Fracture behavior of an austenitic stainless steel with nanoscale deformation twins

A bulk nanotwinned austenitic stainless steel containing a large volume fraction of deformation twins was produced by dynamic plastic deformation. The tensile tests and J-integral fracture toughness measurements indicate that this steel exhibits a combination of high strength (sigma(ys) = 920 MPa) and considerable fracture toughness (K-JC > 126 MPa m(1/2)). The fracture is associated with localized shear band induced destruction of the nanotwinned structure and with micro-void development at the generated nanoscale large angle grain boundaries within the shear bands, which consumes large plastic energy and contributes the fracture resistance. (C) 2016 Acta Materialia Inc Published by Elsevier Ltd. All rights reserved.