EFFECTS OF HARDNESS ON THE WEAR MODE DIAGRAM IN LUBRICATED SLIDING FRICTION OF CARBON-STEELS

The predominant wear mechanisms were studied using discs with five different hardnesses as a function of contact pressure and sliding velocity in thin-film-lubricated sliding under conditions of concentrated contact with a hard chromium stell ball. Mild flow wear, severe flow wear, adhesive wear and oxidative wear were found. These wear mechanisms were plotted in a wear mode diagram for each hardness, representing the predominant wear mechanism as a function of the applied contact pressure and sliding velocity. It was found that the location of each possible region in the diagram changed, depending strongly on the hardness. It was also found that the shapes and sizes of wear debris particles depended strongly on the predominant wear mechanism as well as on the specific wear rate. This diagram was related to the abrasive wear mode diagram and discussed.