Перегляд за Автор "Syrenko, T. O."
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Документ Improvement of welding technology of high power turbine rotor(National Science Center "Kharkov Institute of Physics and Technology", 2024) Dmitrik, V. V.; Glushko, A. V.; Kasianenko, I. V.; Syrenko, T. O.; Baranova, T. A.; Asieieva, I. V.In order to solve the problem of increasing the reliability and increasing the service life of welded joints of rotors of high-power turbines of nuclear and thermal power plants, the technology of their manufacture was improved. The improved technology provided obtaining welded joints of rotors with improved characteristics of their original structure and higher mechanical and physical properties. The given properties were determined by comparing with similar properties that are characteristic of the welded connection of the rotor made according to standard technology. The improvement of the technology involved the modeling of welding heating of manufactured joints, which made it possible to optimize the parameters of the mode of automatic welding of the rotor made of 25Х2НМФА steel. For the first time, the thermal problem was solved as a conjugate one under the conditions of the Navier-Stokes and Fourier laws, which provided the results necessary for increasing the reliability of the rotors, as well as increasing their resource.Документ Structural Engineering and Mechanical Properties of (Ti-V-Zr-Nb-Hf-Ta)N Coatings Obtained at Different Pressures(Сумський державний університет, 2019) Sobol, O. V.; Andreev, A. A.; Postelnyk, H. O.; Meylekhov, A. A.; Sagaidashnikov, Yu. Ye.; Stolbovoy, V. A.; Yevtushenko, N. S.; Syrenko, T. O.; Kraievska, Zh. V.; Zvyagolskiy, A. V.Effect of pressure of the reaction gas on the texture, structural stress state and mechanical properties (hardness and resistance to abrasive wear) in vacuum-arc coatings based on Ti-V-Zr-Nb-Hf-Ta nitrides of high entropy alloys were investigated in this work. At a bias potential of – 200V, an increase in nitrogen pressure during deposition from 2.5·10⁻⁴ to 4.5·10⁻³ Torr leads to an increase in the content of nitrogen atoms in the coating, and the formation of a bittexture state [111] + [311] is established. The formation of a biaxial texture occurs due to the presence in alloys of atoms with very different masses (Ti, V and Hf, Ta). The use of a multi-element composition in a single-phase state with a simple cubic lattice allows to achieve high values of microstrain (up to 1.4 %) with a low deposition pressure. It is determined that the increase of nitrogen pressure during deposition leads to an increase in macrostresses. The highest hardness of 53 GPa is achieved in coatings obtained at a pressure of 2·10⁻³ Torr. It has been established that coatings with high resistance to abrasive wear are found to be: crystallite grain size 12-25 nm, absent of texture (or a low level of texture perfection), and also rather high microstrain in crystallites.Документ Structural Engineering of the Growth of Crystallites with a Predominant Orientation in Bilayer Multi-Period Vacuum arc Nitride Coatings(Sumy State University, 2018) Sobol, O. V.; Mygushchenko, R. P.; Postelnyk, A. A.; Onoprienko, E. V.; Syrenko, T. O.; Men'shikov, A. G.; Zvyagolskiy, A. V.The effect of the MeN (Me-Cr, Mo, Zr) layer composition in multiperiod vacuum-arc (TiAlSi) N / MeN coatings with a nanoscale layer thickness on the predominant orientation of crystallite growth in layer s and hardness was studied. It was found that phases with a cubic crystal lattice (structural type NaCl) in the layers of all types (TiAlSi)N/MeN coatings are formed, although for the MoN phase under equilibrium conditions a hexagonal crystal lattice is preferred. The interrelation between the structure of MeN and (TiAlSi)N layers is revealed, as well as the effect of the structural state on the coating hardness. Defining influence of the MeN layer on the formation of three structural states types was found: with a preferential crystallite growth with the texture axis [111]; with the texture axis [100]; the formation of a non-textured state. The highest hardness of 47.8 GPa was achieved in the (TiAlSi)N/ZrN multilayer coating with the texture axis [111].