An approach to determining the workability diagram based on upsetting tests

Abstract

ABSTRACT To determine a workability diagram for bulk metal forming processes, it is proposed to use experiments in which fracture occurs at a free surface. A good example of such experiments is an upsetting test with profiled dies. An advantage of this method is that fracture conditions are formulated in terms of strain components whereas stresses are excluded using an exact theoretical solution. In the present study three axisymmetric upsetting tests, with flat dies and with conical dies, are carried out to determine the strain to fracture. The method proposed is then combined with these experimental data to find an approximation to the workability diagram of a tool steel.