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No 4 (2025)
Articles
Milestones of a glorious path: 70 years of the Vatolin institute of metallurgy of the Ural branch of the Russian academy of sciences
Abstract
The article is dedicated to a significant date – the 70th anniversary of the establishment of the Institute of Metallurgy named after academician N.A. Vatolin of the Ural Branch of the Russian Academy of Sciences as an independent scientific institution. A brief historical essay on the main stages of the formation and development of the Institute, its scientific areas and schools is presented. The contribution of scientists to the development of fundamental and applied research in the field of physical and chemical foundations of high-temperature processes in the field of ferrous and non-ferrous metallurgy, complex processing of mineral and technogenic raw materials is covered. The results of the Institute’s activities and achievements, which are the result of fruitful work over several decades for the benefit of domestic metallurgy, are summarized.
280–295
Application of titanium and vanadium-alloyed cast irons for the production of replacement metallurgical equipment
Abstract
The article summarizes the long-term experience of JSC ZSMK, research institutes and universities in the field of production of replaceable steel casting equipment. The paper presents the experience of manufacturing ladles made of blast-furnace cast iron, pallets, ladles, intermediate ladle covers made of induction cast iron alloyed with titanium and vanadium; discusses the use of resonant pulsating refining when purging cast iron with nitrogen, and also provides a generalization on the use of thermal melt treatment in refining cast iron used for the production of heat-resistant castings. The compositions of phosphorous and naturally alloyed cast iron of induction and blast furnace melting were developed. The use of resource-saving out-of-furnace processing technology and the transfer of casting of slag bowls from foundry cast iron to economically alloyed blast furnace cast iron made it possible to reduce the consumption of ferrosilicon from 25.6 kg to 12.9 kg, and ferrosilicon manganese from 7.4 kg to 4.27 kg per ton of cast iron, respectively. Consumption of ferrosilicon during the introduction of economically alloyed cast iron during the remelting of steel mills in induction furnaces was reduced from 34.28 kg per ton of cast iron to 18 kg per ton of cast iron, respectively. All technologies have been implemented in production. After the introduction of these technologies, the durability of products for the ferroalloy industry has increased by 10%. The consumption of mills at JSC ZSMK amounted to 11.8-12 kg per ton of steel, which corresponds to the best indicators in the industry. The durability of the caps of the intermediate caster buckets increased and reached 294 melting points. The durability of cast iron slag bowls has reached 700-1500 fillings; the durability of forging molds is 40-60 fillings, through molds – 90-100 fillings, pallets – 140 fillings. Thus, in the Siberian region, thanks to the joint creative work of specialists from JSC ZSMK, mass media, UPI, KemGU, KuzGTU, DonNIIchermet, MGVMI, a complex of technologies for producing replaceable steel casting equipment from blast furnace cast iron and induction cast iron was developed. These technologies have ensured maximum durability of the replaceable equipment at the level of the world’s best indicators with minimal cost of products. The work will be useful for industrial enterprises and research institutes in the development of new resource-saving technologies, as well as in the educational process for graduate students and students in relevant fields.
296–308
On the dependence of the quality indicators of metal products on the structure and properties of melts
Abstract
The article is devoted to a detailed study of the dependences of qualitative indicators of metal products on the structural state and properties of melts. The effectiveness of modern technologies for smelting steels and alloys is based on a deep understanding of the physics-chemical processes occurring in liquid metal. It is the state of the melt before the crystallization process that plays one of the key roles in ensuring the high quality of the finished product. On the other hand, this factor, which requires additional attention, often remains underestimated. The analysis of available theoretical concepts and experimental data on the structure of metallic liquids is carried out. The main attention is paid to the results and prospects of the introduction and application of time temperature treatment (TTT) of the melt, which makes it possible to purposefully regulate its condition and improve the quality of the solid metal. An array of experimental data is provided confirming the positive impact of the technology under discussion. Specific examples of the use of TTT melt in industrial enterprises in the manufacture of a wide range of metal products: structural, tool and stainless steels, as well as cast iron for various purposes are considered. The effects of the TTT melt technology on the behavior of low-, medium- and high-alloy steels are emphasized, demonstrating high efficiency of structure management, which leads to a decrease in the incidence of traditional defects such as shrinkage shells, chemical segregation, and others. It is shown that the use of TTT during the melting of steel makes it possible to significantly expand the range of their hot plasticity. For heat-resistant nickel alloys, the formation of an equilibrium melt makes it possible to obtain the structure and properties of a solid metal that are unattainable by other metallurgical methods. Statistics are presented showing a significant increase in the share of high-quality products and a reduction in losses at subsequent stages of metal processing. The prospects for further improvement of the methodology for the experimental determination of parameters and design characteristics of the optimal mode of thermal processing of metal for specific smelting conditions are considered. It is suggested that the melt has a high potential in the light of the growing requirements for energy conservation and rational use of resources, in order to improve the quality of the metal produced and increase the competitiveness of products.
309–320
Technology of producing Mn-Si-Ba-Fe alloy by carbothermal method
Abstract
The results of theoretical and experimental studies of the technology for producing a complex barium-containing ferroalloy based on manganese for out-of-furnace processing of metal products are presented. Ferroalloys containing barium are of the greatest interest due to the unique complex of its physical and physicochemical properties (solubility in liquid iron is 1.22∙10−4 at.% at T=1600K; relative modifying capacity 69.86∙105; Tm.p.Ba=983K; Tb.p.Ba=1910K; heat of interaction with iron is 212 kJ/mol; enthalpy of dissolution is 300 kJ/g-at at T=1700K). The diagrams of material ratios of the oxide BaO-SiO2-MnO-FeO and metallic Ba-Si-Mn-Fe systems were constructed to determine the rational ratio of the components of the charge and the composition of the alloy by the method of thermodynamic-diagram analysis. This is a simple method for studying phase patterns of complex systems taking into account the features of state diagrams. The values of the change in Gibbs energy (∆G0T) are determined in a homogeneous liquid-phase state using the Gibbs software package developed by scientists of the Chemical and Metallurgical Institute named after Zh. Abishev. The tie lines of coexisting phases are drawn according to Hess’s rule. It was established that the rational composition of the batch for obtaining an alloy with a barium content of more than 1.5% is located in the quasi-system Fe2SiO4-Ba2Si3O8-Mn2SiO4-SiO2, and the composition of the alloy is in the region of the tetrahedron FeSi-BaSi2-MnSi-Si. The large-scale laboratory tests of the smelting of a complex barium-containing ferroalloy based on manganese in an ore-thermal furnace with a transformer capacity of 200 kV×A by a slag-free carbothermal method were carried out on the basis of the results of a thermodynamic-diagram analysis. Manganese ore from the Mynaral deposit (71.67% Mn2O3), barite ore from the Zhumanai deposit (74.35% BaSO4), and quartzite from the Tekturmas deposit (97.05% SiO2) were used as initial raw materials. Chinese coke (82.70% Csol.) was used as a reducing agent. It was established that the transition of barium into the alloy is determined by the accompanying process of silicon reduction. It was determined that to obtain an alloy with 1.5% Ba, the ratio Si/(Mn+Fe) should be at the level of 0.6; for an alloy with a content of 10% Ba – 1.1.
321–329
Thermodynamic modeling of copper ore processing into matte using borate ores
Abstract
The cost of one ton of copper on the London Metal Exchange often reaches 9'000 USD. Such a high price necessitates measures aimed at maximizing the extraction of this metal into final products and minimizing losses. According to open sources, the total amount of copper in technogenic mineral formations of Kazakhmys Corporation LLP (Kazakhstan) is estimated at about 4 million tons. This study proposes measures to reduce copper losses from the pelletizing stage to smelting in metallurgical furnaces. Using full thermodynamic modeling, the effect of boron anhydride and borate ore on the processes of pelletizing, drying, roasting of copper ore concentrates, and matte production was investigated. It was found that the use of B2O3 is expected to increase the strength of wet pellets due to the formation of boron anhydride crystal hydrates (H3BO3), which bind ore particles. During drying, the hydrate loses water at 285 K, turning into boron anhydride, which melts at 723 K during roasting, forming a liquid phase. Upon cooling, this phase creates a solid sinter together with other ore components. Metallurgical processing of such boron-containing material is predicted to improve process performance and reduce matte losses due to the formation of low-viscosity, highly mobile furnace slags. The proposed borate ore contains montmorillonite, a clay mineral typical of bentonites, which ensures sufficient strength of wet pellets for transport from the pelletizing unit to the roasting equipment. The presence of low-melting borate ore in the pellets promotes the formation of a liquid phase during roasting, which solidifies into a strong sinter. As with B2O3, metallurgical smelting is expected to benefit from reduced matte losses due to the formation of lighter, more fluid slags. The calculations and modeling conducted confirm the high potential of the proposed approach for industrial implementation.
330–340
Термодинамическое и экспериментальное моделирование технологического процесса выплавки ферробора карботермическим способом
Abstract
This paper presents the results of thermodynamic and experimental studies of the ferroboron production process by the carbothermic method aimed at improving the properties of ferroalloys and expanding their application in various industrial sectors. Thermodynamic modeling of the process was carried out using the TERRA software package, which allowed for a detailed analysis of phase changes and chemical reactions occurring during the reduction process. This enabled the optimization of conditions for producing ferroboron with the required composition and properties. The physical modeling was conducted on a rudd-thermal furnace with a transformer power of 250 kV·A, providing the possibility of studying the process under real production conditions with precise control over the parameters. A feature of the conducted research was the use of coke from the low-ash coal of the Shubarkul deposit in Kazakhstan as a reducer, which reduced raw material costs and improved the economic efficiency of the process. In addition, various natural boron sources were used for the study, allowing the influence of different types of borate ores on the ferroboron production process to be examined. Experimental data showed that using coke from Shubarkul coal and borate ores, ferroalloy with boron content of 14-15% could be produced, which is highly effective for application in various industries. The ferroboron obtained during the experiments was tested as a modifier at a local machine-building enterprise engaged in the production of cast iron grinding balls. The test results showed that the use of ferroboron significantly improved the operational characteristics of the products: the hardness of the surface of the balls increased by 8%, and impact resistance doubled. These results confirm the high effectiveness of using ferroboron as a modifier to enhance the strength and wear resistance of materials, which is especially important in the machine-building industry. Additionally, the research confirmed the potential for using ferroboron in other industries where the improvement of mechanical properties of materials is required, such as steel and alloy production, as well as other metallic products. Overall, the conducted work demonstrated that the carbothermic process using local raw materials and borate ores is a promising and economically advantageous method for producing high-quality ferroboron, opening up new opportunities for its application in industry.
341–350
Kinetics of natural-technogenic sulfide decomposition processes as an analogue to exogenous processes at the Degtyarsk deposit. Experimental data
Abstract
To develop economically efficient nature-inspired technologies for processing technogenic-mineral formations of sulfide deposits and rehabilitating altered territories, it is essential to understand the transformation processes of sediment composition, water, and biota interacting within waste dumps and mining excavations (mines and pits). Changes in the composition of technogenic sediments and waters under exogenous conditions are analogous to geological processes of physical-chemical weathering. Among natural processes, freezing and thawing of mineral matter are particularly important. The objective of this study is to investigate the kinetics of destruction and changes in the material composition of sulfide minerals and the resulting aqueous solutions using samples from waste dumps of the Degtyarsk deposit subjected to multiple freeze-thaw cycles. The experimental data include the decomposition of sulfides resistant to hypergenic alteration through a sequence of operations: crushing, sieving crushed dump samples into eight size fractions, and subjecting each fraction to freeze-thaw cycles between −15°C and +20°C in open containers with distilled water (3–15 cycles). In all experiments, pH, redox potential and sample mass were measured. Each fraction was analyzed before and after experiments using a benchtop X-ray diffractometer. Mineral grains were examined via scanning electron microscopy, and the chemical composition of post-experimental water was determined using inductively coupled plasma atomic emission spectrometry (ICP-AES). The most significant changes in sediment composition were observed in the –0.1 mm fraction, the measurement results of which are presented in this study. The maximum mass loss rate of sulfides from the Degtyarsk deposit samples reached 2% per cycle, whereas sulfides from other deposits lost up to 20% of their initial mass per cycle. The primary mass loss in the samples (more than half) was attributed to the mechanical removal of fine particles with water, while a smaller portion resulted from physical-chemical decomposition of sulfides through the formation of iron sulfate crystal hydrates, their dissolution, and carbonate dissolution. These experimental studies will serve as a foundation for building a database on sulfide behavior under cryogenic exposure and subsequently developing nature-inspired technologies for managing mineral matter transformation.
351–364
Investigation of medium entropy alloys obtained by electric arc welding with powder wires
Abstract
In modern conditions of intensive technology development and constantly increasing requirements for materials in industry, there is an urgent need to develop fundamentally new metal alloys with special performance properties. Classical materials, including various grades of steels, aluminum and titanium alloys, in many cases no longer meet modern standards in such key parameters as strength, wear resistance, corrosion and thermal stability. In this context, multicomponent alloys with an increased entropy component containing five or more basic elements in close atomic ratios are of particular importance. Due to the unique effect of high configuration entropy, these materials have a number of outstanding physico-chemical characteristics: increased mechanical strength, exceptional resistance to oxidation at high temperatures, as well as excellent wear resistance. However, significant technological difficulties in obtaining high-entropy alloys, combined with the high cost of the initial components necessary to create equal-atomic compositions, have led to increased scientific interest in the study of alloys with an average entropy level (SES), which represent a more affordable alternative. This paper considers the development and investigation of a multicomponent alloy of the Cr-Ni-Co-Fe-Mo system, obtained by electric arc welding using specialized powder wire. The main attention is paid to the study of microstructural features, the distribution of microhardness, and the determination of nonmetallic inclusions in the deposited layer. The choice of this system of elements is due to their complementary properties: chromium (Cr) provides increased corrosion resistance, nickel (Ni) improves ductility and heat resistance, cobalt (Co) increases heat resistance, iron (Fe) serves as the base of the alloy, and molybdenum (Mo) promotes hardening at high temperatures. The combination of these elements makes it possible to obtain a material with a unique balance of characteristics, which makes it promising for use in the aerospace industry, energy, oil and gas industry and other high-tech fields. In the course of the study, comprehensive tests were carried out, including metallographic analysis and microhardness measurements using the Vickers method. Special attention is paid to the identification and classification of non-metallic inclusions, since their presence can significantly affect the operational properties of the material. The results obtained allow us to draw conclusions about the prospects for further study and optimization of this class of alloys for industrial implementation.
365–378
Modeling of crystallization of iron-carbon melts with alloying additives of Al, V, Ti taking into account chemical reactions
Abstract
Solidification is one of the main links in the process of obtaining and processing metals. The structure and properties of the casting and ingot intended for further processing are determined mainly by the solidification process. Elimination or at least reduction of chemical heterogeneity and internal defects in the cast state allows to expand the scope of application of castings and reduce the number of defects, significantly improve the mechanical properties of the products obtained. It should be noted that the processes of metal and alloy solidification and, in particular, primary crystallization have not been sufficiently studied at present. This is explained primarily by the complexity of the processes of nucleation and growth of primary crystallites and the large variety of variable factors that appear during the crystallization of technical alloys. The issue of heterogeneity and internal defects of cast metals and alloys continues to be the focus of attention of scientists and practitioners. The processes of steel production and subsequent processing are based on numerous and varied transformations. Among such transformations, which have a strong influence on the quality and operational properties of the finished steel, are reactions of formation and dissolution of non-metallic inclusions both in molten and solid metal. The efficiency of a particular technological operation of steelmaking ultimately depends on the completeness of the corresponding chemical reactions. The final concentrations of carbon and alloying elements in steel, as well as the concentrations of harmful impurities, depend on how far these reactions go. A physical model of cooling and crystallization for simulating solidification of multicomponent iron melts taking into account chemical reactions between the components and software have been developed. The model is based on the theory of a quasi-equilibrium two-phase zone. The law of conservation of mass is fully satisfied. The model uses a parameter that takes into account the diffusion coefficient of carbon in the solid phase, the distance between the second-order dendritic axes and the local solidification time. The chemical interactions during crystallization in the Fe-C-N-Al-V-Ti system have been simulated and it has been shown that taking into account chemical reactions and diffusion of components in the solid phase has a significant effect.
379–393
The effect of nanoscale samples of silver and polyoxometalate {Mo₇₂Fe₃₀} on the reactions of peroxidation of organic compounds
Abstract
Nanoscale catalytic systems are interesting from the point of view of their application in the field of ecology, organic synthesis, in particular, in redox reactions, where high catalytic activity is required using small amounts of a catalyst. Such reactions are often advisable to implement in liquid media or solutions. The high specific surface area of nanostructured materials has a positive effect on the catalytic activity in cases where their sufficient wettability and contact with a liquid substrate are ensured. When using the above-mentioned catalysts, for this reason, it is necessary to find optimal conditions for the implementation of target reactions in order to prevent possible processes of agglomeration and deactivation of catalytic systems. The different chemical nature of catalytic materials has a very significant effect on the selectivity of oxidation processes in relation to different substances. Therefore, in principle, it is possible to create catalysts that selectively oxidize certain compounds in complex mixtures. The article presents the results of studying the kinetics of liquid-phase catalytic oxidation of water-soluble organic substances by peroxide compounds in the presence of a nanoscale sample of metallic silver, nanocluster polyoxometalate {Mo72Fe30}, heterogeneous iron molybdate and highly dispersed bronze powder of the PBVD brand. Phenol and ethylene glycol were used as model organic substances, the conversion of which was determined during the reaction by gas chromatography with a flame ionization detector, and saturated solutions of potassium persulfate and 36% hydrogen peroxide were used as oxidizing agents. For the catalyst samples that showed the highest substrate conversion, the reaction rate constants were calculated using the Origin program using the pseudo-first order equation. Some oxidation products have also been identified using a mass spectroscopic detector. Porous spherical nanocluster polyoxometalate {Mo72Fe30} turns out to be a more effective catalyst for the oxidation of phenol with persulfate in alcoholic solutions, compared with Fe2(MoO4)3. Among the studied catalysts of liquid-phase peroxidation of ethylene glycol, colloidal silver has the greatest catalytic effect on the oxidation process.
394–404
Influence of heat treatment on the structure of a blank made of heat-resistant nickel alloy EP741NP from metal powder obtained by gas atomization
Abstract
The prospects of using granule metallurgy technology for manufacturing gas turbine engine (GTE) disk blanks are considered. It is shown that there are two main methods for obtaining powder for manufacturing gas turbine engine parts – gas atomization and centrifugal spraying of cast high-speed rotating blanks. The main advantages and disadvantages of the above methods of obtaining metal powders are considered. Metal powder was obtained from heat-resistant nickel alloy EP741NP by gas atomization. The mode of hot isostatic pressing of the compacted blank was carried out. The chemical composition of the EP741NP alloy blank after hot isostatic pressing (HIP) was studied. Samples were cut to assess the effect of heat treatment on the structure of the studied blank. Factors influencing the selection of heat treatment modes for samples were analyzed. he heat treatment modes were selected to assess the influence of temperature-time parameters on the structure of the studied samples of the obtained HIP workpiece. The results of the microstructure analysis after HIP and heat treatment (HT) of the workpiece made of heat-resistant nickel alloy EP741NP from metal powder obtained by gas atomization are presented. The changes in the composition and quantity of carbide phases during heating are analyzed. The processes occurring during the decomposition of a supersaturated solid solution, coagulation of primary and secondary phases, dissolution of primary and secondary phases, and melting are considered. The temperature and time parameters at which the greatest change in the amount of carbide phases occurs are recorded. The results of digital analysis of the distribution of the intermetallic phase after hot isostatic pressing and heat treatment at the periphery and in the center of the samples are presented. The results of the influence of heat treatment on the formation of intermetallic phases are presented, and the influence of the selected heat treatment modes on the structure and grain grade of the studied samples is considered. Microstructural analysis of samples after hot isostatic pressing and various heat treatment modes was performed using optical and scanning electron microscopy. An optimal heat treatment mode was selected that promotes an increase in the volume fraction and average diameter of intermetallic phase components of the EP741NP alloy structure.
405–417
Congratulations on the anniversary of professor V.V. Pavlov!
418–418