FINITE ELEMENT SIMULATION OP INTERNAL VOID CLOSURE IN OPEN-DIE PRESS FORGING

In the manufacturing of heavy forgings, one of the most important aspects of the process is the consolidation of internal voids which result from the ingotmaking process. To insure a good quality finished product, these voids must be closed by proper choice of forging practices - including such factors as die geometry* amount of reduction, reduction speed, and workpiece temperature. This paper focuses on the first two of these factors and reports the results of a study on the effects of die width and reduction on the closing of a void.

The deformation state in the cross-section of an ingot is predicted using a two-dimensional elastic-plastic finite element code for large strain, large deformation analysis. Simulations of forging with no void present are reported and compared with results from plasticine experiments. The effects of die width and amount of reduction on the internal deformation state are examined. A single internal void is then modeled in the same geometry ingot as a smooth cavity at the ingot center. The nature of the void distortion and closure is predicted by the finite element model.