石墨烯作为轧钢机轴承润滑脂添加剂的研究*

为改善轧钢机轴承用润滑脂的性能,采用不同质量分数的石墨烯对润滑脂进行了改性,测定各润滑脂样品的锥入度和滴点,使用四球摩擦试验机研究石墨烯对润滑脂摩擦学性能的影响,使用扫描电子显微镜、白光干涉仪和拉曼光谱仪等分析石墨烯在润滑脂中的减摩抗磨机制。结果表明:石墨烯作为添加剂能提高润滑脂的滴点和改善润滑脂的极压性能以及减摩抗磨性能。当石墨烯质量分数为0.2%时,对润滑脂极压性能的提升效果最好,表现为烧结负荷和综合磨损值最大,较基础脂分别提高了29.0%和24.0%;当石墨烯质量分数为0.3%时,对润滑脂减摩抗磨性能的提升效果最好,摩擦因数和磨斑直径较基础脂润滑时分别下降了22.4%和13.0%,磨损体积减少了43.0%,且最大无卡咬负荷提高了21.2%。石墨烯在摩擦过程中,吸附在摩擦表面,形成保护薄膜阻止了摩擦副材料的直接接触,减少了磨损,同时提高了润滑脂的承载能力。

Study on Graphene as Grease Additive for Rolling Mill Bearing

To improve the tribological properties of rolling mill bearing grease,the grease was modified with different mass fraction of graphene.The penetration and drop point of each grease sample were measured,the influence of graphene on the tribological properties of the grease was studied on the four ball friction testing machine,and the friction reducing and anti-wear mechanism of graphene in the grease was analyzed by scanning electron microscope,white light interferometer and Raman spectrometer.The results show that the graphene can improve the drop point,the extreme pressure performance and the properties of friction reducing and anti-wear of the grease.When the mass fraction of graphene is 0.2%,the best improving effect is got in the extreme pressure performance of the grease,and the sintering load and comprehensive wear value are increased by 29.0%and 24.0%compared with the base grease,respectively.When the mass fraction of graphene is 0.3%,the best improving effect is got in the properties of friction reducing of the grease,the friction coefficient and wear spot diameter are decreased by 22.4%and 13.0%,respectively,and the wear volume is decreased by 43.0%and the maximum non seizure load is increased by 21.2%compared with the base grease.During the friction process,graphene is attached to the friction surface and forms a protective film,which prevents the direct contact of friction surface,reduces wear and improves the carrying capacity of the grease.