SANS and TEM study of Y2O3 particle distributions in oxide-dispersion strengthened EUROFER martensitic steel for fusion reactors

Transmission electron microscopy (TEM) and small-angle neutron scattering (SANS) were used to characterize the microstructure of two variants of oxide-dispersion strengthened (ODS) Eurofer-97 steel (9% CrWVTa), that is being developed for future fusion reactors. More specifically the Y2O3 particle size distributions obtained with different Y2O3 contents have been characterized, since the mechanical properties are strongly correlated with such features. The SANS measurements have been carried out by the D22 instrument at the High Flux Reactor of the Institut Laue-Langevin, Grenoble. There is a good agreement between TEM histograms and SANS distributions of the Y2O3 particles. Furthermore, relevant and unique information is provided by the SANS measurements that reveals particles of size smaller than 1 nm approximately