I. Gas Hoop Forging Computer-aided Analysis And Design Optimization

Ventilate-pipe is a forging workpiece with long axis. To produce qualified forging workpiece with complicated structure, the process needs to be logical and the mould must meet the size accuracy request. This paper analyzes the process characteristic of ventilate-pipe forging and determines a process scheme. The open die drop forging with the 5 T steam-air hammer is selected. The die of the ventilate-pipe forging workpiece is designed by the conventional die-designing method. The structure and size of the die and billet is given. In the following part of simulation, the author expatiates on the basic hypothesis of the rigid plastic FEM (such as the metal being looked as rigid plastic body in the large deformation problem) and the theory principle, and introduces the DEFORM software. Using the DEFORM-3D FEM software, the author simulated the ventilate-pipe forming process (preforging and final forging). The possible problem that existed in the conventional die-designing is predicted. This paper modified properly the size of the die and the forging workpiece and optimized the process scheme. The rationality of the final scheme is validated by analyzing the problem such as stress, strain, the die load, the velocity reducing of forging hammer, the contact between the die and the workpiece, the distribution of the temperature field and etc. in the workpiece-forging process.Reasonable parameter can be confirmed by investigating the forging process at different temperature and lubricating condition. According to the DEFORM FEM simulation, the analyse of the die forging process becomes more convenient. As a result, the die-designing efficiency and the veracity being improved, the cost being saved, and the production period being shortened.