Coupled Thermo-Mechanical 3D-FE Analyses Of Macro-Micro-Deformation In Hot Ring Rolling Process

Hot ring rolling is a complex plastic forming process under coupled effects of multi-factors with interaction between macro-deformation and microstructure evolution. In order to achieve its optimum design and precise control of shape and performance, research on coupled thermo-mechanical effects and microstructure evolution has thus become an important subject urgent to be resolved in the leading field of the hot ring rolling process. Therefore, in this dissertation, a systematic investigation on macro- micro-deformation of hot ring rolling process has been carried out using numerical simulation, combined with the analytical and experimental methods. A brief introduction to the project and its main achievements are as follows:A 3D-FE model under coupled thermo-mechanical effects of hot ring rolling process has been developed based on the rigid-viscoplastic FEM, and some key technologies have been solved, such as materials modeling, element selecting, meshing, contact boundary, fiction, choice of iteration solver and increment step, etc. The model has been validated by experiments to be applicable and reliable.Based on the platform of finite element software DEF0RM-3D, the microstructure models of 40Cr steel have successfully been integrated into the developed the 3D-FE model, and consequently coupled simulations of heat transfer, deformation and microstructure evolution realized.Through comprehensive simulations and analyses of coupled heat transfer, deformation and microstructure evolution of hot ring rolling process, the laws of distribution have been disclosed for deformed mesh, equivalent strain filed and temperature filed. It is found that: (1) strain zone changes from a small local zone into a ring strip and moves from the inner-layer and the outer-layer to the mid-layer; (2) the inner-layer and outer-layer are large strain zone; (3) the distribution of the temperature is inhomogeneous, and because of its large deformation, the high-temperature zone is in the outer-layer; (4) at the first stage of the process, the low-temperature zone is in the contact zone between ring bank and forming roller, and then, it moves into the inner-layer edge, and further, it extends into the outer-layer edge.The influence of main process parameters on deformation filed, temperature filed...