The Effect of Counterbody Material on Tribological Behavior of Active Screen Plasma-Nitrided Inconel 718 Under Saline Solution

Considering the relevance of Inconel 718 alloy for the oil and gas industry and the nature of the tribological system to define the friction and wear behaviors during sliding, this investigation presents results obtained in reciprocating tests under saline solution for active-screen plasma-nitrided Inconel 718. Bearing steel and silicon nitride ceramic were used as counterbodies, balls of 4 mm diameter. Extensive plastic deformation was confirmed using nanoindentation analysis, and oxidation governed the tribological responses when the steel ball was used as a counterbody. In these conditions, the presence of a nitrided layer was significant in reducing wear by one order of magnitude. On the other hand, when the ceramic ball was tested, abrasive wear was the primary mechanism, and the nitrided layer did not affect either the friction or the wear rate of Inconel 718. The corrosion behavior helped to confirm the predominance of described wear mechanisms. Graphical abstract: [Figure not available: see fulltext.].