Probing the tribocorrosion behaviors of three nickel-based superalloys in sodium chloride solution

The tribocorrosion behaviors of three nickel-based superalloys (Incoloy 800, Incoloy 825, and Inconel 625) in 3.5 wt% NaCl are studied under the cathodic, natural-corrosive, and anodic polarization states. XPS depth profiling confirms that the tribofilm compositions not only strongly depended on the alloy compositions but also significantly affected by the polarization potentials. With the potential increases from − 0.80 to +0.25 V, the decreased COF originates from the increasing content of Cr oxides in the tribofilm. The compound Ni/Fe oxides were worn away from Inconel 625 while Fe oxides contribute the main mass loss of Incoloy 800 and 825. The tribofilm with more Fe oxides (Incoloy 800 and 825) delivers a lower COF value but larger wear volume.