Structural evolution during nanostructuring of additive manufactured 316L stainless steel by high-pressure torsion

This study investigates the structural evolution including crystallite size, micro-strain, and lattice parameters of an additive manufactured 316L stainless steel during post-printing nanostructuring by high-pressure torsion (HPT) at room temperature. Formation of a martensite phase was observed in the nanostructured austenitic steel having an average grain size of 60 nm after 8 HPT turns. Significant strain gradients exist between the closepacked planes and out-of-close-packed-planes in the nanocrystalline structure, while such strain gradient was not observed in the as-built material. Structural changes occur in a very early stage of nanostructuring through 1/ 2 HPT turn and are attributed to severe lattice distortion by the excess of dislocations and defects.

Automated summary

In this study, structural evolution of additive manufactured 316L stainless steel through post-printing nanostructuring using high-pressure torsion at room temperature was investigated. The formation of a martensite phase and significant strain gradients were observed in the nanostructured austenitic steel. Early stage structural changes were attributed to lattice distortion by excess of dislocations and defects.