PROSPECTS FOR THE APPLICATION OF ION-PLASMA METHODS FOR INCREASING THE FATIGUE STRENGTH OF TRIBOSYSTEMS

Abstract

Intensive research and development of multicomponent functional coatings and methods of their application on the surface with precision processing, which is required by the components of modern units of aircraft construction, space technology and other industries, are now being carried out in Ukraine and in the world. The Avinit N plasma precision nitriding methods widely used in industrial production of JSC FED have significant differences and advantages over traditional furnace methods of gas nitriding, namely: a significant reduction in the duration of diffusion saturation with nitrogen of the surface layer of iron-based alloys with an overall reduction in the technological time processing cycle up to 3-5 times; completely avoid hydrogen embrittlement; ensure dimensional preservation (nitriding “to size”) and high surface finish, reduction of the brittleness of the nitrided layer and the formation of nitride zones of all compositions without pores, as a result of which surface refinement after nitriding is not required. The article presents the results of tribological studies of the effect of plasma nitriding according to JSC FED technology on the contact strength from fatigue of steel 20X3MVF GOST 20072 during rolling friction with slipping surfaces and comparing the results with the contact fatigue strength of the same steel hardened by traditional gas cementation technology. They showed that the wear resistance of specimens reinforced with Avinit N nitriding is significantly higher than that of specimens hardened by traditional carburizing. The integrated multi-cycle resistance to fatigue wear (fracture) of samples hardened by nitriding Avinit N is more than 10 times higher than that hardened by cementation. This is due to the mechanisms of fatigue failure of cemented samples (spalling along the boundary of the defect). The results of the work can serve as the basis for conducting research on the use of ion-plasma nitriding technologies instead of cementing in order to increase the contact strength of the surface of the parts, taking into account also the advantages of this technology, such as maintaining the size and high purity of the surface treatment, as a result of which there is no need for their mechanical refinement after hardening.