Specific features of the diffusion gas saturation of some alloys under the conditions of internal phase separation

We make an attempt to give an adequate mathematical description of the kinetics of gas saturation of metallic materials by taking into account the surface and bulk phenomena. For this purpose, we pose and solve the initial-boundary-value problems of diffusion of admixtures and alloying elements taking into account their chemical interaction. The process of gas saturation runs in the presence of a given time dependence of the surface. concentration of admixtures and in the absence of mass exchange of alloying elements. We deduce equations for the concentrations of admixtures and alloying elements after subsequent isothermal annealing. The influence of various factors, such as the surface phenomena on the medium-metal interface and the intensity of bulk chemical reactions, on the results of chemical and thermal processing of alloys is estimated. The accumulated analytic results are compared with the experimental data obtained for vanadium and vanadium alloys held in vacuum and helium media at T = 1023degreesK and 1123degreesK for 120-2500h.