Abstract
The fatigue behavior of cemented carbide die under service load in the multistage cold forging of steel was investigated. It was found that the fatigue cracks do not initiate at the stress concentration position. TEM images at the position near the crack tip show dislocation exists in the WC particles and Co phase keeps fee arrangement. EPMA observation of fractograph shows that the volume of WC is about 70-80%. It can be concluded that the fatigue crack propagates in the WC particles and along the interface between WC particle and Co phase.
