Analysis and Design of the Prestressed Cold Extrusion Die

The stress analysis and design of a prestressed cold extrusion die with stress rings has been carried out in this study. The calculation of the contact pressure on the interface between the die insert and stress ring is included. In this method, an elastic finite-element method and Lame’s equation are used for the analyses of the die insert and the stress ring, respectively. The cold extrusion process has been simulated by the rigid finite-element method. Using these results, stress analysis has been performed for shrink fitting and during cold extrusion by using the present method. According to the variation of interferences and diameter ratios of the die with one and two stress rings, the maximum effective stress has been evaluated. In the results, interferences and diameters were determined by the minimisation of the maximum effective stress of the die insert. A comparison of the maximum effective stress between the proposed design and the conventional design has been discussed.