This study is part of a thesis that was awarded a CNRS grant (80/PRIME). This experiment aims at filling the gap concerning the evolution of nano-oxides in 316L parts obtained by laser powder bed fusion with heat treatments in order to understand their contribution to strengthening. USAXS/SAXS/WAXS combined measurements are an opportunity to study, first, the evolution of size with heat treatment temperature and time, and secondly, the change of crystalline structure, both in a quantitative way. This characterization will provide the crystal structure, evidencing possible structure transitions of the precipitates during heat treatment, as well as their geometrical characteristics (size, size distribution and volume fraction). This data will be of high value to understand quantitatively the mechanical properties of the built parts and optimize their heat treatment.