Plasma nitriding was used to form a hard layer containing chromium nitride to a depth of approximately 7 μm on Inconel 718. Tribological properties of plasma nitrided Inconel 718 specimens were examined using an enclosed pin-on-cylinder unidirectional conformal contact wear test apparatus in air and dry nitrogen. Formation of laminar plate-like debris after prolonged sliding contact was observed; this debris contained fragments of the nitrided layer. The main mechanism that caused the observed failure of the nitride film is believed to be due to the high local contact stress between the material transferred from the counterface and the pin specimen. Substitution of air by nitrogen enhanced the formation of wear debris transfer films.