Neutron diffraction investigation of residual stress and texture in additively manufactured AISI 410 and 316L steel plates produced by LPBF and DED

Abstract

Residual stresses pose a significant challenge in additive manufacturing, particularly for large metal parts. Monitoring these stresses is essential to achieving reliable performance characteristics. Neutron diffraction—a nondestructive method that measures residual stresses throughout the entire sample volume—offers key advantages. In this study, we compared residual stresses in steel specimens (AISI 316L and AISI 410) produced by laser powder bed fusion (PBF-LB) and directed energy deposition (DED-LB). The results showed that stresses in DED-LB specimens were lower than those in PBF-LB specimens, owing to the lower crystallization rate. This study also demonstrates, for the first time, the visualization of texture in a DED specimen using monochromatic neutron radiation and high-resolution neutron diffraction. These findings correlate with results from electron backscatter diffraction. Such visualization is valuable for nondestructive analysis and for identifying texture and porosity in large parts.