Enhancing fracture toughness of nanotwinned austenitic steel by thermal annealing

The fracture behavior was investigated of a 316L austenitic stainless steel with heterogeneously distributed nanotwin bundles, prepared by dynamic plastic deformation and subsequent annealing at different temperatures. The results indicate that the controlled annealing causes a slight decrease in the strength, but remarkably improves the fracture resistance, and therefore enhances the strength–toughness synergy. The toughness enhancement is attributable to the formation of recovered sub-micron-sized and recrystallized micron-sized grains postponing crack nucleation and to the remnant nanotwin bundles arresting crack propagation.

Figure optionsDownload high-quality image (293 K)Download as PowerPoint slide