TRIBOLOGICAL BEHAVIOR OF COARSE RAPESEED OIL TESTED ON FOUR BALL TESTER

This paper presents the influence of load and sliding velocity on several tribological parameters like friction coefficient and wear rate of the wear scar diameter of the balls used in a four-ball test, when using rapeseed oil as lubricants. The test parameters for were: loading force - 100 N, 200 N and 300 N (± 5%), sliding speed of 0.38 m/s, 0.53 m/s and 0.69 m/s, corresponding to the spindle speeds of the four-ball machine 1000 rpm, 1400 rpm and 1800 rpm (± 6 rpm), respectively, test time - 60 minutes (± 1%). The test balls are lime polished, made of chrome alloyed steel balls (EN31), having 12.7±0.0005 mm in diameter, with 805 N/mm2 hardness VHN, as delivered by SKF. The sample oil volume required for a test was 8 ml ± 1 ml. A general view of the results on friction coefficient reveals that this vegetal oil could be used in application with mild regime as concerning the load and speed.