Intra granular precipitation and grain boundary segregation under neutron irradiation in a low purity Fe-Cr based alloy

A nanoscale description of intra- and inter-granular segregation and precipitation in a Fe-12 at.%Cr model alloy of low purity after neutron irradiation at 300 °C up to 0.6 dpa, has been performed owing to Atom Probe Tomography (APT). Two different populations of clusters have been observed inside the grains: Cr-enriched and NiSiPCr-enriched clusters. As expected with a process of enhanced precipitation, Cr-enriched clusters are homogeneously distributed inside grains. The NiSiPCr-enriched clusters, which are probably formed by radiation induced segregations, are independent of the Cr-enriched clusters. Investigation of a low angle grain boundary has revealed Si, Cr and P segregation on the dislocation network.