Abstract
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 close-packed 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.
| Original language | English |
|---|---|
| Article number | 130364 |
| Journal | Materials Letters |
| Volume | 302 |
| DOIs | |
| State | Published - Nov 1 2021 |
| Externally published | Yes |
Funding
This study was supported by the National Science Foundation of the United States under Grant No. DMR-1810343.
Keywords
- Defects
- Microstructure
- Nanocrystalline materials
- Phase transformation
- X-ray techniques