Study On Fe Simulation Of Forging Process Of Heavy Axial Forgings

Heavy axial forgings, including large-scale roller, transmission shaft and steam turbine rotor etc, are widely used as key parts of many heavy machines and equipments. Compared with forgings of normal size, heavy forgings are more difficult to manufacture, and also have more severe internal metallurgy defects, such as cavity, segregation, inclusion and porosity. Therefore, appropriate forging process must be exerted on heavy axial forging to eliminate these internal defects and get the final products which satisfy the requirement of size precision and internal quality.The complete forging process of typical heavy axial forging -- 300MW steam turbine rotor is studied and divided into 3 main forging approaches firstly. Then, the finite element code DEFORM is applied to simulate the different forging approach sequentially. And finally, by analyzing the influence of different forging parameters on the internal quality and size precision of the final-shaped forging, optimized forging process of heavy axial forging is obtained according to the simulation results. The main research contents and conclusions of this article are summarized as follows:(1) The forging process from billet with round section to forging with square section is simulated. During this simulation, considering the influence on surface quality of heavy forging, different forging parameters, such as the anvil fillet, the relative feed and reduction during this forging process are analyzed and optimized.(2) The stretching process of forging with square section under flat anvils is simulated. During this simulation, the influence of different parameters, such as the anvil width, the reduction and the reposition of the anvil during each pass on the forging internal quality are discussed. And finally, the optimized pass sequences of this stretching process are obtained.(3) The final chamfering and rounding process of heavy axial forging under different anvils, such as flat, 90o V-shaped and 120o V-shaped anvil are simulated. During the simulation, the influence of different anvil shape on the size precision and strain-stress distribution of the final forging are discussed. And finally, the optimized anvil shape and its pass sequences are obtained.