FEM Numerical Simulation On The Dynamic Recrystallization Of 09CuPTiRE Steel

09CuPTiRE steel is a Cu-P-Ti-RE series weather-resistant steel which is unique in the world. It is widely used for manufacturing the train carriages. In recent years, domestic railway transport develops quickly. With the railways extending to some areas of tough weather conditions, such as QingZang tableland, higher requirements for 09CuPTiRE steel properties are put forward. As we all know, the final microstructure and properties are affected by dynamic recrystallization during the hot deformation obviously. Consequently, the co-relationship between dynamic recrystallization and process parameters of 09CuPTiRE steel has been studied in this paper. The research not only enriches the theory and technology of dynamic recrystallization but also optimizes the process parameters, improves the product quality and cuts down the cost.By integrating the thermal simulating experiment with FEM simulation, dynamic recrystallization of 09CuPTiRE steel is studied. The true stress-strain curves are introduced as a part of material properties. Considering the effects of friction, heat exchange and dynamic recrystallization, the truer deformation distribution is achieved. Then with the dynamic recrystallization model and programs, the simulating results are acquired. The results mainly indicate how the deformation, strain-rate and temperature act on the dynamic recrystallization of 09CuPTiRE steel.Firstly, based on the thermal simulating experiment of 09CuPTiRE steel and relative theories, the model of dynamic recrystallization is established. Secondly, DEFORM is used to simulate hot deforming. Thirdly, program to realize the distribution of dynamic recrystallization volume fraction visible.According to the research, some conclusions are obtained as follows: (1) There is a kind of inhomogenous deformation. Distribution of dynamic recrystallization volume fraction agrees well with the distribution of deformation. (2) The dynamic recrystallization takes place at large deforming area firstly. With the increasing of deformation, dynamic recrystallization extends to the other areas and the volume fraction enhances. (3) When the deformation and strain-rate are changeless, high temperature can reduce the critical condition of dynamic recrystallization. Then the areas of partial and complete dynamic recrystallization become larger and dynamic recrystallization is promoted obviously. (4) When the deformation and temperature are invariable, high strain-rate baffles dynamic recrystallization. So it results in the reduction of complete dynamic recrystallizing area. (5) As for hot rolling, when rolling temperature is 1100°C and strain-rate is 10s^-1, the relative deformation that increases to 0.45 can make the whole section of workpiece at the state of complete dynamic recrystallization. When the relative deformation is 0.5 and strain-rate is 10s^-1, rolling temperature that increases to 960°C can also make the dynamic recrystallization take place completely. When the total deformation is 0.5, rolling temperature is 1100°C and the strain-rate increases to 20s^-1, the section that is 50mm from the exit can only keep the state of partial dynamic recrystallization and the complete dynamic recrystallization disappears. (6) During the hot rolling, dynamic recrystallization is different in the different longitudinal position of workpiece. At the front part, dynamic recrystallization happens inadequately. At the middle part, dynamic recrystallization takes place completely. At the back part, dynamic recrystallization almost takes place entirely.