Effect of pH value on the fretting wear behavior of Inconel 690 alloy

The fretting test was carried out using a SRV IV fretting test rig in order to investigate the effect of pH value on the fretting wear behavior of Inconel 690. The experiment was performed in pH values of 1, 4, 7, 10 and 13. The worn scars were studied by laser scanning confocal microscope (LSCM), scanning electron microscope (SEM) and energy dispersive spectrometer (EDS). The electrochemical data was also obtained to study its corrosion behavior. The results revealed that the pH value had a big influence on the fretting behavior of Inconel 690 due to the change of the galvanic corrosion degree of the fretting pairs with pH value. The surface state of the worn scar also changed at different pH values, which had a big influence on the friction coefficient, wear volume and the electrochemical behavior. Faradays law was used to qualitatively analyzes the relationship between the wear volume and the corrosion current of the fretting pair.