High strength state of UFG steel produced by severe plastic deformation

Abstract

An UFG austenitic stainless steel of type 316 was produced by high pressure torsion at two different temperatures. As a result different nanostructures were observed in the investigated alloy characterized by different grain size and dislocation density. It was reported that the steel processed at both temperatures was characterized by significantly enhanced strength, which, in case of the steel processed at 430°C, exceeds the value expected for the given grain size according to Hall-Petch relation. This extra-strength is supposed to be due to the observed nanostructural features as segregations/clusters of solutes in grain boundary area formed by severe plastic deformation. © Published under licence by IOP Publishing Ltd.