Modern equipment for contact butt welding of railway rails has a huge number of technological parameters (input factors) that affect the quality of the resulting welded joint. These parameters do not allow the optimal welding modes to be fully selected. The study of the processes occurring in the spark gap (formation of microcontacts, increase or decrease in their cross-sectional area, explosion of the resulting microcontacts) will make it possible to determine the amount and uniformity of the invested heat during rail welding. The acquired knowledge will reduce the number of influencing factors on quality of the welded joint. Using a large amount of statistical data, the authors have investigated the processes occurring in the spark gap during contact butt welding of railway rails of R65 type of DT350 category on K1000 rail welding machine. When studying the influence of movable plate movement of the welding machine during reflow on the strength of welding current, it was determined that there is no dependence between these values. The random nature of distribution of the welding current values is assumed, changing as a result of the processes of formation, existence and explosion of a large number of tiny electrical contacts. Based on the analysis of frequency distribution, it is certain that distribution of the spark gap resistance does not correspond to the normal distribution law. As the sample increases, the deviation from it increases; visually the histogram describes the gamma distribution. With the help of the gamma distribution law, the welding current forces during contact butt welding were modeled by reflow. The research results are planned to be used to simulate thermal processes and formation of the structure of weld metal and the zones of thermal influence of railway rails welded joint. 

From the point of metallurgical heat engineering, the Romelt process is promising for processing industrial waste, poor ores and secondary metals without their preliminary preparation and the use of coke. But one of the main disadvantages of this process is high specific consumption of oxygen and fuel for the production of 1 ton of primary metal. The peculiarity of the Romelt process is that the main amount of heat required for implementation of the technological process is supplied to the bubbling layer from the superlayer space due to afterburning of the exhaust gases with technical oxygen. Heat transfer is carried out by a radiation-convective mechanism. Any changes in the afterburning process are possible, if they do not entail an unacceptable change in temperature in combustion zone. In the work, a study was conducted to reduce the specific oxygen consumption per  1  ton of primary metal, based on the data of melting a mixture of blast furnace and converter slurries for pig iron. The authors studied the possibility of reducing the specific oxygen consumption supplied to the superlayer space of the furnace for afterburning gases leaving the bubbling layer during the Romelt process. When using blast heating supplied to the lower tuyeres and oxygen heating supplied to the afterburning zone, it is possible to reduce the specific oxygen consumption per 1 ton of cast iron by 11 % without reducing the furnace performance. In the afterburning zone, it is recommended to use oxygen heated up to 400 °C in the recuperator with simultaneous supply of a blast heated up to 600 °C to the lower tuyeres.

The study presents the method for calculating the distribution of dust and aerosol particles entering the external air environment as a result of man-made emissions of metallurgical cycle enterprises. The paper proposes the method for predicting the degree of pollution of the enterprises influence zones by constructing geographical maps-schemes of industrial regions with application of the areas with a high content of dust particles on them. This method is based on determination of the sedimentation time of dust particles of different fractions in atmospheric air using Stokes’ law (motion of solid particles in liquid or gaseous media), the height of dust particles departure from the chimney and the speed of prevailing wind over the studied period of time. The data necessary for the analysis (wind direction, amount of dust emitted, its fractional and chemical compositions) were found in open sources, reports of the enterprise, statistical data of the region and the metallurgical industry. An estimated calculation of the spread of dust emissions was carried out on the example of the Magnitogorsk Iron and Steel Works PJSC (MMK) during various annual seasons. It was found that the influence of activity of a metallurgical enterprise in Russia can adversely affect cities and residents of neighboring states that are located in the sedimentation zone of solid dust particles. The issue of transfer of sulfuric and nitric acids by dust particles formed in the pores of aerosol particles is considered. The authors calculated the amount of acid that can be carried into the zones of influence of the enterprise in the pores of solid dust particles. The considered calculation model makes it relatively quick and easy to assess the influence zone of the enterprise, assess risks and take measures to  modernize, optimize the production process or aspiration systems.

High-current pulsed electron beam surface treatment is a method of materials modifying, which improves the mechanical properties of metal materials. Due to high-speed heating, evaporation, recrystallization, as well as plastic deformation, dislocations with high density are formed in the surface and, as a result, an increase in indicators of various physical and mechanical properties, such as hardness, wear resistance, etc., is observed. Since currently high-entropy alloys are a relatively new class of materials, the effect of pulsed electron beam treatment on the dislocation substructure has not yet been established. In this work, a non-equiatomic high–entropy alloy of the Co – Cr – Fe – Mn – Ni system, made using a wire-arc additive manufacturing, was subjected to surface treatment using a high-current pulsed electron beam with an energy density 
of 30 J/cm². By the method of studying thin foils using transmission electron microscopy, it was found that the treatment does not affect the chemical composition of the alloy, but leads to serious changes in the dislocation substructure. A nonmonotonic change in the scalar density of dislocations was revealed, reaching a  maximum value of 5.5·1010 cm^–2 at a distance of 25 µm from the irradiation surface. It is shown that an undirected cellular dislocation substructure with cell sizes from 400 nm to 600 nm is formed at this distance from the surface. With further distance from the surface at a distance of up to 45 µm, the dislocation substructure changes from cellular to cellular-mesh. At a distance of 120 – 130 µm, the effect of a high-current pulsed electron beam is not observed – the substructure corresponds to the substructure of the initial alloy with a chaotic distribution of dislocations.

The authors investigated the nature and kinetics of the moving fronts of localized deformation, which are formed at the elastoplastic transition in materials with dislocation and martensitic micromechanisms of plastic deformation under active tension at different velocity. Digital image correlation was used for registration and quantitative specification of front movement. Attained results were discussed under synergistic approach. A deformed subject is considered as open and far-from-equilibrium system (active medium) containing distributed potential energy source stress, which are microconcentrators. In process of external influence these concentrators relax through microslip and cause a form change of the object itself. Each microconcentrator can be considered as an active element, it has two states: metastable elastically stressed and stable relaxed. In external influence, transition is possible only from the first state to the second. Such elements are characterized as trigger elements and active medium is characterized as a bistable medium. In bistable media, switching autowaves propagate. They represent moving boundaries, which separate metastable and stable states. Within this concept considered fronts of localized deformation can be interpreted as switching autowaves. The study showed that shape and kinetic parameters of fronts of localized deformation do not depend on chemical composition, structure and micromechanisms of deformation, it confirms their autowave nature. On the other hand, the kinetics of switching autowaves should be determined by characteristics of the external influence. Genuinely, velocity of localized deformation fronts increases with deformation velocity. It is found that dependence of these fronts on deformation velocity is non-linear parabolic with index less than one and equally for all examining materials.

Based on the state diagrams of two–component silicate systems SrO – SiO₂, BaO – SiO₂, CaO – SiO₂, the authors have determined the activity of components in invariant (eutectic and monotectic) points of the systems under consideration. Crystallization processes at invariant eutectic points l₁ and l₂ are considered as chemical reactions l_e1 (KSiO₂(l) + lMeO(l)) → CSiO₂ (sol) + α(MeO·SiO₂)(sol), l_e2(mSiO₂(l) + nMeO(l)) → (MeO·SiO₂)(sol) + b(2MeO·SiO₂)(sol), for which the values ΔG^°_T and the equilibrium constants were established. The values of a_MeO in the slags were determined at given temperatures and known values of the component activities in metal melts in equilibrium with slag. In homogeneous slag melts, the activity of alkaline-earth metal (AEM) oxides was defined from the constants of equilibrium reactions of reduction of these metals from slags by silicon of iron-silicon metal melts. In the zone of homogeneous slag melts, the dependences a_SiO2 = f (x_(SiO2 )) were constructed at temperatures of 1600 and 1700 °C, and when using data on the activities of AEM (Sr, Ba, Ca) in metallic high-silicon melts, the dependences lga_(SrO) = f (x_(SiO2 ), x_(Si)) at 1493 °C and lga_(BaO) = f (x_(SiO2 ), x_(Si)) at 1450 °C were determined. On a three-parameter diagram in coordinates a_[Si] – a_(SiO2 ) – a_(MeO) (for AEM), the dependencies a_(SrO) = f (a_[Si], a_(SiO2 )) at 1493 °C and a_(BaO) = f (a_[Si], a_(SiO2 )) at 1450 °C were constructed. It is shown that low equilibrium values of a_(SrO) and a_(BaO), lga_(SrO) = f (a_(SiO2 ), a_[Si]) ≤ (–4) and lga_(BaO) = f (a_(SiO2 ), a_[Si]) ≤ (–3), can be achieved at equilibrium values of silicon activity in metal melts a_[Si] > 0,5 during strontium reduction and a_[Si] > 0,7 during barium reduction.

The paper considers the main problem of improving quality of steel sheets for welded pipes obtained at plate rolling mills and the main reasons that reduce it. There is a possibility of improving quality of steel sheets using technological capabilities of the unit of combined continuous casting and deformation. Problem of determining stress state of metal in cyclic deformation zone is posed and solved. The results of obtaining 09G2S sheet steel in pilot unit of continuous casting and deformation are presented. Magnitude of stresses in the center of cyclic deformation during production of steel sheets was determined for welded pipes at the unit. The authors present results of experimental study of the process of steel sheets production at pilot unit of continuous casting and deformation. The article considers the results of microstructure analysis, microhardness determination and microanalysis of chemical composition of the studied steel in various zones of the strip cross section. Structural inhomogeneity development in ferritic-pearlitic steel is interpreted along the thickness of sheet under conditions of combined thermomechanical processing of metal solidified in the mold. Predominantly ferritic microstructure is generated in the central light interlayer of the strip compared to base metal, characterized by a sharp decrease in carbon concentration in it. There is a possibility of such structure genesis at the first stages of crystallization during forging of low-carbon steel, when the excess phase of high-temperature ferrite that solidifies first is located mainly in the strip center. The size of pearlite grains in the light interlayer covariates with the grain structure of pearlite in the strip base metal and does not form precipitates of lath morphology, which increase tendency of steel to brittle fracture.

Recently, researchers have been paying more and more attention to the influence of internal and external factors on stress state of shell mold (SM). Internal factors should include morphological structure of SM, its types and connections between the contacting layers. External factors should include all types of force and temperature effects on SM external surface. The purpose of this work was to establish the sliding effect of SM internal layers in contact with each other on the level of SM stress state. The mathematical model for determining the stress-strain state (SSS) in the multilayer SM when it is filled with a liquid metal is presented. Moreover, the SM is made in such a way that its layers can slide relative to each other with the presence of friction. This work is a continuation of the recent works of the authors, where the influence of the temperature factor on the studied SM was estimated. At the same time, SM layers have the same physical and mechanical properties. The problem was solved in the same formulation as in the previous works of the authors. The task was set to determine the influence of the support filler (SF) and the clamp in the upper part of SM on SSS in its sections. The influence of SF was estimated by the amount of friction between the outer surfaces of SM and SF. Just as in the previous works of the authors, the linear theory of elasticity, heat conduction equations, and numerical methods were used to solve the problem. On the contact of  SM outer surface with SF surface, the contact problem was solved. Solid phase in the liquid metal during cooling was determined from the equation of interphase transition. Results of the calculations are presented in the form of graphs and plots. It is shown that the absence of friction between the layers reduces the crack resistance of SM multilayer.

The emerging growth of industrial and civil construction in Russia and introduction of new technologies have caused the need to increase the production of construction rolled products and, especially, rebar. One of the ways to increase rebar production at existing mills in the shortest possible time without serious capital investments is the use of rolling – separation technology. For successful implementation of this technology, the conditions for the feasibility of this process are given in this report. New dependences were obtained for determining the longitudinal force provided by the reserve of friction forces during formation of an articulated profile taking into account the profile shape and the conditions of shape change.