The Influence of Degumming Process on Tribological Behaviour of Soybean Oil

This paper presents experimental results for pointing out the tribological behaviour of two soybean oils (crude and degummed) in comparison to the transmission oil T90, with the help of tests on a four ball machine. The following parameters were analyzed: the friction coefficient, the average wear scar diameter (WSD) and the flash temperature parameter (FTP). The test parameters are: load 100, 200 and 300 N, sliding speed 0.461, 0.576 and 0.691 m/s, test time being 60 minutes. The friction coefficient was higher for the two vegetable grades, but its values kept in the range of 0.025 ? 0.095 for these vegetable oils, suggest a mixed or boundary regime that could be practically accepted. The WSD was lower for these two vegetable oils under lower load. For 300 N, WSD was higher than 0.4 mm for all tested oils. Flash temperature parameter (FTP) was better for the two grades of soybean oil at tests with 200 N. Under higher load (300 N), this parameter is kept within the range 800 ? 1000 N/mm1.4, for all tested oils. The conclusion is that, for all tested speeds and loads, the soybean oils (crude and degummed) have a better tribological behaviour.