bluuebunny/crossref_metadata_2025 huggingface dataset:
INVESTIGATION OF INTERNAL OXIDATION PROCESSES OF HOT-BRIQUETTED IRON
Authors: GLADKAYA E. A. , TIMOFEEVA E. E. , FEDINA V. V.
Published: November 2023

During cooling of hot-briquetted iron (HBI), storage and transportation of briquettes, the water enters them through the pores, which leads to internal oxidation of the reduced iron, i.e. oxidation without access to an external oxidizer. Due to lack of the research methods of this process at the Department of Metallurgy and Metallology named after S.P. Ugarova, an experimental method for assessment of the internal oxidation of HBI was developed. A general view and description of a laboratory setup for determining the reactivity of the fractional composition of HBI is given. The results of an experimental study of the oxidation of hot-briquetted iron are presented. The experiments were carried out using briquettes of one batch taken after the cooling conveyor. The internal oxidation was defined as the difference between the total (according to chemical analysis) and external oxidation, calculated from the results of oxygen absorption by briquettes. It is shown that the internal oxidation depends on amount of the liquid trapped inside the HBI, which, in turn, is determined by the porosity of the briquette. The dependence of internal oxidation on the duration of its process was established. It is shown that with an increase in the time of the process, the internal oxidation increases proportionally. At the same time, the external diffusion oxidation decreases due to formation of an oxide film on the briquette surface.
SIMULATION MODELING OF ASYMMETRIC SHEET ROLLING STABILITY
Authors: KOZHEVNIKOV A. V. , SMIRNOV A. S. , PLATONOV YU. V. , KOZHEVNIKOVA I. A. , ZHILENKO S. V.
Published: November 2023

Asymmetric rolling using work rolls of different diameters is one of the ways to reduce production costs and optimize the roll stock. It is shown that the use of technology of asymmetric continuous sheet rolling in rolls with different diameters requires the solution of new technological problems associated with the treatment of steel sheets by pressure in conditions of different contact arc lengths in the deformation center. One of the risks of this rolling method is the occurrence of slippage of work rolls relative to the strip, which may lead to the emergence of negative self-oscillation effects. The paper presents the results of simulation of strip gripping stability at different grades in order to eliminate slippage during asymmetric rolling in rolls with different diameters and the same circumferential speed at constant rolling speed. Ways of identifying technological modes, inclined to appearance of rolling process instability in the form of rolls slipping relative to the strip, are offered. Recommendations on the optimum value of roughness of working rolls during asymmetrical rolling on various sections are given
INVESTIGATION OF INDICATORS OF COLD RESISTANCE AND CRACK RESISTANCE
OF WHEELS MANUFACTURED BY JSC EVRAZ NTMK FROM DIFFERENT STEEL GRADES
ACCORDING TO GOST 10791‒2011 AT PROLONGED LOW TEMPERATURES UP TO ‒60 °C
Authors: SHVEDOV K. N. , KHOMENKO D. YU. , BESPAMYATNYKH A. YU. , BRYUNCHUKOV G. I.
Published: November 2023

The Northern Latitudinal Railway is a railway in the Yamalo-Nenets Autonomous District, which is aimed at developing the main oil and gas region of the country. The railway will connect the Yamal-Nenets Autonomous District with the Urals and Central Russia, as well as the south of the country, but first of all, the Northern Latitudinal Railway is considered in close connection with the Northern Sea Route. At present, the solid-rolled wheels are manufactured according to GOST 10791‒2011 and used on Russian railways. At the same time, with regard to the whole-rolled wheels of wheel sets of railway rolling stock, there is data on their basic characteristics that allow them to be reliably operated in temperate climates on most railways. The list of controlled parameters of the whole-rolled wheels is contained in GOST 10791‒2011, GOST 4835‒2013, GOST 11018‒2011, however, it is not exhaustive, as it is directly linked to the production technology and the available operational practice in relation to this manufacturing technology. At the same time, the existing regulatory framework does not practically contain requirements for the properties of wheels at low temperatures. The reliability of the whole-rolled wheels under these conditions has been confirmed empirically. In this connection, the evaluation of the low-temperature reliability of serial whole-rolled wheels according to GOST 10791‒2011 produced by JSC EVRAZ NTMK and the possibility of their use under operating conditions on the Northern Latitudinal Railway was carried out. The comparative studies of the behavior of the metal of whole-rolled wheels made of steel grades 2 and T with the determination of the degree of change in the properties and parameters of destruction under dynamic, static and cyclic loading under conditions of positive and negative temperatures are presented. The serial curves were constructed for changes in the impact strength and in the crack development of rims and discs of the whole-rolled wheels made of grades 2 and T at positive and negative temperatures. The risks of failures during work of railway wheels were assessed under operating conditions with prolonged low temperatures
STUDY OF THE EFFECT OF TITANIUM INTRODUCTION INTO THE FLUX-CORED WIRE COATING OF THE Fe‒C‒Si‒Mn‒Сr‒Mo‒Ni SYSTEM
Authors: KOZYREV N. A. , ZUEVA S. N. , POLEVOI E. V. , KRYUKOV R. E. , SYCHEV A. A.
Published: November 2023

To increase the wear resistance of products to abrasive wear, various electric arc coatings are used, applied by cladding method. For this purpose, the flux-cored wires of the Fe‒C‒Si‒Mn‒Cr‒Mo‒Ni system are used. The effect of introducing titanium microadditives into flux-cored wires has been studied. To apply them to plates made of steel 09G2S, a welding tractor ASAW-1250 was used. The properties of the fused layers containing carbon (0.19‒0.24%), titanium (0.014‒0.025%), chromium (3.23‒6.54%), manganese (1.16‒1.55%), silicon (0.63‒0.98%), molybdenum (0.62‒0.72%), aluminum (0.013‒0.023%) with an increased sulfur content (0.058‒0.076%) were investigated. The chemical composition of the deposited metal was determined by the X-ray fluorescence method using the XRF-1800 spectrometer and the atomic emission method on the DFS-71 spectrometer. The microstructure of the electric arc coatings was studied using the OLYMPUS GX51 optical microscope. The study of phase and elemental composition was carried out by scanning electron microscopy methods using the MIRA 3 LMH device. It has been established that the microstructure of welded coatings is lower bainite of varying degrees of dispersion, which is due to the significant content of chromium and the low carbon content in the deposited metal. In the composition of the non-metallic phase of the deposited metal there are fluorine compounds, oxide and sulfide inclusions. According to the data obtained, the dependencies of the influence of the chemical composition of the cladding on the hardness and rate of wear are con-structed. All the studied experimental coatings have a characteristic structure and consist of zones: deposited metal, thermal influence, recrystrallized grain. In the metal of all samples of experimental coatings there are large inclusions containing fluorine atoms trapped from flux, in combination with oxygen and iron atoms. The size of such inclusions reaches 30 μm. A large number of globular inclusions of manganese sulfides were detected, due to the significant sulfur content in the composition of the cladding materials, as well as silicon and aluminum oxides. Based on the results of the research, the measures have been developed that allow cladding with the studied flux-cored wire under welding fluxes with a high sulfur content without deterioration in the quality of the deposited layer.
THE FACTORY BUZZER OF THE DONETSK IRON AND STEEL WORKS IS 150 YEARS OLD!
Authors: BIRYUKOV А. B. , SIDOROV V. A. , MARTYNENKO V. A.
Published: November 2023

Factory buzzers are a part of the glorious history of our country. Nowadays their use is a great rarity. It is noted that among a small number of metallurgical enterprises, as well as many decades ago, the buzzer of the Donetsk Metallurgical Plant (DMP) works. The facts about the origin of the buzzer of DMP, its use practically without interrup-tion during 150 years were provided. With the use of a sound analyzer Sonic Visualiser the characteristic sound spec-trum of the buzzer of DMP and the spectra of other metallurgical plants’ buzzers were determined. The unique features of each of the preserved buzzers are shown. The results of the research allow understanding the principles of working of these buzzers and provide possibility of their recreating in the future
Effect of vanadium alloying on the phase composition of super duplex steel
Authors: Chumanov I. V. , Sedukhin V. V.
Published: November 2023

The application and advantages of a class of duplex steels (austenitic-ferritic type steels) as a structural material are described. The influence of nitrogen as an alloying element in steels of this class is considered, as well as the peculiarities of structure formation and different types of compounds in the crystallizing melt of the considered compositions of chemical composition. The effect of the concentration of nitrogen, which, when introduced into the steel for alloying, can be in the form of gas filling pores and cracks, the element of introduction in the solid solution based on iron and nitride phases is described. The latter two forms of nitrogen presence in steel are responsible for posi-tive effects on the physicochemical properties, providing in some cases an advantage over traditional stainless steels. Using FactSage software (version 6.4), work was carried out to determine the effect of the main alloying elements of UNS 32750 super duplex steel on its phase composition. As the concentration of the main alloying elements (Cr, Mo, Mn) increased, it was found that in the nitrogen concentration interval of 0.24‒0.35 % (wt.) during melt crystallization there is no zone of existence of purely austenite and ferrite mixture, and the steel cools with formation of metal nitrides in the austenite and ferrite mixture. It can also be noted that this mixture of phases is located at the heat treatment temperatures of this steel 1025‒1125 °C. The proposed composition together increases the temperature existence interval of ferrite during crystallization by an average of 30 °C, which will provide greater nitrogen solubility in the melt. The alloying of this composition with vanadium shifts the formation zone of α + γ + M2N mixture towards less nitrogen concentration, and in the temperature interval below 800 °C an intermetallide phase is formed, which is a compound of CrVN type.
Results of investigation of perspective alloys formation process with the use of software-instrumental simulation and optimization system
Authors: Martusevich E. A.
Published: November 2023

The article discusses the results of a study of the technological process of forming aluminum alloys in electric resistance mixers using the developed mathematical model and the “Alyuminshchik” software package, designed to find the optimal mixing option for the initial raw aluminum, considering the additives of master alloys and fluxes when obtaining a given chemical composition of the alloy. To check the adequacy of the mathematical model, a comparative analysis of actual and model data was carried out. The actual data was taken from 250 melting certificates sold at JSC RUSAL Novokuznetsk. The relative error of the model was calculated as the ratio of the standard deviation of the actual aluminum content, the main component of the melt, from that calculated by the model to the average value of the actual aluminum content. The calculation results showed that the model error does not exceed the measurement error of the chemical composition of aluminum melt. Also, using a mathematical model, optimization tools and the “Alyuminshchik” software package, studies of the technological process of aluminum formation in a mixer were carried out taking into account the mixing of the melt. Аn example of the dynamics of changes in the concentrations of the components of the formed melt of the AL-6 brand is given when raw aluminum is added from the foundry ladles to the mixer at specified time intervals τ.
Advantages and risks of using ore-coal briquettes in blast furnaces
Authors: Milokhin E. A. , Sorokin A. Yu. , Myasoedov S. V. , Titov V. N. , Zagainov S. A. , Travyanov A. Ya.
Published: November 2023

Reducing carbon consumption, and, consequently, CO2 emissions during iron smelting in blast furnaces is a priority for improving the technology of blast furnace smelting. In the literature, the question of the influence of the development of direct reduction of iron on the consumption of carbon as a source of reducing gas and a source of heat has been considered. In this case, the development of direct reduction in the lower zone of the furnace at temperatures above 900 °C is considered. However, direct (solid-phase) reduction can be implemented in the upper zone of a blast furnace when using ore-coal briquettes in the charge. It is shown that the solid-phase reduction reactions can proceed at temperatures above 700 °C in the upper zone of a blast furnace during the reduction of Fe3O4 and FeO. At the same time, the apparent heat capacity of the charge increases and the temperature of the top gas decreases, which is confirmed by data on the operation of blast furnaces of NLMK PJSC, which use ore-coal briquettes. The raw materials for the production of briquettes are iron ore concentrate, sludge, blast furnace dust, aspiration dust. A bentonite and a ce-ment are used as a binder. The briquettes contain 40‒42% iron and 10‒15% carbon. The theoretical analysis and statistical processing of data on the operation of blast furnaces led to the conclusion that the solid-phase reduction of iron oxides actively proceeds at temperatures below 900 °C. The results of experimental heats showed the use of briquettes allows to reduce the specific consumption of coke and the total carbon consumption of fuel. The prospects for the use of the briquettes are associated with an increase in their mechanical properties. The use of ore coal briquettes obtained from a concentrate with an iron content of 65‒68% will reduce the rate of fuel carbon and CO2 emissions.
Scientific and technical support for the devel-opment of sinter plant no. 5 of PJSC MMK
Authors: Chukin D. M. , Gushchin D. N. , Kotyshev V. Е. , Frolov Yu. A.
Published: November 2023

The design characteristics of the sinter plant No. 5 of PJSC MMK, commissioned in 2019, are presented. The results of studies of the processes of homogenization, mixing, moistening and pelletizing of the burden, its burdening on the sintering machine, ignition, sintering and cooling of the sinter cake are presented. The erroneousness of the design solutions for installing the pelletizing drum at the zero level and the charge bunker with a volume of 60 m3 in the sintering body without an intermediate bunker is shown. Technical solutions are presented to prevent a discrete charge descent of the charge from the drum feeder of the loading unit and to form the profile of the charge layer on the sintering machine, which increases the uniformity of the process of its sintering along the width of the pallets. The operation of a multi-roll charge stacker, first used at sinter plants in the CIS, was studied. Industrial experiments were carried out on sintering a conditionally “dense” and loosened by a special device batch layer, the advantage of the latter in terms of the speed of the sintering process was established. A technical solution has been developed and accepted for implementation to reduce the length of the hearth by 40%, which will increase the sintering area of the sintering machine by 3%. The operation of the energy-consuming exhaust gas recirculation system based on their selection from eight vacuum chambers of the sinter machine out of twenty with the installation of a smoke exhauster with a drive capacity of 3.1 MW and gas cleaning from dust was stopped. Vacuum chambers of the recirculation system are connected to two parallel collectors of the sintering machine; an analysis of the impact of these measures on the operation of the sintering machines has been carried out. The possibility of using gas recirculation with the installation of a smoke exhauster with a drive power of 400 kW without additional purification of gases from dust is shown. In the future, it is proposed to increase the open section of the collectors by making them from three sections of different sections. It was found that the area of linear coolers was overestimated due to the use of “direct” loading of sinter on them, in which the cooling of the material is limited by its large lumps located in the upper part of the layer. A sinter back loading system was proposed and implemented in the project, which allows to reduce the cooling area by 30% (turn off two of the six blowers), it was decided to implement it. As a result of development of AF-5, for the first time in the practice of sintering plants in the CIS, the height of sintered charge layer of 700 mm was established. The specific productivity of sintering machines during the sintering of the charge based on the Sokolovsko-Sarbaisky concentrate was achieved, equal to 1.10 t/(m2•h); the cold strength of the sinter according to GOST 15137–77 for impact is on average 82.5%, for abrasion ‒ 4.5%.
Electroslag heating and additional melt feed of steel ingots of semi-continuous casting
Authors: Anikeev V. V.
Published: November 2023

The issues related to the continuous compensation of metal shrinkage during its crystallization are studied. Based on the evaluation of ways to reduce the size of the shrinkage shell, aimed at maintaining the liquid phase for a long time, the most effective ways to reduce the size of the shrinkage shell and reduce the head trim are selected. The influence of electroslag heating and recharge technology on the length of the shrinkage shell and the quality of the metal of the sub-shrinkage area of semi-continuously cast ingots has been studied. The study was carried out on ingots with a diameter of 500 mm weighing 3.5 tons of carbon and alloy steels. The installation consisted of 3 electrodes with a diameter of 75–100 mm, connected to the transformer TSH-3000-3. The transformer power was 570 kVA, the current per phase was 1000–3000 A, the voltage on the electrodes was 40–60 V. Temperature measurements were carried out in the copper sleeve of the mold. For comparison, the temperatures in the walls of the mold were recorded during the cooling of the ingot in the mold without heating. The cooling curves showed that the process of electroslag heating does not cause overheating of the mold walls. This is explained by the appearance of a side metal crust in the upper part of the ingot, which does not melt with liquid slag and protects the walls of the mold. The surface of the ingots had no visible defects (crust inversions, film and slag inclusions). Additional surface treatment (stripping, stripping) was not required. The macrostructure of the ingots is dense, without visible defects, including in the axial zone. Sulfur liquation on sulfur prints according to Bauman was not detected. Electroslag heating had a significant impact on the length and shape of the shrinkage shell. The results obtained show that electroslag heating with graphite electrodes, feeding with consumable steel electrodes of the same composition with the resulting ingot and electroslag casting of steel can improve the structure, density and chemical homogeneity of cast metal, reduce the content of non-metallic and gas inclusions and significantly increase the yield of usable compared to conventional casting.
Increase of durability of railway wheels at JSC “Aktyubinsk ferroalloys plant”
Authors: Еrkinbaiuly Е. , Ganin D. R.
Published: November 2023

Compensate for elastic and thermal deformations of the work rolls, as well as to ensure the possibility of rolling a flat strip, the surface of the barrel of the work rolls is profiled. During the production of steel strips on a continuous mill, the initial grinding profiles of the barrel surfaces change due to their wear. According to a number of studies, the shape of the worn surface will be determined by a number of factors: by sliding the rolled metal along the roll in the deformation zone, which depends, among other things, on the length of the produced strip; temperature conditions in the deformation zone; the presence of a movable intermediate layer between the roll and the strip, for example, mill scale during hot rolling or cutting fluid during cold rolling; chemical composition of the rolled steel; quality of rolling rolls; applied steel strip reduction modes in the mill stands; uneven heating of the rolled metal over the section, as well as some other parameters. A study was carried out on the basis of experimental data on evaluating the profile of the barrel of work rolls after they were dumped and cooled from the rolling stands. It was found that the main parameter affecting the wear of the surface is the length of the strip rolled in a given stand. It has been confirmed that wear along the length of the roll barrel is uneven. A method for calculating the wear of the surfaces of the barrels of the work rolls of a wide-strip mill along their length, based on the operating mode, is proposed. The results of the study can be used to improve the shape of the grinding profiling curve of the work roll barrels and it can be used in models for controlling the shape of a strip, and calculate technological rolling conditions
Metallurgical marketplaces: on the transformation of the sales policy of corporations
Authors: Pleshchenko V. I.
Published: November 2023

At present, the organization of sales of industrial products is characterized by the accelerated implementation of various e-commerce tools in practice. As part of the study of the transformation of sales policy in industry, an analysis of trends in the current metal products sales market under the influence of digitalization of processes is presented, an assessment of changes in the structure of the main entities operating in this market is given. It is noted that in the new conditions, when the maintenance of commercial interaction with customers and distribution logistics have become significantly simpler and cheaper. The metallurgical companies are gradually ceasing to delegate the authority to service customer relations to traditional intermediaries-metal traders. Instead of they are actively developing their own online stores of metal manufacturers, using the services of independent platforms – price aggregators, and the creation of complex electronic services for the sale of metal products – marketplaces is also beginning. Everything that is happening reflects the current trend of transition to a platform economy, which allows metallurgical companies to maintain a direct connection with the clientele, as well as to keep part of the potential profit in the corporate perimeter.
IDENTIFICATION OF FAILURES OF ROLLING MILL DRIVE SYSTEMS BY STATISTICAL METHODS
Authors: KOZHEVNIKOV A. V. , PLATONOV YU. V. , PERSHIN S. YU.
Published: November 2023

Failure diagnosis and defect identification of metallurgical units require, as a rule, specialised equipment and highly qualified personnel. It is shown that a new method of diagnostics based on statistical processing of only one parameter measured in real-time mode ‒ electric motor current ‒ enables to predict occurrence and development of a defect in drive systems of rolling production. A hypothesis about the possibility of using this method for identifying various types of faults has been formulated. Using the database of currents for drives of an intermediate roller-track in a continuous wide-strip mill 2000, the identification of two different reasons of roller drive failure ‒ seizure in the mechanical transmission and violation of cooling parameters was made. The features and differences of statistical analysis of current sampling at roller seizure and failure of its cooling are shown. It is found that the shape of the normalized current distribution curves of the roller conveyor and the variation of the distribution characteristics such as dispersion, kurtosis and asymmetry make it possible to predict the failure and to identify its cause. This research shows the effectiveness of this method, not only in evaluating and predicting the failure and its advance into the hazardous phase, but also in identifying the source of the failure. Further research on the main drives of rolling mills and drives of other units will form a new knowledge base for the development of diagnostic theory methods and predictive analytics of metallurgical equipment.
FEATURES OF MICROSTRUCTURE FORMATION IN THE WELDED PIPE JOINTS DURING HIGH-FREQUENCY WELDING AND SUBSEQUENT LOCAL HEAT TREATMENT
Authors: BAGMET O. A. , STEPANOV P. P. , HLYBOV O. S. , EFRON L. I. , ZHARKOV S. V.
Published: November 2023

The transience of heating and cooling processes during high-frequency welding (HFW) of pipes leads to the formation in the heat-affected zone (HAZ) of a coarse-grained strained bainitic and/or martensitic structure with high hardness. Local or volumetric heat treatment is used to correct the microstructure of the HAZ. The paper presents the results of a study of the structure and properties of welded pipe joints produced at the Vyksa Steel Works. It has been established that the microstructure of the welded joint of pipes made of low-carbon steels (not more than 0.07% C) is mainly bainite of lath morphology, and for steel with a high content of carbon (~0.3%) and manganese ‒ martensite. To estimate the temperature field in terms of the angle and thickness of the pipe wall during local heat treatment a finite element model was created. The paper shows that the use of the model made it possible to optimize the heating parameters during the local heat treatment of pipes of various sizes. The experiments on local heat treatment of pipes with a diameter of 325 mm, made from rolled products 8 mm thick of steel 09Г2С, showed a significant refinement of the initial microstructure of the HAZ, an increase in uniformity and the disappearanc of structural heat-affected zones. In medium carbon steels (~0.3% C) with a high manganese content, the thermal cycle of HFC welding leads to formation of martensite. The local heat treatment in the form of normalization does not allow one to exclude the formation of martensite in the segregation zones due to the high cooling rate. The local heat treatment of welded joints in pipes made of steel 30Г (Russian Standard) in the high tempering mode (650–700 °C), with preliminary cooling of the welded joint to a temperature below the completion of the martensitic transformation (in segregation zones ~50 °C), makes it possible to release the segregation martensite and form the microstructure of sorbitol there.
DEVELOPMENT OF UNIVERSAL MATHEMATICAL MODEL FOR CALCULATION OF THE GEOMETRICAL PARAMETERS OF DEFORMATION ZONE DURING TUBE ROLLING USING PIERCING MILLS WITH CUP-SHAPED, BARREL TYPE AND CONICAL ROLLERS
Authors: SHERBUTAEV N. I. , GONCHARUK A. V. , ISKHAKOV R. V. , STARICHKOVA O. V.
Published: November 2023

The piercing mill parameters directly influence on the quality of pipes. In piercing mills, the process or setting parameters are the distance between rolls, rulers or guiding tools, mandrel extension, feed angle, rolling angle, etc. The geometrical parameters of deformation zone depend on the parameters of piercing mill. Non-optimal setting param-eters of the piercing mill result in defects such as external and internal slabs. The accurate technological parameters of piercing process are needed to define the setting parameters of the piercing mill. There are numerous numbers of math models and methods to calculate the technological parameters, but all of them were developed for one specific type of piercing mill rollers. Taking into consideration all of the disadvantages of the existing math models, the new mathematical model has been developed to define technological parameters of piercing process. The main purpose of the math model is to calculate the technological parameters of piercing mill with barrel type, conical and cup-shaped rollers. The ad-vantages of the math model comparison to the existing models are flexibility, a capability to define the parameters of all
three types of the rollers and high accuracy. The model shows high accuracy even with high angle of rotation and the incline of the rollers up to 45°. The main idea of the model is to define the shortest distance between the rolling axes and the surface of rollers. The results have been evaluated using the CAD software program KOMPAS 3D for all three types of rollers of piercing mill. According to the results of comparison, the identities are equal to 100% for all three types of rollers.
APPLICATION OF FUNCTIONAL-TARGET ANALYSIS TO CHOOSE THE CLASSIFICATION FEATURES OF A SELF-TAPPING SCREW
Authors: DRYAGUN E. P. , POLYAKOVA M. A.
Published: November 2023

Classification and systematization of metal products with a wide range of standard sizes and numerous design features, in particular, various types of hardware products, is a necessary condition for the regulation of their indicators in normative and technical documentation and one of the key aspects to use the computer technologies to solve tasks of modern manufacturing. Analysis of the domestic market of hardware products indicates a significant content of fasteners, including self-tapping screws manufactured by European and Asian companies, which are not subject to mandatory certification and are supplied either according to foreign standards (ISO, DIN, DIN EN, etc.), or in branded versions, which enhances the relevance of activity for their systematization and classification. To select classification features, it is proposed to use a functional-target analysis based on the definition of useful functions of the analyzed object. As classification features of self-tapping screws, it is proposed to use their main structural elements: the shape of the head, the type of thread and point, the shape of the slot, etc. The main structural elements of the self-tapping screw, regulated in the actual normative and technical documentation, are presented in the form of general classification schemes. The proposed classification of self-tapping screws can be used as for the development of normative and technical documentation of this type of fasteners and for technological processes of its production, designing new types of screws.
THE USE OF SOIL MICROORGANISMS AND HIGHER PLANTS IN THE NEUTRALIZATION OF INDUSTRIAL WASTE IN THE METALLURGICAL, ENERGY AND COAL MINING INDUSTRIES
Authors: ZAKHAROVA M. A. , VODOLEEV A. S. , DOMNIN K. I.
Published: November 2023

The self-overgrowth of industrial dumps and tailings of waste from the metallurgical enterprises, energy facilities and coal mining industry is impossible due to the high phytotoxicity of the stored waste. They are dangerous sources of environmental pollution and negative impact on public health. The results of the field experiments on the biological reclamation of the tailings of the Abagur sinter plant, the Baidayevsky coal mine and the Tom-Usinsk State District Power Plant, where the poplar clones obtained from the Botanical Garden of the Siberian Branch of the Russian Academy of Sciences (Novosibirsk), a legume-grass mixture of perennial grasses consisting of hybrid clover and awnless rump served as a plant material. As a soil improver, the wastewater (wastewater sludge WWS) from treatment plants of the city of Novokuznetsk were used. The microbiological fertilizer “BakSib” containing spore-forming bacteria served as a source of the soil microorganisms. The combined use of WWS and the bacterial preparation “BakSib” showed high efficiency in ensuring the survival rate of the cloned poplars, which varied from 70 to 90%. It has been established that the use of bacterial preparations and WWS for the reclamation of technogenically disturbed territories reduces the adverse impact of limiting environmental factors by increasing the water supply and introducing nutritional components into the surface root layer of poplars, hybrid clover and awnless brome. In the reclaimed areas, the moisture content of the substrate was recorded from 5.1 to 14.7%, while the moisture index was 13%.
STUDY OF THE EFFECT OF EXPERIMENTAL 70%-IRON CONCENTRATE ON TECHNOLOGICAL PERFORMANCE INDICATORS AND SINTER QUALITY
Authors: ISAENKO G. E. , MESHCHERYAKOV N. S. , NECHKIN G. A. , CHERNAVIN D. A. , KOBELEV В. A.
Published: November 2023

One of the main functional properties of iron-ore sinter is iron content, which mainly determines the technical and economic parameters of iron production. Metallurgists are ever striving to increase the iron content in sinter. At present, the majority of Russian steelmakers produce sinter from concentrates with iron content of 65‒66%. OJSC Stoilensky GOK has been searching for new enrichment methods to increase iron content in the iron ore concentrate, and it has managed to obtain an experimental concentrate containing 70% iron. Studies conducted in Japan have shown that the productivity of sintering machines deteriorates when the iron content in concentrate rises and the SiO2 content lowers. With increasing iron in sinter, Russian scientists have established a decrease in strength and higher breaking. This required further study, so research was conducted to determine how partial and full replacement of the current iron-ore concentrate with experimental concentrate (70 % Fe) in sinter charge influences technological parameters and sinter strength. Increasing the share of experimental concentrate in sinter charge causes increase in iron content in sinter and decrease in SiO2 content. With this, metallurgical value of sinter goes up, while strength, yield of good sinter, productivity of sintering machines and sinter strength deteriorate. The main reason for the reduction in strength is the reduced amount of melt during the sintering of charge. As a result, the sinter cake structure gets areas of poorly sintered charge material, and vitreous phase is found in the binder along with strong ferrites. These factors are the main drivers of sinter strength reduction observed when the share of experimental concentrate in the charge increases.
APPLICATION OF MARKOV’S CHAIN THEORY TO PREDICT PROPERTIES OF HOT ROLLED STEEL SHEET
Authors: SHIRIAEVA E. N. , POLYAKOVA M. A.
Published: November 2023

The multivariance and multistage nature of manufacturing technological processes of a wide range metal products of different purposes requires the use of special approaches for their formalization in order to find optimal solutions to ensure obtaining the products with the required level of properties. Under conditions of wide variability of the raw materials used, possibility to change the technological modes of processing, use of technological operations of various physical nature, possibility to provide the given level of metal products properties has the probabilistic nature. The theory of Markov processes is used to determine the probability of an object to appear in one of the process states for a certain time or time interval. In the example of the hot rolling process, a graph of the states of rolled steel properties, which are possible during the operation of this technological system, is constructed. It is shown that in this system there is a probability of transition from one state to the next in a finite number of steps, which means the existence of limiting probabilities. Matrices have been constructed to calculate the transition probabilities of the technological system “hot rolled steel sheet” for possible states: compliance of rolled metal with specified properties, partial compliance with specified properties, partial non-compliance with specified properties, and non-compliance with specified properties. Based on the calculations performed, it can be concluded that it is possible to ensure the probability to form the properties of hot rolled steel sheet. The obtained results can be used to improve existing technological processes for the production of hot rolled steel sheet with the required level of properties.
EVALUATION OF THE URAL TITANOMAGNETITE ORES AND INDUSTRIAL WASTE FOR THE VANADIUM EXTRACTION POSSIBILITY
Authors: MAKHOTKINA E. S. , SHUBINA M. V.
Published: November 2023

Vanadium is widely used in various industries. The prospects for its consumption in the world are considered. The relevance of vanadium obtaining from various vanadium-containing materials in connection with the growing demand for it issubstantiated. Information about the most economically significant vanadium depositsin the world is given. An estimate of the industrial reserves of Ural titanomagnetite oresis provided. The study purpose wasto assess the possibility of the vanadium hydrometallurgical extraction from the Ural titanomagnetite ores and technogenic raw materials using various processing methods. The questions of using the acid and water leaching methodsfor vanadium-containing material of various chemical compositions, oxidative roasting at different temperatures, the use of various additives that make it possible to increase the vanadium oxidation state during roasting. In the resulting solutions and solid samples the vanadium content was determined with X-ray fluorescence spectroscopy. It was found that it is possible to recover and additionally extract vanadium from all the studied vanadium-containing materials. Involvement in the processing of new Ural titanomagnetite ore deposits and tails would allow not only obtaining the target product, but also free up the land occupied by waste, reducing the flow of vanadium into the biosphere in a dangerous finely dispersed state. For the processing of vanadium-containing investigated materials, the most effective method is oxidative roasting with special additives and subsequent vanadium leaching. It is recommended to select the processing modes of vanadium-containing material, taking into account its chemical composition.
THE EFFECT OF THE POROSITY OF HOT-BRIQUETTED IRON ON THE RELEASE OF HYDROGEN DURING SECONDARY OXIDATION WITH WATER OF DIFFERENT TEMPERATURES
Authors: TIMOFEEVА A. S. , KOZHUKHOV A. A. , NIKITCHENKO T. V. , NEMYKIN S. N.
Published: November 2023

During storage and transportation of the metallized product, moisture may enter it, resulting its oxidation occurring with the release of hydrogen. When delivering the product by sea, this can lead to fire and explosive situation. It is noted that the physicochemical properties of the metallized product, such as density, porosity, chemical composition, temperature, etc., have a great influence on the release of hydrogen. The purpose of this work is to determine the dependence of hydrogen release during iron oxidation in the metallized briquettes on their porosity and the temperature of the humidifying water. The results of study of the effect of porosity on the density of HBI are presented; the limits of changes in closed and open porosity and their effect on density were determined. It is shown that the bulk density of briquettes decreases with an increase in the porosity of HBI. The experiments were performed in order to determine the dependence of hydrogen release upon contact of briquettes with distilled water on the porosity and water temperature. It was found that with an increase in the open porosity of briquettes, their moisture saturation increases and the release of hydrogen increases. A change in the temperature of water that reacts with iron affects the release of hydrogen, but it practically does not affect the release rate within the parameters studied. When transporting the metallized briquettes it is recommended to take into account the effect of their open porosity on the intensity of hydrogen release in contact with moisture.
STEEL SMELTING BY OXYGEN CONVERTER METHOD FROM VANADIUM-CONTAINING CAST IRON
Authors: VANYUKOVA N. D. , ADILOV A. YU. , WIESINGER H. , KHASILOV KH. N. , VANYUKOV A. A. , KOLLER A. , RUSTAMOV B. Z. , NOVITSKII E. E. , KHODYKO I. I.
Published: November 2023

The results of BOF steel smelting from vanadium-containing cast iron obtained by smelting metallized pellets from titanomagnetite ore of the Tebinbulak deposit in a high temperature tube furnace (Gero HTRV 200-250/17) are presented in the study. Studies were carried out on devanadization and decarbonization of cast iron under the conditions of BOF process in a vertical high-temperature tube furnace. The study presents a description of the scheme of the experimental setup and the methodology of research, which were carried out on the basis of Research Center of the Montanuniversitaet of Leoben (MUL, Austria, Leoben). The samples of cast iron with different chemical compositions obtained by smelting experimental batches of metallized pellets in submerged arc furnace were used in the tests of BOF process. The temperature was 1450°C in the first quarter and 1550°C in the last quarter of the test. The tests showed that the elements transition from the metal phase to the slag phase according to their standard free energies of oxide formation. The titanium and silicon content decreased to almost null values during the first 12,5% of the total blowing time. The content of manganese and vanadium decreased more slowly, but at the end of the tests they also entered the slag phase. The carbon content can be reduced from 4,5% to almost null values. The quantity of slag was small and as a consequence making it difficult to separate the slag from metallic phase, as a result the slag phase contained about 70% FeO. In similar industrial processes, the FeO content is about 25%, which means that the content of other elements is overestimated by almost three times. The values of vanadium oxide content in the slag obtained during smelting by the oxygen-converter method amounted to 6,2% and 8,41%. The excess of three times is consistent with the vanadium content of about 20% and with 25% FeO in the slag phase. The tests have confirmed the suitability of the vanadium-containing cast iron from titanomagnetite ore of the Tebinbulak deposit in the production of steel by the oxygen converter process.
QUANTIFICATION OF INFORMATION AS A BASIS FOR DATABASE CONSTRUCTION (ON THE EXAMPLE OF STANDARDS FOR METAL PRODUCTS)
Authors: POLYAKOVA M. A. , KAZANTSEVA T. V. , KAZANTSEVA N. K. , PIDZHAKOVA Е. N.
Published: November 2023

Determining the amount of information contained in standards is the key issue in the application of digital technologies in the field of practical standardization. Since the practice of developing standards is based on the use of reference standards, the process of updating standards is largely difficult. Digitalization as an activity to present information in the form of numerical data or mathematical models should take into account the specifics of the construction and presentation of the documentation text. Since the structure of standards can contain not only a text part, but also a graphic part, therefore, for their digitalization, it is necessary to use an alphabetical approach using the Shannon formula. Using the alphabetical approach it is possible to calculate the size of the information contained in the standards of various types and categories. In the article, on the example of the GOST 21073.1‒75 standard “Non-ferrous metals. Determination of the grain size by comparison with the scale of microstructures”, the application of the Shannon formula for calculating the amount of information is shown. For calculation the following was taken into account: Russian and Latin letters, digits and numbers, spaces and other characters available in the standard. An analysis was made about the amount of information contained in the current standards of subgroup 77.120.01 “Non-ferrous metals in general” of various periods of their approval. This line of research can be used as basics to adapt the known techniques for building databases and electronic libraries of standards as well as a direction for the digitalization of regulatory and technical documents, taking into account the specifics of presenting information about the requirements regulated in them.
Optimization of technological parameters of the sintering process based on experimental and statistical models of hot strength and recovery of sinter
Authors: KHREEVA S. N. , KUCHIN V. Yu. , DETKOVA T. V. , ELISEEV A. A.
Published: November 2023

This paper presents the results of developing experimental-statistical models of the influence of technological parameters of the sintering process on the reducibility and hot strength of the sinter based on the results of experimental sintering. The statistical data was processed by the method of a two-level factorial experiment (2k or Design Of Experiments) using the Minitab 19 software package for obtaining the regression dependences. The possibility of solving the problem of optimizing the technological mode of the process by the mass fraction of FeO in the sinter with a change in charge conditions based on the obtained regularities is shown
ANALYSIS OF CUTTING METHODS FOR LARGE SECTION HOT STEEL BILLETS
Authors: KOLESNIKOV А. G. , KOMISSARCHUK YU. S. , FILATOV А. A.
Published: November 2023

During equipment selection for cutting large section billets heated to 750‒1000°C the three cutting methods were analyzed: the method of gas cutting, the method of plastic shearing using shears, the method of cutting with saws. The saws use a thin disc with profiled teeth as a cutting tool. The blade performs two movements: rotation at a circumferential speed of 70‒110 m/s, which is called the cutting speed, and movement relative to the centre of the workpiece to be cut, which is called the feed. The high performance cutting with saws can be achieved by increasing the feed rate. This increases the thickness of the cuttings to be removed. The tests on force feed modes have shown that the cutting forces increase to a lesser extent than the thickness of the material removed. The quality of the cut is not impaired and the service life of the discs increases significantly. These results have been taken into account during design of the rotary saws with feed speeds increased to 1‒2 m/s. For the cutting process in rotary saws the planetary movement of the rotating cutting disc is realised. The feed to the cut is carried out by starting and stopping the cutter with 360° rotation. The energy reserve necessary for cutting is accumulated in the rotary flywheel, which is installed in the rotation line of the cutting disc from a separate motor, and the feed to the cut is carried out from the drive motor of the driver. Diagrams of mechanisms ensuring necessary technological modes of the hot billet cutting by means of saw blades are considered.
CONSTRUCTION OF A MATHEMATICAL MODEL OF THE CORROSION DEFECT ON COLD-ROLLED STEEL DEPENDING ON THE PRODUCTION FACTORS
Authors: PARYGINA S. A.
Published: November 2023

Significant economic losses from metal corrosion force metal manufacturers to look for ways to reduce these losses including using the machine learning methods. A regression mathematical model has been built that allows regulating the influence of the initial factors in the production of cold-rolled steel in order to reduce such a common defect as metal corrosion. We have identified 10 significant production factors and selected the equation of linear multiple regression of these factors for the output variable y, which determines the percentage of scrap due to corrosion during production of the cold-rolled steel. The coefficients of the equation of multiple linear regression of 10 production factors for the percentage of scrap and the coefficient of determination were calculated, which assess the quality of the constructed mathematical model. The value of the coefficient of determination equal to 0.96 indicates a high modeling accuracy. The recommendations for the regression equation, e.g. to increase the intermediate storage times, to reduce the pump pressure, to increase the emulsion consumption, etc. allow reduction in the percentage of scrap due to metal corrosion in the production of cold-rolled steel.