The objective of this review is to present the results on the production techniques, process parameters and compositions of heat-resistant coatings for graphite and carbon-carbon composites. The data reported concern the resistance of such protective coatings in air at temperatures up to 2273 K and in the high-speed flows of oxidizing gas media taking place in the spacecraft equipment. Coatings of this type, generally, have a multilayer structure based on the refractory compounds such as carbides, borides, silicides of transition metals and oxides with a high melting temperature. An efficient heat-resistant coating for carbon-based materials should be composed of three layers from which each fulfills its own function. The paper presents a new complex method for formation of heat-resistant coatings on the carbon-based materials. The method combines the vacuum-activated diffusion saturation in the presence of a liquid-phase and self-propagating high-temperature synthesis (SHS) simultaneously. * Corresponding author. V. I. Zmij et al. 880 ical impacts, ablation and electroerosion.However, under conditions of high temperatures, even above 773 K, C/C composites reveal comparatively low oxidation resistance, which restricts to a great extent their wide application in different fields, particularly, in the high-temperature equipment.At present, the problems of effective protection for carbon-based materials, being under conditions of different oxidizing media, are comprehensively discussed in the literature. A current state of this problem is under consideration in the review article [1]. The effective protection of C/C composites against oxidation can be provided with taking into account the following: use of such materials as oxides, carbides, nitrides, borides, silicides and their various compounds; deposition methods and conditions; thickness and crack resistance of coatings; material designing limiting because of the chemical activity of material reinforcement components; new approaches to the choice of a heat-resistant coating material. Main requirements to the carbon composites are: atmospheric oxidation resistance, thermal impact resistance, humidity resistance, and high mechanical strength. The methods of carbon-based material stabilization are based on different approaches: multilayer coating deposition, formation of glass-forming or metallic coatings subjected to chemical transformations by thermal treatment, and glass-forming compound impregnation. In the above-mentioned review, one offers to use for carbon-based material protection the refraction metals such as W

In the work, the surface of samples made of 25X1MF steel was saturated with chromium. For this, the method of vacuum activated diffusion chromium plating was used. In this process, sodium chloride was used as an activator. It was found that vacuum activated diffusion chromium plating of samples made of 25Kh1MF steel leads to the formation of a surface layer containing from 87 to 97 wt.% of this element. It was found that an increase in the temperature of the process and its duration leads to an increase in the chromium content on the surface of the samples. The tests showed that in the case of cavitations-erosion effects on the surface of chrome-plated samples of steel 25X1MF they have higher resistance. With abrasive wear, the resistance of the chrome-plated steel surface is 1.8 to 3 times higher compared to untreated material.