Scientific Journal "Metallurgy"

POSSIBILITIES OF APPLICATION OF POWDER CONSUMABLE ELECTRODES FOR ELECTROSLAG TECHNOLOGIES

Serhiy Popov — 2024-12-30

The work provides examples of industrial applications of electroslag technology that require consumables of varying chemical composition, in particular consumable electrodes. Options for alloying the deposited metal are considered, and the advantage of using a powder electrode is proven. A design has been proposed for a powder consumable electrode consisting of a steel box profile (steel 3ps, 3 kp) and a fixing tape (steel 08 kp), which also works as a dispenser for a charge consisting of crushed ferroalloys. Electroslag ingots with a diameter of 60 mm, obtained using powder electrodes, correspond in chemical composition to steels 20Х13, Х12 and cast iron ЧХ16. It has been established that the chemical composition of the ingots meets the requirements of the relevant DSTU. There is also a refining effect, as evidenced by the sulfur and phosphorus content. When examining the electrode ends, it can be seen from their appearance that there is only one source of droplet detachment on the end of a solid electrode, which is located at the top of the cone, which coincides with the center of the electrode end.At the end of the powder electrode, several sources of droplet formation are formed, which are placed along the perimeter of the steel box profile. This ensures uniformity of heat flow and makes the crystallization front flatter. The work suggests that when ferroalloys with a high melting point are used in powder electrodes, a refinement of the structure (inoculating effect). Crystallization conditions were evaluated by the calculated coefficients of the crystallization front (Kf.k.) and the measured depth of the conical part of the metal baths (Н). The shape of the metal bath was fixed with iron sulfide during electroslag smelting of the ingot with a diameter of 70 mm. It was established that during electroslag smelting with a solid electrode Kf.k. = 0.65, H = 21.1 mm, and when using a powder electrode Kf.k. = 0.87, H = 15.5 mm. It was established that during electroslag surfacing with a powder electrode, a shallow metal bath with a flat crystallization front is formed.

STUDY OF ACID-BASE PROPERTIES OF TUNGSTEN-MOLYBDATE MELTS OF DIFFERENT CATION COMPOSITION UNDER EQUILIBRIUM CONDITIONS

Viktor Malyshev — 2024-12-30

Due to their important properties, molybdenum and tungsten oxides and bronzes of different stoichiometric composition are widely used in various fields of science and technology. Melts based on tungstates and molybdates of alkaline and alkaline earth metals have practical applications for obtaining these materials. According to modern views, molybdenum and tungsten bronzes of alkaline and alkaline earth metals are solid solutions of the entry of these metals into tungsten (molybdenum) (VI) oxide. Obtaining these bronzes is carried out by chemical and electrochemical methods of synthesis. Electrochemical cells with oxygen indicator electrodes and reference electrodes are used to study changes in the activity of oxygen ions in the tungstate melt. The experimental change in the potentials of the oxygen electrode in case of addition of oxygen ion acceptors in the form of molybdates and tungstates of alkali or alkaline earth metals is explained by the proposed model of the ionic composition of the melt taking into account the formation of cationized complexes involving alkali and alkaline earth metals. Mathematical calculations of potential values of oxygen electrodes make it possible to predict the composition (number of cations) of cationized complexes. Cations Sr2+, Ba2+, Li+, Mg2+, Zn2+ interact with molybdate and tungstate anions to form the corresponding cationized complexes. The ability to form complexes increases with an increase in the specific charge of the cation. The production of molybdenum and tungsten bronzes of different compositions is determined by the possibility of changing the electroreduction potential of molybdenum and tungsten compounds, and in the case of high-temperature electrochemical synthesis, by the possibility of their displacement and combination with the potential of the second component of the synthesis.

MARKETING RESEARCH OF THE GLOBAL TITANIUM MARKET

Viktor Malyshev — 2024-12-30

The global titanium market covers the mining, processing, and utilization of titanium. The market expansion depends on the rapid demand increase in the industries related to aerospace and aviation. The logistics supply chain covers the titanium ores extraction and their further processing into titanium and its alloys. Market dynamics, price, and availability of titanium are influenced by geopolitical factors, technological innovations, and end-user sectors. The general characteristics, growth factors, and limitations of the global titanium market are provided. The natural reserves of titanium ore deposits were assessed and indicated as suitable for development. Features of the world market of titanium compounds, as well as the titanium ore reserves distribution by countries, are given. Information is provided on the largest titanium and its alloys producing countries. The global titanium market is segmented by geographic regions, product types, titanium alloys microstructure types, and end users. The factors determining the significant volatility of titanium metal prices were identified. The key "players" of the global titanium market were identified.

ANALYSIS OF RESEARCH METHODS OF SEGREGATION PROCESSES IN BULK MATERIALS

Mikhailo Paziuk — 2024-12-30

The article is devoted to the analysis of methods of studying segregation processes in loose materials with the aim of creating a given segregation. The main idea is that the correct management of the segregation process leads to the improvement of the sintering process of the agglomerate and the saving of energy resources. The authors discuss different approaches to the study of segregation processes and their impact on the quality of the final product. Sintering ore fines on a grate by drawing air through a layer of sintering charge is the most common method of sintering. At the same time, it was determined that the characteristic features of the agglomeration process are preserved regardless of the design of the agglomeration machines. The model describing the performance of the sintering machine was considered and it was concluded that the increase in the performance of sintering machines at the operating sinter plant can be reduced to an increase in the vertical speed of sintering and the output of the finished agglomerate. Special attention is paid to methods that contribute to the prevention of undesirable phenomena in the process of segregation and optimization of this process to achieve the desired result. Thus, the increase in productivity is also associated with a decrease in downtime of the sintering machine. Models of layer formation with different approaches to the movement of individual particles of the charge are considered. Analysis of the obtained dependencies and comparison of the results of mathematical modeling with real processes allows us to conclude that the main influence on the process of formation of a layer of polydisperse material is provided by its physical and mechanical properties and the angle of inclination of the loading tray. Consideration of this topic in the article is of practical and economic importance for manufacturing enterprises engaged in the processing of loose materials. In general, the article is an important contribution to the study of segregation processes and their impact on production processes.

MULTIFUNCTIONAL CHARGES FOR OBTAINING PROTECTIVE COATINGS ON PRESSING EQUIPMENT UNDER SHS CONDITIONS

Boris Sereda — 2024-12-30

Multifunctional SHS charges for the production of chrome coatings alloyed with titanium and silicon have been developed in this work in order to strengthen the working surfaces of press tooling dies used in aggressive conditions during the vulcanization of products made of elastomeric materials. Pressing is performed on a hydraulic vulcanizing press 100-400 2E. with plate sizes 400x400 of new elastomeric materials based on 10 wt.% carbonized PAN fiber (RC Helper), which significantly increases the heat capacity of rubber based on a copolymer of vinyl di-fluoride and hexopropylene by 15-30% in the operating temperature range from 323 to 348 K. One of the newest and most effective technologies for manufacturing a wide range of materials, including composite materials, is the SHS technology, which is based on the direct synthesis of compounds of practical value in exothermic reactions between certain chemical elements. Protective coatings on samples under SHS conditions were obtained at the developed pilot plant DSTU12, which consists of the following main functional systems: reaction equipment; system for monitoring and controlling technological parameters; gas utilization system. Samples from 45 and 40X steels were used for coating. Mixtures of powders with a dispersion of 100-250 microns of the following materials were used as reaction agents. Using a three-factor, three-level composite asymmetric plan of the second order, the optimal blends for obtaining protective alloy coatings were developed. The resulting coatings are characterized by a multiphase structure and thickness uniformity. For titanium-doped chromium coatings obtained on samples from steel 45, the phases (Cr,Fe)₂₃C₆, (Cr,Fe)₇C₃, Fe₂Ti, Cr₂Ti, and α-solid solution of titanium and chromium in α-iron were found. For 40X steel, the phases (Cr,Fe)₂₃C₆ and α-solid solution of chromium in iron with Cr₂Ti inclusions alloyed with titanium are formed.

ASSESSMENT OF OCCUPATIONAL RISKS WHEN DESIGNING EVENTS FOR ELECTRICAL SAFETY AT WORKPLACE

Yevheniia Manidina — 2024-12-30

This work analyzes the causes and identifies the main factors contributing to accidents related to electric shock for workers in the production environment. A risk-oriented approach to managing the occupational safety system is proposed to reduce the level of electrical trauma in the workplace, specifically through the Hazard Identification Studies methodology. The characteristics of the main rooms in electrical substations are detailed. Existing hazards and harmful factors associated with the use of electrical equipment located within the electrical substation during the distribution of electrical energy at a voltage of 6 kV are analyzed. Criteria for assessing the probability and severity of potential hazards in the substation premises are presented. A hazard and risk identification map has been developed for various types of work performed by electricians during the repair and maintenance of electrical equipment located in the substation. It has been determined that the most dangerous processes for electricians involve the overhaul and maintenance of oil circuit breakers VMG-133 and VMG-10 (electrical equipment operating at voltages above 1000 V). Measures to minimize the identified risks are proposed. An approximate assessment of the impact of these occupational safety measures has been conducted, revealing that they reduce the risk level of dangerous incidents by half, from 20 to 10 points. The effectiveness of occupational safety measures in minimizing risk levels for all major technological processes during the repair of electrical equipment at electrical substations for the distribution of electrical energy at a voltage of 6 kV has been confirmed.

INNOVATIVE TECHNOLOGIES FOR INCREASING THE TECHNOLOGICAL SAFETY OF CONVERTER PRODUCTION

Vladislav Rumyantsev — 2024-12-30

The work considers innovative technologies for increasing man-made safety on the example of converter production. In the modern converter production of steel, the latest technologies are used to increase the efficiency of the process. The preferred option for such steel melting is the use of combined purging, when oxygen is supplied to the converter from above and inert gas from below (through the bottom) at the same time, the duration of melting is reduced to 30-35 minutes. Due to the significant increase in the intensity of melting and the complexity of the technological equipment, management of the specified process requires more attention and responsibility of the working personnel in order to increase the level of man-made safety. Violations of the technological process, which are related to the influence of external factors, include the possibility of non-compliance with the scrap metal preparation technology (increased humidity, presence of lubricant), uneven supply of oxygen, as well as interruptions in energy supply. Such violations can lead to splashes of metal and slag, damage to the lining, as well as dangerous stops in the melting process. A dangerous phenomenon is the possibility of metal loss from converters and steel pouring ladles due to a violation of their tightness. Thus, in the lower part of the converter, its lining is systematically subjected to significant dynamic loads during the loading of scrap metal. Wear of the lining occurs due to the reaction of its components with the silicon oxide of the slag, which has acidic properties. Violation of the integrity of the lining under certain conditions can lead to the pouring of metal from the bottom or side of the converter casing. In order to find rational means of protecting workers, a hardware and technological diagram of dangerous process zones has been developed. It is shown that the presence of moisture in the lining of buckets during the pouring of steel poses a significant danger. The condition of the inner surface of the lining of the converter should be included among the standardized safety parameters of the melting process in the converter; physicochemical parameters of charge materials, as well as physical parameters of the oxygen jet. Violations of the safety parameters of the process consist of violations during the supply of oxygen (duration 6.4 hours), violations related to the incorrect position of the oxygen nozzle (duration 14.5 hours), as well as violations of the chemical composition of the metal (13.5 hours).

ANALYSIS OF THE CONDITION OF USED TRANSFORMER OIL IN SWITCHES OF ENERGY SUPPLY SYSTEMS OF METALLURGICAL ENTERPRISES

Serhii Ilyin — 2024-12-30

In the global practice of electrical apparatus construction, special attention is paid to the issue of operational efficiency. To compensate for the loss of kinetic energy spent on switching processes, the leading companies "Poertech Corporation" USA, "Hundai" (Republic of Korea), India, China, "Reinghausen", "AEG" (Germany), "Ferranti" (Italy), "ACEA" (Sweden), "VIT" (Ukraine) use periodic or continuous purification of transformer oil or use materials that do not form by-products during combustion in the form of particles of different dispersion. The desire to increase the service life of switches leads to a redistribution of the role of mechanical and electrical influence on structural elements. Therefore, the study of mechanical damage to parts, the conditions of their occurrence and the regularity of their development acquires an important importance in the development of the concept of management of processes characteristic for the operation of the investigated equipment. The variety of types of particles of contamination of the working environment, the conditions of their occurrence and development, are regulated by factors of external mechanical action in the commutation zone. The main features of the factors that determine the nature, quality and speed of commutation when mechanical, physical and chemical processes occur at high temperatures in switches include: the use of dissimilar materials, conditions, the type and nature of mechanical interaction, the presence of a high density current, etc. In the process of operation of high-voltage switches, the geometry of the surfaces of the contact nodes undergoes significant changes. Kinematic calculation of switching contact details is usually carried out at the design stage for surfaces with ideal geometry, without taking into account subsequent operational changes. In many works, it is noted that damage to the surface layer is a structurally sensitive characteristic of materials. This is what determines the metallurgical approach to the study of contact processes of metal surfaces.

INFLUENCE OF COMPONENTS OF LIGATURES ON THE FUNCTIONAL CHARACTERISTICS OF CALCIUM BABIES

Viktor Skachkov — 2024-12-30

The work is devoted to the processes of creating a high-quality babbitt layer of bearings due to the use of a large amount of primary babbitt in the charge. The formation of a large amount of waste in the production of bronze-babbitt liners reduces technical and economic indicators, worsens the environmental situation at the enterprise and in the region. In this regard, it is necessary to create a technology that uses a larger amount of calcium babbitt waste. Bronze Babbitt liners are the most common design of crankshaft bearings of diesel locomotives. The traditional production technology of bronze-babbitt liners of sliding bearings involves casting an alloy based on calcium babbitt into the bronze frame. Usually, pouring is carried out centrifugally, and the charge is melted in the crucible of an electric furnace. The main task of the research is aimed at a comprehensive study of the functional properties of calcium babbitts and the assessment of the influence of each babbitt component on the quantitative characteristics of quality indicators, including the processes of aging, wear, formation of hardness, mechanical strength and structural defects. The main operational characteristics of bronze-babbitt liners of sliding bearings (hardness, impact toughness, tensile strength, wear intensity) depend on a whole set of structural parameters, technological features of production and chemical composition. At the same time, the influence of each individual factor is significantly non-linear. The study of the hardness of babbitt samples after aging up to one year made it possible to establish that the addition of magnesium helps to increase this characteristic. Thus, due to the addition of magnesium, after 80 days of exposure, the hardness of the samples increases by 1.5 times, reaching HB=25. Mathematical processing of the obtained data established that the influence of alloying elements and duration of exposure on the hardness of babbitt is estimated by a regression equation in the form of cubic splines.Based on the results of a comprehensive study of the influence of chemical elements on the mechanical characteristics of BK2 babbitt, an approximation by quadratic splines for each alloying element was constructed using the regression analysis method.

PROCESSING OF HYDROCHLORIC ACID SOLUTIONS WITH THE PURPOSE OF OBTAINING A COMMODITY PRODUCT

Yevheniia Manidina — 2024-12-30

The study analyzes the dynamics of waste generation and management in the region from 2014 to 2021. It was determined that the majority of waste in the Zaporizhzhia region comes from the metallurgical industry. The specific features of technological processes, particularly the use of pickling solutions in steel production, result in the formation of large volumes of spent pickling solutions containing diluted hydrochloric acid and iron chlorides. The lack of effective methods for recycling these solutions leads to environmental and economic losses. The article proposes a technologically efficient method for processing spent pickling solutions using an ozonator, which ensures the oxidation of ferrous chloride (FeCl₂) to ferric chloride (FeCl₃), producing a coagulant. Experimental studies confirmed the effectiveness of ozone in reducing processing time compared to using air oxygen. It was established that with an air mixture containing ozone at a flow rate of 0.5 L/min, complete oxidation of ferrous chloride to ferric chloride occurs within 36 minutes from the start of treatment, whereas with an ozone-enriched mixture at a flow rate of 1.5 L/min, complete oxidation is achieved in 18 minutes. Experimentally, it was determined that oxidation of ferrous chloride to ferric chloride with air oxygen is 1.3-1.5 times slower than with an ozone-containing mixture. The research results led to the development of recommendations for processing spent pickling solutions for industrial enterprises, including optimization of temperature, process duration, and conditions for coagulate crystallization. The resulting product demonstrated high efficiency in wastewater coagulation processes, confirming the feasibility of implementing the proposed technology in metallurgical plants. The introduction of such solutions will help reduce the negative environmental impact of industrial waste and lower waste disposal costs.

MATHEMATICAL MODELING OF TECHNICAL AND ECONOMIC INDICATORS OF NICKEL-MOLYBDENUM LIGATOR PRODUCTION

Stanislav Hrigoriev — 2024-12-30

In the work, the development and optimization of a multifunctional system of dependencies of the technical and economic indicators of the production of nickel-molybdenum ligature and its use in the smelting of a precision alloy with the use of man-made waste from various sources of formation was carried out. The optimal values of technical and economic indicators and cost factors were found and investigated, as a result of which the quality improvement of the nickel-molybdenum ligature with the most favorable content of alloying and deoxidizing elements in it and the reduction of the cost of smelting a precision alloy with its use were established. In order to achieve optimal properties of the target Ni-Mo ligature of precision alloys, taking into account the complex effect of the composition of the charge on reducing the cost of redistribution of its melt, increasing the degree of use of man-made waste, reducing the consumption coefficients of nickel and molybdenum, regression analysis was used. Using the generalized method of least squares, based on the indicators of industrial tests, a mathematical model of the dependences of the increase in the degree of use of man-made waste from various sources of formation and the reduction of the consumption coefficients of nickel and molybdenum in the smelting of precision alloys on the content of 10 components in the charge for its smelting was developed. The high technical and economic efficiency of the production and use of the new alloying and deoxidizing material has been established.