TEM and EFTEM characterization of solution annealed 304L stainless steel irradiated in PHENIX, up to 36 dpa and at 390 °C

Highlights: ► The combination of EFTEM and TEM allows determining the precipitate characteristics. ► EFTEM can be routinely used for neutron-irradiated specimens because of the lack of their sensitivity to radioactivity. ► The formation of γ' particles and Cr-rich M23X6 had occurred by irradiation. - Abstract: Imaging of solution-annealed 304L stainless steel irradiated in the PHENIX reactor, up to a dose of 36 displacements per atom (dpa) and at a temperature of 390 °C was performed by using conventional transmission electron microscopy (TEM) and energy-filtered transmission electron microscopy (EFTEM). TEM investigations revealed the presence of Frank loops, dislocation lines, cavities and intragranular precipitates of different crystallographic phases. EFTEM investigations clearly show the relative proportion of major chemical elements in precipitates and the relative spatial distribution of these precipitates around cavities. The spatial distribution of Frank loops, dislocation lines and cavities was found to be homogeneous whereas precipitates were found to be most heterogeneously dispersed.