Abstract:In order to study the effect of iron in metal parts on high temperature oxidation of the aviation lubricating oil,the oxidation process of 50-1-4Ф aviation lubricating oil was stimulated by using the high temperature thermal oxidation accelerating device under the condition of containing iron or no iron.The change of the oil samples’ color,viscosity and acid value was observed,and the oxidation induction time of the samples was measured by PDSC.The results show that high temperature oxidation has little influence on the high temperature viscosity of 50-1-4Ф aviation lubricating oil,but has obvious influence on the low temperature viscosity,acid value and oxidation induction time of 50-1-4Ф aviation lubricating oil.Iron has a great influence on the acid value and oxidation induction time of the aviation lubricating oil,and the variation of acid value and oxidation induction time of the oil samples with iron is several times that of the oil samples without iron.Iron has obvious influence on viscosity at higher oxidation temperature (250 ℃,300 ℃),but little influence at lower temperature (180 ℃,200 ℃).