Pub Date : 2021-09-21DOI: 10.32339/0135-5910-2021-9-1033-1038
A. Kozhevnikov, N. P. Brevnov
To prevent losses of equipment downtime, analytical algorithms and data of automated control systems sensors are used to estimate time to the equipment failure approach. It was shown that modern technical systems, such as automated electric drives are equipped by measuring devices which allow to accomplish self-diagnostic of the system in real time mode at existing methods of data processing and analysis. This approach is more effective than traditional methods of diagnostic and does not include additional capital expenses for specialized diagnostic equipment and personal qualification. Hypothesis of forecasting of electromechanical driving system state was elaborated and checked for continuous rolling mill runaway roller, based on character of loading modes by using only one parameter – the electric motor current. Based on the data analysis of wide strip rolling mill 2000 runaway rollers operation, normalized curves of distribution of average values of the runaway roller drive current at its normal operation and origination of a malfunction were built. It was shown that a technical system state change is fixed at appearance of a deviation of load current distribution comparing with a standard deviation. Analysis of dynamics of a statistical parameter, the standard error (the difference between actual and standard distribution) at a transition process allowed to make a forecast of roller jamming several days before the malfunction took place. The proposed approach of equipment state estimation can become a base for elaboration of a principally new methods of diagnostic of metallurgical rotor equipment.
{"title":"Elaboration of forecasting methods of analysis of metallurgical facilities electric drives technical state","authors":"A. Kozhevnikov, N. P. Brevnov","doi":"10.32339/0135-5910-2021-9-1033-1038","DOIUrl":"https://doi.org/10.32339/0135-5910-2021-9-1033-1038","url":null,"abstract":"To prevent losses of equipment downtime, analytical algorithms and data of automated control systems sensors are used to estimate time to the equipment failure approach. It was shown that modern technical systems, such as automated electric drives are equipped by measuring devices which allow to accomplish self-diagnostic of the system in real time mode at existing methods of data processing and analysis. This approach is more effective than traditional methods of diagnostic and does not include additional capital expenses for specialized diagnostic equipment and personal qualification. Hypothesis of forecasting of electromechanical driving system state was elaborated and checked for continuous rolling mill runaway roller, based on character of loading modes by using only one parameter – the electric motor current. Based on the data analysis of wide strip rolling mill 2000 runaway rollers operation, normalized curves of distribution of average values of the runaway roller drive current at its normal operation and origination of a malfunction were built. It was shown that a technical system state change is fixed at appearance of a deviation of load current distribution comparing with a standard deviation. Analysis of dynamics of a statistical parameter, the standard error (the difference between actual and standard distribution) at a transition process allowed to make a forecast of roller jamming several days before the malfunction took place. The proposed approach of equipment state estimation can become a base for elaboration of a principally new methods of diagnostic of metallurgical rotor equipment.","PeriodicalId":259995,"journal":{"name":"Ferrous Metallurgy. Bulletin of Scientific , Technical and Economic Information","volume":"41 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131778252","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-09-21DOI: 10.32339/0135-5910-2021-9-1054-1062
K. Y. Klyuchnikov, V. Razdobreev, A. I. Leshchenko, D. Palamar
The rolling-drawing process is used in the production of a large number of shaped profiles of complex configuration, including thin-walled, strip and periodic section profiles. This process, in comparison with drawing in monolithic dies, allows to reduce energy costs by 20–40 %, to increase deformation in one pass to 40–50 %, to reduce the number of preparatory operations (heat treatment, pickling), to exclude the use of expensive lubricants for drawing. Compared to the production of profiles by the method of cold rolling, the rolling-die process has a higher technological flexibility, does not require significant capital investments when organizing the production of precise profiles. At the same time, due to the presence of tensile stresses at the edges of the profile, which can cause their destruction, the assortment of strip-type profiles produced by this method was previously limited to readymade profiles with a ratio of width to height of no more than two. The authors of this work have previously developed a technology for the production of crimped steel strip with a width-to-height ratio of more than 10 by the rolling-drawing method. However, the developed calibration provides for a large number of transitions, complicates the organization of the production of strip profiles of a wide range of sizes, especially in the production of low-tonnage batches. To decrease the number of transitions, the use of dummy paases was proposed. It was shown that this will make it possible to increase the width-to-height ratio of strip-type profiles to 20, and, accordingly, reduce the production cost. The proposed technology for the production of strip-type profiles by the method of drawing in roller dies using dummy passes will allow to comprehensively solve the problem of providing machine-building and instrument-making enterprises by especially precise profiles of a wide range of sizes.
{"title":"Development of a resource-saving technology of production of strip-type profiles by drawing in roller dies using dummy passes","authors":"K. Y. Klyuchnikov, V. Razdobreev, A. I. Leshchenko, D. Palamar","doi":"10.32339/0135-5910-2021-9-1054-1062","DOIUrl":"https://doi.org/10.32339/0135-5910-2021-9-1054-1062","url":null,"abstract":"The rolling-drawing process is used in the production of a large number of shaped profiles of complex configuration, including thin-walled, strip and periodic section profiles. This process, in comparison with drawing in monolithic dies, allows to reduce energy costs by 20–40 %, to increase deformation in one pass to 40–50 %, to reduce the number of preparatory operations (heat treatment, pickling), to exclude the use of expensive lubricants for drawing. Compared to the production of profiles by the method of cold rolling, the rolling-die process has a higher technological flexibility, does not require significant capital investments when organizing the production of precise profiles. At the same time, due to the presence of tensile stresses at the edges of the profile, which can cause their destruction, the assortment of strip-type profiles produced by this method was previously limited to readymade profiles with a ratio of width to height of no more than two. The authors of this work have previously developed a technology for the production of crimped steel strip with a width-to-height ratio of more than 10 by the rolling-drawing method. However, the developed calibration provides for a large number of transitions, complicates the organization of the production of strip profiles of a wide range of sizes, especially in the production of low-tonnage batches. To decrease the number of transitions, the use of dummy paases was proposed. It was shown that this will make it possible to increase the width-to-height ratio of strip-type profiles to 20, and, accordingly, reduce the production cost. The proposed technology for the production of strip-type profiles by the method of drawing in roller dies using dummy passes will allow to comprehensively solve the problem of providing machine-building and instrument-making enterprises by especially precise profiles of a wide range of sizes.","PeriodicalId":259995,"journal":{"name":"Ferrous Metallurgy. Bulletin of Scientific , Technical and Economic Information","volume":"37 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131501890","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-09-21DOI: 10.32339/0135-5910-2021-9-1071-1086
I. Bashmakov, D. Skobelev, K. Borisov, T. Guseva
The incipient low-carbon transformation of the world economy requires elaboration of market mechanisms, based on determination and comparison of carbon intensity of products (benchmarking), separate facilities, enterprises, countries, regions and the world as a whole. Description of foreign benchmarking systems for specific energy consumption and specific greenhouse gases (GHG) in steel industry given. Results of benchmarking of energy efficiency of steel production in the countries of G20 presented, which was accomplished by International Energy Agency (IEA) in 2021. Russian experience of selective benchmarking by ecological parameters (in information and technical reference books on best available technologies) considered as well as experience of Russian metallurgical companies on evaluation specific emissions of GHG. Comparison of IEA data and those of Russian companies showed that result of benchmarking substantially depends on chosen calculation system and reliability of the initial information, as well as highlighted necessity of harmonization of benchmarking systems and provision of possibility to obtain results in various benchmarking systems based on the same initial information. Actuality and necessity substantiated to create a Russian benchmarking system for specific emissions of GHG first of all to keep ability of exporting Russian products of steel industry into EC, where from 2023 a system of boundary carbon control will come into force, as well as to keep and expand market niches at other markets, including the internal Russian one. The list of products of steel industry and limits of technological processes of their production in the Russian benchmarking system being created, must provide a possibility of comparison with foreign systems and comparison with benchmarking for products which can be covered by CBAM (Carbon Border Adjustment Mechanism) system. Basic items of CBAM concept being discussed by European parliament presented. It was noted that in view of plans to introduce CBAM, the provision of correspondence of Russian system to the system of trade by EC quotas or to other scheme, due to which the CBAM mechanism will be launched becomes a matter of particular actuality. The list of products of steel industry, covered by benchmarking within European system of trade by quotas for GHG emissions, limits of a product production system and significance of benchmarkers presented. It was noted that for Russian exporters of steel industry products, the benchmarking for specific GHG emissions should become a routine procedure. It was proposed to elaborate a calculator “Benchmarking of carbon intensity of products of steel industry of Russia”, which could provide comparison of the results obtained with benchmarkers of other international systems.
{"title":"Benchmarking systems for greenhouse gases specific emissions in steel industry","authors":"I. Bashmakov, D. Skobelev, K. Borisov, T. Guseva","doi":"10.32339/0135-5910-2021-9-1071-1086","DOIUrl":"https://doi.org/10.32339/0135-5910-2021-9-1071-1086","url":null,"abstract":"The incipient low-carbon transformation of the world economy requires elaboration of market mechanisms, based on determination and comparison of carbon intensity of products (benchmarking), separate facilities, enterprises, countries, regions and the world as a whole. Description of foreign benchmarking systems for specific energy consumption and specific greenhouse gases (GHG) in steel industry given. Results of benchmarking of energy efficiency of steel production in the countries of G20 presented, which was accomplished by International Energy Agency (IEA) in 2021. Russian experience of selective benchmarking by ecological parameters (in information and technical reference books on best available technologies) considered as well as experience of Russian metallurgical companies on evaluation specific emissions of GHG. Comparison of IEA data and those of Russian companies showed that result of benchmarking substantially depends on chosen calculation system and reliability of the initial information, as well as highlighted necessity of harmonization of benchmarking systems and provision of possibility to obtain results in various benchmarking systems based on the same initial information. Actuality and necessity substantiated to create a Russian benchmarking system for specific emissions of GHG first of all to keep ability of exporting Russian products of steel industry into EC, where from 2023 a system of boundary carbon control will come into force, as well as to keep and expand market niches at other markets, including the internal Russian one. The list of products of steel industry and limits of technological processes of their production in the Russian benchmarking system being created, must provide a possibility of comparison with foreign systems and comparison with benchmarking for products which can be covered by CBAM (Carbon Border Adjustment Mechanism) system. Basic items of CBAM concept being discussed by European parliament presented. It was noted that in view of plans to introduce CBAM, the provision of correspondence of Russian system to the system of trade by EC quotas or to other scheme, due to which the CBAM mechanism will be launched becomes a matter of particular actuality. The list of products of steel industry, covered by benchmarking within European system of trade by quotas for GHG emissions, limits of a product production system and significance of benchmarkers presented. It was noted that for Russian exporters of steel industry products, the benchmarking for specific GHG emissions should become a routine procedure. It was proposed to elaborate a calculator “Benchmarking of carbon intensity of products of steel industry of Russia”, which could provide comparison of the results obtained with benchmarkers of other international systems.","PeriodicalId":259995,"journal":{"name":"Ferrous Metallurgy. Bulletin of Scientific , Technical and Economic Information","volume":"169 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124721616","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-09-21DOI: 10.32339/0135-5910-2021-9-1020-1023
M. K. Isaev, V. A. Bigeev, A. B. Sychkov, Stolyarov
Metal processing in ladle by calcium-containing cored wires is one of the most spread methods of ladle treatment and modifying. Results of analysis of efficiency induces of existing cored wires application depending on their diameter, wall thickness and filling coefficient presented. It was shown that the basic efficiency index of a cored wire application – recovery coefficient – depending on wire quality (homogeneity of filling by calcium along the wire length), wire grade, conditions of its injection into liquid steel and other parameters can vary within a range from 50 to 95%. Reasons of unsatisfactory calcium recovery at usage of calcium-containing wires of 14–15 mm diameter with steel shell 0.4 mm thick and filling of mechanical mixture of steel shots and metallic calcium in various proportions was considered. Advantages of the modern calcium-containing cored wire with thicker wall were highlighted, including their higher wire rigidity and stability of its supply by a wire feeder into liquid steel. It was established that calcium content in a cored wire at the level of 100 g/m was the most effective composition. It was noted that increase of speed of cored wire feeding into steel will result in an increase of calcium recovery and in a decrease of probability of metal splashing out the steel ladle.
{"title":"Experience of thick-walled calcium-containing cored wire application at steel ladle treatment","authors":"M. K. Isaev, V. A. Bigeev, A. B. Sychkov, Stolyarov","doi":"10.32339/0135-5910-2021-9-1020-1023","DOIUrl":"https://doi.org/10.32339/0135-5910-2021-9-1020-1023","url":null,"abstract":"Metal processing in ladle by calcium-containing cored wires is one of the most spread methods of ladle treatment and modifying. Results of analysis of efficiency induces of existing cored wires application depending on their diameter, wall thickness and filling coefficient presented. It was shown that the basic efficiency index of a cored wire application – recovery coefficient – depending on wire quality (homogeneity of filling by calcium along the wire length), wire grade, conditions of its injection into liquid steel and other parameters can vary within a range from 50 to 95%. Reasons of unsatisfactory calcium recovery at usage of calcium-containing wires of 14–15 mm diameter with steel shell 0.4 mm thick and filling of mechanical mixture of steel shots and metallic calcium in various proportions was considered. Advantages of the modern calcium-containing cored wire with thicker wall were highlighted, including their higher wire rigidity and stability of its supply by a wire feeder into liquid steel. It was established that calcium content in a cored wire at the level of 100 g/m was the most effective composition. It was noted that increase of speed of cored wire feeding into steel will result in an increase of calcium recovery and in a decrease of probability of metal splashing out the steel ladle.","PeriodicalId":259995,"journal":{"name":"Ferrous Metallurgy. Bulletin of Scientific , Technical and Economic Information","volume":"32 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122708922","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-09-21DOI: 10.32339/0135-5910-2021-9-1039-1046
S. Eron’ko, E. V. Oshovskaya, O. A. Kovaleva
Cutting of pipes into measured lengths on-line of pipe welding mill by disc saws and by facilities of abrasive cutting requires special measures of safety of personal. Besides, the necessity of frequent change of cutting instrument results in losses of production time. To eliminate the drawbacks, a study was initiated related to creation of shears which could enable to accomplish a quality transverse cutting of thin-walled pipes of small diameter by flat knives with various form of the working edges. A methodology and the results of study of strain-stress state of flat knives with application of physical and mathematical simulation of the process of transverse cutting of thin-walled pipes of small diameter presented. At the physical simulation using a polarization-optical installation, the pictures of deformation centers arising in the lower part of the knife in the zone of contact of its cutting edges with the body of the hollow circular profile being cut by it were obtained. In the experiment, models of three types of knives made of organic glass on a scale of 1:1 were used. Cutting edges of the knives for cutting pipes of 25 mm outer diameter, wall thickness of 2 mm were wedge-shaped, convex semicircular and concave. The data from studies of the loaded state of transparent knife models served as the basis for mathematical simulation of the strain-stress state of the shears cutting tool in the SolidWork application package using a strength analysis module that implements the finite element method in the form of tetrahedrons. The current values of the pipe cutting force used in the mathematical model were preliminarily calculated according to the previously proposed dependence, taking into account the strength of the hollow profile material and the area of the cut layer of its cross section for a given relative displacement of the cutting edges of the knife. The results of mathematical modeling were the pictures of deformations and equivalent stresses of the cutting part of the knife, determined according to the third theory of strength. A qualitative similarity has been established for the distribution patterns of stress fields recorded using the polarization-optical method on knife models and obtained in mathematical modeling for working samples of the shears cutting tool operated under the conditions of pipe welding mills. The proposed mathematical model makes it possible to estimate the values of the maximum equivalent stresses in the working part of a flat knife, taking into account the shape of its cutting edges, as well as the force required for cutting a thin-walled pipe into measured lengths with the corresponding dimensions of its cross-section and the strength of the material.
{"title":"Study of strain-stress state of flat knives for cutting thin-walled pipes","authors":"S. Eron’ko, E. V. Oshovskaya, O. A. Kovaleva","doi":"10.32339/0135-5910-2021-9-1039-1046","DOIUrl":"https://doi.org/10.32339/0135-5910-2021-9-1039-1046","url":null,"abstract":"Cutting of pipes into measured lengths on-line of pipe welding mill by disc saws and by facilities of abrasive cutting requires special measures of safety of personal. Besides, the necessity of frequent change of cutting instrument results in losses of production time. To eliminate the drawbacks, a study was initiated related to creation of shears which could enable to accomplish a quality transverse cutting of thin-walled pipes of small diameter by flat knives with various form of the working edges. A methodology and the results of study of strain-stress state of flat knives with application of physical and mathematical simulation of the process of transverse cutting of thin-walled pipes of small diameter presented. At the physical simulation using a polarization-optical installation, the pictures of deformation centers arising in the lower part of the knife in the zone of contact of its cutting edges with the body of the hollow circular profile being cut by it were obtained. In the experiment, models of three types of knives made of organic glass on a scale of 1:1 were used. Cutting edges of the knives for cutting pipes of 25 mm outer diameter, wall thickness of 2 mm were wedge-shaped, convex semicircular and concave. The data from studies of the loaded state of transparent knife models served as the basis for mathematical simulation of the strain-stress state of the shears cutting tool in the SolidWork application package using a strength analysis module that implements the finite element method in the form of tetrahedrons. The current values of the pipe cutting force used in the mathematical model were preliminarily calculated according to the previously proposed dependence, taking into account the strength of the hollow profile material and the area of the cut layer of its cross section for a given relative displacement of the cutting edges of the knife. The results of mathematical modeling were the pictures of deformations and equivalent stresses of the cutting part of the knife, determined according to the third theory of strength. A qualitative similarity has been established for the distribution patterns of stress fields recorded using the polarization-optical method on knife models and obtained in mathematical modeling for working samples of the shears cutting tool operated under the conditions of pipe welding mills. The proposed mathematical model makes it possible to estimate the values of the maximum equivalent stresses in the working part of a flat knife, taking into account the shape of its cutting edges, as well as the force required for cutting a thin-walled pipe into measured lengths with the corresponding dimensions of its cross-section and the strength of the material.","PeriodicalId":259995,"journal":{"name":"Ferrous Metallurgy. Bulletin of Scientific , Technical and Economic Information","volume":"19 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125900758","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-09-21DOI: 10.32339/0135-5910-2021-9-1063-1070
A. A. Usol’tsev, N. Kozyrev, S. Knyazev, A. Kutsenko, A. Mikhno
The main process leading to the destruction of the cast elements of gas-collection bell of electrolyzer, made of grey cast iron, is the oxidation of iron by oxygen, SO2 gas and sulfur vapors to form magnetite, hematite and pyrrhotin. The simultaneous formation of iron oxides and sulfides does not prevent further corrosion, since scale is formed with a loose structure that does not have protective properties. Reducing the length of the interfacial boundaries inside the material of the cast enables to reduce the rate of corrosion destruction, which can be achieved by modifying the cast iron to change the shape of graphite inclusions, i.e. obtaining high-strength cast iron with a spherical shape of graphite inclusions. However, the obtaining spherical graphite in cast iron using magnesium modification does not exclude the access of aggressive gases to the surface of the products and the possibility of their diffusion along the grain boundaries. It was shown that alloying can be an alternative, which leads not only to the exclusion of lamellar secretions of graphite in the structure of cast iron, but also to the formation of surface oxide layers based on the alloying element preventing the corrosion. Alloying with chromium gives cast iron high abrasive resistance due to the presence of a carbide component in the structure, as well as corrosion resistance due to the alloying of the metal base, heat resistance due to increasing the electrochemical potential of the metal base and creating a strong neutral oxide film on the surface of the castings, heat resistance, etc. An experimental comparative analysis of the corrosion resistance of cast iron used for manufacturing of gas collecting bell of electrolyzers showed that chromic cast iron ЧХ3 has a higher corrosion resistance than high-strength cast iron with spherical graphite ВЧ50 and much higher than grey cast iron with lamellar graphite. However, chromic cast iron ЧХ3 has low casting properties, is very sensitive to the cooling rate and has a large heterogeneity in structure, which makes it difficult to use it for the manufacture of gas collecting bell of electrolyzers.
{"title":"On a possibility of replacing grey cast iron for manufacturing cast elements of electrolyzer gas collecting bell","authors":"A. A. Usol’tsev, N. Kozyrev, S. Knyazev, A. Kutsenko, A. Mikhno","doi":"10.32339/0135-5910-2021-9-1063-1070","DOIUrl":"https://doi.org/10.32339/0135-5910-2021-9-1063-1070","url":null,"abstract":"The main process leading to the destruction of the cast elements of gas-collection bell of electrolyzer, made of grey cast iron, is the oxidation of iron by oxygen, SO2 gas and sulfur vapors to form magnetite, hematite and pyrrhotin. The simultaneous formation of iron oxides and sulfides does not prevent further corrosion, since scale is formed with a loose structure that does not have protective properties. Reducing the length of the interfacial boundaries inside the material of the cast enables to reduce the rate of corrosion destruction, which can be achieved by modifying the cast iron to change the shape of graphite inclusions, i.e. obtaining high-strength cast iron with a spherical shape of graphite inclusions. However, the obtaining spherical graphite in cast iron using magnesium modification does not exclude the access of aggressive gases to the surface of the products and the possibility of their diffusion along the grain boundaries. It was shown that alloying can be an alternative, which leads not only to the exclusion of lamellar secretions of graphite in the structure of cast iron, but also to the formation of surface oxide layers based on the alloying element preventing the corrosion. Alloying with chromium gives cast iron high abrasive resistance due to the presence of a carbide component in the structure, as well as corrosion resistance due to the alloying of the metal base, heat resistance due to increasing the electrochemical potential of the metal base and creating a strong neutral oxide film on the surface of the castings, heat resistance, etc. An experimental comparative analysis of the corrosion resistance of cast iron used for manufacturing of gas collecting bell of electrolyzers showed that chromic cast iron ЧХ3 has a higher corrosion resistance than high-strength cast iron with spherical graphite ВЧ50 and much higher than grey cast iron with lamellar graphite. However, chromic cast iron ЧХ3 has low casting properties, is very sensitive to the cooling rate and has a large heterogeneity in structure, which makes it difficult to use it for the manufacture of gas collecting bell of electrolyzers.","PeriodicalId":259995,"journal":{"name":"Ferrous Metallurgy. Bulletin of Scientific , Technical and Economic Information","volume":"32 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116677710","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-09-21DOI: 10.32339/0135-5910-2021-9-1047-1053
S. Rakhmanov
The experience of running drives of most of heavy-duty rolling mills shows that the designs of universal spindles with blade hinges under conditions of increased alternating loads are most acceptable comparing with other spindles types. Open friction surfaces are the drawbacks of these types of spindles, which complicate the matter of continuous supply of lubrication. Perfected effective system of forced lubrication of rolling mill spindles hinges proposed. The facility for their lubrication has a bearing support of balancing design, spindle, in radial holes of which spring-loaded plungers are installed in a diametrically opposite order. Besides, the facility has suction valves and force valves installed in the spindle axial holes, connecting with the radial ones. A methodology proposed to select the eccentricity of the internal cylindrical surface of the bearing support of the spindle hinge, the axis of which is located eccentrically relative the spindle rotation axis. A calculating scheme and a mathematical model of the process of lubrication supply into joints of rolling mill spindle hinge elaborated. A differential equation of lubrication motion in the conical slot of the hinge between a blade and insertions drawn up. Parameters of hydrodynamic motion of lubrication in the conical slot established. Modes of the lubrication motion in the conical slot between roller blade and hinge insertion determined. Based on experience of operation of friction couple bronze-steel, a lubrication for rolling mills universal spindles proposed. To improve the operation characteristics of hinges based on the friction couple bronze-steel, a thick lubrication having antifriction properties namely based on oils with additives ИП-10, КП-10 and ДФ-11 proposed. Dependence of pressure distribution along the length of the hinge conical slot presented for various lubrications of low viscosity (ИП-10 + ДФ-11) and high viscosity (КП-10 + ДФ-11). The quality effect of the speed of roller blade movable wall on distribution of speeds of lubrication layer motion over the height of the hinge conical slot for comparatively low and comparatively high boundary speeds demonstrated.
{"title":"Elaboration of a lubrication system for universal spindle hinges of rolling mills","authors":"S. Rakhmanov","doi":"10.32339/0135-5910-2021-9-1047-1053","DOIUrl":"https://doi.org/10.32339/0135-5910-2021-9-1047-1053","url":null,"abstract":"The experience of running drives of most of heavy-duty rolling mills shows that the designs of universal spindles with blade hinges under conditions of increased alternating loads are most acceptable comparing with other spindles types. Open friction surfaces are the drawbacks of these types of spindles, which complicate the matter of continuous supply of lubrication. Perfected effective system of forced lubrication of rolling mill spindles hinges proposed. The facility for their lubrication has a bearing support of balancing design, spindle, in radial holes of which spring-loaded plungers are installed in a diametrically opposite order. Besides, the facility has suction valves and force valves installed in the spindle axial holes, connecting with the radial ones. A methodology proposed to select the eccentricity of the internal cylindrical surface of the bearing support of the spindle hinge, the axis of which is located eccentrically relative the spindle rotation axis. A calculating scheme and a mathematical model of the process of lubrication supply into joints of rolling mill spindle hinge elaborated. A differential equation of lubrication motion in the conical slot of the hinge between a blade and insertions drawn up. Parameters of hydrodynamic motion of lubrication in the conical slot established. Modes of the lubrication motion in the conical slot between roller blade and hinge insertion determined. Based on experience of operation of friction couple bronze-steel, a lubrication for rolling mills universal spindles proposed. To improve the operation characteristics of hinges based on the friction couple bronze-steel, a thick lubrication having antifriction properties namely based on oils with additives ИП-10, КП-10 and ДФ-11 proposed. Dependence of pressure distribution along the length of the hinge conical slot presented for various lubrications of low viscosity (ИП-10 + ДФ-11) and high viscosity (КП-10 + ДФ-11). The quality effect of the speed of roller blade movable wall on distribution of speeds of lubrication layer motion over the height of the hinge conical slot for comparatively low and comparatively high boundary speeds demonstrated.","PeriodicalId":259995,"journal":{"name":"Ferrous Metallurgy. Bulletin of Scientific , Technical and Economic Information","volume":"14 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121247251","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-09-21DOI: 10.32339/0135-5910-2021-9-1011-1019
A. G. Chernyatevich, L. Molchanov, E. Sigarev, S. Dudchenko, V. V. Vakal’chuk, P. Yushkevich, K. Chubin, A. A. Pokhvalityi, E. Chubina
To elaborate blowing and slag modes, a clear picture of BOF bath blowing in various periods of heat is needed. It can be obtained by video registration of physicochemical processes in a BOF cavity. Results of video filming of BOF bath blowing with application two-circuit oxygen lances of five designs presented. Reliable information was obtained on rational form of organization of reaction zone of interaction of ultrasonic and sonic oxygen jets with BOF bath. The picture of physicochemical processes within the reaction zone of interaction of oxygen jets with metal, slag and gas phases of the cavity, preceded to a stable “ignition” of a heat and in the process of the whole heat. A possibility was revealed to accelerate the processes of lime dissolving and slag formation and phosphor removal intensification. The intensification can be accomplished by increase of the number of reaction zones of interaction of ultrasonic and sonic oxygen jets on bath surface and forming of foamed slag-metal emulsion, being stable within the basic part of blowing time. It was shown that at initial period of a heat, it is necessary to ensure consolidation of supersonic oxygen jets, coming out of different reaction zones of interaction. It will enable to oncoming jets to create a curtain on the way of metal and slag drops taking away, to form a flare of CO afterburning to CO2 and ensure heat energy transfer from them to mainly the bath surface. It was established that at the location of the foamed slag-metal emulsion level higher the head end of the lance, the high-temperature products of CO to CO2 afterburning reaction transfer the heat of CO surrounding macro bubble to the shell of slag-metal emulsion. An additional control effect of “hard” supersonic oxygen jets on the bath was also established when replacing the subsonic and sonic oxygen jets by nitrogen ones. At that the flow rate of nitrogen should be big enough to prevent the sealing of cylinder nozzles of the lance head by metal and slag drops during final stage of blowing. The variant of the final stage of blowing was checked experimentally by transfer to the “hard” supersonic oxygen blow, contributing to final metal and slag oxidation decrease.
{"title":"Video registration of physicochemical processes in BOF cavity at bath top blowing at application oxygen lances of various designs. Report 2. The picture of bath blowing at application two-circuit lances","authors":"A. G. Chernyatevich, L. Molchanov, E. Sigarev, S. Dudchenko, V. V. Vakal’chuk, P. Yushkevich, K. Chubin, A. A. Pokhvalityi, E. Chubina","doi":"10.32339/0135-5910-2021-9-1011-1019","DOIUrl":"https://doi.org/10.32339/0135-5910-2021-9-1011-1019","url":null,"abstract":"To elaborate blowing and slag modes, a clear picture of BOF bath blowing in various periods of heat is needed. It can be obtained by video registration of physicochemical processes in a BOF cavity. Results of video filming of BOF bath blowing with application two-circuit oxygen lances of five designs presented. Reliable information was obtained on rational form of organization of reaction zone of interaction of ultrasonic and sonic oxygen jets with BOF bath. The picture of physicochemical processes within the reaction zone of interaction of oxygen jets with metal, slag and gas phases of the cavity, preceded to a stable “ignition” of a heat and in the process of the whole heat. A possibility was revealed to accelerate the processes of lime dissolving and slag formation and phosphor removal intensification. The intensification can be accomplished by increase of the number of reaction zones of interaction of ultrasonic and sonic oxygen jets on bath surface and forming of foamed slag-metal emulsion, being stable within the basic part of blowing time. It was shown that at initial period of a heat, it is necessary to ensure consolidation of supersonic oxygen jets, coming out of different reaction zones of interaction. It will enable to oncoming jets to create a curtain on the way of metal and slag drops taking away, to form a flare of CO afterburning to CO2 and ensure heat energy transfer from them to mainly the bath surface. It was established that at the location of the foamed slag-metal emulsion level higher the head end of the lance, the high-temperature products of CO to CO2 afterburning reaction transfer the heat of CO surrounding macro bubble to the shell of slag-metal emulsion. An additional control effect of “hard” supersonic oxygen jets on the bath was also established when replacing the subsonic and sonic oxygen jets by nitrogen ones. At that the flow rate of nitrogen should be big enough to prevent the sealing of cylinder nozzles of the lance head by metal and slag drops during final stage of blowing. The variant of the final stage of blowing was checked experimentally by transfer to the “hard” supersonic oxygen blow, contributing to final metal and slag oxidation decrease.","PeriodicalId":259995,"journal":{"name":"Ferrous Metallurgy. Bulletin of Scientific , Technical and Economic Information","volume":"25 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129157587","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-09-21DOI: 10.32339/0135-5910-2021-9-1024-1032
P. V. Shilyaev, P. A. Stekanov, V. L. Kornilov, F. V. Kaptsan, V. N. Urtsev, A. Shmakov, D. M. Khabibulin, N. Urtsev, Y. Gornostyrev, V. Schastlivtsev, O. Sych, S. Platov
Understanding the processes that control the formation of precipitates of alloying element, their composition and morphology is important for the choosing of optimal regimes of thermomechanical treatment, providing the required structural state and properties of low-alloyed steels. The use of modern methods of atomistic modeling and ab initio calculations to study the mechanisms and conditions of precipitation depending on the steel composition and temperature is discussed. The enthalpy of formation of Ti, V, Nb carbides and nitrides in γ-Fe was calculated using the methods of the theory of the electron density functional and the temperatures of their dissolution were determined in dependence on the composition of the steel. The results obtained agree with the experimental data and obtained by the CALPHAD method. Calculations of the electronic structure, enthalpy of mixing, energy of effective interactions between atoms of alloying and impurity elements have been performed. It was shown that an essential factor determining the nature of the interaction between alloying elements was the magnetic state of iron. It has been established that the enthalpy of mixing, which expresses the tendency of the system to decomposition, increases with the transition of α-Fe from the ferromagnetic to the paramagnetic state. In ferromagnetic α-Fe energetically, the formation of precipitates of Cu, as well as particles of a mixed composition of Cu‒Al, Cu‒Ni and an ordered phase of NiAl are preferable. It has been shown that precipitates Cu-based can be formed during technological times. The transition of α-Fe to the paramagnetic state results in increase of interactions between alloying elements (the exception is the interaction of Cu‒Cu and Cu‒Ni). As a result, additional combinations of alloying elements appear, the interaction between which lead to the formation of precipitates. At the same time, in γ-Fe, precipitates can be formed only based on Mo and Nb. The role of magnetism in the formation of precipitates and their influence on the γ→α-transformation is discussed. It has been shown that the results obtained make a base for enhancement technologies of high-strength low-alloyed steel production.
{"title":"Formation of carbonitrides and precipitation of alloying elements during thermomechanical treatment of high-strength low-alloy steels. Atomistic modeling","authors":"P. V. Shilyaev, P. A. Stekanov, V. L. Kornilov, F. V. Kaptsan, V. N. Urtsev, A. Shmakov, D. M. Khabibulin, N. Urtsev, Y. Gornostyrev, V. Schastlivtsev, O. Sych, S. Platov","doi":"10.32339/0135-5910-2021-9-1024-1032","DOIUrl":"https://doi.org/10.32339/0135-5910-2021-9-1024-1032","url":null,"abstract":"Understanding the processes that control the formation of precipitates of alloying element, their composition and morphology is important for the choosing of optimal regimes of thermomechanical treatment, providing the required structural state and properties of low-alloyed steels. The use of modern methods of atomistic modeling and ab initio calculations to study the mechanisms and conditions of precipitation depending on the steel composition and temperature is discussed. The enthalpy of formation of Ti, V, Nb carbides and nitrides in γ-Fe was calculated using the methods of the theory of the electron density functional and the temperatures of their dissolution were determined in dependence on the composition of the steel. The results obtained agree with the experimental data and obtained by the CALPHAD method. Calculations of the electronic structure, enthalpy of mixing, energy of effective interactions between atoms of alloying and impurity elements have been performed. It was shown that an essential factor determining the nature of the interaction between alloying elements was the magnetic state of iron. It has been established that the enthalpy of mixing, which expresses the tendency of the system to decomposition, increases with the transition of α-Fe from the ferromagnetic to the paramagnetic state. In ferromagnetic α-Fe energetically, the formation of precipitates of Cu, as well as particles of a mixed composition of Cu‒Al, Cu‒Ni and an ordered phase of NiAl are preferable. It has been shown that precipitates Cu-based can be formed during technological times. The transition of α-Fe to the paramagnetic state results in increase of interactions between alloying elements (the exception is the interaction of Cu‒Cu and Cu‒Ni). As a result, additional combinations of alloying elements appear, the interaction between which lead to the formation of precipitates. At the same time, in γ-Fe, precipitates can be formed only based on Mo and Nb. The role of magnetism in the formation of precipitates and their influence on the γ→α-transformation is discussed. It has been shown that the results obtained make a base for enhancement technologies of high-strength low-alloyed steel production.","PeriodicalId":259995,"journal":{"name":"Ferrous Metallurgy. Bulletin of Scientific , Technical and Economic Information","volume":"19 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129471291","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-08-01DOI: 10.32339/0135-5910-2021-7-829-834
S. Anakhov, Y. Pykin, A. Matushkin, B. Guzanov
Plasma torches of Russian origin concede to import metal-cutting plasma facilities by several parameters, in particular energy efficiency, quality of cut, degree of automation. To increase efficiency and safety of domestic electro-plasma technologies itь is necessary to perfect methods of analysis of known design solutions to provide new developments. The results of the plasma torches design widely used in metallurgical and machine-building technologies for air-plasma cutting of metals presented. It was noted that productivity, cutting quality and reliability of plasma equipment should be chosen as the main criteria of efficiency for plasma cutting technology. It was shown that special attention should be paid to improving the gas-vortex stabilizing method for the plasma forming gas, which ensures the efficiency of both the plasma torch and the plasma cutting process as a whole. Results of studies of a complex system for arranging the flow of plasma-forming gas through the channels of the gas-air path in the plasma torch and the subsequent creation of new systems for stabilizing the arc discharge of metal cutting DC plasma torches with high technological capabilities presented. The study was carried out by the methods of numerical simulation of gas-dynamic and thermo-physical processes for various designs of plasma torches. Optimized designs of plasma torches with various variants of gas-vortex stabilization systems were elaborated. A series of elaborated torches, which includes a single-stream plasma torches ПМВР-5 for precision cutting of medium thickness metals, as well as two-stream plasma torches ПМВР-9 for cutting metals of small and medium thicknesses presented. The last plasma torches use the technology of narrow-jet or compressed plasma and have no domestic analogues. A methodology of metal-cutting plasma torches designing by gas-dynamic, thermo-physical and acoustic criteria was elaborated. The results of experimental studies showed that the use of new ПМВР-5 plasma torches allows to obtain precision cuts corresponding to the 1st and 2nd quality classes according to GOST 14792-80 on steels of the 09Г2С type of medium thickness. It was also shown that the use of new plasma torches makes it possible to perform precision finishing plasma cutting on low-carbon steels of medium thickness (without additional mechanical processing of the cutting edge) in the production technologies of welded joints.
{"title":"Development and research of new technologies for precision plasma cutting of metals","authors":"S. Anakhov, Y. Pykin, A. Matushkin, B. Guzanov","doi":"10.32339/0135-5910-2021-7-829-834","DOIUrl":"https://doi.org/10.32339/0135-5910-2021-7-829-834","url":null,"abstract":"Plasma torches of Russian origin concede to import metal-cutting plasma facilities by several parameters, in particular energy efficiency, quality of cut, degree of automation. To increase efficiency and safety of domestic electro-plasma technologies itь is necessary to perfect methods of analysis of known design solutions to provide new developments. The results of the plasma torches design widely used in metallurgical and machine-building technologies for air-plasma cutting of metals presented. It was noted that productivity, cutting quality and reliability of plasma equipment should be chosen as the main criteria of efficiency for plasma cutting technology. It was shown that special attention should be paid to improving the gas-vortex stabilizing method for the plasma forming gas, which ensures the efficiency of both the plasma torch and the plasma cutting process as a whole. Results of studies of a complex system for arranging the flow of plasma-forming gas through the channels of the gas-air path in the plasma torch and the subsequent creation of new systems for stabilizing the arc discharge of metal cutting DC plasma torches with high technological capabilities presented. The study was carried out by the methods of numerical simulation of gas-dynamic and thermo-physical processes for various designs of plasma torches. Optimized designs of plasma torches with various variants of gas-vortex stabilization systems were elaborated. A series of elaborated torches, which includes a single-stream plasma torches ПМВР-5 for precision cutting of medium thickness metals, as well as two-stream plasma torches ПМВР-9 for cutting metals of small and medium thicknesses presented. The last plasma torches use the technology of narrow-jet or compressed plasma and have no domestic analogues. A methodology of metal-cutting plasma torches designing by gas-dynamic, thermo-physical and acoustic criteria was elaborated. The results of experimental studies showed that the use of new ПМВР-5 plasma torches allows to obtain precision cuts corresponding to the 1st and 2nd quality classes according to GOST 14792-80 on steels of the 09Г2С type of medium thickness. It was also shown that the use of new plasma torches makes it possible to perform precision finishing plasma cutting on low-carbon steels of medium thickness (without additional mechanical processing of the cutting edge) in the production technologies of welded joints.","PeriodicalId":259995,"journal":{"name":"Ferrous Metallurgy. Bulletin of Scientific , Technical and Economic Information","volume":"23 17 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131947869","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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