Microstructure and tensile behavior of duplex low-density steel containing 5 mass% aluminum

Abstract

The microstructure and tensile behavior of low-density steels containing 5 mass% Al were investigated. An alloy obtained under a specific heat treatment condition showed deformation-induced martensitic transformation, which yielded excellent mechanical properties of a high tensile strength of >900 MPa and a high total elongation of >50%. The volume fraction and grain size of the austenite depended on the annealing temperature, which resulted in a transition from stable to metastable behavior of the austenite. The effects of solute content on grains and of austenite grain size on stability were discussed. (C) 2012 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.