Stupnikov

This paper presents a mathematical model of a co-saturating complex alloy steel with carbon and nitrogen in the low pressure atmosphere. They developed software that gave an opportunity to estimate concentration curves of carbon, nitrogen, and basic alloying elements for VKS-10 steel, as well as the main characteristics of the phase composition in tabular and graphical forms on the basis of the parameters of vacuum nitrocarburizing. The effect of the complex chemical composition of the steel on formation of the diffusion layer was taken into account. Sufficient adequacy of the model within the temperature range from 880 to 940 ° C was demonstrated; these temperatures are the same as during high-temperature nitrocarburizing. With the help of this mathematical model patterns of formation of diffusion layers depending on technological factors of vacuum nitrocarburizing were investigated.

Development of new technologies of thermal and thermochemical treatment, based on the activation of cementation processes and which could provide volume and surface finely-divided or nanostructured state of constructional materials appeared to be a very powerful method to increase the durability of critical machine elements. Results of estimating the durability and micro-hardness of VKS -7 and VKS-10 steels were presented in this article after complex processing which consisted of two stages: 1 – preliminary plastic deformation by means of warm shortening and 2- plasma nitration or vacuum carbonization. Analysis of the relation between hardness and durability was carried out.

The authors present results of experimental evaluation of ability of surface layers of nitride steels and alloys to resist damage under conditions of deformation during friction. A new approach to comparative evaluation and selection of nitriding mode of parts and friction joints is proposed.