Fluence dependence of small-angle neutron scattering in neutron-irradiated Fe-Cr

Four Fe-Cr alloys with chromium concentrations ranging from 2.5 to 12.5 at% in three irradiation conditions (0.06, 0.6 and 1.5 displacements per atom) were investigated by means of small-angle neutron scattering. For Fe-12.5 at% Cr, alpha‘–phase particles were unambigiously identified. The size distribution of these particles was estimated and the kinetics of formation were compared with a rate theory model which allows to extrapolate the evolution of the nanostructure to still lower dpa-levels. For 2.5, 5 and 9 at% Cr, the results of the SANS investigation are more complex and the input from other methods, such as APT and TEM, is needed in order to explore the irradiation effects in detail.