ZDDP润滑下表面纳米化316L不锈钢的摩擦学性能

Tribological Properties of Surface Nanocrystallized 316L Stainless Steel Under ZDDP Lubrication

采用SRV摩擦磨损试验机考察了表面纳米化316L不锈钢在PAO4和ZDDP润滑下的摩擦学性能。采用X射线衍射仪(XRD)和金相显微镜表征纳米化样品的微观组织结构,采用扫描电子显微镜(SEM)和X射线光电子能谱仪(XPS)分析摩擦反应膜的微观形貌和化学组成。结果表明,表面纳米化明显提高了316L不锈钢的表面硬度,同时在表面产生了具有储油作用的微坑,在PAO4润滑下,纳米化样品的减摩抗磨性优于未处理样品;在添加ZDDP的PAO4润滑下,在纳米化表面形成了链长较短的磷酸盐膜,膜中Zn和P的含量也高于未处理样品,黏着磨损明显减轻,抗磨性提高幅度更为显著。

The tribological properties of 316 L stainless steel processed by ultrasonic surface nanocrystallization were investigated by a SRV tribometer under PAO4 and ZDDP lubrications.The microstructural evolutions of the nanocrystallized sample were characterized by X-ray diffraction（XRD）and optical microscope.The morphologies of the wear surfaces and chemical composition of tribofilms were investigated by scanning electron microscopy（SEM）and X-ray photoelectron spectroscopy（XPS）,respectively.The results showed that ultrasonic surface nanocrystallization treatment could significantly improve the hardness of 316 Lstainless steel.The micro-dimples on the nanocrystallized surface might play a role as lubricant reservoirs,thus the friction-reduction and anti-wear properties of nanocrystallized sample were much better than those of the original sample under PAO4 lubrication.The wear resistance of the nanocrystallized sample was remarkably improved under PAO4 ＋ ZDDP lubrication, which was attributed to the formation of a polyphosphate tribofilm with shorter chain length and the higher contents of Zn and P in the tribofilm on the nanocrystallized surface,thus the adhesive wear was reduced significantly with obvious enhancement of anti-wear properties.