脲基脂润滑下的钢材料微动磨损研究

 采用微动摩擦磨损试验机进行了脲基脂润滑下的GCr15 钢/45号钢摩擦副摩擦磨损试验。利用激光三维共焦显微镜、EDX元素分析等方法研究了脲基脂润滑减缓钢微动磨损的机理。结果表明：在微动滑移区脂润滑下摩擦系数和磨损远低于干态下的值，且磨损主要发生在微动的早期阶段。在微运初期，脂因微动被排出接触区，高摩擦力导致白层和磨坑的形成；接触区周围的脂剪切分离的油浸入到磨坑中，形成混合润滑状态，摩擦系数降低到较低的稳态值；接触区周围的脂和磨痕上油的存在阻止了空气进入，氧化磨损得以降低。低稳态摩擦力、高硬度白层的存在和低氧化磨损是脂润滑减缓微动磨损的主要因素。

STUDY OF FRETTING WEAR OF STEEL UNDER UREA GREASE LUBRICATION

The fretting behavior in the slip regime with urea grease lubrication for GCr15 steel/45 steel contact was studied and the mechanism of decreasing fretting wear of steel under urea grease lubrication was investigated. Compared with dry condition, the coefficient of friction and wear were decreased drastically and the wear occurred mainly at the early stage of fretting. During initial stage of the fretting, the high friction force owing to grease elimination from the contact zone led to the formation of white layer and wear cavity. The oil separated from the grease around the contact interface penetrated into the wear cavity and the mixed lubrication regime was formed. Thus the coefficient of friction decreased to a low steady value. In addition, the grease around the contact interface and the separated oil at the wear scar zone prevented the penetration of air, so that the oxidation wear was reduced. The low stable friction force, white layer and low oxidation wear were the main factors of palliating fretting wear.