of a martensitic steel (MANET) developed for fusion-reactor technology are presented. The measurements were carried out to investigate Cr-redistribution phenomena in the martensitic matrix, which can play a crucial role in ductile-to-brittle transition changes under irradiation. The nuclear–magnetic interference term and the ratio of nuclear plus magnetic to nuclear SANS cross sections show that such inhomogeneities, which are present immediately after quenching and give rise to Fe-rich precipitates, dissolve even for short tempering times.