Strain hardening behavior of DP 590 steel using dislocation density based Kock-Mecking model

Abstract Flow stress and strain hardening behavior have attracted a prolonged interest in optimising the process parameters and ensuring safe performance during working conditions. The present work investigates the strain hardening behavior of DP-590 steel at various temperatures. Firstly, uniaxial tensile tests are conducted from Room Temperature (RT) to 400 °C at an interval of 200 °C and 0.001 s−1 strain rate to analyse the flow stress behavior of DP-590 steel. Subsequently, microstructural characteristics are examined using Scanning Electron Microscopy. The strain hardening behavior of DP 590 steel is explored using a dislocation density based Kock-Mecking model. The dislocation storage (K1) and dislocation annihilation (K2) parameters are used to describe the strain hardening behavior. Three-stage hardening behavior is found at different temperatures and each stage of hardening is discussed elaborately.