Tensile ductility and deformation mechanisms of a nanotwinned 316L austenitic stainless steel

A nanotwinned 316 L austenitic stainless steel was prepared by means of surface mechanical grinding treatment.After recovery annealing,the density of dislocations decreases obviously while the average twin/matrix lamella thickness still keeps in the nanometer scale.The annealed nanotwinned sample exhibits a high tensile yield strength of 771 MPa and a considerate uniform elongation of 8%.TEM observations showed that accommodating more dislocations and secondary twinning inside the nanotwins contribute to the enhanced ductility and work hardening rate of the annealed nanotwinned sample.