紧固件表面锰系磷化膜的制备及摩擦磨损性能

为了提高核主泵紧固件的摩擦磨损性能,采用三种磷化工艺在40Ni Cr Mo7钢表面制备了锰系磷化膜.采用多功能材料表面性能测试仪进行了往复摩擦磨损试验,并研究了在有无润滑条件下,不同工艺对磷化膜摩擦磨损性能的影响.采用扫描电子显微镜和能谱仪表征了磨损前后磷化膜表面的组织形貌和化学成分,并分析了其磨损失效机制.结果表明,通过工艺Ⅱ制备的磷化膜具有最优的摩擦磨损性能.磷化膜特有的孔隙结构具有储油能力,有利于改善其摩擦学性能.随着法向载荷的增加,磷化膜的塑性变形增大,抗剪切强度降低,且摩擦系数呈先缓慢下降后急剧上升的趋势.

Preparation and friction wear properties of manganese phosphate coating deposited on surface of fastener

In order to improve the friction wear properties of fasteners on reactor coolant pump, the manganese phosphate coating was prepared with three phosphate processes on the surface of 40NiCrMo7 steel. The reciprocating friction wear test was performed with a multifunctional material surface performance tester, and the effect of different processes on the friction wear properties of manganese phosphate coating under different lubrication conditions was studied. In addition, the microstructure and chemical composition on the surface of manganese phosphate coating before and after wear were characterized with scanning electron microscope （SEM） and energy disperse spectroscopy （EDS）, and the wear failure mechanism of manganese phosphate coating was analyzed. The results show that the phosphate coating prepared with processⅡshows the best friction wear properties. The special pore structure of phosphate coating has a capacity of storing lubricants, which is beneficial to improving the tribological properties of phosphate coating. With increasing the normal load, the plastic deformation of phosphate coating increases, while the shear strength decreases. Moreover, the friction coefficient slowly declines firstly and then sharply rises.