The Effect of Certain Nitrogen and Sulphur Compounds in Extreme Pressure Lubrication

The blends of 1-(N,N'-diphenyIamidino)-3-arylthiocarbamides and N-arylthiosemicar-bazides in paraffin oil (0.5% wt/vol) were evaluated as extreme pressure lubricant additives in the four-ball test. The test specimens were 12.7 mmdiameterstecl bearing balls and the parameters studied were wear-scar diameter, 2.5 second seizure delay load, coefficient of friction, flash temperature parameter, mean specific pressure and mean Hertz load. The tested additives were found to reduce wear and friction to appreciable levels and increase the load carrying capacities and weld loads as compared to the base fluid. The surface topography and tribochemistry of the used bearing ball's wear-scar matrix were studied by Scanning Electron Microscopy and Scanning Auger Electron Spectroscopy techniques, respectively.