Numerical Simulation Of Hot Continuous Rolling Process Of 20CrMnTi Steel Rod

In the context of supply-side reforms,the development of high value-added steel products is the way to optimize and adjust the product structure of iron and steel enterprises in China.The microstructure control during the rolling process of steel has a very important influence on the final properties of the steel.Therefore,the simulation and prediction of the microstructure of steel during rolling process can serve as reference for the microstructure control of the steel,and be benefit to the adjustment of process parameters,which can effectively guide the steel production.In this paper,with the background of hot rod rolling of20 CrMnTi steel,through the combination of experiment and finite element simulation,the austenite grain evolution mathematical models of 20 CrMnTi steel have been obtained,and the evolution of temperature,stress,strain and microstructure during the continuous hot rolling process of 20 CrMnTi steel rod have been studied.The research contents are as follows:Through Gleeble thermal/mechanical simulation experiments,the austenite grain growth,dynamic recrystallization,metadynamic recrystallization and static recrystallization behaviors of 20 CrMnTi steel have been studied,and the effects of temperature,strain rate and other factors on the austenite grain evolution of 20 CrMnTi steel have been compared.The corresponding mathematical models of austenite grain evolution have been obtained by fitting method.The comparison between the calculated value and the experimental value has verified the accuracy of the mathematical models.Based on the actual production situation,the large-scale nonlinear finite element software MSC.Marc has been used to establish the finite element models of the continuous hot rolling process of 20 CrMnTi steel rods of ?18mm and ?140mm.Through Fortran secondary development of the finite element model,the 20 CrMnTi steel austenite grain evolution mathematical models have been coupled to the finite element models of the continuous hot rolling process to simulate the microstructure evolution of the 20 CrMnTi steel rod.Through the analysis of the simulation results of the ?18mm and ?140mm rods of20 CrMnTi steel during the hot rolling process,the distribution and evolution of the internal temperature,stress,strain,strain rate,recrystallization fraction and grain size of the rods during the hot rolling process have been studied.It is found that during the hot rolling process,the distributions of variables inside the rod are quite uneven,and the evolution of austenite grains inside the rod is affected by deformation conditions.The simulation results of temperature and grain size of rods and the experimental temperature and grain size have been found to be in good agreement,which has verified the reliability of the models.