Optimal design of assembled and pre-stressed dies by means of numerical simulation

The cost of the tooling can reach up to 25% of total forging cost thus increasing of tool life and reduction of tool cost are vitally important. The dies can failure due to cracks caused by overloading, low cycle fatigue or abrasive wear. On the other hand, elastic die deflection can cause deterioration of the forged part shape. The paper presents the ways for increasing of tool life and product accuracy through systematic implementation of simulation. It can be done by modification of die design that reduces stress concentration in the corners or by using assembly dies that have splits in critical areas in combination with shrink rings and inserts. The approach is illustrated by practical examples.