Effect of Combined Torsion and Tension on the Microstructure and Fracture Behavior of 316L Austenitic Stainless Steel

In this study, the microstructure evolution and fracture behavior of 316L austenitic stainless steel (ASS) deformed by torsion-tension at room temperature was systematically investigated. During combined tension and torsion, the grain size was refined with increasing shear strain. In addition, the microtexture exhibited a preferred orientation with increasing shear stress. The metastable austenite underwent phase transition when the shear stress increased. The shear stress affected the fracture morphology, and dimples with different sizes and depths were observed for different pre-torsions. The dislocation density increased significantly owing to severe shear deformation. In addition, the dislocation structure evolved and subgrains appeared with the accumulation of shear strain during this combined deformation. The result showed that pre-torsion deformation plays an important role in improving the comprehensive performance and controlling the microstructure evolution of the sample subjected to tension deformation.