Structure and Mechanical Properties of High-Strength Austenitic-Martensitic Trip-Steel VNS9-Sh

Abstract

The structure and mechanical properties of cold-rolled thin-sheet austenitic-martensitic trip-steel VNS9-Sh are studied. The method of electron back-scatter diffraction (EBSD) is used to determine the substructural state of the steel represented by mechanically hardened metastable austenite with a great number of strain twins and strain α′-martensite. The preferred places of nucleation of strain martensite in the range of intersection of strain twins and shear bands are detected. The mechanical properties of steel VNS9-Sh and the main deformation stages, i.e., microscopic yield, yield (Luders–Chernov strain) and strain hardening are determined.