Samara State Aerospace University, Samara, Russia:
V. I. Bogdanovich, Professor of a Chair of Aircraft and Quality Management in Mechanical Engineering
I. A. Dokukina, Assistant Professor of a Chair of Aircraft and Quality Management in Mechanical Engineering
M. G. Giorbelidze, Post-Graduate Student of a Chair of Aircraft and Quality Management in Mechanical Engineering

Komsomolsk-on-Amur State Technical University, Komsomolsk-on-Amur, Russia:

S. B. Marin, Professor of a Chair of Mechanical Engineering and Metallurgy, e-mail: maryinsb@mail.ru

The main cause of heat station power generating units' service life exhaustion is the most erosion wear and contact wear of the turbine blade leading edges, the shaft bearing surfaces and other surfaces depended upon high velocity flow, high rotational velocity and loads. The sharp increase of steam turbine elements wear intensity, observed in the last two decades during unit scheduled repair, is closely relating with the change of heat station operation conditions. The main cause of power generation unit elements wear, such as steam turbine blades, shaft bearing surfaces and other surfaces is described in the article. An efficient method of power plant elements repair is significantly increasing service life and extending lifespan of power plants. Spraying process is carried out by small-sized mobile unit, developed by the authors. The coating compositions and deposition technology are identified. Some properties of deposition layers, such as structure, porosity, chemical and phase composition, microhardness, adhesion strength, heat resistance and wear resistance are investigated for the estimate of coating operating capacity. The recovery process of steam turbine blades, shafts and strengthening of their surfaces can be realized without a complete dismounting of the unit. One of the important results of this research is determination of the fact that the formation of coatings with the intercrystalline boundary structure located along the outer surface of the element, is the significantly raising coating-base system performance.
The research was carried out in collaboration with the specialists of Samara State Aerospace University, with the financial support of the Ministry of Education and Science of Russian Federation.

1. Barvinok V. A. Plazma v tekhnologii, nadezhnost, resurs (Plasma in technology, reliability, resource). Moscow : Nauka i tekhnologii, 2005. 452 p.
2. Mann B. S. Water Droplet Erosion Behavior of High-Power Diode Laser Treated 17Cr4Ni PH Stainless Steel. Journal of Materials Engineering and Performance. 2014. Vol. 23, No. 5. pp. 1861–1869. DOI: 10.1007/s11665-014-0927-6
3. Liu-xi Cai, Jing-ru Mao, Shun-sen Wang, Juan Di, Zhen-ping Feng. Experimental investigation on erosion resistance of iron boride coatings for steam turbines at high temperatures. Proceedings of the Institution of Mechanical Engineers, Part J: Journal of Engineering Tribology. 2015. Vol. 229, No. 5. pp. 636–645. DOI: 10.1177/1350650114557105
4. Pérez F. J., Castañeda S. I., Hierro M. P., Escobar Galindo R., Sánchez-López J. C., Mato S. Comparative Study of Micro- and Nano-structured Coatings for High-Temperature Oxidation in Steam Atmospheres. Oxidation of Metals. 2014. Vol. 81, No. 1/2. pp. 227–236. DOI: 10.1007/s11085-013-9447-2
5. Shipway P. H., Gupta K. The potential of WC-Co hardmetals and HVOF sprayed coatings to combat water-droplet erosion. Wear. 2011. Vol. 271, No. 9/10. pp. 1418–1425. DOI: 10.1016/j.wear.2010.12.058
6. Bobrov G. V., Ilin A. A., Spektor V. S. Teoriya i tekhnologiya formirovaniya neorganicheskikh pokrytiy (Theory and technology of formation of inorganic coatings). Moscow : Alfa-M, 2014. 925 p.
7. M. G. Hocking, V. Vasantasree, P. S. Sidky. Metallicheskie i keramicheskie pokrytiya: poluchenie, svoystva i primenenie (Metallic and Ceramic Coatings). Moscow : Mir, 2000. 518 p.
8. Ryzhenkov V. A. Sostoyanie problemy i puti povysheniya iznosostoykosti energeticheskogo oborudovaniya teplovoy elektrostantsii (State of problem and ways of increasing of the wear resistance of energetic equipment of the heat station). Teploenergetika = Thermal Engineering. 2000. No. 6. pp. 20–25.
9. Lisyanskiy A. S., Tikhomirov S. A., Simin O. N., Chizhik T. A. Obespechenie stoykosti k kapleudarnoy erozii i fretting-korrozii lopatok parovykh turbin za schet vakuumnogo ionno-plazmennogo uprochneniya poverkhnosti (Provision of resistance to the impingement corrosion and fretting-corrosion of steam turbine blades due to the vacuum ion-plasma strengthening of the surface). Energomashinostroenie = Power plant industry. 2005. No. 2/3. pp. 43–53.
10. Smyslova M. K. Issledovanie i razrabotka kombinirovannykh ionnoplazmennykh tekhnologiy, obespechivayushchikh povyshenie ekspluatatsionnykh svoystv lopatok gazovykh i parovykh turbin (Investigation and development of combined ion-plasma technologies, providing the increasing of exploitation properties of gas and steam turbine blades). Vestnik Ufimskogo gosudarstvennogo aviatsionnogo tekhnicheskogo universiteta = Vestnik of Ufa State Aviation Technical University. 2004. Vol. 5, No. 3 (11). pp. 67–83.
11. Mann B. S., Arya Vivek. HVOF coating and surface treatment for enhancing droplet erosion resistance of steam turbine blades. Wear. 2003. Vol. 254, No. 7/8. pp. 652–667. DOI: 10.1016/S0043-1648(03)00253-9
12. Perelman R. G., Pryakhin V. V. Eroziya elementov parovykh turbin (Erosion of steam turbine elements). Moscow : Energoatomizdat, 1986. 184 p.
13. Barvinok V. A., Bogdanovich V. I. Physical and Mathematical Simulation of the Formation of Mesostructure-Ordered Plasma Coatings. Technical physics. 2012. Vol. 57, No. 2. pp. 262–269. DOI: 10.1134/S1063784212020053
14. GOST 9.304–87. Edinaya sistema zashchity ot korrozii i stareniya (State Standard 9.304-87. Unified system of corrosion and aging protection. Thermal sprayed coatings. General requirements and methods of control). Introduced: January 01, 1989. (in Russian)
15. Barvinok V. A., Bogdanovich V. I., Dokukina I. A. Plazmennaya gorelka dlya napyleniya metallov i okislov (Plasma torch for metal and oxide spraying). Patent RF, No. 142944, IPC H 05 H 1/26. Applier and Patent-Holder: Samara State Aerospace University. Applied: November 21, 2013. Published: July 10, 2014. 2 p.