The article explains a new temperature-speed mode of rolling long-length rails. Rails up to 50 m long were rolled on linear mills. The production of rails of longer length required the use of larger mass billets and equipment of a new design. At the modern rail-beam rolling mill, the number of stands has increased and some of the stands are combined into a continuous group. Universal rolling stands began to be used not only as calibration stands. Rails with a length of 100 m are rolled from large-mass billets on mills with a continuous reversible group of universal stands. A significant length of the billet leads to the formation of a «temperature wedge» – a decrease in temperature along the length of the rail during rolling in the last stand of the mill. The calculation showed that a decrease in temperature along the rail length can lead to an increase in its height. A similar problem existed in the production of thin sheet metal at continuous broadband hot rolling mill. Rolling the rolled metal in the finishing group of stands with acceleration made it possible to reduce the cooling time of rear section of the rolled metal and warm up the metal due to more intense deformation. The acceleration value is chosen such that at the exit from the finishing group of stands, temperature of the strip is the same along the length of the strip. In this paper, rolling rails with acceleration is proposed. The acceleration value should ensure the same neck temperature along the length of the rail in the mill last stand, which will reduce the height difference along the length of the rolled product. The same rails height along the length will reduce the cost of grinding and accelerate the rail laying, thereby increasing consumer demand and competitiveness of the product.

The balanced development of the world community in the next decade implies achievement of sustainable development goals by increasing the efficiency of resources utilization in the economic, social and environmental spheres of human activity. Within the framework of globalization processes, which inevitably affect the national economic, social and environmental agenda, the last two spheres are becoming increasingly important. The main measures of the state national policy of the Russian Federation are aimed at solving social and economic problems that ensure realization of the right of every person to a favorable environment. Timely solution of the problems of social and environmental well-being, as indicators of the life quality of population, is a priority task of the state authorities of the regions together with the top management of city-forming enterprises that bear major social and environmental burden. Increase in the resources utilization efficiency is of particular importance in regions with a dominant location of metallurgical production. Atmosphere and water pollution, a high level of occupational morbidity and injuries caused by equipment wear and safety violations at production facilities, the prevalence of mortality over births, an intensive migration outflow of the population, depreciation of engineering infrastructure with simultaneously growing industrial output reflect the imbalance in situation of the metallurgical region, delay its sustainable development. The conducted scientific research made it possible to develop a system of indicators for assessing the resource efficiency of metallurgical production with their grouping by development components. It makes possible for the management to evaluate the contribution of each set of components to the resulting value, propose measures and guidelines for optimizing coefficients, identify business competitiveness growth factors, determine investment targets, and also demonstrate to the world community the transformation of production and economic activities of companies in accordance with global trends in resource conservation and sustainability.

The relevance of the development of modern technological solutions for the processing of niobium ore materials used for the production of complex ferroalloys of domestic deposits is shown. The need to develop new technological processes of processing is caused by the fact that when switching to new types of niobium concentrates, the chemical and phase compositions of the starting materials change, and, consequently, this leads to a change in the composition and properties of the melting products (both metallic and oxide). Using an electrovibration viscometer, the temperature dependences of viscosity were studied and the crystallization temperatures of oxide melts of the Nb₂O₅ – SiO₂ – CaO – TiO₂ – Al₂O₃ system were calculated. The compositions of the studied samples correspond to phosphorless niobium slags, which can be obtained by carbothermic method from rough concentrates. The samples were obtained by fusing oxide materials in a high-temperature laboratory electric furnace. On the basis of the obtained data, graphical dependences of viscosity – temperature are constructed. It was experimentally established that oxide melts containing 15 – 26 % Nb₂O₅ are more “long” (having a wide crystallization range) and unfavorable according to the characteristic viscosity – temperature dependence. An increase in the concentration of niobium pentoxide to 40 % translates slags into the category of “short” (with a high crystallization rate). It is shown that an increase in the concentration of niobium oxide Nb₂O₅ from 15 to 40 % leads to a decrease in the crystallization temperature of melts by 200 °C and a decrease in the viscosity of melts from 1.32 to 0.24 Pa·s at 1350 °C. The improvement of the physico-chemical characteristics of oxide melts with an increase in the concentration of niobium pentoxide can favorably affect the technical and economic indicators of ferroalloy production.

The article describes theoretical and experimental studies of dependence of viscosity, coefficients of sulfur and boron distribution between slag and metal, and wear degree of periclase-carbon refractories on basicity and boron oxide content in slag. It is shown that formed slags have basicity of 2.0 – 5.0 and rather high liquid mobility. These slags are characterized by an equilibrium interfacial distribution coefficient of sulfur increased to 5 – 20, which provides equilibrium sulfur content in the metal reduced to 0.001 – 0.005 %. The results of fundamental studies of the physicochemical properties of refining slags of СаО – SiO₂ – В₂O₃ – Al₂O₃ – MgO system formed the basis for development of the composition of environmentally friendly fluorine-free ladle slags and technological methods for their formation in ladle-furnace unit. The recommended composition of such slags of low viscosity, which allows deep metal desulfurization, direct steel microalloying with boron and low aggressive effect on periclase-carbon refractories, provides formation of slags with a basicity of 3.0 – 4.0, containing 1 – 4 % B₂O₃, 15 % Al₂O₃ and 8 % MgO. The formation of environmentally friendly ladle slags of the recommended composition was carried out in a ladle-furnace by loading lime, boron-containing material – colemanite (Turkey) containing 39 – 41 % B₂O₃, 26 – 28 % CaO, not more than 5 % SiO₂ and 3 % MgO, and pyramidal aluminum into the steel-teeming ladle for slag deoxidation and boron recovery. Introduction of the developed technology for the formation of ladle slags of recommended composition ensured the production of economically alloyed low-carbon structural boron-containing steels with a low sulfur content, incl. for large diameter pipes with high strength properties.

The article presents a balance model of the blast furnace process improved by the researchers from UrFU and PJSC “Magnitogorsk Iron and Steel Works” (MMK). It generally represents a system of deterministic dependencies characterizing the thermal, reduction, gas dynamic, blast and slag modes of blast furnace melting. The basic principle underlying the model is full-scale mathematical modeling. Indicators characterizing the properties of the final slag for implementation of normal slag mode of blast furnace melting (slag viscosity in the temperature range of 1350 – 1550 °C, as well as values of the slag viscosity gradients) were proposed. The slag viscosity gradient, along with the acceptable ranges of slag viscosity at different slag temperatures, are used in modeling the slag mode as limiting factors for the diagnosis of slag mode. Selection of the limit values of each of the ranges and the viscosity gradient is carried out by the method of expert evaluation. Structure of the model for calculating the parameters of the final slag is considered. Using a mathematical model of the blast furnace process, analysis of the slag mode of blast furnace melting was performed according to the actual indicators of their operation. It was established that desulfurizing ability of the slag is insufficiently used, as a result of which cast iron of reduced quality is smelted both in terms of content of sulfur and silicon. Change in characteristics of the slag mode, other things being equal, has a positive effect on gas permeability in the slag formation zone, reducing capacity of the gas and productivity of the blast furnace increase, as well as the consumption of coke decreases. The authors describe the results of design calculations of the MMK furnace performance indicators when changing the composition of loaded materials. Recommendations on the slag optimal basicity are given. Calculations showed that the optimal basicity of the final slag, which ensures its maximum liquid mobility, for operating conditions of blast furnaces of the combine is 1.04 – 1.05 for the CaO/SiO₂ ratio and 1.30 – 1.32 for the (CaO + MgO)/SiO₂ ratio.

The article considers the study of composition of the non-metallic inclusions and microstructure of the electric arc coating using the flux-cored wire of Fe – C – Si – Mn – Cr – Ni – Mo system. Formation of the electric arc coating was carried out using the ASAW-1250 automatic arc welding machine by the investigated wire. In order to influence the level of contamination of the deposited metal with non-metallic oxide inclusions, aluminum gas purification dust was introduced into the flux-cored wire (instead of amorphous carbon). Composition of the electric arc coating was determined using XRF-1800 spectrometer. Microstructure of the electric arc coatings was studied by optical microscopy. The phase and elemental compositions were studied using scanning electron microscopy on MIRA 3 LMH instrument. Non-metallic inclusions in the electric arc coating consist of oxides of silicon, fluorine, calcium, aluminum and magnesium oxides. The darker component in the inclusion, which looks like rectilinear crystals directed from the surface deep into the inclusion, has a similar phase composition, but differs somewhat in the content of chemical elements. A small dark component of a rounded shape (aluminum and magnesium oxides) is observed in the inclusion. Traces of sulfur are highlighted along the contour of the globules. Metallographic analysis of the deposited surface showed that the microstructure of the deposited layer is a coarse-needle martensite. The structure is uniform, has a dendritic (columnar) structure characteristic for cast metal. The results of the conducted investigations allow measures to be developed to reduce the content of non-metallic inclusions containing elements of fluorine, sodium and aluminum, which in turn may adversely affect the physical and mechanical properties of the deposited layer, for example, by using refining additives to reduce the contamination of the deposited layer with non-metallic inclusions.

In the past decade the attention of scientists in the field of physical materials science is attracted to studying the high-entropy alloys. By the technology of wire-arc additive manufacturing (WAAM) a high-entropy alloy (HEA) of a nonequiatomic composition was obtained. Deformation curves obtained under uniaxial tension at a rate of 1.2 mm/min at room temperature using Instron 3369 unit were analyzed in two states: initial/after fabrication and after electron-beam processing (EBP). EBP was conducted to detect its influence on structural-phase states and mechanical properties. The EBP leads to a decrease in strength and plastic properties of the HEA. By means of scanning electron microscope LEO EVO 50, analysis of structure of fracture surface and the near-surface zone was performed. Dependences of the ultimate strength and relative elongation to failure on EBT parameters were revealed, and it was shown that values of strength and plasticity decrease nonmonotonically with an increase in electron beam energy density in the range E_S = 10 – 30 J/cm² at constant values of duration, frequency, and number of pulses. Along with a pit character of the fracture a presence of micropores and microlayering was detected. Investigation of the HEA’s fracture surface after EBP except for areas with a ductile fracture mechanism revealed the regions with a band (lamellar) structure. At E_S = 10 J/cm², the area of such structure is 25 %; it increases nonmonotonically to 65 % at E_S = 30 J/cm². The diameter of pits of detachment in fracture bands varies in the limits of 0.1 – 0.2 μm, which is considerably less than that in the remainder of the HEA samples. After EBP the thickness of the molten layer varies in the limits of 0.8 – 5.0 μm and grows with an increase in the energy density of electron beam. EBT leads to generation of crystallization cells, the sizes of which change within the range 310 – 800 nm as E_S increases from 15 to 30 J/cm². It is suggested that the defects being formed in surface layers in ЕВР may be the reason for decreasing the HEA’s maximum values of strength and plasticity.

For enterprises of the metallurgical industry, the task of increasing the operational life of drawing mills is urgent. The reasons for a significant decrease in the resource and an increase in the number of equipment downtime are related to the operational problems. Downtime due to emergency equipment failures account for up to 45 % of the mill’s operating time per month. The paper considers the drive scheme of the drawing mill and analyzes the loss of time to restore its working condition. It is shown that the replacement of a cylindrical gearbox with a gearshift mechanism and a  bevel gear with a planetary gear motor equipped with a frequency converter will increase the productivity of the drawing mill by reducing emergency equipment downtime.

The paper considers the actual problem of human-machine control of complex technological units and complexes, which are characterized by a large variety of states, multidimensionality, variability, and uncertainty. Such units in the ferrous metallurgy include coke batteries, blast furnaces, steelmaking units (arc furnaces, oxygen converters), foundry and rolling complexes, rolling mills, main workshops and production facilities. The effectiveness of the model approach to the creation of control systems for such objects is shown to be insufficient for the XXI century. Alternative approaches based on the concept of best reasoning (CBR) are considered. In particular, they include full-scale model and full-scale approaches to the development of support systems and management decision-making. The well-known full-scale model procedures for applying the best reasoning (methods of typical situations and exemplary technological cycles) are presented. The authors propose a new CBR method of automated selection and implementation of control actions with the participation of process operators for process control systems. A modified CBR-cycle of control selection and the corresponding functional scheme of the software control system for a cyclic technological unit were developed. The improved CBR-cycle includes the following additional operations: correction of control decisions for selected cases; retrospective optimization of implemented control decisions; preservation of not only the best and optimized, but also erroneous decisions; updating of the case base; formation of solutions in unique or previously unreported situations. The structure of the case information model is formed on the example of software control of steel melting in the conditions of an oxygen converter shop. It includes three sections: data on the specific situation in the control system, parameters of the selected control actions, and results of steel melting. An example of the control program formation for the preparation and execution of the upcoming steel melting is based on the data of a pre-selected melting case in the conditions of a modern oxygen converter process.