Global Energy

RAR RUS 9-17 Tremyasov Vladimir emf_tva@mail.ru Krivenko Tatiana tanya-1991mir@mail.ru MULTI-MATRIX MODEL FOR ASSESSING THE RELIABILITY OF AN AUTONOMOUS POWER SYSTEM WITH A PHOTOVOLTAIC CONVERTER Combined solar-diesel installations are currently extensively used in of autonomous power supply systems. A necessary aspect in the planning and design of such systems is the assessment of their reliability. In this study, for the reliability assessment of solar-diesel installations, it is offered to use the multi-matrix method allowing to take into account the changes in solar radiation, as well as the operating modes and failure of installation elements. Reliability calculation of an autonomous solar-diesel installation used in the remote settlement Yaylyu of Altai Republic has been made. 10.18721/JEST.230101 621.311.245 PHOTOELECTRIC CONVERTER; SOLAR-DIESEL INSTALLATION; RELIABILITY; THE MULTI-MATRIX METHOD; MULTI-STATE https://engtech.spbstu.ru/article/2017.99.1/ 1_tremyasov.pdf

RAR RUS 18-26 Zaborova Dariia Mussorina Tatiana https://publons.com/a/ 56426211200 https://orcid.org/ Petrichenko Mikhail fonpetrich@mail.ru THERMAL STABILITY AND THERMAL RESISTANCE OF A MULTILAYER WALL CONSTRUCTION: ASSESSMENT OF PARAMETERS Nowadays energy efficiency is one the main topics in construction industry. Therefore, the main focus of attention is construction and technological methods aimed mainly at increasing of the wall’s thermal resistance. The object of the study is a multilayer enclosing structure (wall). The goal of the article is selecting the optimal enclosing structures for increasing the thermal stability and energy efficiency of the building. The article shows that heat accumulation in the wall and its thermal resistance are opposite factors. The results of the study show that the thermal resistance of the wall does not depend on layer alternation. Stationary and periodic temperature, humidity regimes of the walls depend substantially on layer alternation. The studies were conducted by the methods of thermal engineering 10.18721/JEST.230102 621.311 THERMAL RESISTANCE; THERMAL STABILITY; THERMAL CONDUCTIVITY; DENSITY; SPECIFIC HEAT; ENCLOSING STRUCTURES https://engtech.spbstu.ru/article/2017.99.2/ 2_zaborova.pdf

RAR RUS 27-35 Seredkin Aleksandr PROCEDURE AND CRITERION FOR ENERGY EFFICIENCY ASSESSMENT OF HEAT SUPPLY SYSTEMS The article is dedicated to the important modern problem of assessing the energy efficiency of heat supply systems. The author sets a task to elaborate the criteria of assessing the energy efficiency of building heat supply systems taking into account the key thermal parameters. Thermal parameters of heat supply systems and the factors affecting them were observed. The key parameters for energy efficiency assessment of heat supply systems were identified. A new criterion for practical assessment of energy efficiency in heat supply systems was offered using these parameters. The criterion allows obtaining an estimate for the energy efficiency of a system at minimal measured parameters and simple practical calculation. The criterion can be used for either the heat supply system of a single building or a group of buildings. The author offered the method of energy efficiency assessment of heat supply systems based on pattern comparison of real, optimal and reference systems using the criterion. A brief analysis of the existing scientific researches was given. The author performed a preliminary estimate of the energy efficiency of the largest heat supply system of Chita using the criterion. The most typical problems of low energy efficiency of this system were emphasized using additional energy inspection. 10.18721/JEST.230103 697 ENERGY EFFICIENCY; ENERGY SAVING; HEAT SUPPLY SYSTEM; ENERGY INSPECTION https://engtech.spbstu.ru/article/2017.99.3/ 3_seredkin.pdf

RAR RUS 36-47 Petrenia Iurii Glukhov Vladimir viccrcctor.me@spl5stu.ru Ivanov Sergei DESIGN OF CONSTRUCTIONS OF SEPARATE/COMBINED STEAM TURBINE CYLINDERS BASED ON COMPETITION-ORIENTED PARAMETERS A design for competition (DfC) method using the attractiveness criteria has been proposed for the power equipment market. It is noted that the method is more general compared with the DtC (Design to Cost) method traditionally used by OEMs. The application of DfC with the attractiveness criteria for design of steam turbines with separate and combined high and medium pressure cylinders is presented. It is shown that it is expedient to use structural schemes of turbines with combined cylinders with the parameters increasing to reach and exceed the supercritical region values for a unit capacity of 600 MW (including the existing technical limitations). 10.18721/JEST.230104 621 DESIGNING; STEAM TURBINES; CYLINDER; PATH FLOW; CONSTRUCTIVE LAY-OUT; USC; COMPETITION; ENERGY; POWER CAPACITY https://engtech.spbstu.ru/article/2017.99.4/ 4_petrenya.pdf

RAR RUS 48-60 Fragin Mark Egorshin Vladimir egorshinvp@mail.ru A STUDY OF THE EFFECT OF CLOSED-CENTER ACTUATOR VALVE OVERLAPS ON OSCILLATIONS IN CONTROL SYSTEMS OF STEAM TURBINES The nonlinear hydraulic actuator which includes a hydraulic cylinder and a riding cut-off valve was considered. The valve supplies the oil to the actuator’s hydraulic cylinder. The riding cut-off valve is an overlapping valve. Therefore the time constant in that type of actuator is variable and depends of the valve position. Equations for the value of the time constant at a steady state in an overlapping range depending on the size of the overlapping and a radial backlash were obtained. We have performed calculation of an equivalent time constant for that type of actuator with harmonic disturbances of different frequency and amplitude applied at the input. We have considered a method of evaluating the time constant for the actuator within overlapping range and its influence on the stability of the control system for a steam turbine with this type of actuator and friction forces in the system. 10.18721/JEST.230105 62–82 HYDRAULIC ACTUATOR; TIME CONSTANT; OVERLAPPING VALVE; STABILITY OF THE CONTROL SYSTEM; STEAM TURBINE https://engtech.spbstu.ru/article/2017.99.5/ 5_fragin.pdf

RAR RUS 61-68 Tarasov Sergey SATarasov@mail.ru Fomin Victor Viktor2009@yandex.ru GAS-TURBINE INSTALLATION OF SMALL CAPACITY WITH HEAT UTILIZATION IN A LOW BOILING FLUID CIRCUIT This paper deals with the problem of minimizing waste heat loss in a small-capacity gas turbine using a low-boiling fluid (LBF) circuit working in organic Rankine cycle (ORC). In this study, firstly, we have developed an approach for calculating the heat-and-mass balance for a power installation with a heating fluid. Secondly, we have carried out calculations of installations with various working fluids and analyzed the main characteristics. During the study, four working fluids were taken into account: butane, pentane, R245fa and cyclopentane. The study shows that the working fluid should be selected not only depending on its critical temperature, but taking into account the influence of the weight and dimensional characteristics of the steam generator. Ultimately, working fluid selection is both a technological and economic problem. 10.18721/JEST.230106 62-681 WASTE HEAT UTILIZATION; GAS TURBINE; ORGANIC RANKINE CYCLE; LOW-BOILING WORKING FLUID https://engtech.spbstu.ru/article/2017.99.6/ 6_tarasov.pdf

RAR RUS 69-81 Legkostupova Vera Sudakov Aleksandr EFFICIENCY OF USING A PRELIMINARY SEPARATOR AT THE KURSK NUCLEAR POWER PLANT: EXPERIMENTAL AND COMPUTATIONAL ASSESSMENT This article presents the results of an experimental and theoretical study on using a preliminary separator Powersep to improve the performance of moisture separator-steam reheaters at Kursk NPP. Modernization of SPP-500–1 was completed by «NPO CKTI» together with the German company Balke-Durr. The project of modernizing the MSR of Kursk NPP differs from the MSR modernization projects for Leningrad NPP and Smolensk NPP. The installation of a preliminary separator has led to a deterioration in the performance of the MSR. A few solutions to this problem were proposed, the best option is to install a perforated separator (perforated sheets) at the entrance to the distributing manifold separation units. Therefore, experimental studies on the effect of the preliminary separator and the perforated separator on the performance of the MSR at Kursk NPP were performed at the stand of the Balke-Durr company. The previously proposed technique for modeling two-phase flow was used during the computational research. The obtained results agree rather well with the experimental results. 10.18721/JEST.230107 621.311.25 MOISTURE SEPARATOR-STEAM REHEATERS (MSR); PRELIMINARY SEPARATOR; MODERNIZATION; EXPERIMENT; CALCULATION; TWO-PHASE FLOW https://engtech.spbstu.ru/article/2017.99.7/ 7_legkostupova.pdf

RAR RUS 82-89 Griguleckii Vladimir Savel’ev Yuriy DRAG COEFFICIENTS UNDER TURBULENT FLOW OF A VISCOUS FLUID IN THE ANNULAR GAP OF TWO COAXIAL CYLINDRICAL TUBES The problem of the theoretical description of the dynamics of turbulent fluid flow in two coaxial cylindrical pipelines is considered with the purpose of determining the dependence of the resistance to movement on its viscosity and the ratio of their magnitudes. The dependences of the drag coefficients on the Reynolds number are theoretically investigated for various roughnesses of the pipe surface and various ratios of their diameters. 10.18721/JEST.230108 621 TURBULENT MOTION; ANNULAR GAP; REYNOLDS NUMBER; DEEP ROD PUMPS; DRAG COEFFICIENT; WALL ROUGHNESS https://engtech.spbstu.ru/article/2017.99.8/ 8_griguletskiy.pdf

RAR RUS 90-97 Bocharov Yurij 6603036819 Peter the Great St. Petersburg Polytechnic University, Russia Titkov Vassiliy titkovprof@yandex.ru

Russia, 195251, St.Petersburg, Polytechnicheskaya, 29

Abitaeva Rakhimash Bekbaev Amankeldy Jamambaev Muratkali TORSION VIBRATIONS OF SPLITTED WIRE OF OVERHEAD TRANSMISSION Free torsional oscillation of a split wire of an overhead transmission line is considered. Torsional oscillations of a split wire were calculated based on a non-linear differential equation obtained by the authors using the Bubnov-Galerkin method. Calculated formulas for torsional stiffness of a split wire have been derived. Ratios between the characteristics of torsional and lateral oscillations of a split wire were obtained, which allow optimal selection of parameters of the devices for vibration and oscillation dampening. The results of calculations agree with the experimental data as well as known the theoretical results. Obtained calculation formulas are recommended for use in design of new overhead transmission lines with split wires and reconstruction of lines already in operation. 10.18721/JEST.230109 621.315.176 OVERHEAD TRANSMISSIONS LINES; SPLITTING OF WIRE; TORSION MOTION EQUATION; TORSION HARDNESS; EXPERIMENTAL DATA AND CALCULATIONS COMPARISON https://engtech.spbstu.ru/article/2017.99.9/ 9_bocharov.pdf

RAR RUS 98-106 Shevchuk Roman Gaev Aleksandr AN APPROXIMATE SOLUTION METHOD TO STATOR CORE VIBRATION PROBLEM Resonant frequency tuning of all critical elements is an actual engineering challenge in designing turbo generators. In particular, one of these elements is the stator core. First, the procedure involves assessment of the eigenfrequencies and amplitudes of vibrations of the element. The present study considers the well-known analytical approaches to the calculation of the vibrational eigenfrequencies of stator cores of turbo generators. In these approaches, a mathematical model of the core represents the dynamics of a ring in terms of rod theory. Consequently, it is possible to estimate the eigenfrequencies and vibrational modes correctly only in the case of the thin-walled core. Practically, however, the radial width of the outer side of the turbo generator’s stator core is comparable with its average radius, so the use of these models can result in unsatisfactory accuracy of calculations. In order to solve this problem, the present study provides an analytical method for the calculation of eigenfrequencies of the stator core. The method represents the core as a long thick-walled cylinder. The results of finite-element modeling of the core vibrations verify the accuracy of the calculation of eigenfrequencies. The study shows that the proposed method gives more accurate results than the formulas used in engineering practice. 10.18721/JEST.230110 621.313.322–81 STATOR; CORE; VIBRATION; EIGENFREQUENCY; NUMERICAL MODELING; FINITE ELEMENT METHOD https://engtech.spbstu.ru/article/2017.99.10/ 10_shevchuk.pdf

RAR RUS 107-123 Shakirov Mansur manshak@mail.ru THEORY OF TRANSFORMERS. Part 3 As with the first two parts, the work is dedicated to the development of the theory of transformers and identifying its new features using the concept of magnetic vector potential. It is proved for the idealized shell type transformer that a characteristic surface exists inside the primary winding in which the vector potential does not depend on the load. In opposition to the official theory, it turned out that not the «overall flow of the magnetization in the magnetic», but the magnetic flux covered by the characteristic surface of primary winding is supported constant in the transformer. The condition of active power transmission is the presence of a phase difference between the fluxes covered by the characteristic surfaces of the primary and secondary windings. A new type of the 4T-shaped equivalent circuit is obtained, with magnetic fluxes and transformer topology displayed on it. In case of short-circuit, the flux separation line in windows passes only within shorted winding. At the same time the individual parts of the magnetic circuit are overexcited in relation to their state when idling. These results are not compatible with the dogmas of the official theory and raise the issue of creating a new transformer theory with the development of more grounded standards on their durability to short-circuit needed to improve the construction of transformers at the design stage and, ultimately, to stop the observed increase in their failures. A physical justification of the necessity to increase the normalized impact short-circuit current ratio from 1.8 to 1.9 has been presented. 10.18721/JEST.230111 621.313 TRANSFORMER; PRIMARY AND SECONDARY WINDINGS; MAGNETIC FLUX; VECTOR DIAGRAM; EQUIVALENT NETWORK; VECTOR POTENTIAL; CURRENT IMPACT https://engtech.spbstu.ru/article/2017.99.11/ 11_shakirov.pdf

RAR RUS 124-133 Doronin Mikhail Greshnyakov Georgii B-7916-2013 6601971248 0000-0002-1173-8727 Peter the Great St. Petersburg Polytechnic University, Russia Korovkin Nikolay nikolay.korovkin@gmail.com

Russia, 195251, St.Petersburg, Polytechnicheskaya, 29

MAGNETIC SHIELDS SPECIAL DESIGN The article is dedicated to the optimization and operation of magnetic slip-shields with the purpose of redistributing the field in the space near the cable line (the electromagnetic field source). The optimization was made by means of a genetic algorithm (GA). As a result, the authors found optimal designs of shields for various cable line layouts. Moreover, the study shows manufactured prototypes of the shields and the testing results. This investigation demonstrates the possibility of applying slip-shields to mitigate the amplitude of the electromagnetic field in the specified areas around the cable. 10.18721/JEST.230112 621.315.2.016.2 ELECTROMAGNETIC SHIELDING; SHIELDING RATIO; REDISTRIBUTION OF FIELD; SHIELD ATTENUATION RATIO; SOFT MAGNETIC ALLOYS; MAGNETIC SHIELD; GENETIC ALGORITHM; OPTIMIZATION https://engtech.spbstu.ru/article/2017.99.12/ 12_doronin.pdf

RAR RUS 134-139 Kuchinsky Vladimir vladkuchinsky@raail.ru Siddharth Nandakumar PARAMETRIC STUDY OF A HIGH POWER DC CIRCUIT BREAKER BASED ON VACUUM INTERRUPTERS (VI) AND SEMICONDUCTORS Parametric study of a two-stage high-power DC circuit breaker is carried out. It is a current-limiting breaker which is characterized by a fast opening time. The circuit breaker under consideration consists of two vacuum interrupters in series and one of them has the semiconductors in parallel. The principle of operation of this vacuum interrupter is mainly based on providing an alternate path for the load current to flow through parallel-connected diodes so that the contacts of the vacuum interrupter can be opened under minimal arc conditions. The diodes help restore the dielectric strength of the second vacuum interrupter when the counter pulse capacitor switches the current from the diodes and the second vacuum interrupter to the capacitance and varistor. A fast circuit breaker substantially reduces the short circuit current. This is especially important for the circuits with small inductances and therefore high current derivatives. 10.18721/JEST.230113 621.387.35 DC BREAKER; VACUUM INTERRUPTER; SEMICONDUCTOR; CAPACITANCE; VARISTOR https://engtech.spbstu.ru/article/2017.99.13/ 13_kuchinskiy.pdf

RAR RUS 140-156 Abounakera Shadi Popov Maxim IMPROVING THE EFFICIENCY OF DIFFERENTIAL PROTECTION OF OVERHEAD TRANSMISSION LINES When applied to protecting over head transmission lines, the differential protection may mal-operate due to unbalanced currents caused by electromagnetic saturation of the current transformers under transient conditions. Restrain methods are the most common used to mitigate the effect of these currents. The disadvantage of such methods is that the restrain signal for external fault is significantly reduced by increasing the magnetizing current of the current transformers, whereas the differential signal increases. This leads to a reduction of the sensitivity of protection or increase tripping time to prevent mal-operation. This paper proposes an additional algorithm based on control (calculation) of capacitive currents mathematical models by using MATLAB/Simulink. to improve the sensitivity of transmission lines differential protection. Simulation results on MATLAB/Simulink. Simulation Results show that the new algorithm that using capacitive compensation current signal has better sensitivity than other methods. 10.18721/JEST.230114 621.311: 621.316: 621.317 DIFFERENTIAL PROTECTION; OVERHEAD TRANSMISSION LINES; IMPROVING PROTECTION SENSITIVITY; EFFICIENCY IMPROVEMENT https://engtech.spbstu.ru/article/2017.99.14/ 14_abou.pdf

RAR RUS 157-167 Gerkusov Aleksei Gerkusov_Alex@mail.ru APPLICATION OF THE METHOD OF ECONOMIC INTERVALS IN CHOOSING WIRE SECTIONS WITH A SPLIT PHASE This paper analyzes the existing method of selecting cross-sections of wires by the method of economic intervals, substantiating the the necessity of modernization for power transmissions with a voltage of 220 kV and above, performed with a split phase. The proposed algorithm for determining the current load in which, on the basis of minimum reduced cost, additional reactive power sources should be abandoned and split phase wires should be used. A series of intersecting curves, allowing not only to choose the best wire size, but also to determine the load at which the wire phase should be split into several components. 10.18721/JEST.230115 621.311 OVERHEAD TRANSMISSION LINE; CURRENT ECONOMIC INTERVALS; IMPEDANCE; CONDENSER; NATURAL POWER; ELECTRIC FIELD strength; a SOURCE of REACTIVE POWER; REAC-TOR; INDUCTANCE; PHASE SPLITTING https://engtech.spbstu.ru/article/2017.99.15/ 15_gerkusov.pdf

RAR RUS 168-178 6603036819 Peter the Great St. Petersburg Polytechnic University, Russia Titkov Vassiliy titkovprof@yandex.ru

Russia, 195251, St.Petersburg, Polytechnicheskaya, 29

Bekbaev Amankeldy Sarsenbaev Erlan SOME POSSIBILITIES OF MONITORING TRANSIENT THERMAL PROCESSES IN CONTACTS OF ELECTRICAL POWER SETUPS The paper analyzes the possibilities of registering temperature on the contact surface of a bus bar connection is analyzed. The algorithm for determining the maximal value of temperature on contact surface is proposed. The method is based on dynamic measurement of external surface of contact pair by disconnecting the short-circuit current or by nonsynchronous motor starting. The requirements for the dynamic temperature sensor for typical events with a duration of 0.1–1 s are determined. The different ways of realization of the smart dynamic temperature sensor for high voltage electric power setups are discussed. Two types of designs of the sensor with a thermistor are considered. The sensor based on conductive signal transmission is badly applicable for high voltage setups because it has quite a thick insulation layer between the bus surface and the thermistor, therefore it has a reaction time about 10 s and is not suited for dynamic measurements. The optical channel for signal transmission allows to use thinner insulation layers that provide a 1 ms time reaction sensor. The sample of the sensor design with power supply from the busbar-induced voltage and industrial optical insulator is proposed. 10.18721/JEST.230116 621.3.066.6 BUS BAR CONTACT; HEATING; TEMPERATURE OF CONTACT SURFACE MONITORING; TRANSINT HEATING PROCESSES; TEMPERATURE OF INACCESSIBLE BUS BAR CONTACT SURFACE ; DYNAMIC TEMPERATURE SENSOR; DYNAMIC BUS BAR TEMPEATURE MONITRING;SENSOR FOR HIGH VOLTAGE BUS BAR https://engtech.spbstu.ru/article/2017.99.16/ 16_titkov.pdf

RAR RUS 179-183 Babanin Nikolai Korchagina Elena PARASITIC OSCILLATION DAMPER The object of the study is the damper developed by the authors that reduces parasitic oscillations of the core of the vehicle by automatically increasing the resistance forces in its mains. The damper is installed in the suspension of any vehicle or freight cars. In order to test the effectiveness of the installation effect of the damper for smooth running and maintaining the key characteristics of the car (performance and fuel economy). We have performed simulations of the damper design developed. We have drawn conclusions about reducing parasitic oscillations of the core of the car with the help of the damper on the basis of the frequency response. Studies have confirmed the effectiveness of the damper, since due to its dissipation characteristics a reduction of up to 60 % in the average amplitude range is achieved. 10.18721/JEST.230117 62–314.1 DAMPER; PARASITIC OSCILLATIONS; AUTOMATIC THROTTLING; THE CAR’S SUSPENSION https://engtech.spbstu.ru/article/2017.99.17/ 17_babanin.pdf

RAR RUS 184-189 Akopyan Misak Reznikov Stanislav Fedotova Viktoria COMPARISON OF THE RESULTS OF SIMULATED GEAR WEAR WITH IN SITU TESTS The article dedicated to comparing the results of mathematical modeling of the interaction between toothed wheels with the results of tests. The analysis of the literature in the field of experimental study of wear in gears and transmissions to highlight the most appropriate conditions for the comparison. We have studied the methods of mathematical modeling of gears and transmissions. We have identified the most appropriate mathematical model for comparison with in situ tests. We have revealed the peculiarities in comparing the results of mathematical modeling and tests. Wear diagrams obtained by calculation and experiment are presented. We have performed a comparison of the experimental results, and mathematical modeling at different stages of wear of the gears and described the mathematical model. We have verified the method of experimental and computational studies of the process of wear and designing wear-resistant gears and transmissions. The aim of this study was to evaluate the reliability of the results of mathematical modeling of gear wear process, which takes into account the evolutionary nature of the interaction process, by comparison with the result of in situ tests. 10.18721/JEST.230118 531.01, 621 GEARWHEEL; TESTING; WEAR; DIAGRAM OF WEAR; EXPERIMENTAL AND COMPUTATIONAL STUDY; GEAR; SIMULATION; EXPERIMENT https://engtech.spbstu.ru/article/2017.99.18/ 18_akopyan.pdf

RAR RUS 190-199 Arsentyeva Xenia xenia.ars@gmail.com WRINKLING ISSUES IN THIN SHEET METAL DURING IMPULSE AND QUASI-STATIC METAL FORMING The author developed a mathematical model of thin sheet metal drawing processes in impulse and quasi-static forming conditions using the LS-DYNA finite-element complex. During the calculation, a gap magnitude between a holder and a die was varying and its influence on the forming process was studied. Forming limit diagrams of the considered processes allowed obtaining an overall view of wrinkling probability on the flange and center of blank. Moreover, the study showed a wrinkling probability dependence on strain rate and gap magnitude between the holder and the die. Thus, finite element calculation allowed making a comparison of the effective plastic strain magnitudes as well as considering the characteristics of the drawing processes, depending on the strain rate. As a result, favorable gap magnitudes between the holder and the die were determined for different strain rates. 10.18721/JEST.230119 621.73.011 IMPULSE DRAWING; QUASI-STATIC DRAWING; WRINKLING; THIN SHEET METALL https://engtech.spbstu.ru/article/2017.99.19/ 19_arsenteva.pdf

RAR RUS 200-208 Gorynin Vladimir z1dehy97@mail.wplus.net Olenin Mihail 1951vika@mail.ru Stolniy Viktor metlabprom@mail.ru INCREASING THE BRITTLE FRACTURE RESISTANCE OF 15Cr11MoVNb STEEL WELDED JOINTS DUE TO HOMOGENIZING ANNEALING The influence of temperature and time parameters of heat treatment on the structure and properties of martensitic-ferritic class steel 15Cr11MoVNb was investigated. The paper analyzes the obtained results of the structural changes in 15Cr11MoVNb steel after homogenization with subsequent thermal improvements in metal of welded joints. It is shown that homogenization at a temperature of 1150°C can significantly reduce the -ferrite content in the steel structure and improve the ductility and plastic properties of steel without changing its strength properties by more than 2 times. Estimation of the distribution of micro hardness of weld metal of the 15Cr11MoVNb steel before and after homogenization and subsequent thermal improvements was revealed. It is established that the proposed thermal treatment eliminates a soft stratum in the weld metal. The investigated heat treatment mode of the 15Cr11MoVNb steel enhances the strength of metal in the heat-affected zone of the welded joint in its entirety, from the line of fusion to the base metal. 10.18721/JEST.230120 669.1.017:621.78:620.18 HEAT TREATMENT; MICROSTRUCTURE; PHASE COMPOSITION; MECHANICAL PROPERTIES; STEEL https://engtech.spbstu.ru/article/2017.99.20/ 20_gorynin.pdf

RAR RUS 209-218 Matveev Mikhail matveev_ma@inbox.ru INFLUENCE OF THE γ↔α TRANSFORMATION ON HIGH-TEMPERATURE DUCTILITY OF MICRO-ALLOYED PIPE STEELS We have investigated the ductility of micro-alloyed pipe steels in the temperature range of γ↔α transformations for physical modeling of continuous casting and hot rolling conditions. Physical simulation was performed on the thermomechanical Gleeble-3800 complex. It was found that the decline in the ductility of steel studied in a two-phase region in the simulation of continuous casting of steel due to the conditions of allocation of ferrite grain boundaries of austenite to form a thin layer on the boundaries. This causes strain localization and premature failure of the metal. It is shown that the formation of cracks at the interfaces during a simulation of austenite-ferrite hot rolling in a two phase region does not occur and the steel has high ductility. However, the study of limiting stresses (tensile strength) that could cause the destruction of the metal has shown that these stresses have a complex temperature dependence, and are structurally dependent, their size determined by the type of the transformation (ferrite and bainite) in the steel. The nature of bainite transformation determines the rise and fall of tensile strength. 10.18721/JEST.230121 620.172.2 HOT DUCTILITY γ↔α REGION ULTIMATE STRAIN MICRO-ALLOYED STEEL HOT ROLLING CONTINUOUS CASTING PHYSICAL SIMULATION https://engtech.spbstu.ru/article/2017.99.21/ 21_matveev.pdf

RAR RUS 219-225 Kuchumov Vladimir Shoomkin Sergei ANALISYS OF THE CHEMICHAL COMPOSITION OF THE BEARING ALLOY USED IN THE PRODUCTION OF Sm-Co-BASED PERMANENT MAGNETS The possibility and feasibility of atomic-emission spectral analysis in serial production of permanent magnets based on rare earth alloys has been proved. The application of microwave plasma method in the analysis of the chemical composition of alloys based on rare-earth metals has been argued and substantiated. A preproduction model of a spectrometer was created. The method of component analysis Sm-Co system alloys was developed, certified and implemented in the production process of «Spetsmagnit» JSC. Standard samples with the chemical composition of the Sm-Co system alloy were manufactured and certified. The dependence of magnetic parameters of magnetic material samples on the original chemical composition of the five-component system Sm-Co-Cu-Fe-Zr-based alloy was investigated. The equations describing the dependence of the magnetic properties of the alloy’s chemical composition were discovered. A mesh nomogram based on the equations needed to predict the magnetic properties by chemical composition analysis was created. 10.18721/JEST.230122 535–15:543.421/424 SPECTRAL ANALYSIS; MICROWAVE PLASMA; CHEMICAL COMPOSITION; REM; SAMARIUM; COBALT; PERMANENT MAGNET; MAGNETIC PROPERTIES https://engtech.spbstu.ru/article/2017.99.22/ 22_kuchumov.pdf

RAR RUS 226-235 Khaydorov Aleksandr haidorow@yandex.ru Yunusov Firuz VACUUM HEAT TREATMENT OF HIGH ALLOY CORROSION-RESISTANT STEELS The influence of the high pressure gas quenching on the structure and properties of some high-corrosion-resistant steels was studied. It is shown, that the influence of the tempering temperature on the structure and properties of these steels at this conditions is very significant. The graphical representation of the hardness with tempering temperature is revealed. The most effective temperature ranges that achieve the desired properties are defined. A comparative analysis of the structure and the properties after hardening and high pressure gas in the oil carried out. It is shown that the microstructure and properties of the steel after hardening high pressure gas hardly differ from those after quenching in oil. 10.18721/JEST.230123 669.017:669.018.8:669–15 GAS QUENCHING WITH HIGH PRESSURE; HIGH-CORROSION RESISTANT STEELS; MICROSTRUCTURA; CARBIDE PHASE; HEAT TREATMENT https://engtech.spbstu.ru/article/2017.99.23/ 23_khaydorov.pdf

RAR RUS 236-246 Shvecov Oleg shvec_off@mail.ru IMPROVING THE OPERATIONAL RELIABILITY OF DRILL PIPES OF ALUMINIUM ALLOYS D16T AND 1953T1 The paper presents the results of the experimental study and analysis on the influence of operational and technological factors on the structure, mechanical and corrosion properties of aluminum alloys D16T and 1953T1 used for the manufacturing drill pipes for the petrochemical industry. It was found that the aging processes of these alloys during manufacturing and further operation have a different character. It is shown that the D16T alloy is much more resistant to softening under technological heated and operating conditions of extraction in comparison with the 1953T1 alloy. Practical recommendations to improve the maintenance ability drill pipes of aluminium alloys D16T and 1953T1 were formulated. 10.18721/JEST.230124 621.785.3:669.715.017:620.18:622.24.05 DEFORMABLE ALUMINUM ALLOYS; MECHANICAL PROPERTIES; MICROSTRUCTURE; AGING; TECHNOLOGICAL HEATING; OPERATIONAL RELIABILITY; DRILL PIPES https://engtech.spbstu.ru/article/2017.99.24/ 24_shvetsov.pdf

RAR RUS 247-255 Grigoriev Alexey alex@klimov.ru Razumov Nikolay n.razumov@inbox.ru Popovich Anatoliy popovicha@mail.ru Samokhin Andrei PLASMA SPHEROIDIZATION OF Nb-Si-BASED POWDER ALLOYS OBTAINED BY MECHANICAL ALLOYING Additive technologies are a method of making products of various shapes by adding layers of material in powder using a computer model. The general requirement to powders for additive technology is a spherical particle shape and particle size distribution of high uniformity. Today, the characteristics of powders limit the field of application of additive technologies. Development of new methods for obtaining raw materials for additive technologies will expand the range of used alloys. This paper presents the results of experimental studies of a Nb-Si-based powder alloy, produced by mechanical alloying of Nb, Si, Al, Ti and Cr elemental powders in the flow of thermal plasma. Experimental results show that plasma spheroidizing of Nb-Si-based powders obtained by mechanical alloying is possible. It is shown that after spheroidization the particle surface is rough, which indicates the cast structure of the material. Three phases having different optical contrast are revealed on microsections: Nb5Si3, Nb3Si and Nbss, which is confirmed by X-ray diffraction. 10.18721/JEST.230125 621.762.2:621.926 MECHANICAL ALLOYING; PLAZMA SPHEROIDIZATION; THERMAL PLASMA; HEAT RESISTANT ALLOY; SPHERICAL POWDER https://engtech.spbstu.ru/article/2017.99.25/ 25_grigorev.pdf

RAR RUS 256-270 Alexeyeva Tatiana Galevsky Gennadiy kafcmet@mail.ru Rudneva Victoria Galevsky Sergeii nirs@spmi.ru TECHNOLOGICAL SOLUTIONS IN PRODUCTION ZIRCONIUM CARBIDE: ANALYSIS, EVALUATION OF AND PROSPECTS The paper presents the analysis and systematization of information about the production of zirconium carbide. It has been shown that the basic carbothermic synthesis method is implemented in various options (furnace synthesis from traditional and highly disperse batches, crystallization-melting, plasma heating, in electrothermal fluidized bed). SHS process is not widely used, but may be in demand for multifunctional nanostructured films containing zirconium carbide. Mechanosynthesis produces nanocrystalline zirconium carbide, but in preparative amounts. Results obtained by plasma synthesis allow to consider it as the most promising of the known methods for producing nanostructured zirconium carbide. The deposition method of vapor-gas phase is focused on the formation of carbide film coatings and has no independent value for the production of zirconium carbide. 10.18721/JEST.230126 621.762 PRODUCTION; ZIRCONIUM CARBIDE; PLASMASYNTHESIS; NANOPOWDERS; MECHANOSYNTHESIS; SHS; PRECIPITATION https://engtech.spbstu.ru/article/2017.99.26/ 26_alekseeva.pdf

PER RUS 271-275 Lopota Aleksandr rtc@rtc.ru EVGENY YUREVICH: dedicated to the 90 anniversary of birth The article is dedicated to the creator of the Central Research Institute of Robotics and Technical Cybernetics, Honoured Scientist, Professor of the Polytechnic University, Evgeny Yurevich. The author tells about the life of the scientist, about his main studies, about the scientific schools he founded. 10.18721/JEST.230127 001:929 CRDI RTC; PHOTONIC TECHNOLOGY; ROBOTICS; ENGINEERING CYBERNETICS; EVGENY YUREVICH https://engtech.spbstu.ru/article/2017.99.27/ 27_lopota.pdf

PER RUS 276-290 Shaplygin Nikolai interserv@stu.neva.ru T.N. SOKOLOV: CHIEF DESIGNER OF THE LPI DESIGN BUREAU The article is dedicated to the participation of employees of the M.I. Kalinin Leningrad Polytechnic Institute in space exploration. In accordance with the Decree of the Government, the team of the Department of mathematical and computing instruments and devices set up CVM was on magnetic elements for information processing. CVM «Quartz» was part of the satellite flight tracking system, and on April 12, 1961 provided the flight of the first man in space. Another major project has been the creation of EDO LPI ACS Strategic Missile Forces. After the system was commissioned, agreement OSNV2 was concluded. 10.18721/JEST.230128 001:929 SPACE; M.I. KALININ LPI; SATELLITE TRACKING SYSTEM; FIRST CVM IN THE SOVIET UNION; FERRY DIODE BASIC ELEMENT; WORK DIGITAL COMPUTER IN THE FIELD; MEASURING POINTS FROM THE CRIMEA TO KAMCHATKA; FLIGHT OF HIS THIRD 15.05.1958 T; CVM «QUARTZ» AND «TEMP»; ACS https://engtech.spbstu.ru/article/2017.99.28/ 28_shaplygin.pdf

PER RUS 291-295 Demidov Alexander ph-chem@ftim.spbstu.ru THE HISTORY OF PROFESSIONAL EDUCATION IN RUSSIA: IVAN ANDREEVICH SHLATTER (1708–1768) The paper presents an essayy on the life and scientific work of the Russian scientist and public figure Ivan Andreevich Shlatter, who was President of the Collegium of Mining and at the same time Director of the St. Petersburg Mint. His major studies on the coin business, art, assay, mining and metallurgy served as manuals for students of mining-factory schools, students of the Mining school, and then the Mining cadet corps. A magnificent silver reliquary for the relics of St. Alexander Nevsky was made under I.A. Schlatter’s the leadership. 10.18721/JEST.230129 001:929 COINAGE; METALLURGY; MINING; FAMOUS SCIENTISTS https://engtech.spbstu.ru/article/2017.99.29/ 29_demidov.pdf