Models Of Tensile Behaviour Of Meta-Stable Fe-Mn-Mo Alloys

ABSTRACT 

A semi-mechanistic model for predicting the flow behaviour of Fe-Mn-Mo steels displaying transformation-induced plasticity is developed in this paper. The model, based on the law of mixtures, takes into account the work-hardening of the individual principal phases (namely, lath-martensite and austenite/epsilon martensite). The composite strength of such a steel may be given by a modified law of mixtures which incorporates a dislocation density effect. To test the validity of the model, experiments have been performed using a magnetic reluctance technique to determine the extent of 'f + F.: 7 a.' transformation induced by tensile plastic deformation at room temperature. As the 'f + e: 7 a.' transformation progressed the work-hardening of the steels was found to increase rapidly. It is concluded that the induced lath-martensite in a work-hardened austenite/epsilon matrix is most effective in enhancing strength and ductility.