Modeling of luders elongation and work hardening behaviors of ferrite-pearlite dual phase steels under tension

Because of their good combination of strength and ductility, ferrite-pearlite (F-P) dual phase steels are widely used as structural components for various engineering applications. Several numerical models have been developed to predict the flow behavior of F-P steels with a focus on the strain hardening effect. However, little attention has been put on modeling the Luders elongation phenomenon, which dominates the plastic behavior of F-P steels at a relatively low-strain range. This research is to establish a stress strain model capable of predicting both the Luders elongation and work hardening behaviors of F-P steels subjected to room temperature tension. Representative volume element method in combination with finite element simulation is used for the overall stress strain relationship prediction. The effects of ferrite grain size, pearlite volume fraction, and pearlite inter-lamellar spacing on flow behaviors are investigated. Model validation is achieved by comparing the simulation results with experimental data from literature.