At the blast furnace of PJSC “Magnitogorsk Metallurgical Plant” (MMK), the specific consumption of coke was reduced by impact on thermal reverse zone (TRZ) by increasing the consumption of natural gas above 120 m³/t of cast iron under conditions of increased reactivity and reduced hot strength of coke. In the first pair of periods, an increase in CRI from 38.4 to 39.3 % with a decrease in CSR from 36.3 to 34.6 % was accompanied by an increase in the ratio of natural gas consumption and total oxygen entering the furnace from 0.43 to 0.45 by increasing the specific gas consumption from 123.2 to 133.5 m³/t of cast iron. The set of actions increased the TRZ length towards the blast-furnace mouth by 1.9 % with its unchanged location along the lower part. Reducing the heat consumption in the TRZ increased the temperature difference between gas and materials there by an average of 36 °С. In the second pair of periods, the consumption of natural gas was 143.9 m³/t of cast iron with a decrease in the oxygen content in the blast from 27.6 to 27.0. They were accompanied by the following changes in the processes under consideration: an increase in the length of the TRZ towards the blast-furnace mouth by 2.6 % and the distance from the tuyere hearth by 3.4 %, an increase in the degree of carbon reduction from 32.0 to 33.3 %, an insignificant (on average 0.3 °С) increase in the temperature difference of gas and materials in the TRZ. In the first pair of periods, reduction in the coke specific consumption was 4.7 kg/t of cast iron with an increase in furnace productivity by 27 t/day. Conditions and course of the processes of the second pair ensured a decrease in the coke specific consumption by 1.6 kg/t of cast iron and led to a decrease in cast iron production by 41 t/day.

The paper considers research of quality of the electric arc coating obtained using flux-cored wire of the Fe – C – Si – Mn – Cr – W – V system with additives of carbon-fluorine-containing material and titanium. The formation of an electric arc coating was carried out using an automatic arc welding machine ASAW-1250 with a new chromium-containing flux-cored wire on plates made of St3 steel. To exclude mixing of the deposited metal with the substrate steel, multilayer surfacing was conducted. The surfacing mode was calculated and refined experimentally. The authors studied the composition and properties of the surface of the electric arc coating after surfacing. As a substitute for amorphous carbon they used a carbon-fluorine-containing material (dust of gas purification of aluminum production). Surfacing was carried out under a flux made from slag produced by silicomanganese with a high content of sulfur. A regression analysis of influence of the deposited layer’s chemical composition on its hardness and wear rate was carried out and mathematical models of the investigated performance characteristics of the electric arc coating were obtained. With an increase in the content of chromium, tungsten, carbon and silicon, hardness of the deposited metal and its resistance to abrasive wear increase. The results of the conducted research make it possible to develop measures ensuring the required level of performance characteristics of the electric arc coating and can be used to make a forecast of hardness of the deposited layer and its wear resistance when the chemical composition of the metal changes, to predict the operational resistance of rolling rolls deposited with wires of the PP-Np-35V9Kh3SF type. Mathematical models of hardness of the deposited layer and its wear resistance help to clarify the mechanism of hardening and formation of protective properties of the surface layers of rolling rolls by means of electric arc coatings deposited with flux-cored wires.

Modern machine-building production equipped with high-performance mechatronic systems and numerically-controlled and adaptive control machines for blade cutting of heat-resistant chromium-nickel and titanium alloys requires increasing the operating properties of cutting tools working at high temperature-force loads in the contact zone, respectively with a significant stress-strain state of the cutting wedge. It is possible to solve the problem of increasing wear resistance and serviceability by developing and introducing new tooling material, as well as by applying wear-resistant coatings. The paper presents the results on development of technology for obtaining high-entropy target cathodes by spark plasma sintering with subsequent application of wear-resistant coatings on metal-cutting tools by both magnetron and ion-plasma methods. Samples of sintered high-entropy target cathodes of different compositions (more than fourteen) and at different modes of their sintering (depending on temperature in five modes) with their subsequent optimization and two standard sizes (20 and 80 mm) were obtained for further application of wear-resistant coatings on the magnetron unit. The authors carried out structural and phase analysis and studied physicomechanical properties of the obtained high-entropy target cathodes: density, hardness, electrical conductivity, emissivity. The possibility of obtaining high-entropy target cathodes by spark plasma sintering was confirmed experimentally, and the effect of sintering temperature on structure and properties of the sintered samples of high-entropy target cathodes was established. Dependence of physicomechanical and electrophysical parameters of target cathodes on technological modes of spark plasma sintering is shown.

One of the main disadvantages when supplying natural gas to the air tuyere of a blast furnace is low intensity of its combustion inside the tuyere blast channel. Ring groove on the surface of blast channel improves the mixing of natural gas with blast and increases completeness of gas combustion in it, but reduces the tuyere durability. One of the ways to simultaneously solve these problems is to install a heat-insulating ceramic insert in the tuyere blast channel. The insert significantly reduces heat losses through the tuyere surface, improves natural gas combustion in the blast channel due to its contact with hot walls of the insert instead of cold copper walls in its absence. This increases the temperature of the hot blast at the tuyere outlet. In addition, the insert affects the tuyere durability by reducing the heat flow acting on the tuyere. In this work, we studied influence of the ring groove and its parts in the insert on efficiency of its work. In the Ansys 21.1 software, the processes occurring in the blast channel of a blast furnace tuyere with a ceramic insert installed in it, having a groove of a quadrangular section in the form of a ring or its part in the circumferential direction, were simulated. It was established that improvement of natural gas combustion in the tuyere blast channel is achieved using a ring groove or part of it from the side of gas supply.

The paper considers the effect of combined electromechanical processing in three different modes on the structure and hardness of the surface layers of 40Kh steel, which was in a normalized state (the original structure). The modes differ from each other by the different applied load and the number of pulses. The applied load in modes 1 and 2 (current strength 39 kA, pulse time 0.02 s, number of pulses 1) is 100 and 250 MPa, respectively. A distinctive feature of mode 3 compared to mode 2 is a greater number of pulses (two). Metallographically it was established that in all three cases a hardened surface layer of different thickness (from 300 to 1200 μm) with a hardness of 593 – 598 HV is formed, consisting of two zones (a surface zone with a structure of fine-needle martensite; a transition zone smoothly transitioning into the initial ferrite structure). The transition zone (treatment according to mode 1) in its structure contains martensite and ferrite. The transition zone (mode 2 processing) consists of a Widemannstett structure. A more substantial surface heating zone according to this mode (700 μm) in comparison with the processing according to mode 1 (300 μm) in combination with intensive heat removal contributed to the formation of a Widmanstett structure, which is defective and unacceptable for operation. The transition zone with the processing according to mode 3 has the structure of martensite and ferrite. The formation of a defective Widmanstett structure in the transition zone does not occur, since 2 times more pulses are used during processing than in mode 2. This contributes to the heating of the surface layer to a greater depth (1200 μm), and, consequently, the structure formation in the transition zone occurs from the intercritical interval Ag₃ – Ag₁.

High-entropy alloys (HEAs) are the most actively researched materials of recent decades. In the present work, the non-equiatomic AlCrFeCoNi wind turbine is manufactured using cold metal transfer technology and investigated by the methods of modern physical materials science. The authors analyzed the elemental and phase compositions, defective substructure and tribological properties of the HEA surface layer formed as a result of complex processing, which combines the deposition of a film (B + Cr) and irradiation with a pulsed electron beam in an argon medium. In the initial state, the alloy has a simple cubic lattice with a lattice parameter of 0.28795 μm, the average grain size of the HEA is 12.3 μm. Chemical composition of the HEA is as follows, at. %: 33.4 Al; 8.3 Cr; 17.1 Fe; 5.4 Co; 35.7 Ni. The elements are distributed quasi-periodically. The irradiation mode was revealed (electron-beam energy density 20 J/cm²; irradiation duration 200 μs, number of pulses 3; pulse frequency 0.3 s^–1), which allows to increase microhardness (almost twice) and wear resistance (more than by five times), to reduce the friction coefficient by 1.3 times. At an electron-beam energy density of 20 J/cm², the surface is fragmented by a grid of microcracks. Size of the fragments varies between 40 – 200 μm. An increase in the electron-beam energy density leads to complete dissolution of the film (B + Cr). Regardless of the magnitude of the electron-beam energy density, the wind turbine is a single-phase material and has a simple cubic crystal lattice. High-speed crystallization of the surface layer leads to the formation of a subgrain structure (150 – 200 nm). It is suggested that an increase in the strength and tribological properties of wind turbines is due to a significant (by 4.5 times) decrease in the average grain size, formation of chromium and aluminum oxide particles, and introduction of boron atoms into the crystal lattice of wind turbines.

The authors studied the influence of volume fraction and morphology of δ-ferrite on hydrogen embrittlement of austenitic stainless steel 08Kh19N9T obtained by electron beam additive manufacturing. It is experimentally shown that in additively-manufactured samples, long lamellae of δ-ferrite form a dense “net” of interphase boundaries (austenite/δ-ferrite, the volume fraction of the δ-phase is 20 %) and contribute to the hydrogen accumulation. Also, being the “easy” ways for the diffusion of hydrogen atoms, the dendritic lamellae of ferrite provide hydrogen transport deep into the samples. Post-production solid-solution treatment (at T = 1100 °C, 1 h) leads to a significant decrease in the fraction of δ-ferrite in steel (up to 5 %) and partial dissolution of dendritic lamellae. A decrease in the volume fraction of ferrite and a change in its morphology hinder the diffusion of hydro­gen deep into the samples and its accumulation during electrolytic hydrogen-charging and subsequent deformation. It contributes to a decrease in the total concentration of hydrogen dissolved in the steel samples. Despite the lower concentration of dissolved hydrogen in the solid-solution trea­ted samples, the solid-solution strengthening by hydrogen atoms is higher (\(\Delta \sigma _{0.2}^{\rm{H}}\) = 73 MPa) than for the initial samples with a high content of δ-ferrite (\(\Delta \sigma _{0.2}^{\rm{H}}\) = 55 MPa). The solid-solution treated samples are characterized by a smaller thickness of the brittle surface hydrogen-charged layer and a lower hydrogen embrittlement index compared to the post-produced samples (D_H = 55 ± 12 µm, I_H = 32 % for initial samples and D_H = 29 ± 7 µm, I_H = 24 % for samples after post-production solid-solution treatment).

Steels with regulated austenitic transformation during exploitation (RATE) are a new class of ferritic-based tungsten-free tool steels for hot forming. The study obtained quantitative data on the high-temperature strength of RATE steel of new composition after quenching and tempering. The stress-strain curves are plotted and the tendency of steel to strain hardening at temperatures of 450 and 750 °C is estimated. It was established that at a temperature of 750 °C, corresponding to the operating temperature, RATE steel has a stronger tendency to work hardening than at a temperature of 450 °C.

The properties, application, and methods for producing chromium and zirconium carbides are considered. These carbides are oxygen-free refractory metal-like compounds. As a result, they are characterized by high values of thermal and electrical conductivity. Their hardness is relatively high. Chromium and zirconium carbides exhibit significant chemical resistance in aggressive environments. For these reasons, they have found application in modern technology. Chromium carbide is used mainly as component of surfacing mixtures to create protective coatings that resist intensive abrasive wear, including at elevated temperatures (up to 800 °C) in oxidizing environments. This compound is also used in the manufacture of tungsten-free hard alloys and carbide steels. Chromium carbide, along with vanadium carbide, is used as a grain growth inhibitor in WC – Co hard alloys. Powdered zirconium carbide can be used to polish the surface of items made of ferrous and non-ferrous metals. The properties of refractory compounds depend on the content of impurities and dispersion (particle size). To solve a specific problem associated with the use of refractory compounds, it is important to choose the right method for their preparation, to determine the permissible content of impurities in the initial components. This leads to the existence of different methods for the synthesis of carbides. The main methods for their preparation are: synthesis from simple substances (metals and carbon), metallothermal and carbothermal reduction. Plasma-chemical synthesis (vapor-gas phase deposition) is also used to obtain carbide nanopowders. A characteristic is given to each of these methods. Information on the possible mechanism of the processes of carbothermal synthesis is presented.

The paper considers theoretical issues of reduction of zinc and iron by carbon from oxides of concentrates and zinc-containing metallurgical waste (dust and sludge of metallurgical furnaces). The described parallel reduction of zinc and iron by carbon from oxides undergoes with the formation of solid metal solution of Fe – Zn containing up to 46 wt. %  of zinc, melts and the vapor–gas phase of CO – CO₂ – Zn, the equilibrium composition of which is determined by the temperature and zinc content in solid solutions and melts. The authors determined the activity and elasticity of zinc vapor in solid solutions and melts of the Fe – Zn system and the activity of components in slag melts of the ZnO – SiO₂ system. Thermodynamic assessment showed that in the absence of solid carbon, the reduction of zinc from oxide by carbon monoxide is possible at temperatures above 1320 °C, and reduction by iron is possible in the temperature range of 1320 – 1500 °C. During reduction from slag melts at reduced activity values of zinc and iron oxides and elevated temperatures, reduction of zinc is carried out more efficiently than reduction of iron. In the presence of solid carbon in all temperature ranges (above 620 °C) and concentrations of zinc and iron monoxides at values a_ZnO > 0, a_FeO > 0.4, reduction of iron undergoes more efficiently (\(\Delta G_{\rm{FeO}}^{\rm{o}} \) <  \(\Delta G_{\rm{ZnO}}^{\rm{o}} \)). In the case of co-reduction of iron and zinc, the primary reduction product is solid iron. Thermodynamically, the possible introduction of zinc atoms into a solid solution of α-Fe is practically not realized due to the high elasticity of zinc vapor even at low concentrations in the outer layers on the surfaces of crystalline nuclei of α-Fe, which causes the possibility of a sufficiently deep degree of reduction and sublimation of zinc during its carbon-thermal reduction from concentrates and waste from metallurgical enterprises.

The effect of basicity and content of boron oxide on viscosity, crystallization temperature, phase composition, and structure of the 
СаО – SiO2 – B₂O₃ – 12 % Cr₂O₃ – 3 % Аl₂O₃ – 8 % МgO fluorine-free slag system in the range of boron oxide content 3 – 6 % and basicity 1.0 – 2.5 is studied by vibrational viscometry, thermodynamic phase composition modeling (HSC Chemistry 6.12 (Outokumpu)), and Raman spectroscopy. It was found that physical properties of the studied slags mainly depend on the balance between the degree of structure polymerization, nature of the bond with it, and phase composition. With a low basicity of 1.0, slags are “long” and an increase in the content of boron oxide from 3 to 6 % makes them more fusible, reducing the crystallization temperature of the slag from 1340 to 1224 °C, and its viscosity from 1.0 – 0.8 to ~0.25 Pa·s at 1600 – 1660 °C, despite the significant complication of the structure, reflected in the growth of the bridging oxygen index BO from 1.10 to 1.49. With an increase in basicity, slags transfer from “long” to “short” and the content of calcium oxide increases, which, being a donor of free oxygen ions (O^2–), acts as a modifier of the slag structure. Thus, with a basicity of B = (CaO/SiO₂) = 2.5, slags have a simpler structure (BO = 0.50 – 0.53) relative to slags with a basicity of 1.0, while the addition of boron oxide complicates it only slightly (an increase in BO from 0.5 up to 0.53). Increasing the concentration of B₂O₃ lowers the crystallization temperature from 1674 to 1605 °C and the viscosity from 1.0 to 0.3 Pa·s at 1660 °C as a result of the formation of low-melting compounds (mostly 2CaO·B₂O₃).

Selective solid-phase reduction of iron and phosphorus in oolite ores of the Lisakovsky and Ayat deposits was experimentally studied. Using X-ray phase analysis, the phase composition of the initial ores and samples after reduction roasting was determined. Goethite, magnetite and quartz were found in the ores of both deposits. Phosphorus in the ore of the Ayat deposit is in the form of aluminum phosphate and iron hydrophosphate, and in the samples of the Lisakovsky ore – as a component of calcium hydrophosphate. Experiments on reduction roasting were carried out in a resistance furnace at 1000 °C with holding time of 5 h. After roasting in CO atmosphere, α-Fe appears in the samples, while phosphorus remains as a component of iron, calcium and aluminum phosphates. After roasting in a mixture with graphite, phosphorus is reduced by solid carbon from iron and calcium phosphates and passes into metal, but remains as a component of aluminum phosphate. Studies using microroentgenospectral analysis show that phosphorus content in the metal phase after reduction with solid carbon is 2.0 – 3.5 at. %. When CO is reduced in the atmosphere, phosphorus in the metallic phase is practically not detected. At the same time, the amount of residual iron in the oxide phase after carbon monoxide reduction significantly exceeds the amount of iron after reduction in a mixture with carbon. The experimental results confirm the possibility of selec­tive reduction of iron by carbon oxide CO without phosphorus reduction.

The substantiation of the relevance of obtaining continuous cast steel pipe hollow billet is given from the position of improving the quality of pipes made of carbon and alloy steels is given. The article presents an assessment of the quality of the inner surface of pipes made of solid steel pipe billet. A new technology is proposed for the production of hollow steel pipe billets on a resource-saving unit of combined continuous casting and deformation. The photo of the continuous casting and deformation section of JSC Ural Pipe Plant is given, where a pilot unit of combined continuous casting and deformation is installed. The paper presents the results of a theoretical study of stress-strain state of the mandrel and sections of a pipe billet when it is compressed by the strikers of the unit of combined continuous casting and deformation. The authors discuss the general model of the mold – striker system. The initial data on calculation, dimensions of the hollow pipe billet and a description of the calibration of strikers for compression of a hollow steel billet are given. The temperature field of a hollow billet was determined. To simulate the stress-strain state of the metal in the roll pass and the mandrel, four contact pairs were considered. Calculations were made by the finite element method. The dimensions of the final element in the roll pass of hollow billet were determined. The authors established the values and patterns of changes in metal displacements and axial stresses in the roll pass during the production of hollow steel billets in the unit of combined continuous casting and deformation (strikers are made along a constant radius). The stress state of metal in the roll pass was assessed from the standpoint of improving the quality of hollow steel billets.

The paper describes design features, methodology and results of the study of 10 induction electromagnetic crucible furnaces with a C-shaped magnetic core (MC). The core is covered by turns of an electric coil (EC) of small volume up to ~14.56 dm3. The furnaces have MC from a set of used transformer plates with a working volume of ~ 28.5 – 30.8 dm3, a capacitor bank (CB), the number of turns w = 23 – 50 of copper or aluminum wire, voltage 380 – 390 V, frequency 50 Hz. The water-cooled EC is placed in a rubber tank and creates a horizontal electromagnetic flow with induction of ≈70 mT, which is amplified by MC and directed beyond EC into a larger working volume of ~30.7 dm3 between its poles with induction up to ≈100 mT. When placing a steel crucible in the volume, induction increases up to 125 – 150 mT and the experimental furnace EMC‑30.7‑23A with a capacity of 44 kVA allows melting 21 kg of silumin at a speed of 10 °C/min in 65 min, which is faster than in the resistance furnace СAT‑0.16 with a power of 40 kW in 2 h. With strong compression of MC plates, the noise decreases from 80 – 85 to 40 – 48 dB. To increase the furnace efficiency, it is proposed to use pole plates with a width of 155 mm, mineral wool in the thermal insulation of the crucible, tuning capacitors in CB, and EC from copper cable. For melting of high-temperature alloys, it is advisable to connect this furnace to a step-up transformer in order to increase the current density from 3.7 to the permissible 20 A/mm2, power in the EC – CB circuit, and EC induction. The authors suggest to continue research on electromagnetic furnaces made from cheap transformer scrap to determine the scope.

Currently, a new development trend is being formed in the world associated with the decarbonization of economies. This process is based on the institutionalization of ESG-principles – an approach to doing business, characterized by the involvement of companies in solving environmental, social and governance problems. The process of institutionalization of ESG-principles at the international level was initiated in 1948 with the adoption of the Universal Declaration of Human Rights under the auspices of the UN. The active involvement of Russia in the formation of the institutional framework in the field of ESG has begun only in 2020. The reason for this was the ratification of a number of international documents, as well as the active promotion of climate policy by many countries of the world. The stages of the institutionalization process at the international level discussed in detail in Report 1. The decarbonization of economies creates development risks for industries whose products are characterized by high carbon and energy intensity. Ferrous metallurgy also belongs to them. This report presents the results of a study of the effectiveness of measures taken by the Russian Government in the field of reducing atmospheric air pollution in large industrial centers of the ferrous metallurgy based on data from the Unified Information System for Monitoring Air Quality, as well as the results of an analysis of the ESG-practices of the largest Russian ferrous enterprises and compliance with carbon intensity and energy intensity of their products according to the criteria of sustainable (including green) development projects established in our country. As a result of the study, it was found that despite the use of ESG-principles in their activities, the specific emissions of CO₂-equivalent of the largest iron and steel enterprises significantly exceed the criteria for sustainable (including green) development projects established by the Russian Government.