Wear resistance of mine rock bit bearing friction couple between carburized-quenched EX30 steel and 55SiMoV steel

Generally,early failure of the bearing system is caused by low wear resistance of rolling friction couple consisted of the roller race way on jaw and roller.In this study,different carbon content of carburizing layer surface and the surface hardness are designed for EX30 and 55SiMoV steels,which are used as jaw and bearing roller of Mine Rock Drill Bit,respectively.The effect factors of wear resistance and optimum surface characteristic by carburizing-quenching treatment are determined by orthogonal abrasion test and SEM analyzing morphology of abrasive dust.The results show that influence degree of wear resistance is the sequence of surface carbon content of EX30 steel quenching hardness of 55SiMoV steel quenching hardness of EX30 steel;optimum surface characteristic matching are 1.0%-1.1%C in surface of EX30 steel with surface hardness of 58-59 HRC and 0.80%-0.90%C in surface of 55SiMoV steel with surface hardness of 58-59 HRC.In addition,the wear manner is contact fatigue wear of surface shallow exfoliation.