The effect of normal force on fretting corrosion behavior of Inconel 690 in 3.5% sodium chloride

The effect of normal force on fretting corrosion behaviors of Inconel 690 in 3.5% sodium chloride was investigated. The results indicated that fretting corrosion behaviors strongly depended on fretting regime and normal force. In gross slip regime, the wear volume increased but coefficient of friction (COF) decreased with increasing normal force. The damage mechanism was nanostructures and delamination cracks, and the tribologically transformed structure was separated into Ni-rich/Cr-rich oxide zones. The wear mechanism was delamination/oxidation wear. In partial slip regime, wear volume and COF decreased with increasing normal force. The main damage mechanism was fatigue cracks and asperity corrosion. The fatigue cracks propagated along the direction of 40-50° to the surface. The wear mechanism was oxidation/abrasive wear.