ВПЛИВ ОБРОБКИ В АЗОТОВМІСНОМУ ГАЗОВОМУ СЕРЕДОВИЩІ НА ХАРАКТЕРИСТИКИ ПРИПОВЕРХНЕВИХ ШАРІВ ТИТАНОВИХ СПЛАВІВ

Abstract

Kinetic regularities of the interaction of titanium alloys (BT1-0, OT4-1, BT6C) with a nitrogen-containing gas medium are presented. In particular, it was shown that the maximum intensification of the process of saturation of titanium alloys with nitrogen in the range of rarefactions of the active gas 10...10^-1 Pa is observed when a dynamic equilibrium is established between the adsorbed and diffusedly removed into the depth of the titanium matrix by nitrogen. This is achieved at a nitrogenation temperature corresponding to the value of the nitrogen pressure and its flow rate and depends on the chemical composition of the nitrided material, since, depending on the temperature range of the polymorphic transformation, the alloy at the appropriate temperature is nitriding in the α-, α+β- or β regions. With the decrease in the partial pressure of nitrogen to 0.1...10 Pa, nitride formation is inhibited. The absence of a nitride film on the surface or substantially less than its thickness substantially attenuates the diffuse barrier, and then the penetration of nitrogen into the titanium matrix is intensified.