Analysis Of Metal Flow And Die Stress For Eyelet Machine Of Seamless Steel Pipe

In the process of steel tube in periodic tube rolling plant, huge piercing die hold the balance of produce cost, produce efficiency and product quality. The temperature on the inner wall of the piercing die is more than 600°C when it is working, and it also suffers invert stress. Therefore, fatigue crack is easy to form on the inner wall of the piercing die, which will lead to the decline of the fatigue life, the increase of production costs, and the downgrade of steel tube quality.In the process of punching hole, cavity die structural stress change is extremely complex, moreover because the temperature difference between the inwall and ectotheca when it works, there is also thermal stress besides the structural stress. It is difficult to analyze the die stress and metal flow accurately with the traditional engineering analysis method. So, based on the domestic and foreign detail reviews of the development of materials deformation and die stress analysis used finite element method (FEM), simulated the punch forming of the billet at the deformation temperature with FEM, and thus obtained the situation of the die stress and metal flow.Firstly, simulated the punch forming of the billet with the FEM simulation method, analyzed the metal flow in the deformation process; obtained the formed punch unit pressure distribution situation and how the pressure change with stroke; analyzed the stress situation of the cavity die inwall in the deformation process detailed, and knew how the deformation band, friction condition, deformation degree and deformation material influence the cavity die inwall lateral pressure through changing deformation condition. Next, simulated the temperature field generated because of the inside and outside temperature difference with the FEM analysis method; obtained each direction thermal load distributed situation with the direct thermal energy coupling method. Finally, briefly introduced the basic principle and method how to estimate fatigue life uses the local stress-strain method as well as the optimum design of die.Synthetically utilize the above method to analysis the metal flow and die stress deeply, is helpful to know the die stress situation in all kind of condition as well as the stress distribution situation in each deformed area. So we can increase the operating life of the die by optimizing the die structure and improving running condition. By ding this,...