Study On Recrystallization Behavior And Cellular Automata Method Of Cr5 Steel For Large Roller

Large forgings are generally the core components of heavy equipment,due to the special work environment,they required excellent comprehensive mechanical properties.The macroscopic mechanical properties of metals are determined by the microstructure,during the hot working process,the macroscopic shape and microstructure of the metal will change.In industrial production,it is an important way to improve the quality of the products by using the dynamic recrystallization mechanism to improve the microstructure of the material.Therefore,it is very important to understand and master the law of microstructure evolution during hot forming,which can improve the comprehensive performance and control the quality of the products.In this paper,the Cr5 steel for large roller material is taken as the research object.The microstructure evolution model of Cr5 steel was established by combining the macroscopic process parameters with the cellular automata and using the dislocation density as the internal variable.And then the relationship between the evolution of dynamic recrystallization behavior and the deformation parameters of Cr5 steel was studied,which could be used to predict the microstructure property and optimize the process parameters.The details of the research are as follows:The flow stress behavior and microstructural evolution of Cr5 steel under different deformation conditions were analyzed by thermo-compression physical simulation experiment,initial dislocation density measurement experiment and initial grain size measurement experiment.The peak stress model of Cr5 steel was established.And obtained the material parameters required for CA simulation.Based on the physical metallurgy theory of dislocation density evolution,recrystallization nucleation and grain growth in dynamic recrystallization,the cellular automata model for simulating dynamic recrystallization process of Cr5 steel was established with the dislocation density as the unique internal variable.Based on the established cellular automata model,the high temperature flow stress curves and microstructural evolution of Cr5 steel under different deformation conditions were simulated.And the reliability of the model was verified by comparison with the experimental results.The influence of thermal parameters on the dynamic recrystallization behavior of Cr5 steel was studied by changing the strain rate,deformation temperature and strain.The results show that the cellular automata model based on the principle of physical metallurgy can accurately simulate and predict the dynamic recrystallization microstructure and flow stress of Cr5 steel,thus providin g the basis for predicting and controlling the performance of the product.