Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
10620518 | Acta Materialia | 2012 | 13 Pages |
Abstract
By means of dynamic plastic deformation (DPD) with high strain rates, a bulk nanostructured 316L austenitic stainless steel consisting of nano-sized grains embedded with bundles of nanometer-thick deformation twins was synthesized. The average transverse grain size is â¼33 nm and the twin/matrix lamellar thickness is â¼20 nm. The nano-twin bundles constitute â¼24% in volume. The nanostructured samples exhibit a high tensile strength of â¼1400 MPa but a limited ductility with a uniform elongation of â¼2%. Subsequent thermal annealing of the as-DPD samples in a temperature range of 730-800 °C led to a single-phased austenite structure consisting of static recrystallized (SRX) micro-sized grains embedded with remaining nano-twin bundles and nano-grains. The annealed DPD samples exhibit an enhanced strength-ductility synergy and much more enhanced work-hardening rates than the as-deformed samples. Work-hardening rates of the annealed DPD samples can be even higher than that of the original CG sample. Tensile ductility was found to increase almost linearly with the volume fraction of SRX grains. A combination of 1.0 GPa tensile strength with an elongation-to-failure of â¼27% is achieved in the annealed DPD 316L stainless steel samples.
Related Topics
Physical Sciences and Engineering
Materials Science
Ceramics and Composites
Authors
F.K. Yan, G.Z. Liu, N.R. Tao, K. Lu,