Summary
The strain hardening exponent (n) in the stress strain relationship of metals and alloys is an indicator of their stretchability during press forming operations. The larger the n value, the more the material can deform before instability, and the material can be stretched further before necking starts. This paper aims to investigate work hardening behavior of dual phase steels. A series of dual-phase (DP) steels containing ferrite and martensite with different volume fractions of martensite (Vm) were produced by intercritical heat treatment. Work hardening behavior was analyzed in terms of Holloman analysis. Results showed that in DP steels with less than %50 Vm, the work hardening took place in one stage and the work hardening exponent increased with increasing Vm. By increasing the volume fraction of martensite (Vm>%50) more than one stage will be observed in the Holloman analysis.