Abstract: The effect of anti-oxidation properties of three 150BS bright stocks (150BS-1,150BS-2 and 150BS-3) from different sources on performance of gear oils blended with the bright stocks were studied by RPVOT, oven oxidation test (OOT) and extreme pressure performance test. The results showed that, compared with the solvent refined 150BS-2, the hydrotreated stocks of the domestic 150BS-1 and the imported 150BS-3 have the better anti-oxidant sensibility to antioxidant. The saturated polycyclic naphthene has a negative effect on the oxidation resistance of 150BS hydrotreated. The better of the oxidation stability of the 150BS is, the better the anti-oxidation resistance of the industrial gear oil with bright stock.

Key words: 150BS Bright Stock, oxidation stability, gear oil