Investigation of metal flow and preform optimization in flashless forging of a connecting rod

Abstract In conventional hot forging of connecting rods, the material wasted to the flash accounts approximately 20 to 40% of the original workpiece. In order to reduce the cost of forged products, the forging must be performed in a closed cavity to obtain near-net or net shape parts. In flashless forging, the volume distribution of the preform must be accurately controlled to avoid overloading the dies and to fill the cavity. Additionally, the preform must be simple enough to be mass produced. This study deals with the design of the optimum preform to forge a connecting rod without flash. The initial preform design was obtained from physical modeling experiments. The optimization of this preform was found through 3D FEM process simulations. The advantage of performing simulations is that no tooling has to be built and the number of experimental tryouts can be significantly reduced. A preform optimization methodology was derived for this investigation.