The Nature of the Friction Transition as a Function of Load and Speed for the Steel/Steel System©

In this paper the load-speed diagram of steel/steel rubbing pair wider lubricated conditions was measured using the ball-on-disc lusting machine and the stepwise loading method. The role of the lubricating oil at the various transition regions was examined. It has been shown that the transition between lubrication states in the load-speed diagram was completed within a certain interval of load, i.e. the load-speed diagram was constituted by not three, but five regions. In this paper the composition and valence state of surface film was systematically analyzed by AES and ESC A within the different lubrication states. This paper also discusses the role of oxide film in the transitions of load-speed diagram, and proposes a model about the structure and role of oxide film as well.