The main task of the technology of the steel sheet flattening is to calculate the optimal reduction of a sheet billet by the working rollers of straightening machines so that the sheet at the outlet from the machine has the minimum residual stress and curvature. In the mathematical and numerical modeling of the steel sheet flattening process in the multiroll straightening machines, in the beginning we calculate the curvature and bending moments of the steel sheet at the points of the tangency with the machine’s working rollers, and then we calculate the energy-power parameters of the sheet’s flattening. The calculation of energy-power parameters of the multiroll sheet-straightening machines is an important technological estimation at the steel sheet’s flattening. The basis of energy-power calculation includes the estimation of the support reactions of working rollers and the efforts of upper and lower rollers’ cassettes of straightening machine at the sheet flattening. When there is an insufficient bending moment of steel sheet, it is impossible to eliminate the harmful residual stresses in the sheet wall and the surface defects of the sheet. If the force of the upper cassette rollers is insufficient, then to achieve the required reduction of the sheet for the quality flattening is impossible. The excessive values of the rollers’torque moments and the efforts of rollers’ cassettes often lead to the sheet defects, breakage of the working and supporting rollers and breakage of whole sheet-straightening machine. The approximate method for determining the optimal technological parameters of steel sheet cold flattening on multiroll sheet-straightening machine is proposed in this paper. The calculations allow us to determine the type and curvature of neutral plane of the steel sheet under flattening, residual curvature of the sheet after flattening, sheet’s bending moments, support reactions of working rollers, residual stresses in the wall of the steel sheet, proportion of plastic deformation on the sheet thickness and the relative deformation of the longitudinal surface fibers of the sheet under the flattening depending on the rollers’ radius, the pitch between the straightening machines’ working rolls, magnitude of the sheet reduction by the upper rollers, the sheet thickness, as well as the elastic modulus, yield stress and hardening modulus of the sheet metal. The research results can be widely used at the engineering and metallurgical plants.

Nowadays, the railways in the Russian Federation are moving to the path of seamless construction. The development of technologies to ensure the possibility of continuous welded rail track with the desired quality characteristics is the actual direction now. One of the key technologies for the construction, repair and maintenance of a seamless path is welding of rails, for which various methods have been developed and are used, such as: electric-contact, gas-press, induction, laser welding, friction welding, aluminothermic, electric arc electrodes, in the environment of protective gases, electroslag, powder wires, etc. The article describes the advantages and disadvantages of the main types of welding rails that are most widespread today: resistance flash welding and aluminothermic welding. It is shown that as the primary method of rails welding in Russia, electric-contact welding is used. However, in connection with the inability to weld rails in the zones of turnouts by contact machines, the use of aluminothermic welding of rails started on the railways of Russia. It has been shown that the most important factors that determine the quality and reliability of welded rails are metallurgical and welding technologies, as well as subsequent processing methods that reduce the impact of high temperature effects. The technological features of these methods, advantages and disadvantages of modern methods of solving problems in welding, as well as economic costs were considered taking into account operational properties of joints. Experience has shown that during the exploitation of welded joints made by aluminothermic method on the railway and at testing on the experimental ring of JSC All-Russian Scientific Research Institute of Railway Transport, their quality is slightly inferior of electric-contact welding. Special attention is paid to the peculiarities of welding technology for differentially thermally strengthened rails. The analysis of existing methods of rails welding allows working out the main directions of research to solve this problem.

Recultivation includes a set of measures aimed at forming of a favorable root layer on the surface of industrial dumps in various ways with subsequent use of this area. Conservation is the fixation of dumps surface by mechanical means or by gardening the surface of the dumps with a preliminary application of a minimum layer of soil, peat, mineral fertilizers, growth substances and unconventional soil improvers – sewage sludge (WWS). As a result of the work carried out on the surface of the iron ore enrichment waste of the Abagur agglomeration factory, techno-soils were formed – artificial soils with a root layer consisting of a mixture of WWS and tailing material. Recultivated areas have been created on iron ore enrichment waste, which ensure erosion stability of the tailing dump surface and conservation of enrichment wastes. The chemical and agrochemical parameters of techno-soils over the two years of their development have changed. Some alkalinization of the medium and a sharp decrease in the amount of organic matter and all forms of nitrogen in substrate of the root layer are observed. Biomonitoring of recultivated experimental sites makes it possible to optimize and to accelerate the process of crop plants formation on industrial waste, to monitor the condition and development of the grass stand, to monitor the restoration of fertility of disturbed lands and to calculate the ecological and economic effect of reclamation works. Based on the results of monitoring of experimental sites in the tailing dumps of the Abagur agglomeration plant, it was established that in 2 to 3 years favorable conditions are created for the formation of a root layer on the substratum of the root layer and a stable crop-forming phytocenosis. As a result of introducing WWS, the physical and nutritional regimes on the surface of the tailing pond are improved. In all variants of WWS placement a positive effect has been achieved – the growth of terrestrial biomass with an increase in the rate of introduction of WWS. The soil-ecological perspective of the use of sewage sludge as an ameliorant that significantly improves the chemical-physical properties of industrial dumps is shown, which makes it possible to create long-term, stable phytocenoses of protective and sanitary-hygienic purposes.

By the methods of optical and transmission electron diffraction microscopy the evolution of structural-phase states of the surface layers in the head of differentially hardened rails of category DT350 was studied to the depth up to 10 mm in the fillet after the passed tonnage of 691.8 million gross tones on the experimental ring of JSC “VNIIZhT”. It is shown that in the initial state the following structural constituents present in the rail head: grains of lamellar perlite (relative content is 0.7), grains of ferrite-carbide mixture (0.25) and grains of structurally free ferrite. After the passed tonnage of 691.8 million gross tones this state is preserved only at a depth of more than 10 mm. A distinctive feature of the structure at this distance is a large number of bending extinction contours, which reveals elastoplastic distortions of the crystal lattice in the material. Stress concentrators of the steel under study are intra- and interphase interfaces of grains of ferrite and perlite, cementite plates and ferrite of perlite colonies, globular cementite particles and ferrite. The transformation of the structure is manifested at the macro level in the formation of microcracks at an acute angle to the surface to a depth up to 140 μm, and in the formation of the decarburized layer. At the micro level, the formation of elastoplastic stress fields and the destruction of cementite plates of perlite colonies have been revealed. It is shown that stress concentrators are intra- and interphase interfaces of ferrite and perlite grains, cementite and ferrite plates of ferrite colonies, globular cementite particles and ferrite. In the grains of structurally free ferrite, the formation of nano-sized particles of cementite was observed. The comparison is made with the results of the evolution of structural-phase states in the fillet of volume-hardened rails after the passed tonnage of 500 million gross tones: the most significant transformations of structural-phase states are observed in the surface layers. The evolution of the structural-phase state of perlite of lamellar morphology consists in the dissolution of cementite plates, which leads to the formation of a chain of particles of the carbide phase with globular shape in place of the cementite plate. This is possible due to the transfer of carbon atoms from the crystalline lattice of cementite to dislocations.

The features of macroscopic strain inhomogeneity in the form of Chernov–Lüders bands development on elastic-plastic transition were investigated in the mild steel. The main regularities of nucleation and propagation of the bands are established. Particular attention was paid to the kinetics of moving boundaries (fronts) of bands, characteristic velocities were determined. It is shown that the rate of formation of nucleus of the Chernov–Lüders band is more than an order of magnitude higher than the rate of its expansion. Situations are considered when more than one band develops simultaneously in the object and therefore several moving fronts are observed. It is established that in all cases the velocities of fronts of the Chernov–Lüders bands are mutually consistent so that at any instant the generalized rate of expansion of the deformed zone is a constant value. The effect of the deformation rate on the kinetics of the Chernov–Lüders fronts was analyzed. Both the generalized rate of expansion of the deformed zone and the speed of individual fronts increase with the increase of the loading rate. A  nonlinear (power-law) character of this dependence is established. The fronts of the bands have a complex structure. Different parts of the front can move with unequal velocities, so that the front line is locally curved and split. Ahead of the front, in the undeformed part of the sample, the forerunners may appear, the configuration of which resembles the Chernov–Lüders bands nuclei. When encountering the fronts of adjacent bands are annihilated. Annihilation of the fronts is a complex process, which is also characterized by the formation of a precursor and secondary diffusion Chernov–Lüders bands. These facts demonstrate that a simplified view of the Chernov-Lüders band as a deformed region in a loaded sample, and the front of the band as a boundary between deformed and undeformed zones, should be revised. The microscopic theory of Lüders deformation is based on the avalanche growth of the density of mobile dislocations due to breaking from an obstacles and subsequent multiplication, which is realized simultaneously at the upper yield point within the crystallite (grain). At the same time, to form a mobile macroscopic deformation front it is necessary that plastic deformation should be transferred to neighboring grains without hardening, that is, grain-boundary accommodation is needed. The results obtained in the paper suggest that such a zone of accommodation is apparently the Chernov–Lüders band front, and, therefore, it has a complex structure.

The work is focused on the identification and the analysis of regularities in formation of nanostructured, multiphase surface layers in high-chromium steels 12Cr18Ni10T and 20Cr13 subjected to irradiation with an intense pulsed electron beam (installation “SOLO”). A  thermodynamic analysis of Fe – Cr – C system was carried out. It is shown that carbon-doping of Fe – Cr alloys leads to a significant change in the structural-phase state and has a determining effect on existence regions of carbides Me23С6 , Me7 С3 , Me3 С2 , and Me3 С with α- and γ-phases. Numerical calculations of the temperature field formed in the surface layer of steel during the irradiation with an electron beam were carried out. It is shown that at a beam energy density of 10  J/cm2 , regardless of the pulse duration of the electron beam (50  –  200  ms), the maximum temperature reached at the sample surface by the end of the pulse is below the melting point of steel. At an energy density of the electron beam (20  –  30) J/cm2 and pulse duration of 50  µs the maximum temperature of irradiated surface is equal to the boiling point of steel; at a pulse duration of 200  µs it reaches or exceeds the melting point of steel. The structure, mechanical and tribological properties of surface layer of the samples of high chromium steels 12Cr18Ni10T and 20Ni13 formed under the irradiation with an intense pulsed electron beam were studied. It is established that the electron-beam treatment of steel in the melting mode and the subsequent high-speed crystallization is accompanied by dissolution of particles of the initial carbide phase of the composition Me23С6 ((Cr,  Fe)23C6 ), saturation of the crystalline lattice of the surface layer with chromium atoms, formation of cells of the dendritic crystallization of submicron sizes, and release of nanosized particles of titanium carbide and chromium carbide. Together, this made it possible to increase (relative to the initial state) the strength and tribological properties of the studied materials. For steel 12Cr18Ni10Т, an increase in the hardness of the surface layer by 1.5  times, the wear resistance by 1.5 times, and a decrease in the friction coefficient by 1.6 times are revealed. For steel 20Cr13, an increase in the microhardness by 1.5 times, the wear resistance by 3.2 times, and a decrease in the friction coefficient by 2.3 times are revealed.

A thermodynamic analysis of the physicochemical processes taking place in the converter bath using gas-oxygen burners for intensive bath heating was performed. In the working space of the unit, when the combustion flanks interact with the converter bath, the oxygen supplied by the burners and the natural gas, as well as the oxygen supplied through the tuyere, react in a bubbling slag and metallic emulsion, as a result of which iron and impurities are oxidized. It is established that the use of flank burners changes the composition of the gas phase in which in H2 and H2O, changing the oxidizing ability of the gas phase, are found in addition to O2 , CO, CO2 . The presence of solid carbon (for example, pulverized coal fuel) in the flank burner can control and intensify the burning process. The burning process is the most efficient in the oxidation of carbon to CO with the excess oxygen factor less than 1.0. During melt carbon oxidation at a change in the carbon activity depending on its concentration in the melt and temperature, the oxidation conditions of carbon also change. As a universal characteristic of the description of Me – O – C system equilibrium it is proposed to use the oxygen partial pressure PO2 , as well as the accompanying characteristics PCO /PCO2 and PH2 /PH2O . It is determined that the oxidation of iron can be carried out by oxygen to insignificant degree with carbon dioxide, while water vapor at temperatures of 1600  –  2000  K practically does not oxidize iron. Oxidation of carbon dissolved in the metal is carried out quite efficiently with oxygen and carbon dioxide to the concentration less than 0.1  %. The water vapor is a very poor carbon oxidant, a weak oxidant of manganese and silicon. The intensity of oxidation of oxygen dissolved in the metal of carbon increases with the increase of temperature, of silicon and manganese – decreases. The reoxidized slag with a high content of FeO oxide at temperatures above 1800  K can serve as an oxidizer for: silicon (up to Si <  2 %), manganese (Mn  <  1  %), carbon (C <  1.5 %).

The effect of the B2O3 content and the slag basicity on the viscosity of the CaO – SiO2 – B2O3 system containing 25  %  Al2O3 and 8  % MgO2 was studied using a simplex-lattice method of experiment planning that allows obtaining mathematical models describing the dependence of the property on the composition as a continuous function. Synthetic slags, corresponding to the composition of simplex under study, were smelted in graphite crucibles from pre-calcined oxides. The composition of slags, corresponding to the remaining points of the local simplex plan, was obtained by counter-packing the slags of simplexes. The viscosity of the slag was measured in molybdenum crucibles by means of an electrovibrational viscometer in an argon flow with continuous cooling of the melt from a homogeneous-liquid to a solid state. Mathematical models were constructed that describe the relationship between the temperature of a given viscosity and the composition of the oxide system using experimental data. Then, a set of viscosity isolines was obtained by combining the obtained composition-temperature diagrams of the given viscosity with the isothermal section of the composition-viscosity diagram. The generalization of mathematical modeling results and graphical imaging on the isothermal profile of the composition-viscosity diagram made it possible to obtain new data on the viscosity of the CaO – SiO2 – B2O3 oxide system containing 25  %  Al2O3 and 8  %  MgO in the basic 2  –  5 range and 1  –  10  % B2O3 content. The slags of the oxide system under study in the temperature range of 1400  –  1500  °C are characterized by low viscosity. At a temperature of 1400  °С, the viscosity of slag with basicity 2.0  –  2.5, containing 7  –  10  % B2O3 does not exceed 3  –  4  Ps. The displacement of the slag into the basicity of 3  –  5 is accompanied by a decrease in B2O3 content to 2  –  6  % by increasing the slag viscosity to 12  Ps. An increase in temperature to 1450  °C leads to a significant decrease in the viscosity of slags with basicity of 2  –  3, even for slag with B2O3 content of 4  %, it does not exceed 4  Ps and increases to 6  Ps in the basicity of 3  –  5 and B2O3 content of 1  –  3  %. The slag viscosity in the basicity of 3  –  5 at B2O3 content of 1  –  4  % does not exceed 4  Ps at a temperature of 1500  °С.

Development of new methods for production of continuous cast slab blanks shall not be based on low speed equilibrium crystallization processes in steel. Feeding melt into crystallizer side-wall layers through feed rising construction of submerged nozzle with eccentric outlet holes allows a significant increase in steel crystallization rate during slab casting. The main results of large section slabs casting using new technology providing improvement of their quality are given. When casting steel through an experimental nozzle, considerable decrease in width of columnar crystals zone and increase of disoriented crystals zone are observed, as well as decrease in index of centerline segregation. When casting with a new technology, heat transfer in crystallizer increases by 10 – 12  %. In impact test, a number of qualitative characteristics of metal have been identified that are not captured in other types of tests. The main regularities in metal structure formation in continuous finishing mill group of continuous wide strip mill (CWSM) and subsequent cooling were studied using physical modeling method. Wedge-shaped samples of industrial melted low-carbon steel, withdrawn from semi-finished rolled stock cooled on CWSM intermediate rolling table, were rolled in one and two passes on twohigh speed laboratory rolling mill with a bypass device. Geometric and kinematic resemblance of rolling process was observed. Rolled samples, after fixed exposures on air, were dropped by a special device onto the lateral edge for partial hardening in cooling solution. A  set of relative reductions were received longwise the sample, a set of cooling rates – edgewise. Based on results of physical modeling, the main formation regularities of low-carbon steel structure during rolling and accelerated cooling of strips on continuous wide strip mill were established. Using these regularities and the Hall-Petch equation, it is possible to provide specified structure and flow limit of the finished hot-rolled plate. By eliminating of additional heating of slabs for rolling and improving quality of rolled products, a significant economic effect can be obtained.

The analysis of existing methods of theoretical determination of the resistance of steels plastic deformation revealed a number of significant shortcomings of the loading history, particularly, the lack of consideration the influence of chemical and phase composition of the steel. Due to limitations on the application of these drawbacks do not allow to consider these techniques as suitable for the preparation of reliable predictive values of energy-power rolling parameters according to the newly developed steel grades, in particular for complex-alloyed rail steel. Therefore, the conclusion about the necessity of experimental studies on plastic deformation resistance of steels at various combinations of temperature and speed of rolling, the degree of deformation and varying the chemical composition of steel was made. These studies applied to E78KhSF steel were performed using the complex for physical modeling for thermomechanical processes “Gleeble System 3800”. On the basis of mathematical processing of the experimental data the technique of numerical determination of the resistance of rail steel to plastic deformation under varying thermomechanical rolling parameters (temperature, speed and degree of deformation) and volatile chemical composition of steel was carried out. The nature of the experimental dependences indicates a decline in resistance to plastic deformation of E78KhSF steel with increasing temperature deformation in the rolling temperature range and improving the resistance to plastic deformation with increasing strain rate in the range of variation of this parameter in the rolling mill, which is consistent with the generally accepted views. Experimental evidence suggests the pronounced nonlinear character of dependence of the resistance of E78KhSF steel to plastic deformation on the degree of deformation that indicates the occurrence of dynamic recrystallization in addition to the dynamic recovery and polygonize. Analysis of the chemical composition of E78KhSF steel influence on the resistance to plastic deformation indicates an increase of this characteristic by increasing the concentration in the steel of carbon, manganese, sulfur and phosphorus, and decrease in resistance to plastic deformation by increasing the vanadium content in the steel. The obtained data on the absence of influence of the change in the concentration of silicon and chromium (within the interval of variation meeting the requirements of standards) on the resistance to plastic deformation of E78KhSF steel make it possible to draw a conclusion about the possibility of using the developed calculation technique for determining plastic deformation resistance of rail steels not alloyed by these elements. The adequacy of the proposed method was confirmed by studies of power parameters of rolling at the existing universal rolling mill of JSC “EVRAZ ZSMK” for steels with different chemical composition.

The description of a single-roll crusher developed at Siberian State Industrial University with a forced feeding of the crushing material into the fracture zone due to the abutment located on the roll is provided. The forces acting on the crushed material from the side of the roll and the fixed cheek are defined in function of the force magnitude acting on the material from the side of the stop. On the basis of the obtained results, it is determined that when the force applied on the side of the abutment is constant, the friction coefficient between the cheek and the material to be crushed decreases, the forces acting on the fractional piece on the side of the roll and the cheek increase. It results in the reduction of energy consumption required for crushing of all other things being equal, which lowers the energy capacity of the single-roll crusher operation with forced feeding of material into the crushing zone.