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The paper presents a brief analytical review of the current state of research in the field of recovery and its modeling in order to predict the structure and properties, as well as a review of experimental research methods and mathematical models of the processes of structure formation during annealing of cold-rolled steels. The paper also presents the results of an experimental study of the recovery process in cold-rolled automotive steels using various techniques and describes a mathematical model for calculating the kinetics of this process depending on the temperature and chemical composition of steels. [ABSTRACT FROM AUTHOR]

The paper offers a detailed description of the application and significance of machine learning methods during various processing stages of modern metallurgy. The relevance of this topic is based on the significant positive technical and economic effects from the use of machine learning noted by both Russian and world-leading manufacturers in the field of metallurgy. [ABSTRACT FROM AUTHOR]

This paper presents the results of experimental studies of heat transfer in electric arc furnaces, which showed that heat fluxes incident from arcs on a heating surface comprise 85%–95% of thermal radiation fluxes. The thermal radiation laws of ionized and nonionized gas volumes are stated, according to which the heat transfer in electric arc furnaces is calculated. The experimental and calculated data on the heat fluxes of arc radiation on a heating surface differ by no more than 5%–8%, indicating that the thermal radiation laws of gas volumes correspond to real heat transfer processes in electric arc furnaces. The heat exchange of arcs in an electric arc furnace bath was calculated. When the arcs are completely buried in the recesses of the bath, their slag and heat radiation fluxes are converted in the recesses into convective heat fluxes and heat conduction flows, heating the entire volume of the metal bath and slag. [ABSTRACT FROM AUTHOR]

This paper discusses the effect of NaCl on the secondary oxidation rate of hot-briquetted iron (HBI) during its transportation to consumers in Russia, former Soviet republics, and other foreign countries by both rail and water transport. This results in distinct atmospheric conditions surrounding the briquettes, leading to varied oxidation processes. This study is significant as the oxidation rate directly affects the metallurgical properties of the briquettes. The article presents experimental investigations on the impact of different NaCl concentrations (0–4%) in water, which evaporates into the atmosphere surrounding HBI, on its reactivity. The findings reveal that the reactivity of briquettes increases with up to 4% NaCl content in the water surrounding the HBI. Consequently, the iron oxidation rate in the briquettes also rises, with reactivity increasing from 0.234 to 0.412 nm3/(ton·day) and the rate from 0.0833 to 0.1459 kg/day. These results suggest that seawater, particularly with NaCl content up to 4%, significantly impacts the iron oxidation rate in HBI. Therefore, when transporting by sea, it is essential to consider this influence and implement measures to mitigate this type of oxidation. [ABSTRACT FROM AUTHOR]

The paper examines the technological properties of diverse vanadium-containing raw materials, including titanium-magnetite concentrate, converter slag, dump sludge, neutralization sludge, slag from ferrovanadium smelting, fuel oil ash and slag, black shale, and spent catalysts. The existing chains of their formation and processing are described, considering the volume of raw materials underutilized for vanadium extraction, such as blast furnace slag, tailings, ilmenite concentrate, red mud, vanadium slag, and titanomagnetite concentrates. Most of these materials prove suitable for vanadium extraction. According to our estimates, annually produced industrial raw materials involve approximately 53.6 thousand tons of vanadium relative to V2O5. This includes 4.4 thousand tons of V2O5 suitable for extraction and 12.0 thousand tons of V2O5 potentially suitable for extraction. Additionally, about 28.5 thousand tons of vanadium relative to V2O5, found in titanium magnetite concentrates and converter slag, could be further engaged in processing. Consequently, the reserve of raw materials unused for vanadium extraction amounts to 45 thousand tons relative to V2O5. Processing these raw materials holds the potential to manufacture vanadium-containing products of a deeper degree of processing, including purified vanadium pentoxide V2O5, vanadium trioxide V2O3, and vanadium alloys, thereby reducing dependence on imported equivalents. [ABSTRACT FROM AUTHOR]

The paper introduces a mathematical model based on the discrete element method, presenting the results of its application to simulate the movement of briquetted mass within the working chamber of the extruder. This model accounts for the adhesive interaction among particles within the mixture. The simulation results provide a qualitative and quantitative description of the displacement and compaction of the briquetted mass. They allow the flow structure to be visualized and the distribution of velocities and the moment on the screw axis during the extrusion process to be determined. Furthermore, a digital twin of the pug sealer–extruder unit was created through finite element modeling. The results obtained from this digital twin can be used to optimize the operational parameters of extrusion briquette equipment. In addition, by using the developed model, the process of mixing binder materials with a briquetted mixture at various volumes of the added binder was studied. [ABSTRACT FROM AUTHOR]

Electromagnetic stirring (EMS) of the liquid phase of billets is one of the most technologically advanced methods to enhance the macrostructure quality of continuously cast slabs produced on high-performance continuous casting machines (CCMs). Under the influence of EMS, a forced movement of the melt is created relative to the crystallization front. The temperature gradient across the cross-section of the slab and the chemical composition of the steel are stabilized via heat and mass transfers. A project was implemented at Novolipetsk Iron and Steel Works to equip a slab CCM with an EMS system in the secondary cooling zone of a continuously cast ingot (CCI). This paper presents the industrial development results of the teeming electrotechnical steel technology using the EMS system. Furthermore, the key aspects of stirring and technological parameters of teeming electrotechnical steel are presented. The effect of EMS on the quality of a CCI is confirmed in terms of crystallization structure variations with an increase in the zone of equiaxed crystals by more than twice in comparison with the typical teeming practice. Furthermore, it has been established that using EMS can effectively influence liquid steel and considerably enhance the quality of the CCI macrostructure and the uniformity in the properties of finished rolled products. [ABSTRACT FROM AUTHOR]

As part of the development of critical technologies, it is necessary to search for alternative replacement of components in the compositions of aluminum ligatures, including known modifying additives of scandium and yttrium with other rare-earth and rare elements. Aluminum ligatures with rare-earth metals are widely considered in many scientific papers, but the research on the production of Al-Yb ligatures is limited. In this paper, the authors describe the results of studying the production of ligatures of the aluminum-ytterbium system from ytterbium oxide by aluminothermic reduction, containing nanoscale Al3Yb intermetallic compounds and eutectics in their structure. Serving as crystallization centers, the optimal-size particles of intermetallic compounds provide uniform fine-grained structure in aluminum alloy castings. The relationship has been obtained that enables the maximum transition of ytterbium into the alloy depending on the quantitative and qualitative composition of the reaction mixture and various melting process parameters. The conducted studies have shown that ligatures obtained by aluminothermic reduction of ytterbium oxide with the addition of 5 to 15 wt. % Mg to the reaction mixture have the highest characteristic of ytterbium transition into the ligature. [ABSTRACT FROM AUTHOR]

The paper describes the results of implementing modified designs of the working tools of a plug rolling mill. The plug design is modified to improve the rolling of the pipe wall thickness. The design of the bottom guide tool (the inlet trough of the mill) is improved to eliminate metal ruptures at the rear ends of thin-walled pipes, as well as to reduce downtime and rejection as unfinished products. The economic indicators of the proposed designs implemented in the longitudinal rolling process are presented. [ABSTRACT FROM AUTHOR]

This paper presents the generalized experience in developing and implementing technology for high specific natural gas consumption in blast furnaces at the Severstal Company. In-depth analysis was performed, problem areas in the technology of replacing coke with natural gas were identified and described, and corrective measures were developed at four process control levels. Only a systematic application of all elements of the developed technology enables us to achieve high economic indicators. Experience in technology development has made possible a specific natural gas consumption of more than 190 m3/t of cast iron and a solid fuel consumption of less than 350 kg/t of cast iron. The most efficient technology development was achieved at blast furnace No. 3, with natural gas consumption of over 210 m3/t of cast iron and solid fuel consumption of less than 325 kg/t of cast iron. [ABSTRACT FROM AUTHOR]

This paper presents the results of laboratory experiments to study the effect of the consumption of gaseous fuel (natural gas) supplied into a sintered charge layer on sintering process indicators and sinter quality under the charge conditions of the Ural Steel Company at charge layer heights of 350 to 500 mm.It was established that an increase in the consumption of natural gas supplied to the sintered charge layer in the range from 3 m3/t to 7 m3/t of sinter increases the vertical sintering rate, yield, specific productivity, and strength properties of the sinter. The benefit of supplying gaseous fuel to the layer is due to improvement in the temperature-time conditions of sintering, which increases the degree of involvement of the charge ore in the processes of melt formation and ensures a more complete use of solid fuel at lower consumption. The efficiency of supplying gaseous fuel to the sintered charge layer increases substantially with increasing sintered layer height because of a decrease in the proportion of the upper part of the sinter, which is formed under less favorable thermal conditions.According to the totality of indicators, considering the cost of natural gas, its optimal consumption in the charge conditions of the Ural Steel Company is 3.0 m3/t of sinter, which ensures the maximum increase in sintering indicators and sinter quality compared with traditional sintering technology. [ABSTRACT FROM AUTHOR]

Reducing the volume of manual work improves the processing speed of blanks, along with reducing the number of rejected products and overall production costs in large batches, while increasing repeatability. The concept of lean manufacturing is gaining popularity among manufacturers, with one of its main goals being the continuous elimination of waste. The paper presents a method for enhancing the production technology of cast blanks for gas turbine engine blades. Device designs were developed to minimize losses during the production of castings. [ABSTRACT FROM AUTHOR]

The paper discusses specifics of the process of carbothermic reduction of metallurgical silicon in ore-smelting furnaces. The reaction zone represents a heating area for the charge materials, formed around the electrodes in all electric furnaces, and facilitates the release of thermal energy by passing electric current through a resistance and/or by creating an electric arc, change in the aggregate state of the loaded materials (e.g., quartzite, bituminous coal, needle coke), and a complex of chemical reactions that occur within such materials. When properly controlled, the operating conditions of the ore-smelting furnace provide optimal specific performance relative to specific power consumption. However, in case of deviations, such as high or low placement of the electrodes, excess or lack of reducing agent in the charge material, furnace throat level being too high or too low relative to technical guidelines, electrode voltage imbalance, etc., the furnace performance can be significantly reduced due to a non-conformant granulometric composition. If the furnace is operated with such deviations for extended periods of time, an emergency shutdown may occur. If the power generated at the electrode is insufficient, the reaction zone becomes significantly narrower, this leads to a change in the rate of chemical reactions. The excessive power levels, on the other hand, may cause intensive entrainment of microsilica along with the formation of blowholes capable of disabling water-cooled panels or shutting down the furnace transformer due to an overload. The location of the reaction zone in the furnace space plays a key role in ensuring effective operation of the ore-smelting furnace. Shifting of the reaction zone upward or downward may result in the grade drop of metallurgical silicon and reduced performance of the furnace, which will subsequently increase the product cost. [ABSTRACT FROM AUTHOR]

The paper analyzes the possibility of creating a titanium porous fiber material for implants, which is made of fibers of various transverse sizes and has gradient pore architecture. The architecture of the porous space, structure, and mechanical characteristics of such material have been studied. It is shown that the strength of the porous fiber material can be improved by increasing the temperature of diffusion bonding and by performing hydrogen heat treatment. The specifics of the mechanical behavior and fracture of the material samples were studied by performing a fixed-end bending test. [ABSTRACT FROM AUTHOR]

In this paper the influence introducing various plasticizers into an initial charge on the structure and properties of iron-based powder materials alloyed with copper is considered. It is shown that introduction of copper stearate into an initial powder mixture and warm mixing, pressing and subsequent sintering makes it possible to obtain low-porosity workpieces with relative porosity of 95%. Pores within the workpieces obtained have a small size of 10–15 microns and a rounded shape. Also, bending strength is determined for sintered samples of all the compositions of powder mixtures studied and the Rockwell hardness is determined on the C scale. Powder steels based upon mixtures have the best set of mechanical propertiesPZhRV 2.200.28 + 0.7 wt.% Br + 0.7 wt.% Cu + 1 wt. % StCu + warm mixing—hardness HRC 58. flexural strength 600 MPaPZhRV 2.200.28 + 1.4 wt.% Br + 1.4 wt.% Cu + 1.4 wt.% C + 1.0 wt.% StFe + warm mixing—hardness HRC 100, flexural strength 530 MPaPZhRV 2.200.28 + 0.7 wt.% Br + 0.7 wt.% Cu + 1 wt. % StCu + warm mixing—hardness HRC 58. flexural strength 600 MPaPZhRV 2.200.28 + 1.4 wt.% Br + 1.4 wt.% Cu + 1.4 wt.% C + 1.0 wt.% StFe + warm mixing—hardness HRC 100, flexural strength 530 MPa [ABSTRACT FROM AUTHOR]

This paper presents a variant of compensation for the occurrence of an impact load during the operation of a rolling mill using a regulatory method based on the integration of a neural network into a control device. The neural network can effectively select the speed and preacceleration time for the main drive of the rolling stand. Due to the neural network adaptation, the system receives information updates during the process of work, predicting changes in the technological process. A block diagram of a neural network is developed. This work describes the developed block diagram of the main electric drive of the rolling mill, which includes an additional speed sensor based on an automatic adjustment system with a neural network, which is employed to improve the quality indicators of the engine preacceleration control. Experiments on the developed system showed that when using a neural network, the maximum value of the resulting torque decreased by 9.8% with decreasing speed overshoot by 14.3%. Using an automatic control system based on prediction with the use of neural networks, it was possible to decrease the kinetic moment occurring during the metal rolling process. [ABSTRACT FROM AUTHOR]

In this paper, the results of the study on the deformation effect by the screw piercing method on the mechanical properties and macrostructure of a continuously cast blank made of wheel steel are presented. It is revealed that when piercing in a screw rolling mill with small extraction coefficients of the billet (feed angle β = 14°, extraction coefficient μ ~ 1.36), the quality of the macrostructure improves, the strength properties (σv, σ0.2) increase by 1.1–1.6 times, the plastic properties (δ, ψ) improve by 1.4–5.4 times, and the impact strength of the wheel steel increases. [ABSTRACT FROM AUTHOR]

This paper is dedicated to studying the effect of replacing molybdenum with vanadium on the tendency to amorphisation, structure, and thermal properties of high-entropy alloys of the (Fe0.25Ni0.25Co0.25Cr0.125Mo0.125‑xVx)100‑yBy system, where x = 0; 0.0625; 0.125 and y = 17–25. The alloy structure was analyzed using X‑ray diffraction, scanning and transmission electron microscopy methods. Thermal properties were determined by differential scanning calorimetry. It was found that the replacement of molybdenum with vanadium leads to the formation of crystalline particles of complex nitrides (V, Cr, Mo)(N, B) in the ribbon structure. The dependences of the characteristic alloy temperatures have been established. Molybdenum replacement with vanadium was shown to stabilize the supercooled liquid in alloys with completely amorphous structure. [ABSTRACT FROM AUTHOR]

This paper presents examples from the practice of operating arc steel-smelting furnaces (EAFs), verifying the hypothesis on the complex heat exchange of arcs in spherical segments in the bath. The thermal radiation of arcs in spherical segments is converted into convective and thermal conduction flows, heating the entire volume of metal and slag. No more than 3%–4% of the arc power is spent on evaporation of the metal under the arcs, while 76–78% of the arc power is converted into convective and thermal conduction flows that heat the bath. The metal waste under the arcs is 8–9%, in which 91–92% of the metal waste is accounted for in the zones of exposure to the bath with oxygen. With an oxygen consumption of 10–15 m3/t in the EAF, metal waste is 3%; with an increase in oxygen consumption to 50 m3/t, metal waste increases by 2.5–4 times to 7.5–12%. With an increase in the absorption coefficient of the gaseous atmosphere of the DSP-100 furnace, the maximum density of thermal radiation fluxes from the arcs to the walls decreases proportionally. With an increase in the height of the slag layer by 3.7 times, the maximum density of thermal radiation fluxes of the arcs on the water-cooled wall panels decreases by 2.6 times. [ABSTRACT FROM AUTHOR]

Piercing represents one of the key processes in the production of hot-rolled pipes on screw rolling mills due to its determinative effect on the quality of the resulting bloom. The main factor affecting the quality of hot-rolled pipes is the wear resistance of the working tool. The work equipment frequently fails due to high wear of the surface. It is known that the mandrel affects the quality of the inner surface of the resulting pipes and the accuracy of geometric dimensions. In addition, increased wear of piercing mandrels leads to a decrease in the productivity of industrial units. In this paper, the mandrel wear was studied during the piercing of billets, made of 12Kh18N10T corrosion-resistant steel, into pipes on a MISiS-130D pilot-industrial screw rolling mill. Using the SolidWorks software package, the process of piercing blanks with a diameter of 60 mm and a length of 400 mm was simulated in order to assess the wear of mandrels using the QForm software package. The modeling of piercing processes was carried out by varying the rolling conditions: rolling speed, feed angle, and ovalization factor of the deformation zone. It is concluded that the distribution of the wear value along the length of the mandrel is uneven; the dependence of the mandrel wear value on the variable technological factors of the piercing process is revealed. The dependence of the wear depth of piercing mandrels on the temperature of their working surface and the duration of rolling was studied. Methods for increasing the wear resistance of piercing mandrels based on the selection of rational rolling modes are proposed. [ABSTRACT FROM AUTHOR]

Tajikistan possesses large reserves of dump tailings characterized by a high gold content. The formation of these dump tailings is associated with the low cost of gold in the past, since rich ores with a gold content above 6–8 g/t were more often involved in processing. At recovery of ≈ 70–75%, tailings with a gold content below 1.8 g/t were disposed of. The paper studies the material composition and carries out an assessment of the degree of refractoriness of the studied dump tailings to leaching. It was established that the main components of tailings are SiO2 and Al2O3. The dump tailings contain 2.4 g/t of gold and 7 g/t of silver. In terms of material composition, the sample of the dump tailings belongs to a readily cyanidable type. Gold finely disseminated in acid-soluble minerals represents 6–6.5%, while minerals insoluble in acids and quartz contain 15% of gold. In addition, the tailing sample contains gold encapsulated in minerals soluble in sulfuric acid. In terms of gold form, the dump tailings are classified as medium refractory to leaching processes. The diagnostic leaching test results for gold showed that the use of thiourea as a lixivant in the further development of the leaching process is promising. Gold recovery by thiourea leaching was 78%. [ABSTRACT FROM AUTHOR]