Durability of the “Coating–Base” Composition during Rolling Friction

In this paper, we study the effect of various physical and mechanical properties, chemical and phase compositions of diffusion coatings of steels on the durability of tribosystems during rolling friction with point and linear contacts in an I-20 oil medium. Gradient coatings obtained by ion nitriding in anhydrous media and titanium and chromium nitride coatings, respectively, obtained by cathode-ion bombardment and galvanic deposition on steels with various levels of hardness after heat treatment were considered. The main factors affecting the contact endurance of coated steels and ways to increase the durability of tribosystems during rolling friction were identified in comparative tests using friction machines. A direct linear dependence of the durability of the coating-base composition on the hardness of the base for steels without metastable structures in the material and a deviation from this dependence toward increasing durability for steels with residual austenite in the structure of the material were established.