Reasons for teeth fracture of 20CrMnTi steel gear shaft

Chemical composition analysis, fracture analysis, metallographic examination, hardness test were used to analyze the causes of tooth fracture of gear shaft for a crane. The results show that the decarburization phenomenon in the carburizing layer of the gear shaft and the low strength of the core tissue were the main reasons for the fracture of the gear shaft. The metallographic examination method had limitations in measuring the thickness of carburizing layer.