Study of Crack Initiation and Fracture Behavior of Large Carbide Top Hammer.

In view of the problem that the top hammer was prone to structural failure caused by cracking hammer and collapse hammer during long-term loading and unloading, taking Ф240 large top hammer as the research object, the stress distribution in sensitive areas of the super large top hammer in the working process was calculated and analyzed by finite element software. The stress situation of the small top hammer under the same working conditions was compared and studied, and the reasons for the super large top hammer easy to break were analyzed from the stress aspect. Then, the elemental mapping analysis was carried out by scanning electron microscopy, and the fracture morphology and chemical composition of the broken top hammer were studied. The results show that the tensile stress and shear stress of the top hammer slope are greater than those of the core, the crack source is easy to occur at the inclined surface, and the crack mainly extends along the WC / WC interface. The high pressure anvil has a higher degree of fracture oxidation and Co phase precipitation accumulation due to the temperature being higher than the slope. [ABSTRACT FROM AUTHOR]