Electrochemical study on the fretting corrosion synergistic damage mechanism of Inconel 690 alloy in different dissolved oxygen solution

In-situ electrochemical measurement was used to investigate the fretting corrosion synergistic damage mecha-nism of Inconel 690 alloy in the solution with different dissolved oxygen (DO) concentrations. The synergistic mechanism of fretting corrosion was quantified. Results show that the minimum fretting corrosion damage of Inconel 690 was obtained at DO concentration of 2 ppm and the corrosion-accelerated wear, which can be represented by the influence of third body layer (TBL) on the fretting corrosion damage mechanism, is the key contributor. The formation and rupture of TBL have been observed under different DO concentrations. In transitional stages of TBL formation and the stage where uniform morphology formed, the TBL with excellent ductility can improve the contact behavior and reduce fretting corrosion damage. In stages during which TBL breaks into hard spinel oxides, severe abrasive wear and fretting corrosion damage will be caused.