Tribological Characteristics of Plasma Nitrided and PVD Coated Cr-Mo-V Steels

The paper summarizes the results of tribological testing of duplex coating tool steels. Steel samples (31CrMoV9) were nitrated and subsequently treated by PVD process. There were deposited different types of coatings (TiN, CrN, TiAlN and multilayer 3 × (CrN-TiN)) with thickness 1 and 3 μm. Similar to these modified samples were tested and theirs characteristics were detected such as e.g. coating nanohardness (TiN – 35.5 GPa; CrN – 26.9 GPa; TiAlN – 32.9 GPa; 3 × (TiN-CrN) – 34.2 GPa), hardness of duplex coating, friction coefficient (Pin on Disc), coating thickness – Calotest (corresponds to information from the manufacturer), resistance against adhesive wear – Scratch test (TiN – 87 N; CrN – 52 N; TiAlN ^– 61 N; 3 × (TiN-CrN) ^– 61 N) and abrasion size – HEF (Hydromecanique Et Frottement) (TiN – 44.4 × 10–6 kg; CrN – 416.8 × 10^–6 kg; TiAlN – 23.9 × 10^–6 kg; 3 × (TiN-CrN) – 103.8 × 10^–6 kg for distance 10 000 m)