Influence of die parameters on internal voids during multi-wedge-multi-pass cross-wedge rolling

The formation of internal voids in workpieces during cross-wedge rolling affects die design and limits their widespread applications. This article investigated the formation of internal voids during the multi-wedge-multi-pass rolling production of connecting rods. A three-dimensional numerical simulation model of cross-wedge rolling (CWR) was established using the rigid-plastic finite element method, and a density change model of the porous material was developed to characterize the degree of internal void formation in the connecting rod during CWR. The optimal die parameters (forming angle, spreading angle, and distribution coefficient of area reduction) were determined by determining their relationship to the density. The stress and strain of characteristic points near the loose longitudinal sections were used to study the void formation mechanisms. The accuracy of the numerical simulations was verified by rolling experiments, which showed no void formation in the internal sections of the connecting rod after production, confirming the feasibility of using this scheme to prevent void formation.