Understanding the Microstructure Evolution of Ni-Based Superalloy Within Two Different Fretting Wear Regimes in High Temperature High Pressure Water

The microstructure evolution of the worn scar central areas formed on Ni-based Alloy 690 (Ni-30Cr-10Fe, wt.%) within two different fretting wear regimes in high temperature high pressure (HTHP) water were studied in detail by high resolution characterization techniques. A very complex stratified structure was found within gross slip regime while only a relatively simple structure was found within partial slip regime.The wear mode and the evolution mechanisms of specific microstructures within the two different fretting wear regimes are clarified.