THE SYNERGISTIC EFFECTS OF EP AND AW ADDITIVES WITH OXYNITRIDED SURFACE OF STEEL

The addition of various extreme pressure (EP) and anti-wear (AW) addit ives in lubricating oil is an important and effective way to reduce fr iction and wear. The application of chemico-thermal treatments on the surface of materials is another effective way for improving the tribol ogical behaviour of rubbing pairs. In this paper the synergistic effec ts of two EP/AW additives, sulphurized olefin and tricresyl phosphate, with an oxynitrided surface of 1045 steel on the tribological behavio ur were studied systematically on a 'ball-on-disk' testing machine. An excellent result of increasing load-carrying capacity and reducing fr iction and wear was obtained. The mechanism of this synergistic effect was discussed based on the microanalysis of surface film by AES and X PS.