COMPARISON OF FORGING LOAD, MATERIAL FLOW AND PRESSURE DISTRIBUTION OF THE UNI-DIRECTIONAL, BI- DIRECTIONAL AND TWO-STEP FORGING PROCESSES

Because of high productivity, closer dimensional tolerances, and minimal material waste precision forging (net or near net shape) processes have been used for manufacturing automobile components. The primary disadvantage of precision forging is the encountered higher tool stresses due to applied higher forging loads. Thus, forging load reduction is a higher priority in precision forging in terms of energy consumption and cost because higher loads required higher investment and higher energy consumption. Forging load is affected by several parameters such as temperature, material flow, the geometry of the billet, and punch movement. In this study, forging load, material flow, and normal pressure distribution in the forged part were investigated considering uni-directional, bi-directional, and two-step forging processes. FEM simulations were performed by using a solid cylindrical billet. To perform FEM simulations, the finite element analysis package (DEFORM 2D) was used. Also, experimental studies of the FEM models were performed. For bi-directional and step-forging experimental studies, a double-acting servo press was used because the movement of the top and bottom punch can be controlled accurately. Then the results of FEM and experimental studies were compared with each other. The results of the FEM simulations and experimental studies show two-step forging offers lower forging load and energy consumption whereas the uni-directional closed die forging process needs higher load and energy consumption.