Ferrous metallurgical industry is the main consumer of m nese. The production volume of manganese ferroalloys in the world is approximately 1 % of steel production. After the collapse of the Soviet Union, Russian Federation found itself without any manganese ore base. At present, only high-carbon ferromanganese and ferrosilicomanganese are smelted from imported ore in Russia in a limited quantity. The mineral and raw base of manganese ores in Russia is quite large: the balance reserves of manganese ores are about 230 million tons (approximately 2 % of the world), forecast resources – more than 1 billion tons. Quality of the manganese ores is lower than the manganese ores of most major producing countries. Average manganese content in Russian ores is 9 – 23 %. Basis of mineral and raw base of these manganese ores are carbonate ores, share of which is more than 77 %. Manganese ore mining in Russia is sporadic and does not exceed 66 thousand tons per year. Demand of Russian ferroalloy plants, producing manganese ferroalloys, in manganese ores and concentrates is covered by imports. The problem of accelerating the creation of domestic manganese ore base from the position of economic security seems to be very important. It is necessary to solve a number of issues related to the enrichment of poor manganese ores, development of effective technologies for manganese ferroalloys smelting from concentrates obtained after the enrichment of these ores, as well as creation of more advanced methods of manganese concentrates dephosphorization. In the production of manganese ferroalloys from ore to finished alloys, about 50 % of manganese mined from the subsoil is lost; a large number of by-products are formed (sludges of enrichment, slags, screenings of small fractions of ore raw materials and finished products, sludges of smelting process and dust). The use and processing of them allow not only to reduce the consumption of initial mineral raw materials, but also to increase the efficiency of main production and to reduce environmental pollution. Additional extraction of manganese from industrial wastes and improvement of the technological processes for manganese ferroalloys smelting are the ways to increase the through extraction of manganese.

A review of methods for processing dispersed waste from f loy production was performed. In ferroalloy plants there is a problem of formation and accumulation of cyclone dust (the catch product from crushing – CPC), formed during the grinding and fractionation of ferroalloys. The drawbacks of the known methods for the disposal of such dust are shown. The authors have investigated the possibility of obtaining commercial nitrided ligatures from CPC’s and substandard ferroalloy fines using the technology of self-propagating high-temperature synthesis (SHS). On the basis of the proposed “metallurgical” SHS method, a technology has been developed and the possibility of largescale production of nitrided ferrosilicon, ferrovanadium, ferrochrome and other materials has been shown, which has demand on the world market. Synthesized SHS materials are superior in quality to nitrided ferroalloys obtained by conventional furnace method, in particular, they have a lower content of oxygen, hydrogen and other impurities, and differ in better physical and mechanical properties: density, porosity, strength, and others. Based on the method of metallurgical SHS, the production of nitrided ferroalloys and composite ligatures with the possibility of processing up to 5000 ton per year of cyclone dust of ferrosilicon and other alloys was established in Russia, Magnitogorsk on the production base of scientific and technical production company LLC “STPF “Etalon”. A new approach to the practical implementation of the SHS method is developed and the possibility of using synthesis products in metallurgy is shown. The main application of these products is the use of alloying additives in smelting of a wide range of steels and alloys: transformer, rail, stainless, high-strength structural, and others. Another popular consumer of composite “metallurgical” SHS materials is the refractory production. Modification of traditional refractories used in smelting of cast iron, steel and non-ferrous metals with new composite SHS materials based on nitrides, borides, carbides and other refractory compounds can significantly increase the service life and reduce the expenses for refractories.

Development of ferroalloy production directly depends on p ress of steel industry. Therefore, an increase in steel production inevitably entails an increase in the production of ferroalloys. Over the past 10 years, global steel production has increased by about 30 %. This article discusses general condition of the ferroalloy sector in the CIS countries and, in particular, in the Russian Federation. The main consumers (among Russian metallurgical enterprises) of ferroalloy products in the domestic market were listed, and the structure of production and consumption in other producing countries (China, India, the EU, USA, Japan) was examined. It was revealed that the overproduction of ferroalloys in the CIS countries is about 400 %. In addition, the ways of development of the ferroalloy field were also considered, aimed at reducing the contribution to the production cost of ore raw materials, reducing agent and electricity, which is achieved through the use of cheaper ore, the use of new types of processes and units, and development of other alternative types of ferroalloys, replacing classic ones. For example, it can be smelting in DC furnaces, which allows the use of small unprepared chrome ore as a raw material for the production of ferrochrome containing scarce lump in combination with small cheap reducing agent (anthracite). Melting in an oxygen reactor is also a promising technology, based on the principle of gaseous oxygen, which results in the reduction of carbon monoxide inside the unit itself. The alternative types of ferroalloy products can be used, such as calcium carbon “KAUR”, which can replace calcium carbide in steelmaking.

The systems of alloying Fe – Cr – N, Fe – Cr – Mn – N, Fe – Cr – Ni – Mn – N, Fe – Cr – Ni – N are considered and attention is paid to the compositions of developed or already used steels. Mechanical, operational and other properties of a number of modern nitrogenalloyed steels with an equilibrium and super-equilibrium concentration of nitrogen are considered. The optimal intervals of their doping with nitrogen are given and the contribution of nitrogen to formation of the structural-phase state and the complex of their properties is estimated. For example, in the Fe – Cr – N system of practical interest are the austenitic steels Fe – (21 – 22) Cr – (1.1 – 1.3) N, solid solution hardened, technologically plastic, with a yield strength of 800 MPa and high corrosion resistance. Corrosion-resistant high-strength austenitic steels are in demand of the Fe – Cr – Mn – N system, such as Fe – (18 – 21) Mn – (14 – 22) Cr – (0.4 – >0.6) N, in which nickel as austenite-forming element is completely or partially replaced by manganese and nitrogen. Examples of steels of the Fe – Cr – Mn – Ni – N system with high service properties are given. Since alloying steels with nitrogen requires an assessment of the maximum possible level of its content (solubility) in the metal and the creation of conditions for the introduction of nitrogen into the liquid metal and its preservation in the solid metal, attention is paid to: calculations of nitrogen solubility, taking into account the effect on it of the chemical composition of steel, temperature and pressure at which alloying occurs; the concept of compositionally stable nitrogen content and the coefficient of compositional stability. The main methods of production of nitrided steels are considered. The quality of metal in open smelting and after refining electro-slag remelting (ESR) is compared. The latter makes it possible to preserve nitrogen during the remelting of nitrided steels, to ensure its uniform distribution along the height and cross-section of the ingot, to obtain ingots with a good surface and a dense structure with a radialaxial orientation and without shrinkage defects. The advantages of the method of electroslag remelting under pressure (PESR) are noted – the ability to obtain high-quality metal with a nitrogen content above its equilibrium concentration (under standard conditions) and to provide an almost ideal ecology of production.

The modern development of technology and industry depends to a large extent on improving the quality and performance of equipment. Additive technologies allow production of optimized designs and equipment while maintaining all operational characteristics. The use of additive technologies in the production of parts for aerospace engineering requires a thorough study of the operational properties of materials at each stage of production, a comparative assessment of the test results with the parameters of products obtained by traditional technologies, as well as predicting the characteristics of the final product. In this work, a study of changes in the chemical and phase compositions, microstructure and microhardness of the VT6 titanium alloy samples was carried out at various stages of production: initial cast billet; a powder obtained by plasma centrifugal spraying of an ingot and a product obtained by selective laser melting (SLM). Analysis of the samples’ chemical composition was carried out on an X-ray fluorescence spectrometer with wave dispersion Rigaku Primus ZSX II, X-ray structural studies – on a Rigaku MiniFlex 600 diffractometer (CuK_α -radiation, λ = 1.54178 Å), equipped with a linear (1-D) D/teX semiconductor detector. Study of the microstructure of powder (granular) samples was carried out using the methods of optical and scanning electron microscopy, the measurement of microhardness – on a microhardness tester LECO M-400-H by the Vickers method. It was shown that microstructure of the samples after centrifugal sputtering was a combination of two solid solutions based on the hexagonal titanium modification (HCP) with slightly different crystal lattice parameters due to difference in concentrations of the alloying elements. Chemical composition of the alloy after selective laser melting practically did not differ from the alloy in the initial state.

In electric-arc furnace dust zinc content can reach 43 %, lead content can reach 4 %. The content of ecotoxicants such as dioxins and furans (D&F) adsorbed on dust particles achieve 500 ng/kg of dust. Generally, zinc and lead are reduced from their oxides by dint of carbon (an average of 500 kg/t dust). The results of thermodynamic calculations and experimental studies have shown that these metals can be extracted from dust without the participation of carbon or at its low content (less than 3 %) [1]. Temperature of about 1400 K is required to extract lead, and about 2000 K is required for zinc extraction. The temperatures of their extraction depend on the dust composition, in particular, on the content of carbon, chlorine and the O/C ratio [2]. They can also depend on phase and dispersed composition of the dust. A physicochemical analysis of the dust formation processes in electric arc furnaces (EAF) has been carried out, the composition and properties of dust have been investigated, and experimental studies of the zinc and lead selective extraction process in laboratory conditions have been leaded. A dust processing technology has been developed and the possible innovative potential of the expected results has been assessed. The approaches we propose are based on the study of a continuous two-stage process of carbon-free and zinc and lead selective extraction from EAF dust of different composition. One of the main results of the work, along with the creation of a technology that ensures the selective zinc and lead extraction up to 99 %, is the development of a process for neutralizing EAF dust from D&F to an environmentally safe level.

The paper presents a comparative study of the accuracy of d mining the physical friction coefficient during cold rolling by the methods of forced strip braking f_Q and torque f_М , proposed by I.M. Pavlov and D. Bland together with G. Ford. The compared methods have a sufficient theoretical basis, which contributed to their widespread use. They are based on experimental measurement of the braking force of the rear end of the strip Q, the resultant of normal rolling forces N and torque M. It is shown that, because of the approximate determination of position of the point of resultant rolling force application on the contact arc, the friction coefficient values are always overstated when determined by the method of forced strip braking. The method of torque moment is devoid of this shortcoming. It provides more accurate and reliable data on the value of the physical friction coefficient at cold rolling and allows us to recommend it as the main method for the experimental determination of this parameter. A comparative experimental study of the physical friction coefficient was performed during cold rolling using technological lubrication under laboratory conditions. It is established that, other things being equal, the values of the friction coefficient found by the method of forced strip braking are 1.25 – 1.40 times higher than by the torque method, thereby confirming the validity of theoretical conclusions. It is shown that the torque method is more accurate than the method of strip forced braking and is one of the most reliable methods for determining the physical coefficient of friction during cold rolling.

The paper presents studies on the effect of external influences when pouring-in high-strength alloyed steel into thin-walled metalshell molds with external cooling and into the same molds with suspension pouring-in (complex effect on hardened casting). Prerequisites for the selection of these technologies are considered. As control metal, we have investigated the casting received in volume liquid glass form. Macrostructure, cross-sectional view and mechanical properties of the metal at normal (+20 °C) and raised (+350 °C) temperatures were studied. The most dense and uniform structure and cross-sectional view were received in casting at complex influence. It was established that the main advantage of the offered technologies is increase in uniformity of mechanical properties on the section and height of castings, especially of plastic properties and impact strength. The anisotropy of properties on the section and height of pilot castings is much less, than in control casting. As a result of the studies, it was found that the external and complex effect on the forming casting allows one to affect the macrostructure and to improve the mechanical properties of castings at various test temperatures of the samples. In castings obtained in a metal-shell form with forced cooling, there is no noticeable difference in the mechanical properties both in height and in cross section of the casting. Moreover, the strength properties are by an average 100 MPa higher than that of the control casting, while maintaining high values of ductility and toughness.

A simple theory of thermodynamic properties of liquid nitrogen in Fe – Mn alloys is proposed. This theory is completely analogous to the theory for liquid nitrogen solution in alloys of the Fe – Cr system proposed previously by the authors in 2019. The theory is based on lattice model of the considered Fe-Mn solutions. The model assumes a FCC lattice. In the sites of this lattice are the atoms of Fe and Mn. Nitrogen atoms are located in octahedral interstices. The nitrogen atom interacts only with the metal atoms located in the lattice sites neighboring to it. This interaction is pairwise. It is assumed that the energy of this interaction depends neither on the composition nor on the temperature. It is supposed that the solution in the Fe – Mn system is perfect. Within the framework of the proposed theory, a relation was obtained that expresses the value of the Sieverts law constant for solubility of N in liquid Mn through the similar constant for the solubility of N in liquid Fe and the Wagner N – Mn interaction coefficient in liquid Fe. The values of the Sieverts law constants in this relation are taken directly from the experimental measurements of the solubility of N in liquid Fe and in liquid Mg. In this case, the obtained relation is considered as an equation with respect to the Wagner interaction coefficient ℇ^Mn_N. The solution of this equation gives the value of Wagner interaction coefficient ℇ^Mn_N = –5.25 in liquid steel at a temperature of 1273 K. Wagner interaction coefficient ℇ^Mn_N is related with Langenberg interaction coefficient e^Mn_N by the relation deduced by Lupis and Elliott in 1965. The relation includes the atomic masses of Fe and Mn. Substituting to the relation under consideration the value ℇ^Mn_N = –5.25 and solving the resulting equation with respect to e^Mn_N we obtain the value e^Mn_N = –0.0230. This value corresponds to the experimental data of Beer (1961). It seems to us that is one of the most probable of all experimental values of e^Mn_N for liquid steel at 1873 K. Another such value is e^Mn_N = 0.0209 obtained by Shin with coworkers in 2011.

The article presents the process of creating a computer model for predicting the distribution of particles during centrifugal casting using the ANSYS FLUENT 16.0 software module. To predict the distribution of particles by volume in the world at the moment there are several mathematical models. Most of them are based on the steady state assumption: models describing the criteria for dropping particles by a growing crystallization front and models calculating critical particle absorption rates by growing dendritic crystals. Some models attempt to describe the dynamic state of the system or to determine the criterion for capturing non-metallic inclusions by the solidification front during centrifugal casting of metal. The process of creating the new model, its scheme and geometry are described. Its preprocessor takes into account such phenomena as two-phase flow, energy equation, lamellar flow, introduction of discrete phases (strengthening particles), melting/crystallization. The model considers account of interaction of two liquid phases: air and steel melt; interfacial interaction is described by the equation of surface tension. As the materials used, the authors used steel grade 12Kh18N10T as the base metal, carbides of tungsten, boron and yttrium oxide as input particles. During simulation, the physicochemical parameters of these substances were taken into account. The process of modeling the distribution of particles during centrifugal casting using the Skif-Ural computing cluster, included in the TOP-500 of the world’s most powerful computers, is presented. As a result of the simulation, in addition to graphical display, data arrays were obtained that describe the coordinates of each particle at each moment in time in increments of 0.00001 seconds, which allows us to predict the exact location of each particle at each moment of casting. The results of the work indicate that centrifugal casting technology with the introduction of dispersed particles during the casting process allows obtaining dispersion-strengthened metal materials with predicting the distribution of refractory particles.

On the basis of radial-axial rolling of ring billets, resource-saving technologies for metal forming have been created. Determining the rational parameters of this process is the actual scientific and technical task at development of new profiles. The method of three-dimensional finite element modeling is the most effective tool for improving the technological conditions of ring rolling process. However, as practice has shown, the finite element modeling method requires adaptation to each process of metal forming. This is the subject of the present work. The expediency of using dependency for calculating the metal flow stress for finite-element modeling of ring-rolling processes is substantiated. This dependence was developed on the basis of a theory that takes into account the chemical composition of structural carbon steel, its temperature, strain rate, accumulated deformation, and also the processes of dynamic transformation of the metal structure during hot rolling. A computer program for automated determination of dependency parameters has been developed. The analysis of the accuracy of the obtained dependence was performed in relation to the experimental data. In the course of these calculations, the method of automated determination of the metal flow stress was used by spline interpolation of the experimental data included in the computer database of digital information for a particular steel grade. The average relative error of calculated values of the metal flow stress was 8 % relative to the experimental ones. An improved method is proposed for calculating the parameters of ring billets rolling and reaching the required growth rate of the ring diameter implemented in a finite element modeling system, which is similar to the way the control system of the ring-rolling mill works in solving the same problem (reaching the required growth rate of the ring diameter) when implemented appropriate rolling in practice. When calculating the size of the compression, the iterative process and the method of half division were used. The average deviations of calculated values of the parameters of ring billets rolling from the experimental did not exceed 12.4 %, which makes it possible to apply the proposed approach to study the patterns of the rings rolling process and to improve the rolling technology.