提高车用发动机活塞环摩擦学性能的试验研究

制备了直接离子渗氮环与超声滚压加工-离子渗氮环两类摩擦学试样。利用电子显微镜、硬度计、X射线衍射仪和能谱仪,对表面改性层进行了表征,分析了超声滚压预处理对316L不锈钢活塞环离子渗氮行为的影响;在润滑油条件下,使用往复式摩擦磨损试验机,对比考察了直接渗氮环和超声滚压-渗氮环的摩擦学性能。结果表明,超声滚压-渗氮环相对于直接渗氮环渗氮层的氮含量增加了2.9倍,显微硬度提高了1.1倍,摩擦因数降低了0.04,耐磨性提高了2.8倍。发动机台架试验表明,超声滚压-渗氮环与硼铸铁氮化气缸套的匹配性最好。

Experimental Study on Improving Tribological Properties of Piston Ring for Vehicle Engine

Two kinds of test specimens were prepared by direction nitriding and ultrasonic rolling following with ion nitriding respectively .The surface characteristics were expressed by using electron microscope ,sclerometer ,X-ray diffractometer and energy dispersive spectrometer and the effect of ultrasonic rolling pretreatment on ion nitriding behavior of 316L stainless steel piston ring was further analyzed .Then the tribological properties of direct nitriding rings and ultrasonic rolling /nitriding rings were compared and investigated with friction-abrasion testing machine .The results show that the nitrogen content of nitriding layer for the ultrasonic rolling /nitriding ring is 2 .9 times as that of direct nitridation ring .The microhardness increases by 1 .1 times ,the friction factor decreases by 0 .04 and the wear resistance increases by 2 .8 times .The further engine bench test shows that the ultrasonic rolling /nitriding ring has the best matching performance with the boron cast iron nitriding cylinder liner .