초록
The design of the prestressed cold extrusion die with two stress rings has been performed in this study. The cold extrusion has been simulated by the rigid-plastic FEM. The stress analysis of die has been performed for both after shrink fitting and during extrusion by using the elastic FEM and the Lame's equation. According to the variation of interferences and diameter ratios, the maximum effective stress has been evaluated. As results, interferences and diameters were determined by the minimization of the maximum effective stress of die insert. The comparison of the maximum effective stress between the proposed design and the conventional design has been discussed. It was found that the maximum effective stress in the die insert is considerably affected by the stiffness of the first stress ring.
