At present, the cross-section profile of the rolled strip is characterized by geometrical parameters such as wedge, convex, difference of thickness, displacement of convex, and edge wedge. Some of these parameters are redundant. Techniques for calculating the values of these parameters are known and generally accepted. However, there are features of the cross-section profile of rolled strips, such as local thickenings/thinnings, the methods of calculating values of which are not common: practically every scientific school of rolling scientists or specialists of rolling production use their own techniques, which often produce different results for the same cross-section profiles. The problem of identifying and calculating the local thickenings/ thinnings parameters of the rolled strips cross-section profile is to define a so-called “zero level”, the excess/understatement of which is a sign of local thickenings/thinnings. The paper continues to analyze the accuracy and adequacy of the calculation of the cross-section profile parameters of rolled strips for local thickenings/thinnings. A new method based on statistical methods is proposed. The target function that the thickness distribution across the width of the rolled strip must correspond to is a symmetrical quadratic parabola. However, the actual distribution is always different from the target one for a number of reasons, such as ring wear of the work rolls. In the first step, in the proposed technique, the Walter-Shuhart procedure (control cards) eliminates as emissions of strip thickness values that are dramatically different from the target distribution. But since without excluding the nonlinear (parabolic) component of the measured cross-section profile this procedure cannot be applied, it applies to the first derivative of the cross- section profile thickness distribution function. To determine the “zero level,” after calculating the upper and lower limits of the allowed values of the first derivative, all thicknesses associated with these emissions were eliminated. The result of the repetitive process is a “zero level” according to which the local thickening/thinning parameters are calculated.

Titanium dioxide is the most common titanium-containing product on the world market, and the demand for it is increasing. The global consumption of TiO₂ is 7 – 7.5 million tons annually. Titanium dioxide is mainly obtained from ilmenite and rutile concentrates. The largest producers are China, USA, Germany, UK, Mexico, and Saudi Arabia. In addition to the natural resources of titan, there are man-made sources. This type of resource includes titanium-containing slags obtained as a result of pyrometallurgical processing of ores and concentrates containing titanium dioxide. These slags, in addition to titanium dioxide, contain silicon in the form of dioxide, silicates or aluminosilicates, whose chemical processing is difficult due to their high melting point (more than 2000 °C) and the chemical stability of these compounds in mineral acids (sulfuric, nitric, hydrochloric). Processing of such raw materials is carried out by “classical” chlorine and sulfuric acid methods. The use of fluorides in industry is realized in the production of aluminum, zirconium, uranium, beryllium, niobium, etc., which indicates the possibility of using fluoride methods for titanium slags processing. The article discusses a method for producing titanium dioxide based on the use of ammonium hydrodifluoride NH₄HF₂ , which has a high reactivity to a number of chemically resistant oxides (oxides of silicon, titanium, aluminum, etc.). The fluoroammonium method for processing titanium slag using NH₄HF₂ involves slag decomposition of in NH₄HF₂ melt followed by silicon admixture sublimation. Cleaning from iron, aluminum and other impurities is carried out using a solution of NH₄HF₂. Further precipitation of titanium with treatment of the precipitate by AlCl₃ and ZnCl₂ solutions followed by calcination allows to obtain a rutile modification of titanium dioxide.

The sintering intensity is an important factor determining techno-economic efficiency of sinter production which provides the blast-furnace process with the main type of agglomerated iron ore raw materials. The charge sintering rate depends on technological parameters of the sintering process. Therefore, a systematic study of sintering technological parameters, which determine its intensity, is of practical and scientific interest. Indicators of the sintering process intensity are considered that assess it from both the mechanical and heat engineering positions. It is shown that in its purest form the sintering process intensity is characterized by the vertical agglomeration rate and combustion intensity of the sintering charge carbon. Two other indexes − the specific productivity for suitable sinter and intensity of heat output in the combustion zone – are less representative for the comparative estimation of sintering intensity, since their values depend on sintered mass strength and thermal effect of carbon combustion respectively. These factors go beyond the essence of the sintering intensity concept. Since content of fines of 5 – 0 mm at different sinter plants is not equal, representative performance comparison of sintering process is possible only taking into account the total amount of fines generated throughout the agglomerate transport path from sinter machine to blast furnace or the results of testing the agglomerate strength in a drum. A comprehensive systematic classification of techniques has been developed to intensify the sintering process based on the material-component principle using four levels of separation – objects, directions, paths and methods in which each subsequent level concretizes and develops the previous one. Its value is universality, which makes it possible to apply a systematization and separation system for almost all already known and future methods of sintering process intensification.

The actual problem of mineral resources depletion in ferrous metallurgy can be effectively solved by complex reuse of technogenic waste. That waste is mostly presented by EAF (electric arc furnace) slag and LF (ladle furnace) slag. These two kinds of slag have no complex full utilization. The residues of slag are going to the dump and then the slag dump locations pollute the environment. However, the residues of EAF and LF slag can be transformed into the valuable industrial product by interaction of the slag components. This work presents the research for joint wasteless processing of EAF and LF slag with production of Portland clinker and cast iron. The article describes disadvantages of known methods of each slag processing; the paper also shows the significance of LF slag utilization. Design and calculations of the research are presented as well as its experiment methodology. The final results show five chemical compositions for the mixtures, which allow the complex processing of this slag without any waste left. Such processing provides the production of cast iron and Portland clinker both meeting requirements of normative documents. The paper also describes the results of viscosity measurements of slag compositions, the obtained slag phases, and presents the final temperature conditions. The work also considers the results of industrial tests for the developed processing technology and a complete technological chain involving the use of tilt rotary furnaces.

Features of the chemical composition and structural-phase state of samples of steel 18Cr-10Ni (AISI 304) were investigated, which could contribute to the occurrence of general corrosion damage and the pittings formation on parts made of this steel under the influence of an aggressive environment. It has been established that the sulfur content in steel is almost 10 times higher than the level established by the standard for this steel (0.03 % S), therefore, it contains about 3 vol. % of manganese sulfides, 1 – ~ 50 μm in size, forming stitches and accumulations along direction of rolling. According to the literature, it is the particles of manganese sulfide (MnS) that are most corrosive in corrosion-resistant steels and alloys. They significantly reduce the ability of Fe – Cr – Ni steels to passivate in a corrosive environment. For the formation of FeSH⁺ ions, a high concentration of S2– ions is required. The larger the inclusions of sulfide particles are, the higher is their ability to reduce the corrosion resistance of steel. Therefore, the large size of MnS particles found in steel plays an important negative role. It is shown that an additional factor contributing to a decrease in the corrosion resistance of the studied steel is the presence of deformation martensite in the surface layer of the steel, which was formed in the process of machining during manufacturing by cutting and grinding parts from a billet. The appearance of this martensite is due to the low concentration of austenite-forming elements (0.01 – 0.04 % C, 7.96 – 8.23 % Ni). The steel on the modified Scheffler-Delong diagram is in the region where martensite can form; the calculated value of М_d(30/50) for it was 28 °С. According to literature data, deformation martensite in steels of 18-10 type causes a decrease in their resistance to pitting corrosion in solutions of acids and salts. It is shown that the presence of an electric potential activates the corrosive effect on 18Cr-10Ni steel samples in an acidic environment. It is concluded that the corrosion damage of parts made of the studied steel was facilitated by the presence of accumulations of sulfide particles in individual areas of the metal, combined with the presence of deformation martensite in these areas.

 The graphitized steel has attracted considerable attention due to its excellent cutability and good properties at cold forming. Compression deformation at room temperature of graphitized steel (0.43 % C) with a ferrite-graphite microstructure was performed on a universal testing machine. Microstructures of deformed samples were studied using the analysis technique of Electron Back-Scattered Diffraction (EBSD). The evolution of microstructure morphology, texture, distribution of Kernel Average Misorintations (KAM) and the Taylor factor in the zone of large deformations of deformed samples with different degrees of deformation is discussed. The results show that the studied steel has a good ability to compression deformation. During compression deformation, with an increase in deformation degree the deformation morphology of the ferrite grain and graphite inclusions gradually stretch in the direction perpendicular to the compression axis and they are represented as fibrous forms. The orientation of ferrite grains in the matrix is gradually obvious, and the orientation of ferrite grains around graphite inclusions is not obvious, that is, the number of grains oriented to <100>, <111> in the matrix is much greater than around graphite inclusion. In addition, KAM and the Taylor factor in the large deformations region of compression samples show that the deformation degree of ferrite grains around graphite inclusions is less than that of ferrite grains in the matrix. The reason for this is that the soft graphite inclusions can reduce the degree of dislocation pile-up.

The simplest model of the structure and interatomic interaction is applied to nitrogen solutions in liquid alloys of Fe – Ni system, which earlier (2019) was used by the authors for nitrogen solutions in alloys of Fe – Cr system. The principles of statistical mechanics are used in this model. Thus, three formulas were obtained. The first formula expresses the Sieverts law constant for the solubility of nitrogen in liquid nickel through a similar constant for the solubility of nitrogen in liquid iron and the Wagner interaction coefficient of nitrogen with nickel in low-concentration liquid iron-base alloys. The second formula expresses the partial enthalpy of dissolution of nitrogen in liquid nickel during the formation of an infinitely dilute solution through a similar value for dissolution of nitrogen in liquid iron and the Wagner interaction coefficient of nitrogen with nickel in iron-base liquid alloys. The third formula expresses the Wagner interaction coefficient of nitrogen with iron in low-concentration liquid nickel-base alloys through the Wagner interaction coefficient of nitrogen with nickel in liquid iron-base alloys. The constant of the Sieverts law for the solubility of nitrogen in liquid iron at T = 1873 K is assumed to be 0.044 mass. %. The partial enthalpy of dissolution of nitrogen in liquid iron assumed to be 5.0 kJ/mol. For Wagner interaction coefficient of nitrogen with nickel in iron-base liquid alloys at 1873 K three variants of values were studied: 2.4, 2.6, and 2.85. For the first option, theoretical value of the Sieverts law constant for solubility of nitrogen in liquid nickel at T = 1873 K, equal to 0.00195 mass. % was obtained. Theoretical value of the enthalpy of dissolution of nitrogen in liquid nickel is 52.7 kJ/mol. Theoretical value of the Wagner interaction coefficient of nitrogen with iron in nickel-base liquid alloys is –4.0. The agreement of theory with experiment seems to be satisfactory.

The significance of research on recovery of metals from oxide melts is primarily associated with pyrometallurgical processing of ferrous and non- ferrous metals. The main task during the processing of oxidized nickel ores is to increase the extraction of valuable metals with the required (10 – 20 %) nickel content in ferronickel and a minimum amount of impurities. The indicators achieved during the reduction of iron and nickel from oxide melt were evaluated by the thermodynamic simulation methods. Two series of calculations were carried out. In the first series, the working medium composition was changed by the amount of iron and nickel oxides at a С_FeО / С_NiО ratio equal to 10. In the second series, at a С_NiО content equal to 1.8 %, С_FeО value for С_FeО / С_NiО ratios was varied from 10 to 20. A dosed increase of CO amount in the working medium made it possible to trace the changes in compositions of oxide (С_МеО ) and metal (С_Ме ) melts, as well as the transition degrees of nickel (φ_Ni) and iron (φ_Fe) to the metal state. The С_NiO , φ_Ni = f (C₀ , V_CO ) correlation dependences are presented in form of the second-degree polynomials. The φ_Ni and φ_Fe indicators are changed with amount of introduced reducing agent, but it depends little on the initial condensed phase composition. The composition of the formed Fe – Ni alloy is affected by the content of elements in the initial melt and amount of the introduced reducing agent. Alloys are characterized by the high (65 – 90 %) nickel content. The φNi value of about 98 % was achieved with the amount of introduced CO of about 80 m³ per ton of melt. In this case, the degree of iron reduction was no more than 5 %. When the С_FeО / С_NiО ratio is 10, the nickel content in the alloy is practically independent of the content of its oxide in the initial ore melt and is close to 65 %. An increase in the С_FeО / С_NiО ratio from 10 to 20 leads to the change in С_Ni from 68.5 to 52.9 %, respectively. The data obtained are significant for substantiation of the technology for processing low-quality oxidized nickel ores with the release of the required ferronickel composition.

The chemical process appearing at thermal contact of hematite with carbon monoxide was modeled using TERRA software package. In this case, the molar ratio of CO/Fe₂O₃ components varied in the range of 1 – 15, and the process temperature – in the range of 25 – 1500 °C. Carbon monoxide at normal temperature decomposes almost completely to form carbon and carbon dioxide (the Bell-Boudoir reaction). When the process temperature increases, this carbon consistently participates in formation of the phases of magnetite, iron and cementite, and carbon dioxide participates in vustite formation and in iron decarburization. The carbon monoxide does not directly participate as a reducing reagent in local chemical reactions of this process.

To select the compositions of high-entropy alloys (HEA) consisting of five or more elements, it is necessary to use methods that take into account many variables and the complexity of assessing the relationships between them. Based on chemical information approaches to the analysis of Web of Science databases, data on the frequency of use of chemical elements in the described HEAs were obtained, which allow us to determine trends in the research and development of new materials.

A significant influence on stability of the process of filling the CCM mold with liquid metal is exerted by the structural and technological schemes and designs of used devices, modes and parameters of filling the mold with the melt. All this is due to the features of the devices used and the improvement of their design. The high requirements for such devices have determined the need to create new devices designs to reduce the time spent on preparation for work and maintenance and to improve the quality of resulting metal billets. In scientific literature, including patents, more and more articles and materials are devoted to the development of new and improvement of the existing methods of supplying and stirring liquid metal in CCM and devices for their implementation. Experimental studies of liquid metal flow in CCM are a long, complex and laborious process. Therefore, mathematical modeling by numerical methods is increasingly used for this purpose. The authors have proposed a new technology for pouring liquid metal into a mold and a device for its implementation due to the use of effect of a deep-bottom submersible nozzle rotating in the mold with eccentric outlet holes. The purpose of this work is to simulate by proven numerical method a new process of filling a rectangular CCM mold with liquid steel and stirring it. Based on the developed numerical schemes and algorithms, a calculation program was compiled. The article describes an example of calculating the steel casting into a mold of rectangular cross-section and flow diagrams of liquid metal in it.