The article presents research findings in the development of a  specialized SHS technology for composite ferrous alloys for steel melting and blast furnace iron-making. To resolve the principle goal of creating metallurgical production lines it was developed a new approach to practical implementation of the SHS method – a metallurgical SHS process. The metallurgical version of SHS is based on using different metallurgical alloys as the main raw stock; those include dust-type wastes of ferrite alloys production. In this case, the process of synthesis by combustion is implemented via exothermic exchange reactions. Here, composite materials form; they are based on inorganic compositions bound with iron and/or an alloy based on iron. It has been shown that depending on the aggregate state of source reagents, metallurgical SHS processes can be gasless, gasabsorbing or gas-yielding. Combustion modes for these processes largely differ. To arrange for metallurgical SHS process in weakly exothermic systems, one can use different versions of the thermal bonding principle. The authors have investigated self-propagating high-temperature synthesis of nitrided ferrovanadium and ferrochrome. It has been shown that the phase composition of the source alloy has strong impact on the consistent behaviors of the combustion flow and the combustion mechanism of ferrovanadium (if combustion is taking place in nitrogen atmosphere). In the course of nitriding σ-(Fe – V), process activation takes place; the activation is related to the transformation of the intermetallide into α-solid solution when the phase transition temperature is reached (~1200  °C). The composition structure of ferrovanadium nitride products is formed by the confluence of solid-liquid droplet-particles that consist of molten Fe and solid vanadium nitride. A 3-phase mechanism of ferrochrome interaction with nitrogen facilitates the achievement of a high degree of nitriding. It was shown that the combustion rates of ferrochrome (and chrome) during nitriding in coflow filtration mode increase as the nitrogen flow rate is increased. Here, the degree of ferrochrome nitriding during forced filtration (4.7  –  7.5  %  N) is much less than that during non-forced filtration (8.8  –  14.2  %  N).

Based on the Jourdain variation principle, a mathematical model of the process of free widening in hot rolling of thin sheet metal is developed. The principle applies to rigid-plastic materials and for the cinematically admissible area of speeds. As a functional of the variational equation, sum of the powers of internal resistances, frictional forces, shear forces, front and back tension was used. When solving the Jourdain variational equation for the case of rolling with tension, the Ritz method was applied. The Jourdain variational equation was transformed into a system of homogeneous equations, the left side of each represented a derivative with respect to a varying parameter. Varying parameters were the exponent of the kinematic condition, general widening in the plastic deformation zone and the widening in its neutral section. The developed model allows to study the distribution of the widening on length of the deformation zone depending on the parameters of rolling process and sheet metal. To test the adequacy of the developed free-widening model, experimental studies were carried out on a two-roll cold rolling mill. Lead samples were rolled, the measured widening values of which coincided with the theoretical calculated with an accuracy of less than 10%. Cold rolling of lead samples simulates hot rolling. Theoretical analysis of the influence of tension on the process of free widening when applying tension is consistent with the practical results presented in the literature. It is shown that the unevenness of tensile stresses in the input and output sections of the deformation zone arising from the application of tension causes the appearance of additional powers in the power balance equation, leading to a decrease in magnitude of the widening. The resulting unevenness of the tensile stresses can be used to control magnitude of the widening in thin-sheet rolling. In turn, unevenness of the tensile stresses along the width of rolled strip can be increased or decreased by means of the bending forces of work rolls of the rolling stand. The article presents a scheme for controlling the value of the rolling band widening during hot rolling with the help of bending forces of work rolls.

The use of natural gas reduces the amount of coke to produce pig iron. The flow of hot blast pushes natural gas to the surface of blowing channel in the conventional tuyere. Natural gas is poorly mixed with natural gas. This causes incomplete natural gas combustion and pyrolysis. Therefore, the problem of the completeness of combustion of natural gas is relevant. One way to improve the mixing of natural gas and hot blast is the gas pipe in the blow channel. However, dynamics and change of the thermal state of the tuyere are understudied for this option. The possibility of ignition of natural gas inside tuyeres must also be taken into account. The authors have investigated the inf­luence of the method of natural gas supplying on gas dynamics and heat transfer in air tuyere of a blast furnace with the help of modeling in ANSYS Fluent 15.0.7. Simplifying assumptions were adopted. Only fluid inside the blowing channel is considered as the modeling zone, and the processes of heat transfer to the water of cooling system are considered in the extended boundary conditions. A simplified diagram of the computational domain was created in DesignModeler and a computational mesh – in AnsysMeshing. The boundary conditions were set for blowing, natural gas, and also for the border of the fluid with copper walls. The calculations were carried out for half of the tuyere. It is shown that under the given conditions of flow of air and natural gas, combustion inside tuyere with extended to mid-channel gas blowing nozzle does not occur, and natural gas is mixed with the hot air. Improving the mixing of natural gas and hot air, one side, reduces heat flow at the exit of the blowing channel and the average temperature of the gas mixture, on the other side, creates conditions for complete combustion of natural gas outside the tuyere.

Using the ideas of systems concept and based on the experience of a theoretical study, design and industrial mastering of processes of section rolling of a wide range of profiles at the Chair of Metal Forming of Ural Federal University the universal “Concept of optimum calibration” was developed. The general ideology of optimization of roll pass design was explained in Report 1 of the article. Within the developed intention, concepts of the continuous and discrete space of calibers are considered. For creation of the discrete space of calibers it is offered to use a classification method. As measurements of calibers space are the most significant, simple and evident characteristics of calibers are used. As an example of use of the considered procedure, creation of the discrete space of rail calibers was executed. At the same time, as measurements (characteristics) of calibers space technological and geometrical features of rail calibers are used: T – caliber type on character and the purposes of forming, С – existence of axes of symmetry and P – provision of the connector of caliber rolls or quantity of the rolls forming caliber. Filling of calibers space was carried out in the course of structural analysis of working calibrations of the rolls known from literature and factory atlases of calibrations. The calibers space is presented in the form of the three-dimensional table reflecting a complete set of all possible rail calibers in the structured form. It was set that for each of the selected characteristics of calibers (T, С and P) the limited number of levels of variation exists (6, 4, 7, respectively). Geometrically it is possible only 97 combinations of levels of characteristics, each combination are single-digit defined by a type of specific rail caliber and has native formal code. Change in level of any characteristic in this table leads to transition in calibers space to other point of this space i.e. using caliber of other type. The present approach to the construction of calibers space can be used to create computer-aided design and optimization of roll pass design.

The paper presents the current state of the problems of automation and control data of wet magnetic concentration for iron ore mining and processing plants. Data on the measurement errors of modern analyzers and material composition of the pulp are considered. The possibility of using Kalman filter in order to obtain the most accurate information about the content of valuable component in concentrate and tailings of magnetic separator products is shown. The mathematical description of the dynamics of concentration indicators is given in state coordinates in the form of differential equations system. The author has selected maximum allowable and nominal values of the water flow in the separator bath and the rotation frequency of its drum as well as the corresponding data for the mass fraction of iron in magnetite concentrate and tailings, based on the reference information. With MATLAB program of computer simulation the nonlinear static characteristics were composed, reflecting the dependence of technological parameters of the magnetic concentration from control actions. The linearization dynamic model of the system is held using expansion in Taylor series in the neighborhood of the points, corresponding to a nominal operation mode. The transfer functions of control valve of water flow rate of induction motor rotating the drum were calculated. Standard deviations of control parameters affecting the separation process were determined. The calculated ratio are obtained for determining the covariance matrices of the system noise, describing dynamics of indicators of magnetic concentration, and the noise of their measurement by devices that control the content of magnetite iron in concentrate and tails. The presented algorithm of estimating the coordinates of the Kalman filter state consists of two stages: prediction of the system state and adjustment of the state vector. Simulation results of the MATLAB programming environment are presented in the form of time diagrams reflecting the dynamics of technological indicators of concentration, the evaluation of the Kalman filter and measurement error. The system has been considered in case of random changes of control actions. At the end of the article, the results are summed up, where it is reported that the Kalman filter should be used in tasks of automation and control of the iron ore concentration process.

One of the most productive and reliable methods for studying the processes of metal forming is direct physical modeling on a real metal. The limitations of this method, as applied to the production of electric welded pipes, are generally related only to the lack of specialized equipment for modeling the continuous roll forming process. In 2014, a laboratory for modeling the most common processes of forming welded straight-seam pipes produced by continuous or discrete methods was established at the “Metal Forming” Department of NUST “MISIS”. The laboratory includes a specialized “TESA10-50TRAINER” (TRAINER), which allows simulation of continuous processes of electric welded pipes of small diameter. At the TRAINER, it is possible to simulate the processes of continuous forming of pipes of small and medium diameter by the basic production schemes of the pipe-electric welding manufactory: obtaining welded pipes of circular cross-section from strand; production of profiled pipes from sheet billet; obtaining profiled pipes from a preformed round or oval billet. In the research part of the article, the focus of deformation of the pipe blank, including the non-contact focus of the folding, the contact deformation center and the sprung portion, is considered. Initially, the shaping parameters of pipe billet in monotonous and roll forming centers were calculated by the adopted methods. The obtained results were compared by dynamics of the change in the width of billet from fixed sections of the deformation center. Further, the parameters of the roller tool were checked for compliance with the calculated dimensions. For the first roll stand of a continuous focus, an experiment was organized and conducted for the same conditions, but in a real roll center. The obtained experimental sample, marked out in eight sections, was measured after the billet had left the drive stand and the obtained data are listed in the table. Analysis of the results showed that the shape change of the cross-section parameters corresponds to the accepted provisions on geometry nature of the billet in the roller drive calibers. The discrepancy between the theoretical and experimental data for the roll center does not exceed 1.5 %.

Ensuring the stability of the dimensions of the stamped-rolled railway wheels, the rational power modes of the press operation and durability of the metal deformation tool parts, as well as reduction of the initial billets mass, are actual scientific and technical tasks. This durability largely determines the costs associated with the choice of steel grade for dies, technology of their manufacture and process lubrication. In the present work, based on the results of finite element modeling, the analysis of the influence of stamping schemes of wheel billets on the power modes of operation of a forming press and on wear of the deformation tool was made in relation to modern press rolling lines. It is shown that the stamping schemes, which provide for the regulated distribution of metal between the central and peripheral parts of the billet delivered to the stamps, are characterized by a  rational power mode of the forming press. The average force in this case is 63  –  70  % of the average force when stamping out of the billets, sagged by smooth slabs. Elimination of premature filling of the hub contributes to a decrease in the average (by the upper and lower stamps) of the wear of molding dies by 20  –  24  %. It was established that in the process of metal reduction in the disk zone, as the earlier formation of the resistance to flow of metal from the side of the molding ring is formed, the smaller slip of the deformable metal relative to the surface of the molding dies is in the zones of their most intense wear (the transition from the disk to the rim) and, as a consequence, less wear amount appears. It has also been found that the metal deformation scheme in molding dies ensuring filling of the flange during axial metal reduction in the rim zone, decrease the metal slippage relatively to the surface of the molding dies at the zones of transition from the disc to the rim. The additional decrease of wear in this case is 27  –  33  %. Ensuring the dimensions stability of the stamped-rolled railway wheels is possible on the basis of stamping schemes, providing a regulated distribution of metal between the central and peripheral parts of the billet and its self-centering in molding dies. This will reduce the weight of the initial billet by 7  –  10  kg.

Amorphous and nanocrystal magnetic soft Fe-based alloys are widely used for the shielding materials production, which are effective in the wide range of magnetic and electromagnetic fields. These alloys are obtained in ribbons by an ultra-quick quenching of the melt flow on the high-speed rotating refrigerator-disk. During the amorphous ribbons production process, melted in the high-frequency inductor metal is fed through the dye on the surface of the quenching disk, wherein the surface layers, contacted with the refrigerator-disk, of the forming amorphous ribbon are cooled quicker than the top ones, which are not in contact with the refrigerator-disk. As the result on the “contact” side of the ribbon the residual compression stresses can occur, wherein on the “free” side – the tension stresses. All these can lead to the structure anisotropy along the ribbon thickness, therefore also to the properties anisotropy during the further heat treatment. In the present paper, the results of the TEM structure analysis (planar geometry and transversal cut geometry) along the ribbon thickness of the AMAG200 alloy (Fe – Nb – Cu – Si – B system), obtained by the spinning method, are presented. The relation between the structure changes in the amorphous AMAG-200 alloy (Fe – Nb – Cu – Si – B system), which occurred during the process of the controlled crystallization, with the structure features of the amorphous ribbon, obtained by the ultra-quick quenching of the melt (with the cooling speed up to 106 K/s) is determined, explaining the structure anisotropy along the ribbon thickness. It is stated that the heat treatment under 530 °С forms high magnetic properties and lowers the destruction energy by the formation of the optimal amorphous-nanocrystallline structure in part of grains volume fraction and size. Using the SEM the fracture appearance analysis was performed, connected to the structure obtained during the ultra-quick quenching from the melt and after the heat treatment under 530  °С. It is stated that the fracture surface at the as-build state provide viscous type and after heat treatment-completely brittle type.

The most significant trend in recent decades in the field of continuous casting of steel billets is a partial transfer of the process of deformation of the exposure to the field of complete solidification (rolling mill) in the area of two-phase (solid-liquid)state (technological line of CCM). However, the implementation of such two-stage deformation of the continuous cast ingot leads to the need for changes to the methodology of physical simulation of the behavior of defects (surface and bulk) in the course of the subsequent rolling, first and foremost, in terms of the correct choice of their geometric shape and spatial orientation. The paper presents the results of a study of the influence of spatial orientation of the surface defects and continuity of the macrostructure of the metal axial region deformed in the line of the continuous casting machine using layered physical models. An experimental study performed in the conditions of deformation of reduced billets by two schemes with rolling simulation scale1:5: in smooth rolls, simulating the process of groоvelles rolling as applied to the first two stands of the crimp group of medium-section mill 300; in the first and second pairs of rectangular grooves of breakdown stand of the mill 500/370 of PJSC “Donetsk Metal Rolling Plant”. According to the multiplicity of the problem, the universal design of physical models was developed to simulate the spatial location of both surface and internal defects. Studies have shown that in case of rolling of physical models with extract ratio over 2.0 and an angle of misalignment defects imitators close to 60° their complete “healing” is possible. In turn, decrease in the angle to 30° contributes to greater extraction of the defect-simulator and only a small decrease in their width. In the case of total misalignment of defect-simulators (angle 90°) there is a broadening of the defects and their deposition to the initial length after tilting by 90°. The obtained experimental data allowed understanding of the mechanisms of “healing” defects integrity of metal depending on magnitude of the total extracts, the angle of misalignment of the longitudinal axis of the defect with the rolling direction and the distance of their occurrence from the longitudinal-transverse plane of symmetry.

The article presents a study of the interaction of tungsten monocarbide and carbon steel by contact and non-contact methods. Substrates of compressed powder of tungsten carbide, sintered in a vacuum furnace, were impregnated with carbon steel with certain chemical composition. The whole process was recorded on a high-speed video camera that allows to measure the contact angle of the experiment at any time. The practical study was conducted on the experimental complex in the center of high-temperature studies of the Research Institute of Casting (Foundry Research Institute, Krakow, Poland). The experimental course and microstructures of obtained substrates were represented. The study of the chemical composition of tungsten monocarbide reaction products with low carbon steel was carried out by a scanning electron microscope “Jeol JSM-6460 LV”. According to the study of all areas on the substrate sections it can be observed the same structure, consisting of three phases: the grains of tungsten carbide and iron-carbon-tungsten compounds with different iron content. On the edge regions, adjacent to the upper face can be seen more of Fe – C – W-compounds with iron content of 22.86  %  –  23.68  %. This is because these areas impregnation occurred at the last turn, and dissolved the iron carbide to a greater extent than in other areas. In areas of direct interaction between the substrate and the metal clearly identified tungsten carbide grains, bonded together by molten iron (with different content of iron in different phases). On both samples on horizontal surfaces of the substrates in the region adjacent to the absorption field, partially iron film covering is observed over the sample surface. Boundary zone horizontal surfaces of substrates are completely covered with iron film, under which the tungsten carbide grains are located. Despite the use of different methods of studying the interaction of tungsten monocarbide with low carbon steel (contact and contactless heating), a significant difference is not observed between the structure of the samples.

Abstract. Ensuring the stability of the dimensions of the stamped-rolled railway wheels, the rational power modes of the press operation and the durability of the metal deformation tool parts, as well as the reduction of the mass of the initial billets, are actual scientific and technical tasks.

This durability largely determines the costs associated with the choice of steel grade for dies, technology of their manufacture and process lubrication.

In the present work, based on the results of finite element modeling, the analysis of the influence of stamping schemes of wheel blanks on the power modes of operation of a forming press and the wear of the deformation tool in relation to modern press rolling lines.

It is shown that the stamping schemes, which provide for the regulated distribution of metal between the central and peripheral parts of the billet delivered to the stamps, are characterized by a rational power mode of the forming press.

The average force in this case is 63-70% of the average force when stamping out of the billets, sagged by smooth slabs.

Elimination of premature filling of the hub contributes to a decrease in the average (by the upper and lower stamps) of the wear of molding dies by 20 - 24%.

It is established that in the process of metal reduction in the region of the disk, the earlier the formation of  the resistance is formed to flow of metal from the side of the molding ring is formed, the smaller the slip of the deformable metal relative to the surface of the molding dies in the zones of their most intense wear (the transition from the disk to the rim) and, as a consequence, less wear amount.

It has also been found that the metal deformation scheme in molding dies ensuring filling of the flange during axial metal reduction in the rim zone, decrease  the metal slippage relatively to the surface of the molding dies at the zones of transition from the disc to the rim. The additional decrease  of wear in this case is 27 - 33%.

Ensuring the stability of the dimensions of the stamped-rolled railway wheels, possibly on the basis of stamping schemes, providing a regulated distribution of metal between the central and peripheral parts of the billet and its self-centering in molding dies. This will reduce the weight of the initial billet by 7 - 10 kg.

Recently, the demand for iron ore concentrates of the Kovdor deposit has been maintained, despite the complexity of their use for the production of man-made raw materials. Magnetite of Kovdor ore has a heterogeneous structure and its iron does not participate in melt formation processes during sintering of agglomerates. Therefore, up to the basicity of 2.0, a silicate glass phase is a binder of ore grains of the finished product. With the increase in basicity above 2.0, the mineral composition and microstructure of the agglomerates change. Magnetite is oxidized to hematite, an alumino-siliciferite appears on the hematite contact with the high-calcium melt, the residual melt crystallizes to form a titanium-containing silicate.

The results of numerical experiments on studying of influence of technological errors on the vertical and horizontal forces of rolling are given. A full factorial computational experiment was performed by varying factors: initial wall thickness variation of pipes, feed and friction factor. The regression equations were obtained by the vertical and horizontal forces from these factors. It was found that the force values obtained when the maximum values of the factors are much higher than the values obtained at minimum values of factors: the vertical force varies by more than 2 times, and the axial force – more than 8 times. It was concluded that the errors of setup rolling parameters can cause a multiple increase in the forces of rolling, especially, in the horizontal component. Therefore, for stable rolling mills operation the observance of procedures discipline and control the initial wall thickness variation of pipes are necessary.