One common challenge for designers of power equipment to be operated at high temperatures is the reduction of radiation heat transfer. As the emissivity factor of radiating heated surfaces of such equipment in most cases can be reasonably approximated by a constant, the power emitted by them is directly proportional to the fourth power of their absolute temperature. A solution of this problem is the use of thermal radiation shields made from low-emissivity and highly reflective materials. Traditionally heat insulation structures employ aluminum foil as such a shield. However, aluminum is soft and rather expensive, and it also has a low tensile strength. An alternative to the use of aluminum foil is the application to the external surface of the thermal insulation structure of a reflective metal layer via ion-plasma spraying (bombardment) in vacuum or metal spraying (metalizing) by means of an electric arc. In order to find out which method of reduction of radiation heat transfer offers the best results, we have compared a number of methods of thermal radiation shielding (foil winding, ion-plasma spraying in vacuum or electric arc wire spraying) in terms of thermal resistance of proper heat insulation structure. In our paper we have used heat insulation structures with thinfilm heat insulation coatings. The experiments were carried out in conditions simulating real conditions of operation of pipelines and power equipment in Russia. The results of the experiments show that the alternative methods of thermal radiation shielding are more efficient than the traditional one (aluminum foil winding). In particular, the use of an aluminum coating applied to the surface of a heat insulation structure via ion-plasma spraying allows the thermal resistance to increase by 35%; in case of metalizing via electric arc wire spraying the thermal resistance increased by 15% or more.

The reliability and efficiency of power equipment is largely depend on the degree of wear in its most loaded elements, which during operation undergo the cumulative effects of various factors. The mutual manifestation of several kinds of wear leads to the intensification of the destruction processes that will reduce efficiency, and sometimes lead to the complete failure of power equipment. Nowadays, in the field of power engineering, different ways to improve wear resistance are used, but the problem remains unsolved. There is a necessity to develop new methods of universal protection based on modern technologies, which can effectively resist the combination of different kinds of wear. Modern ion-plasma technologies can be applied as the solution to this problem, which have broad application possibilities in surface layer modifications and the formation of multi-functional coatings. To solve such problems, the National Research University "Moscow Power Engineering Institute" (NRU "MPEI") created a unique experimental and industrial complex, which includes specialized ion-plasma equipment for coatings production, including large, cumbersome products (up to 3000 mm in length and up to 5000 kg in weight), experimental facilities for extensive materials and coatings testing, complex with the modern analytical equipment and appliances for studying the structure and properties of coatings. Laboratory results and field tests of ion-plasma coatings developed in NRU "MPEI" have shown that their use leads to a manifold increase in erosion, abrasion, corrosion resistance, fatigue strength, heat resistance, and the significant reduction of the friction coefficient.

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The paper is devoted to experimental investigation of ion-plasma coatings solid particle erosion resistance at high-speed impact of gas-abrasive flow. The relevance of the investigation is stipulated by the still unsolved problem of steam turbines first stages' blades protection against solid particle erosion. The results of solid particle erosion investigations of three types of ion-plasma coatings (Ti-TiAlN, Cr-CrC, NiCrC-CrC), formed on samples of blade steels 20Kh13 and 15Kh11MF, are shown. Comparative tests showed the effectiveness of applying NiCrC-CrC and Cr-CrC coatings on blade steels 20Kh13 and 15Kh11MF for solid particle erosion protection.