Tool Life Evaluation of Cold Forging Dies Using Numerical Prediction Model Based on Fatigue Characteristics of Tungsten Carbide

A simple tool life prediction model was proposed for the fatigue crack failure of tungsten carbide tool in the cold forging process. To model the fatigue characteristics of tungsten carbide material, the axial tension-compression tests and the 4-point bending tests were carried out under several cyclic loading conditions to cover various stress variations. The proposed tool life prediction model was based on a simple stress-life theory using the mean value and the amplitude of stress variation during a forging cycle. To calculate the tool stress distributions at the initial and the loading status, the general-purpose forging simulation software DEFORM-2D/3D was used for the forging process and the elastic tool stress simulations. The proposed model was applied to several forging process examples to evaluate its accuracy and robustness.