The second part of the paper describes the method practical use on four-stand rolling mill 1400. When rolling the chosen typical sizes, the task was to determine the specific rolling mode, which will ensure a minimum of the total specific energy consumption at the maximum rolling speed, maximum process stabilization (minimum breaks, idle times, etc.) and obtaining the specified quality of the rolled strips (no surface defects, meeting the thickness and flatness requirements). It was achieved by including the above requirements in the constraint system with respect to the determined rolling modes for the selected strip sizes. For example, ensuring a given (maximum) performance for a specific size and brand of a strip is equivalent to realizing a gi673 ven (increased) rolling speed in the absence of unscheduled downtime occurring in emergency situations (in particular, in strip breaks). The speed limit depends on the power of engines, which is included in the complex of structural and technological limitations. The obtained examples, given in the article, have shown that the use of the method leads to fulfillment of all the specified requirements, which, in turn, ensures a reduction in production cost and an increase in the mill’s productivity. The calculation of the cold rolling modes was reduced to selection and distribution of the crimping along the stands (passages – in the reversible mill) and to a choice of specific strip tension in the interstand spaces, on decoiler and coiler, and in setting the wedge of speeds in a particular system of constraints imposed on the input and output process variables as a function of the adopted optimality criterion. The task was solved using the conditional optimization method, through the specification of the optimization criterion. As such criterion, the total energy consumption of the rolling process was used, as requirements – technological and design constraints on the rolling parameters and conditions for strip stability to breaks and to formation of rolls surface defects (“brews”, “chippings”, etc.), as well as to strip breaks.

To restore the shape of curved low-rigid cylindrical details such as shafts and axles, bending straightening under distributed loading is proposed, followed by hardening of the billet using surface plastic deformation based on transverse cheesing of it by flat plates. It is known that after straightening by transverse bending, non-equilibrium stresses are formed over the entire volume of the billet and over time the shape of the detail may again be distorted. Therefore, after performing the straightening process by bending, it is necessary to additionally strengthen the billets by surface plastic deformation based on the transverse cheesing of them by flat plates. The aim of the work was to determine the condition of capture and stress state of the billet during such transverse cheesing. We used the mathematical apparatus and software package Ansys Workbench. The novelty of the work is a new way to manage the stress state when straightening cylindrical billets. As a result, the value of the capture limiting angle α is in the range of 2 – 8°. Maximum value of the absolute reduction depends on friction coefficient and diameter of the billet. Optimal value of the absolute compression is in the range of ΔH = 0.07 − 0.15 mm. The calculation results have shown that after transverse cheesing, in the center of the billet’s cross section there is a stress state of all-round tension, and a stress state of compression is formed in the billet’s shell. The method of hardening by transverse cheesing with flat plates eliminates the cracks formation and material destruction in the central part of cylindrical products.

The stamps for hot deformation are widely adopted in industry. In use they are affected by high temperatures, tension (close to a fluidity limit) and variable thermal loadings. High-hardenability tool steels with high mechanical characteristics are used for stamps production. In this article, the possibility of use of 5KhNM steel for this goal is considered. One of technological operations at production of stamps is training in oil. It is rational to apply volume and superficial hardening, in particular chemical heat treatment, to improve operational characteristics of stamps, including wear resistance. The way of superficial hardening by the combined heating under chemical and thermal and heat treatment is presented. As a superficial way of hardening of largesize stamps of hot deformation, it is offered to use borating. Optimum temperature and time parameters of heating under the combined heat treatment are chosen and confirmed. The offered mode of chemical heat treatment allows receiving the necessary thickness of the borated layer providing high hardness and corrosion resistance in the working range of temperatures of a stamp. Also the influence of heat treatment on structure and grain size of the samples has been researched. It is shown that with increase in temperature and hold time, the size of grain increases. It leads to decrease in strength, fluidity, hardness and impact strength that can negatively influence operational properties of stamps. For definition of mechanical characteristics, the samples (in the studied range of temperatures and excerpts) have been tested for stretching and impact strength. All tests were carried out according to the existing state standard specifications. On the basis of these results, temperature and time of borating are chosen providing high mechanical properties and thickness of a borated layer. The offered approach has allowed reducing economic costs of stamps production from 5KhNM steel by exception from technological process of repeated heating for training with saving the required operational characteristics of largesize stamps.

A model of four-high screw rolling mill was developed and manufactured with the help of additive technologies. The work rolls are installed: the main ones – by cup-shaped scheme and auxiliary – by mushroom scheme with an angle of rolling of ±7 degrees, with an unregulated feed angle of 15 degrees. The main and auxiliary rolls have a barrel length of 70 mm. Diameter of the main rolls in pinching is 50 mm, of auxiliary rolls – 36 mm. At the exit in cross section of the tube outlet from the rolls, their diameters are almost the same and are 72 mm. Each of the four rolls is driven by an individual drive with a 100 W motor-reducer and a rotational speed of 60 rpm by a mushroom scheme and of 83 rpm by a cup-shaped one, which minimizes the divergence of peripheral speeds in the deformation zone at different roll diameters. On the developed model of four-high rolling mill, rolling of liners from plasticine with a diameter of 25 mm with a wall thickness of 7.5 was carried out; 5.5 and 3.5 mm, corresponding to the ratio of diameter to wall thickness 3; 5 and 8. Pipe rolling was carried out on floating mandrels with diameters of 9, 13 and 17 mm. After rolling, measurements of the diameter and wall thickness of the pipes were carried out in 5 cross sections that were equally spaced from each other. In each cross section, the diameter was measured at 5, and the wall thickness at 10 points. The finite element method has been used to simulate the process of rolling these pipes in the QForm program. Assessment of the model adequacy was carried  out by comparing the size of pipes and their accuracy after rolling with the results of computer simulation. When rolling at a four-high rolling mill, the wall thickness is significantly reduced.

The mechanism of plastic crimping of the strand has been identified and justified, as the process of formation of arches: a strong arch of wires, the appearance of each leads to a change in stressed state of the strand at reduction stages. It was established that before appearance of the first arch, wires of the outer layer and the central wire are the most priority to deformation, with the initial absence of side contacts. After appearance of each arch, stresses in wires of the arch layer become predominantly compressive, which temporarily prevents the given layer from actively deforming, up to the formation of arches in all other layers of the strand. After formation of all arches, wires of the upper layer again become the most priority to deformation. Central wire of the strand is overstrained in relation to all other wire strands at all stages of compression. The developed technique allows analyzing the degree of working out of each wire of a lock at a certain amount of reduction. It reflects the features of a multilayered strand deformation: sharp increase in width of the newly appeared contact at almost constant reduction; arches formation; non-simultaneous occurrence of new contacts in layers of strands due to the geometry of the strand and direction of the wires displacement. Application of the proposed technique allows to make rational designs of strands and ropes subjected to small and medium circular plastic crimping, as well as to determine the necessary amount of compression of strands and ropes of a particular design, proceeding from the conditions for retaining the flexibility of the rope and forming the required contact geometry of the wires. It was found that for strands with a diameter of 7.68 mm in the construction of 1 + 5 + 5/5 + 10, the most uniform development of the strand and the contacts is ensured during the reduction in the range of 3.74 < Q < 7.06 %. Intensive filling of the gaps in the strand begins at Q = 7.06 %, which determines the subsequent deformation as the limiting for the ropes working on bending both for performance characteristics and for the conditions of operation of the round caliber of a roller die.

The mechanism of metal flow during circular plastic calibrating (small) compression of a multilayered strand has been revealed and justified, on the basis of which a model for the deformation of wires has been developed. The technique allows to analyze the features of each stage of deformation of the strand, estimating the geometry of the contact of the wires and the nature of their interaction. This ensures the determination of the required amount of compression and the design of rational strand construction. It is shown that the entire crushing process is divided into five main stages.

The ability of saving energy in the production of compressed air is one of the most energy-consuming production in which much of the used energy is lost. The proposed technical solution is based on the united use of two energy-saving technologies. The first of them is the use of technological pressure drop of transported natural gas which lost irrevocably when it is throttled at gas control stations. The second one is air cooling before the compressor sections to reduce compression work. A scheme of a combined steam blowing and heat power plant of a metal manufacturer is proposed. In addition to a power and heat generating turbine and a two-section air compressor with a steamturbine drive, a two-stage expander-generator unit (EGU) producing electricity and cold is used. The thermodynamics of gas expansion processes in the expander is considered, the choice of a two-stage scheme is founded. The cold produced in the EGU is used to lower the air temperature at the inlet to the first and second sections of the compressor, thus reducing fuel consumption for air compression. Using the proposed scheme allows to reduce fuel consumption to the compressor drive, to use the heat of compressed air to preheat the transported gas before the steps of the expander and to generate additional electric power. At the same time, fuel is not used to generate electricity, and the heat of the cooled air is not discharged into the environment, therefore the plant operation is characterized by high environmental performance. The procedure for calculating of fuel economy when using the proposed scheme is given. The assessment has shown that the use of this scheme allows, under given conditions of calculation, to reduce fuel consumption at the combined heat power and steam blowing plant by 11.2 thousand tons of fuel equivalent per year, which is 0.84 %. The generated electric power of the EGU will be 5.3 MW.

The results of the practical use method of calculation the cold rolling schedules of strips for the our-high cold-rolling mill 1400 are presented. When the chosen sizes are rolling, the task was to determine the specific rolling regime, which will ensure a minimum of the total specific energy consumption at the maximum rolling speed, maximum process stabilization (minimum breaks, idle times, etc.) and obtaining the specified quality of rolled strips (no surface defects, thickness and flatness requirements of the regulations). This was achieved by including the above requirements in the constraint system with respect to the determined rolling regimes for the selected strip sizes. For example, ensuring a given (maximum) performance for a specific size and brand of a strip is equivalent to realizing a given (increased) rolling speed in the absence of unscheduled downtime occurring in emergency situations (in particular, in strip breaks). The speed limit depends on the power of the engines, which is included in the complex of structural and technological limitations. The obtained examples, given in the article, showed that the use of the method leads to the fulfillment of all the specified requirements, which, in turn, ensures a reduction in the cost of production and an increase in the mill's productivity. The calculation of the cold rolling regimes was reduced to the selection and distribution of the crimping along the cages (the passages were in the reversible mill) and the choice of the specific strip tension in the intercellular spaces, on the decoiler and the coiler, and in setting the wedge of velocities in a particular system of constraints imposed on the input and output variables process as a function of the adopted optimality criterion. The task was solved using the conditional optimization method, through the specification of the optimization criterion. As a criterion for optimization, the total energy consumption used for the rolling process was used, as technological and design constraints on the rolling parameters and the conditions for the stability of the bands with respect to breaks and the formation of surface defects. rolls ("brews", "chippings", etc.), as well as strip breaks.

During operation, the structural elements of cars are exposed to temperatures and vibrations. Overwhelming majority of the destruction of metal structures is caused by their fatigue. It causes economic losses and often human casualties from accidents. Therefore, the task of ensuring the operability of parts and components of automobiles is one of the most relevant in the modern automotive industry. So it is necessary to know the patterns of behavior of metallic materials, obtained by different technologies, when they are exposed to vibration. Destruction of the metal structure directly affects the behavior of the samples deflection, reflecting the competition of two mutually opposite
phenomena – hardening and softening. It directly influences structural damageability of the metal. The article is devoted to the study of kinetics of fatigue failure of automotive materials using the calibration of structural damage to their surface with behavior of the curves of changes in current deflection under alternating loading. The paper considers automotive materials (steel grades 20KhI3, 14Kh17N2, 35KhGSА) and model metals and alloys (Copper M1, Brass L63T, aluminum alloy V95pchT2) in different structural state under cyclic loading for low, room and high temperatures with fixation of the sample deflection and structural damage corresponding to it. It is possible to study kinetics of fatigue destruction of the sample material by the deflection curves, which is an integral characteristic of destructive processes occurring under alternating loading. Using these processes, one can track the stages of damage during fatigue of metallic materials – damage to the structure at the initial stage, moment of the macroscopic crack appearance, its subsequent advancement up to complete separation of the structural material. It is probable to identify ratio of the period duration before the appearance of a fatigue crack and its subsequent growth, as well as to determine the average rate at which the fatigue crack moves through the body of the metal sample. It is important that it is also possible to estimate the kinetics of materials destruction under the conditions when direct study of the structural state of the sample surface is impossible, for example, in conditions of cryogenic and high temperatures, and also, for example, in the presence of corrosive media. In combination with fractographic and metallographic analysis of the fatigue process, the deflection curves allow, based on the evaluation of the stages of materials destruction, to carry out selection of the latter for the structural elements of a car taking into account its operating conditions and optimizing the technology of parts manufacturing to increase serviceability and maintainability. 

Thermodynamic analysis of carbon gasification process in the presence of moisture was carried out. The chemical process was displayed by the system C – O – H with the ratios of elements in it: 1:1:2 and 1:2: 2. To work out the methods of research and verification of the results, we used a well-studied subsystem C – O. The initial array of processed data was presented by the contents of chemical components C, CO, CO2 , CH4 , H2 and H2O calculated by TERRA program. There is no single chemical reaction in the C – O – H system, so the full operating temperature range of 298 – 1400 K was divided into three characteristic areas, and each of them was analyzed separately. By comparing the numerical values of the components contents at the regions’ boundaries, we determined changes in their values during the transition from one region to another. These values were multiples of stoichiometric coefficients of the expected chemical reactions. Thus, the problem with establishment of the chemical reactions’ type was solved. But two areas of three identified reactions were complex containing more than four components. Therefore, their decomposition was performed on the basis of three more simple and characteristic reactions for these areas. As a result, the total number of reaction varieties was reduced to four – two main reactions of carbon gasification (C + 2Н2О = CO2 + 2Н2, C + CO2 = 2СО) and two reactions of formation and decomposition of methane (2C + 2Н2О = CH4 + CO2 , CH4 = C + 2Н2 ). At the same time, the proportion of each reaction in the total chemical process was determined by the balance coefficients β.The type of chemical reactions provides the necessary information about content of the system components only at the regions’ boundaries. A quantitative assessment of the chemical process within the regions can be obtained by determining the temperature dependence of the reaction coordinates on Gibbs energy of the reactions and the pressure – ξ(Т) = f [ΔrG°(Т), Р]. The coordinates of reactions ξ in combination with the balance coefficients of reactions β allow us to calculate not only the content of reagents and reaction products at any moment of reactions, but also the conditional temperatures of the beginning and end of the reactions themselves. No coefficients and parameters of the fitting character were used in the calculations. The average absolute error of the quantitative description of the results of machine simulation of the system C – O – Н – is less than 0.02 mole (per 1 mole of carbon), and for the subsystem C – O it is almost zero. 

The article considers basic expansion of thermodynamics and thermodynamic interaction coefficients of the first, second and third orders of low-concentrated binary alloys. The values of interaction coefficients of the first and second orders in 37 such systems were estimated according to experimental thermodynamic data on the concentration dependence of excess chemical potential of an impurity in liquid alloys of binary systems. Estimates were obtained by the numerical differentiation method. This method is based on Newton first interpolation formula. Calculation formulas for the corresponding estimates are given. A simple theory is proposed that relates the thermodynamic interaction coefficient of the second order with the first-order one in the liquid alloy of certain system. The theory is based on the lattice model of a solution and the principles of statistical mechanics. The FCC lattice is adopted as a model lattice. The model of pair interaction between metal atoms in the alloy was used. The radius of this interaction corresponds to radius of the nearest atomic shell. Using the proposed theory, thermodynamic interaction coefficients of the second-order for all 37 systems considered in this work, as well as the values of the third order interaction coefficients for 23 systems out of 37 mentioned above, were calculated. For these 23 systems, theoretical estimates of the second-order interaction coefficients are in agreement with experimental ones both by sign and by order of magnitude. This circumstance can be considered as evidence of applicability of the numerical differentiation method for estimation of thermodynamic interaction coefficients of the first and second orders in liquid binary alloys. The accuracy of estimating the values of the third derivative by numerical differentiation is insufficient. That makes it impossible to compare the calculated values of the interaction coefficients of the third order with the experimental ones, obtained by this method. It can be assumed that the theoretical calculations just give an idea of the magnitudes’ order of these coefficients.

The paper discusses the results of molecular dynamic simulation of a melt of the multicomponent oxide-fluoride system CaO – SiO2 – – Al2O3 – MgO – Na2O – K2O – CaF2 – FeO, corresponding to composition of industrial slag-forming mixture (SFM) used in steel casting for slag targeting in the mold of a continuous casting machine (in wt %: 35.35 % SiO2 , 30.79 % CaO, 8.58 % Al2O3 , 1.26 % MgO, 13.73 % CaF2 , 7.57 % Na2O, 0.88 % K2O, and 1.82 % FeO). These concentrations were converted to mole fractions, and the number of ions was calculated for each of the components in the model. An eightcomponent oxide-fluoride melt containing 2003 ions in the main cube with a side length of 31.01 Å was simulated under periodic boundary conditions at an experimentally determined solidification onset temperature of 1257 K at constant volume. Coulomb interaction was taken into account by the Ewald–Hansen method. The time step was 0.05t0, where t0 = 7,608·10–14 s is the internal unit of time. The melt density was taken to be 3.04 g/cm3 based on our experimental data. The interparticle interaction potentials were chosen in the Born–Mayer form. Based on the simulation results, the structure of subcrystalline groups of atoms present in the melt at the temperature of solidification onset was determined. A discussion of the simulation results and their comparison with the literature data was held. It is shown that the computer model allows one to obtain a fairly realistic picture of atomic structure of the slag melt, indicating that the main structural component of all silicate systems is silicon-oxygen tetrahedron. Tetrahedra in silicates are either in the form of structural units isolated from each other, or, connecting together through peaks, they form complex anions. It is consistent with the theory of slag melts. Molecular-dynamic simulation allows one to obtain adequate information on structure of the melt of a certain chemical composition.

The problem of dephosphorization of iron-carbon alloys is relevant for the metallurgical industry, since a high concentration of phosphorus contributes to the appearance of a number of extremely undesirable phenomena. A lot of experimental work has been devoted to solving this problem, but it has still not been completely possible to cope with it. Any field experiments aimed at studying the process of phosphorus removal, require considerable material and time costs, but at the same time do not guarantee getting the desired result. Therefore, to search for new approaches to solving this problem, it is much more rational to use numerical simulation methods involving the computational capabilities of modern computers. At present, computer experiments are the same recognized research method as theoretical research and real experiment. To study the behavior of phosphorus atoms in iron using a numerical experiment, it is necessary to build a computational model and test it by calculating various characteristics whose values are known in advance. In this paper, the method of molecular dynamics was chosen as the method of computer simulation. Using this method, one can conduct experiments with given atomic velocities and describe dynamics of the studied processes. To describe the interparticle interaction, we used the potential calculated in the framework of the immersed atom method. The study was conducted on a computational cell simulating α-iron crystal with phosphorus substitution atoms. The constructed model demonstrated satisfactory results when calculating the known characteristics of the simulated system. Dependences of changes in such characteristics as temperature coefficient of linear expansion, melting point, latent heat of melting and heat capacity on the concentration of phosphorus atoms, as well as in some cases on magnitude of the applied external pressure were established. Calculations showed that, for example, the phosphorus concentration of 0.5 % leads to an increase in the average thermal coefficient of linear expansion by 9 %, a decrease in temperature and latent heat of fusion by 5 % and a heat capacity by 7 %.