Investigation of Weight Saving Potentials in Complex Steel Forgings via Extrusion and Forging Combination using Finite Element Analysis

摘要

Closed-die forging with flash is the most common method of bulk metal forming processes. In this processes, two or more dies are pushed towards each other to form a simple billet into a more complex shape. The billet always includes surplus material which flows during forging out of the die cavity through the flash land. This flash ensures complete filling of the forging die cavities. However, flash should be trimmed and discarded after forging operation which requires an additional process and simultaneously results in material waste. In the current study, the potential of extrusion process to generate pre-shape for a forging operation is investigated using finite element analysis. A complex ball joint body part of the car suspension system is used as a demonstration element in the study. Material flow and die filling is analyzed using finite element method with Simufact.forming software. Different strategies are tested in the design of extruded pre-shape for forging using finite element analysis. In these tests, besides material flow and die filling, contact normal stresses as well as billet weight are investigated. A test die set is produced to validate the finite element simulation results. With the newly designed system, flash amount could be reduced from 33% to 12%. Moreover, as a result of lower weight of the billet, contact normal stresses between the forging dies and the billet material could be reduced about 38%. This aspect should reduce wear and consequently increase tool life.