A study on flash- and flashless-precision forging by the upper-bound elemental technique

Abstract

An upper-bound elemental technique (UBET) program has been developed to analyze the forging load, die-cavity filling and effective strain distribution for forgings with and without flash. The simulation program is applied to axisymmetric, plane-strain and non-axisymmetric closed-die forging with a rib-web type cavity. Inverse triangular and inverse trapezoidal elements are used to analyze the axisymmetric and plane-strain forging process without flash. To analyze the process easily, it is suggested that the non-axisymmetric forgings is divided into two different parts, these being on the axisymmetric part in corners and a plane-strain part in lateral areas. The analysis is described for the merit of precision forging without flash. Experiments have been carried out with pure plasticine specimens at room temperature. Theoretical predictions of the forging load and the flow pattern are in good agreement with experimental results.