The Bauschinger effect is a phenomenon of a decrease in material resistance to small plastic deformations after preliminary plastic deformation of the opposite direction, discovered in 1881. This effect is of great importance and is used, in particular, in studying the fatigue strength of materials under alternating loads. The Bauschinger effect is inherent in all metals and alloys, although it is most pronounced in steels. Therefore, it is one of the factors affecting the quality of finished metal products subjected to alternating loading during manufacture. This review analyzes the literature data on the problem of the Bauschinger effect in the case of alternating deformation of metals. Various mechanisms explaining the Bauschinger effect are briefly considered. The factors that qualitatively and quantitatively affect the Bauschinger effect are described in detail, namely the degree of preliminary deformation, composition, structure and properties of the material, deformation conditions, the phenomenon of dynamic deformation aging, and temperature. The problem of the Bauschinger effect in the case of alternating deformation of steel products is considered, in particular, in the production of oil and gas pipes of large diameter. Various methods and approaches to the evaluation and quantitative measurement of the Bauschinger effect are described; the dependence of the Bauschinger parameter on the value for residual deformation is shown. It is concluded that the Bauschinger effect plays both a positive and a negative role in the production of metal products, in particular oil and gas pipes. On the one hand, the Bauschinger effect has a negative effect, reducing the level of mechanical properties of the final product below the required one. On the other hand, it creates a certain margin of plasticity of the deformable material in the process of forming and laying pipes.

The coating of a high-entropy alloy (HEA) of non-equiatomic composition was formed on a substrate of alloy 5083 using the technology of wire-arc additive manufacturing (WAAM) in an atmosphere of pure nitrogen. Analysis of the structure, elemental composition, micro-hardness, and wear resistance of the coating/substrate system was carried out using the methods of modern physical materials science.

X-ray diffraction (XRD), X-ray fluorescence (XRF), scanning electron microscopy energy dispersion spectroscopy (SEM–EDS), and differential thermal analysis (DTA) measurements were used to investigate the mineralogical characteristics and distribution of data set in limonite soil from Indonesia. The findings point to a complicated inner core in laterite ore. Ni, Fe, Mg, Al, and Si levels in limonite are 1.4, 50.5, 1.81, 4.86 and 16.5 wt %, respectively. The iron oxide/oxyhydroxide content of limonite is 94.4 and 5.6 % silicate. DTA shows that limonite has a phase transition in the low temperature (200 – 300 °C) with the goethite transformation to hematite. This phase is good optimalization for nickel diffusion in the iron. Moreover, for this limonite, the thermal upgrading was used as a good method.

The company "Rifar" is a domestic manufacturer of a new series of bimetallic and aluminum sector radiators of high quality. Production of bimetallic heating radiators is carried out using a hydraulic press. For the least adhesion of the alloy to the molds walls (especially when casting aluminum) the lubrication of the molds with a separating lubricant is used to reduce the wear of molds and refills on the blanks. Currently, the lubrication of the molds is used. Separating lubricant for the molds is taken from the individual intermediate tank standing near each foundry complex. In this case, the lubricant is filled once, and it is used throughout the shift. After that, the tank with the help of forklifts is sent to refueling. To increase the operational reliability and ease of maintenance of foundry complexes, it is proposed to replace the individual supply of separating lubricant to the molds of foundry complexes with a centralized supply system. As a result of development of a system for the centralized supply of separating lubricant to casting complexes molds, it was possible to simplify the lubricant supply scheme, to reduce fuel costs and maintenance complexity. Replacing the individual supply of the separating lubricant to the molds of the casting complexes with the centralized supply system improves the reliability of separating lubricant supply to such complexes molds. Calculations showed that implementation of design solutions does not require large capital expenditures, and as a result of the implementation of the proposed measures, the production cost will decrease by 0.02 %; the payback period of the proposed investment project does not exceed 1 month.

Optimization of the technological process of manufacturing long-length rail lashes is a difficult task, since in addition to a large number of operations, the equipment used today for contact butt welding of railway rails by pulsating reflow has a large number of technical parameters (input factors) affecting the quality of the resulting welded joint (output factors). Such a number of parameters does not allow us to fully select the optimal welding modes and leads to the impossibility of using a full or fractional factor experiment. In the work, data processing of 79 experimental welds was carried out using regression analysis. The main stages of the welding process are highlighted: the first stage is melting; the second stage is melting, forcing, precipitation. Based on the obtained oscillograms of the welding process on the K1100 rail welding machine, average values of current, voltage, speed of movement of the movable bed were obtained at various stages of melting, as well as precipitation forces, precipitation time under current, precipitation paths at the last stage when welding R65 rails of the DT350 category. The obtained regression equations determining the results of tests for static three-point bending were analyzed and unsatisfactory parameters according to the Student’s t-criterion were excluded from them. These equations in the end take into account the influence of each technological stage of the process of contact butt welding of railway rails on the output properties and the model is adequate according to the Fischer’s F-criterion. With the help of these regression models, the recommended modes of contact butt welding by pulsating reflow were obtained and their testing was carried out at a rail welding company.

The improved performance properties of metals are ensured by introducing into them certain set and amount of alloying elements. Nitrogen, which is an area of growing interest, is one such element. Publications show that nitriding with gaseous nitrogen is also used for plasma-arc remelting. They provide data on metal alloying with nitrogen at the granules and powders production stage. This paper studies the process of nitriding in obtaining metal microgranules from EP741NP alloy by means of plasma centrifugal atomization. Metal powders are obtained by melting the end face of a rotating workpiece with a stream of ionized gas (gas mixture). The technology allows for nitrogen-alloyed fine metal powders of multicomponent alloys of spherical shape with a minimum number of satellites, which do not differ in size or chemical composition, to be obtained. The study of the nitriding rate is of great interest, especially in production of powder metal. One parameter which affects the degree of metal saturation with nitrogen is the residence time of the liquid melt under the nitrogen-containing plasma, and the crystallization time of a metal droplet. This paper presents a methodology which allows quantification of the role of these parameters on the absorption of nitrogen by the metal in obtaining powder. The kinetic parameters of the nitriding process are influenced by the interface area of two metal – gas phases. In the case of obtaining powder, this parameter depends on the size of the powder particle. In this regard, this paper presents a calculation method which allows the average fractional composition of metal powders to be estimated depending on a number of process factors. The values obtained are compared with the data of semi-industrial melting. It is demonstrated that the fractional composition of microgranules depends on the rotation speed and diameter of the workpiece to be remelted, as well as the alloy density and the surface tension force. It has been established that by increasing the rotation speed of the consumable electrode it is possible to achieve a decrease in the dispersiveness of metal powders.

Metallurgical plants in the Urals are experiencing a shortage of iron ore. This has been compensated by the use of materials imported from Central Russia, the Kola Peninsula and Kazakhstan. Replacing them with local resources would increase the competitiveness of the metal produced in the Urals, which makes the question of assessing the possibility of replacing imported resources with local ones very relevant. Siderite ores from the Bakal deposit could be such resources. They are not in demand among metallurgists because of their low iron and high magnesium content. Calculations of blast furnace smelting made with the help of a balance logical-statistical model showed that additions of calcined and metallized concentrates improve performance. However, with increasing amount of siderites in the charge, the content of magnesium oxide in the slag increases. This in turn affects the viscosity and makes it difficult or impossible to smelt using more than 20 % siderites. The use of boron oxide for slag liquefaction is proposed. Thermodynamic modeling has been used to evaluate the effect of adding 1 – 3 % B₂O₃ to the charge on  chemical composition of the slag and the distribution of boron between the metallic and oxide phases. It is shown that in the process of smelting, Boron is reduced from the slag phase, resulting in its partial transition into metal. This causes a decrease in the B₂O₃ content in the final slag. A comparative analysis of the calculated and experimental data shows a similar content of boron in metal, which has been determined both theoretically and experimentally. This should be taken into account when calculating the charge. According to the data obtained, the main reducing agent of boron is silicon, while experimental data show that it is carbon.

The problem of depletion of available mineral resources is identified and the reasons for its actualization are characterized due to incomplete extraction of metals from mined ores. It is noted that the strategy of the mining industry may be the use of unconventional technologies of metal extraction within the framework of combining traditional technologies with innovative leaching ones. It is proved that utilization of enrichment tailings, formation of the processes algorithm and engineering forecast of the prospects of the new technology are the real directions of mining production development. The paper considers a method of experimental substantiation of the possibility of waste-free utilization of ferruginous quartzite dressing tailings from the Kursk Magnetic Anomaly. The planning matrices and the results of comparing the technologies of traditional leaching of dressing tailings in conditioners and leaching in a high-speed disintegrator mill are presented with regression analysis of experimental data and graphical interpretation. A reference is given on the processes of mechanical activation, as a real opportunity to improve the indicators of  the processing metal-containing raw materials, including involving dressing tailings in production. The experimental results obtained can be used in hydrometallurgical processes, including leaching of metals from dressing tailings, increasing the extraction of metals with a higher content. The  paper considers the data on the metals content in secondary tailings after leaching in a disintegrator with mechanochemical processes activation. The directions of improvement of preparation of metal-containing raw materials for leaching in conditioners – disintegrators are indicated. The economic efficiency of waste-free disposal of dressing tailings is composed of the cost of extracted metals, raw materials for related industries and reducing environmental damage from the storage of toxic tailings of primary processing.

The simplest model of the structure and interatomic interaction is applied to hydrogen solutions in liquid alloys of Fe – Ni system, which earlier (2019 – 2021) was used by the authors for nitrogen solutions in alloys of Fe – Cr, Fe – Mn, Fe – Ni, Ni – Co and Ni – Cr systems. The theory is based on lattice model of the Fe – Ni solutions. The model assumes a FCC lattice. In the sites of this lattice are the atoms of Fe and Ni. Hydrogen atoms are located in octahedral interstices. The hydrogen atom interacts only with the metal atoms located in the lattice sites neighboring to it. This interaction is pairwise. It is assumed that the energy of this interaction depends neither on the alloy composition nor on the temperature. For simplicity it was assumed that liquid solutions in the Fe – Ni system are perfect. Within the framework of the proposed theory an expression is presented for the Wagner coefficient of interaction between hydrogen and nickel in liquid steel. The right-hand part of the appropriate formula is a function of the ratio of the Sieverts law constants for hydrogen solubility in liquid iron and in liquid nickel. The values of these constants for a temperature of 1873 K are taken equal to K′_H(Fe) = 0,0025, K′_H(Ni) = 0,0040 wt. %. At the same time, an estimate was obtained for the Wagner coefficient of interaction between hydrogen and nickel in liquid steel  ε_H^Ni = –0,54. This corresponds to the value of the Langenberg interaction coefficient e_H^Ni = –0,002, wich is very close to the experimental estimate e_H^Ni = –0,0022.