Microstructure-based finite element modeling of a martensitic stainless steel during hot forging

This study aims to analyze material flow behavior and microstructure evolution during the hot deformation of a martensitic stainless steel with the view to simulating the open die forging process. For this purpose, hot compression tests were conducted using a Gleeble-3800 thermo-mechanical. A material model, based on the Arrhenius equation, was developed and implemented into the finite element simulation code Forge NxT 3.0® using a special user subroutine. Microstructure maps for the entire volume of the specimen were determined, and the occurrences of different softening phenomena were predicted as a function of hot deformation parameters. Good correlations were obtained between the simulation predictions and experimental results. The flow behavior of the material was also analyzed using the dynamic material model, and the unstable regions were identified. The obtained results were compared with the experimental and numerical simulation findings. The approach proposed in this paper, which integrates microstructure-based finite element simulation combined with a three-dimensional processing map, can be used for rapid and accurate optimization of the hot deformation process of martensitic stainless steels.