Constitutive model and numerical simulation of HSLA steel during isothermal compression

The true stress-strain curve of HSLA steel was obtained though a MMS-200 experiment machine. The flow behavior of HSLA steel during isothermal compression at different deformation conditions was investigated. The result indicated the flow stress increases as the strain rate increases or the deformation temperature decreases, and the flow curves show obvious dynamic softening characteristics at low strain rate or high temperature. The peak stress constitutive equation was established and the activation energy be calculated as 437955 J/mol. The effective strain and flow stress during isothermal compression were studied by finite element method. The simulation results show that the effective strain distribution at different regions is inhomogeneous. The flow stresses obtained by FEM are consistent with the corresponding test results.