Authors: Seawoong Lee Bruno C De Cooman
Publish Date: 2013/07/17
Volume: 44, Issue: 11, Pages: 5018-5024
Abstract
A model is proposed to predict the room temperature austenite volume fraction as a function of the intercritical annealing temperature for medium Mn transformationinduced plasticity steel The model takes into account the influence of the austenite composition on the martensite transformation kinetics and the influence of the intercritical annealing temperature dependence of the austenite grain size on the martensite start temperature A maximum room temperature austenite volume fraction was obtained at a specific intercritical annealing temperature T M Ultrafinegrained ferrite and austenite were observed in samples intercritically annealed below the T M temperature The microstructure contained a large volume fraction of athermal martensite in samples annealed at an intercritical temperature higher than the T M temperature
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