润滑环境下QT600-3、QT600-10球墨铸铁与锰系磷化处理DC01钢摩擦特性研究OA北大核心

When the differential of new energy vehicles operates at high speed,thermal fatigue,adhesive wear,and abrasive wear caused by friction and wear between the differential housing and the gasket can dete-riorate the transmission efficiency and service life of the differential.Therefore,sliding friction and wear tests were conducted on QT600-3,QT600-10 ductile iron,as well as manganese based phosphating and unphos-phating DC01 cold-rolled steel gaskets,using the CETR multifunctional friction and wear test machine.The tests were performed against friction pairs in an environment of lubricating oil(Castrol BOT 805C EV).The experimental results show that the friction coefficient between QT600-3 ductile iron and phosphate gasket is 0.39～0.41,while it is 0.42～0.45 for unphosphated gasket.For QT600-10 ductile iron,the friction coeffi-cient with phosphated gasket is 0.41～0.45,and with unphosphated gasket,it is 0.42～0.47.The manga-nese phosphate coatings reduce the friction coefficient of the sliding friction pair.Specifically,the QT600-3 ductile iron exhibits a smoother and lower friction coefficient due to its higher graphite content.The friction and wear process primarily occurs within the manganese phosphate coatings on phosphated gaskets,which re-main relatively intact with a maximum wear depth of approximately 5 μm.The wear loss of QT600-10 ductile iron,when paired with both phosphated and unphosphated gaskets,is lower than that of QT600-3 ductile iron,attributed to the higher hardness.During friction and wear,the grains of the manganese phosphate coat-ings on phosphated gaskets are crushed and damaged,forming wear debris that acts as third type of abrasive particles,causing slight grooving on the coating surface.The wear mechanism involves mild abrasive wear and oxidative wear.In contrast,the unphosphated gasket surfaces exhibit more pronounced grooving,with oxide abrasive particles generated by sliding acting as abrasive particles.The wear mechanism for unphos-phated gaskets are mainly abrasive wear and oxidative wear.