Mechanical Behavior of Nitrocarburised Austenitic Steel Coated with N-DLC by Means of DC and Pulsed Glow Discharge

AISI 316L steel was subjected to nitrocarburizing under glow discharge conditions, which was followed by DLC (diamond-like carbon) coatings deposition using the same device. The coatings were applied under conditions of direct current and pulsed glow discharge. In order to determine the influence of the produced nitrocarbon austenite layer and the type of discharge on the microstructure and mechanical properties of the coatings, the following features were analysed: surface roughness, coating thickness, structure, chemical composition, adhesion and resistance to frictional wear. For comparison purposes, DLC coatings were also deposited on steel without a nitrocarburised layer. The obtained results indicate a significant influence of the type of glow discharge on the roughness, hardness, nitrogen content and of the nitrocarburised layer on the resistance to wear by friction and adhesion of the produced coatings.