Кафедра матеріалознавства та термічної обробки металів ( ІПБТ)
Permanent URI for this community
UK: Кафедра матеріалознавства та термічної обробки металів (Інститут промислових та бізнес технологій, ІПБТ)
EN: Department of Material Science and Heat Treatment of Metals
Browse
Browsing Кафедра матеріалознавства та термічної обробки металів ( ІПБТ) by Title
Now showing 1 - 20 of 89
Results Per Page
Sort Options
Item Comparative Analysis of Technologies for the Production of Hardened Steel Products(Український державний університет науки і технологій; Університет Аалто Гельсінкі, Фінляндія, 2021) Perchun, HalynaENG: Comparative analysis of the known technologies for manufacturing hardened steel products using the methods of heat hardening and the methods of thermomechanical hardening shows that the developed technology favourably differs from the others by using only one type of hardening – deformation, which gives better logistics and ecology due to exclusion of the technological operations of high-temperature heating and rapid cooling; reduces the price of the billet, since the cold deformation does not require alloying. In the known methods of hardening of steel products, the corresponding structural state is formed most often by the heat treatments leading to various phase and structural transformations. At the same time, during operation these products are subjected primarily to deformation effect. In the products manufactured by the new technology, their structural state is formed by the deformation effect, i.e. effect of the same type as during operation. This makes it possible to state that their operational reliability is higher, including under the cyclic loading.Item Determining the Thermally-Stressed State of Motor-Driven Bowls for Transporting Liquid Slag(РС ТЕСHNOLOGY СЕNTЕR, Kharkiv, 2024) Povorotnii, Viktor V.; Shcherbyna, Iryna V.; Zdanevych, Serhiі V.; Diachenko, Nina K.; Kimstach, Tetiana V.; Solonenko, Lyudmila I.; Usenko, Ruslan V.ENG: Slag bowls were chosen as the object of research, as important components of blast furnace, steelmaking, and ferroalloy shops of metallurgical enterprises. The main problem of operation of any slag trucks is their limited durability and frequent destruction of slag bowls. The reason for these problems is changes in the shape of the bowls during operation, manifested in the formation of narrowing places in the area of the support ring – for rail-mounted bowls, destruction of supporting pins – for rail-mounted slag trucks, or cracks in the walls. Those defects appear as a result of cyclic thermal effects of liquid slag on the bowl. Based on the results of computer simulation, it was established that the main role in the destruction of the support pins of motor-driven slag bowls belongs to temperature changes. The temperature stresses arising in the bowl are localized in the area of the slag mirror (200–250 MPa for 25L steel, 280–350 MPa for 30HML steel). The results provide grounds for improving the presented slag bowl to reduce temperature stresses in its walls and structures of the supporting trunnions. The results reported here are explained by the fact that with uneven heating of elastic bodies, temperature stresses appear, which, under certain configurations of temperature loads, lead to the destruction of structures. The findings from these studies are recommended to be used at enterprises for the design and manufacture of slag bowls, as information on the localization of dangerous places of the structure. In addition, the data presented here could be useful for metallurgical enterprises for detailed technical diagnosis of bowls in their dangerous places.Item Development Features and Principles of Blockchain Technologies and Real Options as the Main Components of the Digital Economy(Springer, Singapore, 2022) Vazov, Radostin; Shvachych, Gennady; Moroz, Boris; Kabak, Leonid; Kozenkova, Vladyslava; Karpova, Tetiana P.; Busygin, VolodymyrENG: The paper shows that the digital economy reveals a huge range of opportunities for various enterprises. It noted its strengths: costs reduction, in-creasing the level of transactions’ security and transparency, close focus of vari-ous sectors of the economy. In this regard, for a clear and definite understanding of the problems under consideration, the authors introduced the definition of the digital economy, digital technologies in the economy, and “end-to-end” digital technologies in the economy. The authors’ proposed approach allowed concluding that the digital econo-my term is distinguished by several subtleties associated with insufficient knowledge, understanding of technical implementation, and flexibility. The research aims at revealing the development features and principles of the main components of the digital economy: distributed ledger technology (blockchain) and option technologies. The paper shows that blockchain technology, as a decentralized data ledger, is the most discussed and relevant topic in the development of the digital econ-omy. Its strengths are analyzed, such as cost reduction, increased security and transaction transparency affecting various sectors of the economy. The conducted research exposes the essence of the main provisions of tac-tics and strategies when solving the problem of options pricing. At the same time, there is presented a new classification of options contracts allowing to de-termine the ways of their application and development. Whereas, the analysis of the problem of options contracts pricing demonstrated the relevance of new mathematical methods developed for their reliable and accurate evaluation. The paper shows that at present, interest in the concept and technique of re-al options application has significantly increased; as they draw attention as a po-tentially essential tool for evaluation and improving an enterprise development strategy.Item Development of a Model for Calculating Changes in K76f Rail Steel Temperature to Determine the Heat Treatment Parameters(National Academy of Sciences of Ukraine, 2021) Babachenko, Oleksandr; Kononenko, Ganna; Podolskyi, RostyslavENG: Introduction. The conditions of operation of the railways of Ukraine and the prospects for their entry into the international system of transport corridors require the development and modernization of railway tracks, including rails. Problem Statement. Given the necessity to ensure the main operational parameter of the rails (wear resistance), regulatory and technical documents standardize hardness. The most progressive European standard EN 13674-1-2011 establishes that the hardness of the rail head at a depth of 20 mm shall be, at least, 321 HB, while STU 4344:2004 requires, at least, 321 HB at a depth of 11 mm. At the same time, according to EN 13674-12011, the rail surface hardness without the formation of needle structures shall be, at least, 405 HB. Purpose. To determine the possibility of achieving hardness without needle structures for rail head made of steel 0,80% C, 0,25% Si, 0,97% Mn, 0,055% V (hereinafter referred to as K76F), which complies with the world requirements, based on the calcination experiment and calculations with the use of the model; to determine the rational cooling rate for K76F steel during heat treatment. Materials and Мethods. K76F rail steel with 0.80% C, 0.25% Si, 0.97% Mn, 0.055% V. Techniques: metallographic studies, hardness measurements, determination of calcination by end quenching, modeling by means of mathematical calculation with the use of QForm heat treatment software package. Results. The change in temperature, the formation of structure and hardness across the section of a K76F steel sample for calcination tests according to GOST5657 has been modeled. The changes in the hardness and microstructure has been experimentally established, depending on the distance to the heat sink surface; the cooling rate in the points where the hardness meets the requirements of EN 13674-1-2011 for rails has been determined. Conclusions. The analysis of the model has shown a high accuracy of the model and the convergence of the experimental results with the calculated ones. It has been established that the requirements of EN 13674-1-2011 can be achieved up to a hardness of 405 HB without the formation of needle structures on steel that meets the chemical composition of K76F according to DSTU 4344: 2004.Item Features of the Ferrite-Bainite Structure Low-Alloy Low-Carbon Steel after Heat Hardening and Subsequent Tempering(Prydniprovska State Akademy of Civil Engineering and Architecture, 2021) Deineko, Leonid M.; Borysenko, A. Yu.; Taranenko, A. A.; Zaitseva, T. O.; Romanova, Nataliia SerhiivnaENG: Problem statement. In recent decades, there has been a tendency to increase the mechanical properties of low-carbon, low-alloyed steel plate iron by using controlled rolling or hardening heat treatment of finished steel parts. At the same time, for welded parts, the most suitable is a metal having a ferrite-bainite (or bainite) structure. The work investigated the features of the ferrite-bainite structure of low-carbon and low-alloyed steel 15ХСНД for the production of connecting pipeline parts. Purpose of the article. To establish the laws of formation of a ferritic-bainitic structure in low-carbon low-alloy steels depending on the parameters of heat treatment. Determine the effect of heat treatment parameters on the properties of the connecting parts of pipelines made of these steels. Conclusion. The regularities of the influence of heat treatment parameters on the structure, mechanical properties and topography of fractures of impact samples of 15ХСНД steel with a ferrite-bainitic structure are established.Item Features of Using the Distance Learning Model(Ukrainian State University of Science and Technologies; Aalto University Helsinki, Finland, 2021) Shvachych, Gennady G.; Khokhlova, Tetiana S.; Stupak, Yurii O.; Moroz, Boris; Kabak, LeonidENG: Purpose. To analyze models of distance learning (DL) that have been implemented in the world and have shown effectiveness in order to determine promising directions for the development of DL: testing, educational research, contextual learning, mobile learning, development of social networks, application of mobile educational games, implementation of mobile voice content with interactive assessment etc. Methodology. Literature review of open access information sources. Findings. It has been determined that special attention should be paid to the technologies of educational institutions, in which it is possible to involve highly qualified teachers in reading lectures; there is a significant saving of teachers' time; there is a possibility of increasing the amount of material presented within the budget allocated for regular classroom activities in the curriculum. Originality. It consists in a certain set of criteria, based on the analysis, which are necessary and sufficient to achieve the final goal. Practical value. The methods of selection of educational tools make it possible to increase the effectiveness of the educational process, make it attractive and exciting for students and motivate them to an active educational process always and everywhere, which allows students to receive a quality education.Item Forecast and Control of Structure and Properties of Ultra-Low-Carbon Steels(G. V. Kurdyumov Institute for Metal Physics of the N.A.S. of Ukraine, 2021) Koval, Yu. M.; Kutsova, Valentyna Zynoviivna; Kotova, T. V.; Kovzel, M. A.ENG: Concentration ranges of elements’ containing to optimize the composition of 01YuTA, 01YuT steels and to ensure the required set of rolled products properties are obtained using the method of physico-chemical modelling. The effect of rolling deformation modes in the ferritic temperature range on the formation of the structure and on the properties of ultra-low-carbon steel is investigated. The obtained data can be used to control the processes of structure formation and to establish rational technological regimes for the processing of rolled sheet material for automobile and machine-building enterprises.Item Influence of Ice Structure on Vitability of Frozen Sand-Water and Sand-Clay Mixtures(Dnipro University of Technology, Dnipro, Ukraine, 2024) Solonenko, L. I.; Uzlov, Kostiantyn I.; Kimstach, Tetiana V.; Mianovska, Ya. V.; Yakymenko, D. Yu.ENG: Purpose. To establish influence regularity of sand, water and clay preparation conditions on vitability of frozen mixtures made from combinations of these components and to increase the castings quality in foundries, as well as to improve technologies for artificial freezing of soils for underground constructions. Methodology. In this research, sand, clay, and water are used. Ice quality is estimated visually after water freezing at -15 °C in glass tubes. Frozen mixtures’ vitability at -15 °C is studied on beam-type samples. As indicators of survivability, the time to 1 mm bending of samples on supports and the time to their destruction are accepted. The time is recorded with a stopwatch, the temperature with an alcohol thermometer, the mass with electronic scales and the deflection arrow with a clock-type indicator. Findings. The presence and amount of water-soluble impurities in rare water significantly influence the nature, size and distribution of gas bubbles in ice, as well as frozen sand-water mixtures vitability. Frozen mixtures’ survivability increases with water content in them increasing, and, for sand water mixtures, survivability is maximum if ice has a homogeneous structure. Among mixtures with clays, the mixture with non-swollen kaolin clay has the greatest vitability. Regarding survivability, recommendations for manufacturing products from frozen foundry mixtures have been developed. Originality. For the first time, deformation change kinetics (bending arrows) under the influence of beam-type samples’ self-mass from mixtures of quartz sand and water and quartz sand, clay and water frozen at -15 °C, which have been previously prepared in different ways, have been investigated. Insights into the influence of various factors and ice quality on the vitability of frozen mixtures have been further developed. Practical value. The obtained results can be useful for expanding ideas about natural frozen soils’ behavior during their cyclic temperature changes, soils artificially frozen during mine shafts elaboration, escalators’ and junctions’ tunnels, etc. when constructing subways. In foundries, the developed recommendations will reduce technological losses and will improve casting quality made using frozen casting molds and cores from sand-water or sand-clay-water mixtures, castings’ patterns and their pouring systems from sand-water mixtures.Item Influence of Physico-Chemical Processing in Solid and Liquid States on Hypereutectic AlSi18(B-Sn) Alloy Structure and Properties(Харківський національний автомобільно-дорожній університет, Україна, 2023) Aiupov, Oleksandr; Nosko, Olha A.; Aiupova, Tetyana A.; Kupchinska, AlinaENG: The peculiarities of AK18 alloy (B-Sn) structure formation, mechanical properties, friction and wear parameters formation depending on the regimes of physical and chemical melt processing and thermocycling in the solid state have been established. Observed structural changes (the β-Si and eutectics ratio, the primary and eutectic β-Si crystals shape and size, eutectics differentiation increasing, the pseudoprimary aluminum solid solution (α-A1) dendrites appearance provide an improvement in the complex of mechanical properties and a reduction in wear friction parameters. The obtained experimental data allow to recommend a complex treatment "hydrogen treatment for 40 min + thermal cycling in the solid state at 475-485°C for 5 cycles" to improve the complex of mechanical properties and reduce the wear friction parameters.Item Kinetics of Quartz Sand and Its Mixtures Drying by Microwave Radiation(Dnipro University of Technology, 2021) Solonenko, L. I.; Repiakh, Serhii I.; Uzlov, Kostiantyn; Mamuzich, I.; Kimstach, Tetiana; Bilyi, OleksandrENG: Purpose. Kinetics research and description of drying by microwave radiation mechanism development of quartz sand and its mixes with sodium silicate in limited quantity of water steam medium. Methodology. Distilled water, sodium silicate solute and quartz sand have been used in this research. Study has been performed on sand samples weighing 200 g. Mixtures drying and structuring have been performed by microwave radiation with power of 700W with frequency of 2.45 GHz in air and in saturated water weighing 1 g steam medium. Accuracy of temperature measurement is 1, mass is 0.02 g. Realized in this investigation drying kinetics has been specified as specimen weight change dependence and moisture evaporation from this mixture rate vs. drying duration. Dependencies have been built on the results of video recording and corresponding chrono-gravimetric measurements data digitalization. Mixtures during heating by microwave radiation temperature changes registration has been performed with an interval of 1560 s. Samples average heating rate has been estimated by calculation based on results in their temperature change determination during first 2 minutes of heating with microwave radiation. Findings. For the first time, microwave drying kinetics of quartz sand and its mixtures with sodium silicate in limited water medium (structured by SMS-process) has been studied. For the first time, based on SMS-process material balance, analytical dependence has been developed. This dependence application allows sand-sodium-silicate mixture structured by SMS-process maximum mass to calculate when using sodium silicate solute (silicate module 2.83.0) for quartz sand cladding and 1 g of saturated water steam for mixture structuring. It has been established that when mixtures structuring according to SMS-process water extraction from them takes place in three stages at ~100, 100108 and at 125138. Maximum appropriate heating temperature of sand-sodium-silicate mixture during structuring by SMS-process has been recommended as ~125. Exceeding of specified temperature leads to hydrated water from mixture releasing in steam form and its condensation on colder working surface of model-rod rigging. Resulting condensate leads to mixture restructuring in contact with equipment places and, accordingly, sharp quality deterioration in prepared molds and rods. For manufactured molds and rods quality stabilization, it has been recommended to pre-dry the quartz sand cladded with sodium silicate solute in microwave field for at least 3 minutes before structuring according to SMS-process. Originality. For the first time, data on drying kinetics has been obtained and quartz sand and its mixtures with sodium silicate in limited water steam medium microwave drying mechanism description has been developed. Influence of number of SMS-process basic parameters on structured quartz sand weight regularities has been established. Practical value. Research results will be useful in terms of ideas expanding about the processes that accompany granular materials drying, as well as in technologies and equipment for drying and structuring fine-grained dielectric materials and their mixtures development, creating new capillary-porous media, etc. under microwave radiation influence.Item On Some Aspects of the Study of Pulverized Coal and Fuel Mixtures Combustion in a Drop Tube Furnace(НМетАУ, Дніпро, 2021) Stupak, Yurii O.; Khokhlova, Tatyana S.ENG: Analysis of the operation of fluid friction bearings (FFB) of mills 630 showed that the loss of oil on the cages 630 reaches up to 10 tons per year. The reason for this is the imperfection of the seal design, which in turn does not provide the required mode of lubrication of the FFB and leads to high-intensity wear of the surfaces of the sleeve and bearing liner. Which leads to the failure of the FFB before the deadline for replacement of the sleeve and liner. The aim of the study is to determine the load of FFB by mathematical modeling to determine the energy and power parameters of rolling on the example of channel No14, determine the coefficient of friction, study the wear of the surface of the sleeve and liner FFB and provide recommendations for possible ways to improve FFB seals 630. To determine the energy and power parameters of the rolling profile of the channel profile, mathematical modeling was performed using the software product QForm 9. The QForm program is designed for mathematical modeling, based on the finite element method, technological processes of metal forming by taking into account thermomechanical processes of heating and cooling of metal, including in the process of deformation, as well as the interaction of the deformable workpiece with technological tools and equipment. The greatest rolling forces and, accordingly, the load on the FFB will act in the cage No4 and reach 2.8 MN when the roll is captured. The obtained result indicates that the increase in the load acting on the bearing does not significantly affect the change in the coefficient of friction in it, which is in the range of 0.0027 - 0.00274. The value of the friction coefficient μ will be most affected by the viscosity of the oil η and the value of the radial gap δ. The calculation confirmed the transition to the maximum friction during wear to a radial gap of 4 mm, which was observed during the operation of the FFB. The value of the gap δ = 1.8 mm, at which the replacement of the liner and the bearing sleeve will be obtained after 8.8 years of operation. But operational data show that such a gap is reached in 3 years of operation. The reduction in bearing life is due to inadequate friction, namely non-compliance with the viscosity parameters of the oil and its insufficient amount in the bearing. The reason for this is the leakage of oil due to unreliable sealing and ingress of abrasive and coolant rolls. An improved design of seals using V-shaped cuffs is proposed.Item Regularities of Formation of Structure, Phase Composition and Properties of Chromium–Manganese Alloys in the Initial Cast State during the Process of Friction Wear(G. V. Kurdyumov Institute for Metal Physics of the N.A.S. of Ukraine, 2021) Koval, Yu. M.; Kutsova, Valentyna Zynoviivna; Kovzel, Maksim A.ENG: Structural and phase transformations, as well as changes in the microhardness of the matrix, austenite-carbide eutectic, and total hardness that occur in chromium–manganese alloys in the cast state during wear by friction under different loads are studied. As shown, a high wear resistance of chromium–manganese alloy (C—3.1%, Cr—13.1%, Mn—15.75%, Ni—1.15%) is associated with high microhardness of the matrix, austenitic-carbide eutectic based on Me7C3 carbide and determined by the degree of doping and the parameter of the shape of the eutectic carbide, as well as due to the deformation-phase transformations that occur in the investigated alloys during friction wear.Item Regulations of the Formation of Bainetic Component Matrix in Economy Alloyed Chromo-Manganese Alloys(Prydniprovska State Academy of Civil Engineering and Architecture, Dnipro, 2023) Pohrebna, N. E.; Nosko, O. A.; Aiupova, Tetiana A.; Hrebenieva, А. V.; Aiupov, O. A.ENG: Purpose. The purpose of the investigation is to establish the regularities of the kinetics of supercooled austenite decomposition in the bainite temperature range (400−200 °C) in chromium-manganese cast iron for the development of thermal hardening regimes that increase the service life of products. Methodology. The object of the study are samples of research and industrial smelting of chrome-manganese cast iron containing 3,1 % carbon, 13,1 % chromium, and 15,75 % manganese. The study of the supercooled austenite decomposition kinetics was carried out by the dilatometric method in the temperature range of 400−200 °C, the study of the microstructure, phase composition, as well as the measurement of microhardness and hardness was carried out according to standard methods. Scientific novelty. The peculiarities of the supercooled austenite decomposition kinetics in the bainite temperature range (400−200 °С) in chromium-manganese cast iron were determined, the structure of the cast iron after aging consists of eutectic carbides Me (Cr, Mn, Fe)7C3, products of austenite decomposition, secondary carbides Me (Cr, Mn, Fe)7C3, Me (Cr, Mn, Fe)3C, as well as untransformed austenite in the amount of 70...75 %. The maximum hardness of the experimental cast iron was established during isothermal exposure at 350 °C for 35 hours. Practical value. The established regularities of the chromium-manganese cast iron structure formation and the determined and optimized temperature-time intervals of the supercooled austenite isothermal decomposition in cast iron are the basis for the development of heat treatment regimes to increase the strength, wear resistance of the material and the service life of its products.Item Sand-Sodium-Silicate Mixtures Structured in Steam-Microwave Environment Effective Values of Thermo-Physical Properties(Dnipro University of Technology, Ukraine, 2021) Solonenko, L. I.; Repiakh, Serhii I.; Uzlov, Kostiantyn I.; Dziubina, A. V.; Abramov, Serhii O.ENG: Purpose. Sand-sodium-silicate mixtures, structured by steam-microwave solidification, thermo-physical properties integral-effective values during Al-Mg alloy and graphite cast iron pouring determination. Sand-sodium-silicate mixture apparent density changing according to quartz sand, cladded with sodium silicate solute, fractional composition and its influence on BrA9Zh3L bronze microstructure establishment. Methodology. Quartz sand with 0.23 mm average particle size, sodium silicate solute, aluminum alloy with 8.5 % Mg, flake graphite cast iron SCh200 (DSTU 8833:2019), bronze BrA9Zh3L (GOST 493-79) were used. Mixtures structuring was carried out in 700 W magnetron power microwave furnace. Sand-sodium-silicate mixture thermo-physical properties integral-effective values were calculated by G. A. Anisovich method, using castings results and molds thermography. Structured mixtures apparent density was determined on samples 50x120 mm dimension. Metallographic studies were realized using Neophot-21 optical microscope. Findings. It was found that with sodium silicate solute, used for sand cladding, amount increasing from 0.5 to 3 % mold material apparent density decreases and thermal activity lowers. This leads to castings grains size increasing. Mixture sodium silicate solute content was recommended limiting 1.5 % for fine-grained microstructure castings obtaining and cladded sand using, which particles pass through mesh side less 0.315 mm sieve. Sands with sodium silicate solute content more than 1.5 %, which don’t pass through sieve 0.4 mm mesh side, were recommended as casting molds heat-insulating material using. Originality. For the first time, when aluminum-magnesium alloy and graphite cast iron pouring, quartz sand cladded with sodium silicate solute in amount from 0.5 to 3.0 % (weight, over 100 % quartz sand), steam-microwave radiation structured, thermo-physical properties integral-effective values were determined. Practical value. Data obtained using will improve castings solidification time and rate analytical calculations accuracy, forecast level and residual stresses sign in them, shrinkage defects locations. This will reduce casting technology developing time and costs and castings manufacturability.Item Simultaneously Enhancing Strength, Ductility and Corrosion Resistance of a Martensitic Stainless Steel via Substituting Carbon by Nitrogen(Springer, 2023) Li, Fuyang; Tian, Jialong; Li, Huabing; Deineko, Leonid M.; Jiang, ZhouhuaENG: Two martensitic stainless steels of 2Cr12Ni6 type hardened and tempered at 773 K have been studied: the first with 0.2% carbon content and the second with partial replacement of carbon by nitrogen (C0.1N0.1) in the first steel. It is found that the partial substitution of carbon with nitrogen contributed to an increase in ductility and strength of the steel, presumably due to the formation of more dispersive carbonitrides. Meanwhile, the addition of nitrogen suppressed the precipitation of carbonitrides, so that the solid solution strengthening effect of C0.1N0.1 did not decrease significantly after tempering treatment. In addition, the partial replacement of carbon by nitrogen contributed to improved ability against pitting corrosion (PC) in chloride-containing medium (3.5%NaCl at 303 K). The higher resistance to PC of tempered nitrogen-containing steel is apparently due to the lower content of massive carbonitrides, especially the reduced aggregation at grain boundaries. This leads to a lower acidity and aggressiveness of the test solution near the sample surface due to the accumulation of NH4 + ammonium ions in it. As a result of nitrogen addition, exception for Cr 23 C 6 and VC, Cr 2 N and (Cr, V) N type precipitates have also been found in C0.1N0.1 steel and this is consistent with the thermodynamic calculation results. In conclusion, substituting carbon by nitrogen in traditional martensitic stainless steel could realize the simultaneous improvement of multiple properties of martensitic stainless steels. This result provides a promising composition optimization route to develop novel martensitic stainless steels.Item Strengthening of Pipe Tools for Cold Roller Rolling of Corrosion-Resistant Pipes by Application of Amorphous Alloys(Національний науковий центр «Харкiвський фiзико-технiчний інститут», 2021) Krivchik, Lilia; Khokhlova, Tatiana; Pinchuk, Victoria; Holovachov, Аrtem; Srebryansky, Grigory; Nosenko, Victor; Zagorodniy, OleksiyENG: In the production of pipes from corrosion-resistant steels on pipe rolling plants, the current problem is the low stability of the pipe tool. Therefore, the creation of high-performance and durable tools is associated primarily with the production and processing of materials that could withstand harsh working conditions. The technology of heat hardening of the pipe tool for cold roller rolling of corrosion-resistant pipes (rollers and support laths of HPTR mills) from 4Х5МФ1С steel which excludes the third holiday and uses drawing of a covering from powders of amorphous alloys 100…150 µm thick is offered in the work. As a result of the offered technology durability, wear resistance, and also hardness to HV0.1 950–1050 (in comparison with HV 587–690 on existing technology of heat treatment in factory conditions) increases. A wide range of studies of the structure of the coating and industrial tests of rollers and support bars. It is shown that gas-plasma coating of amorphous alloy based on Fe–Si–B system increases the hardness of the tool surface by 1.3–1.6 times and their stability by ~ 30…50%.Item Structural Formation Regularity of Cu-Sn-Si System Low-Tin «Singing» Bronze(Baltija Publishing, 2022) Uzlov, Kostiantyn Ivanovych; Mazorchuk, Volodymyr Fedorovych; Dziubina, Alina ValentynivnaENG: Based on the task of acoustic bronzes containing about 20%Sn cost reducing, the aim of economically alloyed bronze composition with expensive tin replacement by silicon developing has been formulated in the present work. Three-component system Cu-Sn-Si bronzes structure formation has been studied and conodes triangle copper corner alloys phase transformations regularities were determined. It was established that in Cu-Sn-Si system alloys with Si content more than 4wt.%, original β-phase is stabilized by silicon and in solid state does not undergo low-temperature eutectoid transformations with small (up to 4wt.%) tin amount in bronze. It is shown that this «singing» bronze structural state is the basis for two systems of structural stresses in castings body existence, which act as acoustic resonators in products material. These systems are: α-Cu solid solution liquated areas of different genesis and interphase boundary α-Cu↔β-Cu5Sn, which causes occurrence of II type internal structural stresses between α-Cu and chemical compound Cu5Sn, which are fundamentally dissimilar in nature. For the first time, with comprehensive using of scanning electron microscopic, X-ray spectral, energy dispersive, X-ray structural phase and metallographic studies of Cu-Sn-Si alloys with optimized composition (silicon 4.5...5.5% by mass and tin 2...5% by mass at mass ratio Si/Sn≥1), tin-silicon bronzes with main components optimal ratio structural formation regularities are established. New bronze for bells and percussion musical instruments in terms of strength and impact toughness exceeds «classical» bell bronze indicators by~1.5...2.5 times with comparable relative elongation values. This evidences that, compared to «classic» bell bronze, elaborated cast bronze products with developed optimal chemical composition are characterized by greater reliability and durability during operation within its application specified area. Present work innovative solutions on methods of making musical bronze, obtaining bronze castings and making bells and percussion musical instruments acoustic elements are covered by intellectual property protection documents.Item Transition from Engineering Strain to the True Strain in Analytical Description of Metals Hardening(Prydniprovska State Academy of Civil Engineering and Architecture, Dnipro, 2021) Dolzhanskyi, A. M.; Ayupova, T. A.; Nosko, O. A.; Rybkin, O. P.; Ayupov, О. А.ENG: Purpose of the work is related with the impossibility of correctly estimating the strain hardening of metals (alloys) in the area of their large total deformations due to absence of additivity in the traditionally used value of engineering strain , its nonlinear change in the area of large values, and absence of data in the technical literature Hall-Petch coefficient Ai for logarithmic true deformations, which led to the task of correct transition from the values of the engineering strain 0 < < 50...60 % to the value of the true logarithmic strainn 0 < < 1...3. Methodology. The theoretical analysis of the regularities of deformation hardening of metals (alloys) from the engineering strain is carried out, the transition from engineering to logarithmic ("true") strain of metals (alloys) by analytical representation of metal hardening graphs as a function of logarithmic (true) strain. in contrast to the degree of engineering strain is presented. Originality. Analytical expressions are presented that allow the use of known theoretical data on the strain hardening of metals (alloys) at small (50...60 %) total engineering strains during cold pressure treatment to transition to logarithmic (true) strain with large total deformations. Practical value. The obtained mathematical expressions allow to use the accumulated in the technical literature experimental data on the hardening of metals and alloys with small engineering strains in the processes of cold processing of metals (alloys) by pressure to determine the hardening with large total logarithmic (true) strains. These data can also be used to solve metallophysical problems of metal processing by pressure associated with large total compressions.Item Use of the Dactyling Effect to Obtain a Compositional Structure in White Iron during Forming(IOP Publishing, 2021) Myronova, T.; Ashkelianets, A.; Chukhlib, V.; Biba, N.; Gubskii, S.; Okun, A.ENG: Cast iron is traditionally used as a casting alloy for the manufacture of products operating in various industries. White cast irons are used for parts with high wear resistance due to the presence in their composite structure a large number of eutectic carbides, which are located around the dendrites of the solid solution and provide a high level of hardness and strength. The location of eutectic colonies in the form of a mesh causes a low level of ability to withstand impact loading, facilitates the chipping of individual "grains" in abrasive wear and limits the use of these alloys. The use of forming process allows us to grind the eutectic mesh in the structure of white cast iron, which significantly improves the complex of mechanical and operational properties. But the low level of plasticity of white cast iron in the cast state does not allow widespread using white cast iron plastic deformation. The possibility of hot deformation of cast iron workpieces with different speeds and schemes was investigated. The deformation rate of alloys was varied due to the use of different equipment for mass and small-series production using different types of metal forming.Item Water Resistance of Structured Sand-Sodium-Silicate Mixtures(Dnipro University of Technology, 2021) Solonenko, L. I.; Repiakh, Serhii I.; Uzlov, Kostiantyn I.; Mamuzich, I.; Bilyi, Oleksandr P.; Kimstach, Tetiana V.ENG: Purpose. To establish regularities of changes in sand-sodium-silicate mixtures (SSSM) relative water resistance, structured by steam-microwave solidification method (SMS), on their structuring parameters and sodium silicate solute (SSS) dissolution conditions. Methodology. Technical purity water, SSS with 2.8–3.0 silicate modulus, quartz sand with 0.23 mm average particle size were used in this work. Studies were carried out on quartz sand samples, which were preliminarily cladded with 0.5–2.5 % (by weight) SSS and structured by SMS method. The fracture time of structured mixtures was evaluated on cubic specimens with 20 mm rib length, which were immersed in water at different temperatures. Findings. Changes in SSSM water resistance in water regularities depending on their manufacturing, use and storage conditions were established. Recommendations for SSSM rods removal from castings in water were developed. Originality. For the first time, it has been established that relative water resistance of the SSSM structured by SMS method decreases along with increase in water temperature in which it is destroyed. Depending on SSS mass used for quartz sand cladding in range 0.5–2.5 %, water resistance dependence on treatment in steam-microwave environment with 2–7 minutes’ running time acquires an inversion character with inversion point ∼3.1 minutes into the processing. For the first time, it has been discovered that in boiling water the relative water resistance of SSSM, structured by SMS-process and having preheating, monotonically increases with preheating temperature rising from 100 to 600 °С, sharply increases when heated to 600–700 °С and practically becomes absolute after preliminarily preheating to higher temperatures. Practical value. Research results will be useful in concepts of processes accompanying destruction of structured sands with water-soluble binders expanding, as well as in technologies and equipment development designed for SSS rods and mold rests removing from castings.