Small angle neutron scattering study of martensitic/ferritic ODS alloys

Small Angle Neutron Scattering (SANS) is a key tool in material study at the nanoscale. This method allows characterization, in a non-destructive way, of small particles (precipitates, cavities, etc.) ranging in size between 1 and 100 nm. This technique, giving statistical data representative of the whole sample, is particularly adapted to the study of steels. l present an overview of the SANS possibilities applied to the ODS ferritic/martensitic steels. The main objective is to study the evolution of the oxide dispersion during the different stages of the fabrication, that is, after mechanical alloying, consolidation process (extrusion or HIP) and after thermal treatments. The treatments of SANS data obtained on different ODS Fe9–14%Cr alloys are detailed by discussing the strengths and limitations of the technique. Various Fe–Cr–W–Ti experimental alloys have been characterized.