Plasma nitriding and nitrocarburising of sintered FeCrMo and FeCrMoC alloys

The effect of plasma nitriding and nitrocarburising on the microstructure, and the microhardness and the wear resistance of two sintered alloys, FeCrMo and FeCrMoC, was studied. Nitrocarburising improves the microhardness profile and the wear resistance of the C-free material with respect to nitriding, while it does not induce any appreciable improvement with respect to the nitrided C-alloyed material. The wear resistance of the nitrocarburised C-free material is the same as that of the nitrided C-alloyed material. Nitrocarburising tends to induce the grain boundary precipitation of carbonitrides in the diffusion layer.