BASIS OF A COATING CHOICE METHODOLOGY IN FRETTING

The fretting behaviour of Cr-Mo steel, either uncoated or coated with various materials (nitriding, electrolytic cadmium, plasma spray chromium carbides), was studied using fretting maps. Tests were carried out using 52100 steel cylinders as the counterface. The major parameters of the tribological system were identified and then quantified. They involved four different aspects: mechanical properties of the surface, coating-steel interface properties, running conditions in the contact and material response. The values of the parameters obtained for each coating were compared with the corresponding values for uncoated steel. The parameters were plotted using a polar diagram in order to give an overview of the fretting behaviour of each coating. Differences were underlined and the corresponding parameters were identified.