Effect Of Cryogenic Treatment Process On Wear Resistance Of YG8 Cemented Carbide

Cutters are the key parts and wearing parts on the coal shearer and boring machine that break rock and fall coal.It is welded by cemented carbide tips and alloy steel teeth.Our country's coal mine field study shows that the proportion of tooth failure due to tooth tip accounts for 35%to 45%,and wear is the most common failure mode.Increasing the wear resistance of the pick is the focus and focus of current research.Cryogenic treatment is an effective process method to improve the material properties.This paper takes the YG8 cemented carbide tip material as the research object to investigate the influence of cryogenic treatment on its wear resistance and obtain a reasonable heat treatment process.The cryogenic treatment of cryogenic treatment of YG8 cemented carbide was conducted by orthogonal design with five factors of cryogenic temperature,cryogenic rate,cryogenic time,tempering temperature and tempering times.The effect of hardness and friction and wear properties,and the combination of the best process parameters for the corresponding properties are obtained through range analysis.The results show that the deep cold tempering treatment plays a positive role on the wear resistance and micro Vickers hardness of YG8 cemented carbide.Compared with the untreated sample,the wear resistance increased by10.07%and the micro Vickers hardness increased by 4.35%.The influence of various process factors on the wear resistance of YG8 cemented carbide is the tempering temperature>cryogenic rate>tempering times>cryogenic time>cryogenic temperature,and the order of the micro Vickers hardness is the cryogenic rate>tempering times>cryogenic temperature>cryogenic time>tempering temperature.Scanning electron microscopy?SEM?,energy dispersive spectroscopy?EDS?,and X-ray diffraction?XRD?were used to analyze the changes in the phase structure of the samples and explore the mechanism of their improved wear resistance.The improvement of wear resistance is related to the increase of?-phase?Co₆W₆C?and the uniform distribution of point-like bulk dispersion.At the same time,the increase of?-Co in the cohesive phase Co?from the face-centered cube to the close-packed hexagonal body?is also one of the reasons that promotes the wear resistance of the YG8 hard alloy.