Lashnev

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.

The regression dependence of the carbon and nitrogen potential on the acetylene temperature and concentration at saturation of iron and complex-alloy steels in glow discharge plasma was determined. The defining influence of the adsorption rate of acetylene molecules on the intensity of carbon mass transfer was revealed. The most probable reaction of acetylene dissociation was determined according to the analysis of experimental data, thermodynamic calculations and the structure of the acetylene molecule. The influence of the solid solution and the reaction mechanisms of saturation on the mass transfer kinetics of carbon during ion carburizing were described.

An experimental study of carbon and nitrogen saturation of complex-alloyed steel in low-pressure atmosphere was conducted. After the process of vacuum nitrocarburizing the quantity of austenite was increased. Also the dimensions of carbonitride particles were decreased. The control factors of vacuum nitrocarburizing technology were optimized with use of a mathematical model.