Experimental study and numerical simulation of dynamic recrystallization behavior of a micro-alloyed plastic mold steel

To research the dynamic recrystallization (DRX) characteristics of a micro-alloyed plastic mold steel (MnCrNb, SDP1®), a series of hot compression tests using Gleeble-3500 thermo-mechanical physical simulator are implemented under different temperatures and strain rates. In addition, the microstructure of specimens after hot compression tests are also observed by optical microscope. Combined Estrin and Mecking mathematic model (EM) with Avrami equation, the important material genome data of SDP1, such as DRX kinetic model, dynamic recovery (DRV) kinetic model and grain size evolution model, is established by the inverse analysis of flow stress curves to estimate the microstructure evolution during hot deformation. Furthermore, combined with the obtained material kinetic model, an elastic-plastic finite element (FE) model is built to simulate the microstructure evolution of SDP1 during the single-pass hot compression and compare with the experimental results. The results indicate that the simulation results agree well with the experimental ones, which verifies the availability of obtained material genome data. The finite element method (FEM) is an effective approach to analyze the hot compression process, which can provide a theoretical guidance and optimization scheme for making the more reasonable hot working procedure.