Strength, damage and fracture behaviors of high-nitrogen austenitic stainless steel processed by high-pressure torsion

A high-nitrogen austenitic stainless steel (HNS) was processed by high-pressure torsion (HPT) for up to 5 turns to reveal the microstructural evolution and mechanical properties. The effects of the microstructure refinement and the increasing density of defects with imposed strain on the strength, damage and fracture behaviors of the HNS were investigated through the Ellipse criterion. The influences of these processes on the critical shear (tau(0)) and normal (sigma(0)) fracture stresses determine the fracture mode. (C) 2014 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.