Coupled thermal-mechanical FEM analysis on multi-way loading forming process of triple valve body

Multi-way loading forming process is a effective way to form the complex structure integral components (such as triple valve body), with loading in axial direction and lateral direction at the same time or in sequential. During the forming process, not only the procedures were decreased but also the quality of the product was improved. Considering the complicated forming mechanical and the numerous influence factors in the multi-way loading forming process, a sound 3D coupled thermal-mechanical rigid-viscoplasticity FEM model for multi-way loading forming process of triple valve body is established based on the software DEFROM-3D, and its reliability is validated. Then, a reasonable loading program is established, and the distribution of velocity field, temperature field, effective stress field, effective strain field and the load during the multi-way loading forming process of 40Cr triple valve body are discussed and analyzed. The result show that the diversion line appear on the horizontal branch tube at the loading program in the text, where crack is easy to appear. The horizontal branch tube is formed before the upright branch tube. The load of horizontal punch increase rapidly when the horizontal branch tube is formed completely, but the load of horizontal and upright punches increases rapidly together when the forming is completed. The high temperature region centralizes in the center of the billet with large deformation and deformation velocity, where the temperature increases obviously because of the plastic deformation energy. The achievements of this research provide guidelines for the controlling of disfigurement and the optimization of parameters.