The article discusses the prospects of recycling the most massive wastes of aluminum production (namely, used cathode blocks of electrolyzers, gas treatment dust, gas treatment residue, and flotation tailing). It have been indicated the volumes of wasteaccumulation and a special attention has been focused on the need of their disposal with a view to improve the environmental conditions of the territories adjacent to the industrial zones. Specific characteristics of the generated waste have been determined, which indicate the possibility of their secondary use and transfer from waste to by-products.Existing technical solutions relevant to the issue have been reviewed, and the reasons preventing their implementation have been explained. The most promising methods of waste processing to be carried out successfully in the current economic conditions have been identified. Spent cathode blocks can be used at ferrous metallurgy enterprises (in blast furnaces and converters) as a substitute for expensive coke and fluorspar, and finely dispersed waste can be used at cement enterprises. The areas have been determined that in the future will significantly increase the volume of processing and the demand for these wastes of the aluminum industry in technological processes of ferrous metallurgy. The possibilities for cooperation between aluminum refineries and ferrous metallurgy enterprises, as well as other related industries, were emphasized in detail.

The article considers research on the history of nitrided ferroalloys appearance and development of technologies for nitrogen-containing steels and ligatures. The most important advantages of nitrogen as an alloying element are its availability and almost unlimited reserves in nature. The technology of nitrogen extraction does not cause any harm to the environment and is not accompanied by the formation of waste. New technologies of nitrided ferroalloys and new compositions of nitrogen-containing ligatures emerged as a response to the creation of new grades of nitrogen-alloyed steels. At the same time, researchers in Europe, the United States, and the Soviet Union made the greatest contribution to the development of nitrided steel and ferroalloys technology. Nitrided ferrochrome emerged from the need for alloying stainless steels of various classes. Nitrided ferrovanadium was created for microalloying high-strength low-alloy steels. For nitrogen alloying of transformer steel, an alloying material based on silicon nitride was developed. Nitrogen-containing compositions based on manganese are universal alloying materials for a wide range of applications. Technologies of nitrided ferroalloys developed in the direction of creating compositions with the maximum nitrogen content with minimal consumption of material resources. Currently, technologies for direct introduction of nitrogen gas into liquid metal during out-of-furnace processing are being successfully developed. Alloying with its solid carriers remains a universal method for smelting nitrogen-containing steels. Nitrogen in nature occurs exclusively in a gaseous form, so for introduction to steel, it is necessary to fix it in the composition of a solid substance. At the same time, such a nitrogen-containing material must be compatible with the steel melt and technological in use. This problem is completely solved by the technology of self-propagating high-temperature synthesis (SHS), which allows obtaining composite ferroalloys based on nitrides, with properties that are unattainable for the furnace process.

Modern trends in the automotive industry are aimed at reducing vehicle weight and increasing its safety. The high ductility of IF-BH steel in combination with increased strength allows the use of thinner rolled products in the car body structure. Achievement of high plastic properties in IF-BH steel is ensured by the low content of nitrogen and carbon (C <40 ppm, N <40 ppm) and controlled carbon content in the solid solution. The majority of sheet surface defects are associated with non-metallic inclusions. The presence of non-metallic inclusions in the finished product violates its homogeneity, deteriorates the surface properties of steel, fatigue strength and plastic characteristics of the metal. As a result of the work performed by the methods of fractional gas and micro-X-ray spectral analysis on a scanning electron microscope, metal samples of three IF-BH steel melts were analyzed, taken along the entire process chain of production. The main types of oxide non-metallic inclusions in the steel were quantitatively determined, as well as the total oxygen and nitrogen content in the metal. It is shown that the main types of oxide non-metallic inclusions in the investigated metal samples are aluminates, silicates and spinel. An increase in nitrogen content in the metal after breakdown of the vacuum on the VD was established, which indicates secondary oxidation of the metal. In metal of the samples in the section between the tundish and the crystallizer, nitrogen content in the metal increases which indicates the secondary metal oxidation. At the same time, the content of inclusions of aluminates in the metal increased and the number of inclusions of aluminum-magnesium spinel decreased. A mathematical model and software have been developed that describe the formation and removal of oxide nonmetallic inclusions. Adequacy of the program was confirmed by good convergence between the calculated and laboratory data on the total content [O] in various types of oxides for the first sample at the ladle-furnace unit and in the slab.

The main product of ferroalloy plants is standard ferroalloys. They often do not have all the necessary service characteristics and are not very suitable for metal processing in a ladle. The developing progressive technology of steelmaking is forced to adapt to the existing range of ferroalloys, the standards for which have not been updated for 50 years or more. In addition, in recent years, the sources and markets of ferroalloy raw materials have changed, and their quality and content of leading elements have decreased. This makes it difficult or excludes the possibility of obtaining ferroalloys according to existing standards. In this regard, the production of more efficient ferroalloys of a new generation is required, suitable for progressive processes in the developing areas of ferrous and non-ferrous metallurgy 795 and smelted from non-traditional types of domestic ore raw materials. These include complex or multicomponent ferroalloys containing, in addition to iron, two or more functional elements. Complex ferroalloys should be created in the most favorable combinations of component. It contributes to the necessary effective impact on the iron-carbon melt with a high degree of assimilation of useful elements in it. The creation of scientific foundations for the formation of new compositions of multicomponent ferroalloys with high consumer properties, and the development of physicochemical processes for obtaining these alloys from unconventional ore raw materials contributes to solving the problems of developing compositions of effective new generation ferroalloys and expanding the ore base of ferroalloy production. When using the developed method of designing the composition of complex ferroalloys using unconventional raw materials, melting technologies were developed; various alloys of the systems were obtained and applied on a laboratory and industrial scale: Fe – Si – Cr, Fe – Si – B, Fe – Si – Ba – Ca, Fe – Si – Al – Nb, Fe – Si – Ca – Mg, Fe – Si – V – Ca – Mn, Fe – Si – Al.

The paper contains informational material about the essence of the discoveries made by D.K. Chernov in the field of metal science, theory and practice of heat treatment, new types of tests and investigations. D.K. Chernov was a real pioneer of extremely important phenomena in the field of phase and structural transformations, casting structure, and study of strength of steel products. Significance of his discoveries, undoubtedly, puts D.K. Chernov’s name on the first place in a row of world scientists – metallurgists and metal scientists. Later his discoveries allowed one to develop the science of metals and its subdisciplines – metallurgy, steel deformability, theory of phase and structural transformations, tests and research of metals, theory and technology of heat treatment.

Cold drawn calibrated steel is an effective blank for the manufacture of low-rigid cylindrical parts such as shafts and axles. High accuracy of the diametric size along the length of the workpiece, low surface roughness, increased hardness and strength of the surface layer compared to hot rolled products allow us to produce a variety of parts with high metal utilization and high machining performance. The main disadvantage of calibrated metal is the residual stresses that occur during pressure treatment. To reduce or change the nature of the distribution over the cross section, it is proposed to use small plastic deformations in the surface layer of the hire. Known in practice methods of surface plastic deformation (PPD) usually lead to the curvature of non-rigid workpieces. To intensify the stress-strain state in the deformation zone, we propose a method of orbital surface deformation. Based on the finite element modeling, influence of the main parameters of orbital surface deformation on stress state in the deformation zone and residual stresses in the finished products is considered. Compared with the traditional PPD process, the stress intensity during orbital surface deformation will increase by 10 – 15 %. The residual compressive stresses that form in the surface layers reach 70 – 85 % of the material tensile strength. In the second part of the article, it is supposed to provide information on a more effective method of surface deformation and on the change in initial residual stresses that are formed during the calibration of cylindrical rods.

The final stage in the production of hot rolled steel is leveling on roller levellers under cyclic alternating deformation. When laser is cutting a sheet it may bend due to the release of residual stresses that are unevenly distributed over the volume. The majority of roller leveller models for calculating the process under cyclic alternating deformation does not provide an adequate assessment and prediction of residual stresses in a steel sheet. On the basis of finite element analysis, formation of residual stresses owing to roller levelling of hot rolled strip is disclosed. The implementation of a model of the levelling process was performed in SIMULIA Abaqus. Models are verificated by comparing forces under the rollers. We have experimentally confirmed the convergence of the simulation results with the measurements of the strip flatness obtained after sheets plasma cutting. It was found that after levelling, tensile longitudinal residual stresses remain on the upper surface of the sheet, compressive ones remain on the lower surface, stresses are zero in the middle in thickness, and the stress values are opposite in sign in the remaining parts of the section. It was established that the same parameters of the levelling process of different strength categories lead to different deviations of stresses. An increase in yield strength of the strip leads to an increase in the deviation of residual stresses along the strip thickness. The proposed method of simulation of roller levelling process should be used to study the stress-strain state of hot-rolled steel and to design improved strip levelling setting modes with minimal residual stress deviations.

For the upper blasting lances of 250-tons oxygen converters at PJSC «DMС» (Kamenskoe, Ukraine) the author has proposed a number of welded structures of 5-nozzle lance heads with increased resistance. A set of industrial studies of their operation made it possible to establish that the devices which provide cooling of the areas back from the nozzle zone of the tip have the highest resistance. Measures to increase the values of the average cooler speeds in welded structures of the lance heads and their rigidity also turned out to be quite effective. The transfer of copper welds holding the nozzle inserts in the copper tip from its outer surface to the inner proved to be ineffective from the point of increasing resistance of the lance head (the average resistance of the heads increased by only 7 heats – from 78 to 85 heats). This allows us to assert the need for complete elimination of copper welds in the head (both external, exposed to high-temperature and mechanical stresses, and internal) that hold nozzle inserts in the holes of the welded tip and lance head collector. Thus, in spite of all the measures taken to transfer the welds from the outer surface of the tip to its inner surface, to improve cooling of the tip and its back from the nozzle zones, which also include sections of copper welds around the nozzles, as well as to increase the rigidity of the blast welded structure heads, this led, although to positive, but still to relatively low results. The data obtained indicate that welds made of copper around the nozzle inserts, which are held by this in the tip (also in the collector) of the head, are the limiting link that does not significantly increase the resistance of welded lance heads, and it is urgently necessary to back off its use.

The quality metrics of foundry coke are determined by testing at coke plants. Foundry coke consumers are foundry enterprises which are usually located far from the coke plants. Foundry coke is transported in bulk in open railway wagons. Therefore, this paper is aimed to determine the impact of transportation on the quality of foundry coke. The test conditions were as close as possible to real life conditions of foundry coke transportation. To estimate the impact of transportation distance we introduced the destruction index Pт (%). The results of experimental studies have shown that the destruction of foundry coke is not the same at different intervals of transportation. When transporting up to 300 km, the coke with the minimum durability index M40 is destroyed. When the distance is increased from 900 km up to 2500 km, the foundry coke destruction index (Pт , %) increases by 2.08 – 3.02 % depending on the batch. For all batches, a size fraction of less than 40 mm was noted depending on the durability index M40 from 0.25 to 1.41 %. The size fraction of more than 80 mm stays the same for foundry coke with higher durability indices. When the air humidity rises by 40 % during transportation, the amount of moisture in the coke samples of a 40 – 60 mm size fraction is more than 24 times higher than usual, a 60 – 80 mm size fraction – more than 17 times, an 80 mm and larger – more than 10 times. When the air humidity decreases by 34 %, the amount of moisture in a gram of coke of a 40 – 60 mm size fraction becomes 2 times lower than usual, a 60 – 80 mm size fraction – 1.26 times, an 80 mm and larger – 1.45 times. Compared to coke of size fractions 60 – 80 mm and 80 mm and larger, the moisture of the 40 – 60 mm size fraction coke grows faster when the air humidity increases as well.

One of the ways to increase economic efficiency of the foundry is to reduce the product cost by reducing scrap, a significant proportion of which is formed due to formation of hot and cold cracks during solidification and cooling in the casting-mold system. The formation of cracks occurs due to the force interaction of casting with mold. Currently, a number of approaches are used to determine the value of stress state in the casting material and, accordingly, to determine the value of force interaction. The paper considers the developed estimation of stress-strain state of the casting-mold system, which is determined by deformation resistance of the molding mixture. Change in deformation resistance of the molding mixture is complex due to the multi-factor nature of resulting stresses interaction with thermal and component composition of the sand-clay layer. We have studied the influence of geometric parameters and thermophysical properties of the casting on deformation resistance of the molding mixture. A mathematical model was developed that takes into account the heat transfer between casting and mold, increase in mold dry layer, and the migration of moisture in layer of the sand-clay mixture. On the basis of mathematical modeling, we have made a quantitative analysis of the influence of thermophysical properties of casting (thermal conductivity, volumetric heat capacity, heat of crystallization, geometric parameters) on ductility of raw sand-clay mold with humidity of 5 % expressed in terms of the average resistance to deformation under an obstruction element 100 mm long. It was established that increase in the above-mentioned factors, at a fixed time, increases the average value of deformation resistance. The quantitative relationship of the released heat with growth of the dry layer of the molding mixture is described. It was noted that dynamics of changes in the average temperature does not always coincide with increase in deformation resistance of the molding mixture.

The chemical process, accompanied by iron reduction from hematite, was modeled by computer program complex TERRA (product of MGTU im. N.E. Bauman). Carbon, hydrogen and methane were used as reducing agents. By varying the costs of reducing agents and process temperatures, equilibrium concentrations of the system components were determined. Change in these concentrations at the boundaries of individual temperature regions was regarded as a result of the passage of appropriate chemical reactions in them. At the same time, it was noted that the nonvariant type reactions begin and end at the same fixed temperatures. Calculations have shown that the conversion of Fe2O3 → Fe3O4 in all cases was thermodynamically possible at temperatures exceeding 65 °C. Therefore, at operating temperatures of the furnace it will be implemented without complications. The second stage of reduction also took place under a single scheme Fe3O4 → Fe, bypassing the participation of FeO oxide. The temperatures of beginning of iron reduction by components C, H2 and CH4 were respectively 680, 350 and 520 °C. In this case, there was only a direct reduction of iron by these components. An attempt to fix the fact of indirect reduction, using carbon monoxide as a reducing agent, was unsuccessful even with a large consumption of it. Carbon monoxide decomposed at low temperatures by the Bell-Boudoir reaction. Therefore, later iron was restored by means of “soot” carbon and that is also a direct method. In the final stage of the carbon thermal process, depending on the system composition, formation of iron carbide at 720 °C can occur with the possible subsequent conversion back to iron, as well as secondary oxidation of iron to form wustite. Carbon dioxide takes an active part in these reactions. Based on the results of calculations of chemical processes at high temperatures, a numerical assessment of the reducing (or oxidative) efficiency of all elements and components of the Fe – O – C – H system was given. This made it possible to predict with a high degree of reliability the phase composition of the reaction products at maximum process temperature (1500 °C).

The article analyzes the piercing and rolling process of seamless pipes on PRP 70-270 of JSC “VMP” in terms of power parameters, piercing time and geometric sizes of pipes. The research results were compared with the results of computer simulation on software package QFORM 3D. For simulation, the deformation zones were designed for piercing a mold tube with dimensions of 203×16.5 mm in one pass on a mandrel with diameter of 162 mm and in two passes of piercing and rolling-off on mandrels with diameter of 76 and 162 mm, respectively. From the obtained data on the power parameters, it was found that from the point of view of energy consumption, piercing in one pass seems more appropriate. However, when piercing in one pass, wear resistance of the mandrels sharply decreases, since the contact time between the tool and the hot metal increases. This leads to a decrease in quality of the pipes’ inner surface, more frequent replacement of the tool and increased downtime of the equipment. During simulation, the selected parameter of the friction factor has a significant impact on the value of power parameters (torque and power consumption) and piercing time. The dependences of changing power parameters and piercing time on the friction factor during piercing in a two-roll mill with guards are obtained. With increase of the friction factor, piercing time decreases and torque and rolling power increase. The simulation results are correlated with results of experimental rolling. With a correctly chosen value of the friction factor, power parameters and geometry of the mold tube can be quite accurately predicted by computer modeling.

The article considers the issues of monitoring the thermal conditions of alloys melting and casting at foundries. It is noted that the least reliable method is when the measurement and fixing the temperature is assigned to the worker. On the other hand, a fully automatic approach is not always available for small foundries. In this regard, the expediency of using an automated approach is shown, in which the measurement is assigned to the worker, and the values are recorded automatically. This method assumes implementation of an algorithm for automatic classification of temperature measurements based on an end-to-end array of data obtained in the production stream. The solving of this task is divided into three stages. Preparing of raw data for classification process is provided on the first stage. On the second stage, the task of measurement classification is solved by using neural network principles. Analysis of the results of the artificial neural network has shown its high efficiency and degree of their correspondence with the actual situation on the work site. It was also noted that the application of artificial neural networks principles makes the classification process flexible, due to the ability to easily supplement the process with new parameters and neurons. The final stage is analysis of the obtained results. Correctly performed data classification provides an opportunity not only to assess compliance with technological discipline at the site, but also to improve the process of identifying the causes of casting defects. Application of the proposed approach allows us to reduce the influence of human factor in the analysis of thermal conditions of alloys melting and casting with minimal costs for melting monitoring.