Pub Date : 2018-06-01DOI: 10.17073/0368-0797-2018-5-372-377
N. V. Osipova
The paper presents the current state of the problems of automation and control data of wet magnetic concentration for iron ore mining and processing plants. Data on the measurement errors of modern analyzers and material composition of the pulp are considered. The possibility of using Kalman filter in order to obtain the most accurate information about the content of valuable component in concentrate and tailings of magnetic separator products is shown. The mathematical description of the dynamics of concentration indicators is given in state coordinates in the form of differential equations system. The author has selected maximum allowable and nominal values of the water flow in the separator bath and the rotation frequency of its drum as well as the corresponding data for the mass fraction of iron in magnetite concentrate and tailings, based on the reference information. With MATLAB program of computer simulation the nonlinear static characteristics were composed, reflecting the dependence of technological parameters of the magnetic concentration from control actions. The linearization dynamic model of the system is held using expansion in Taylor series in the neighborhood of the points, corresponding to a nominal operation mode. The transfer functions of control valve of water flow rate of induction motor rotating the drum were calculated. Standard deviations of control parameters affecting the separation process were determined. The calculated ratio are obtained for determining the covariance matrices of the system noise, describing dynamics of indicators of magnetic concentration, and the noise of their measurement by devices that control the content of magnetite iron in concentrate and tails. The presented algorithm of estimating the coordinates of the Kalman filter state consists of two stages: prediction of the system state and adjustment of the state vector. Simulation results of the MATLAB programming environment are presented in the form of time diagrams reflecting the dynamics of technological indicators of concentration, the evaluation of the Kalman filter and measurement error. The system has been considered in case of random changes of control actions. At the end of the article, the results are summed up, where it is reported that the Kalman filter should be used in tasks of automation and control of the iron ore concentration process.
{"title":"THE USE OF KALMAN FILTER IN AUTOMATIC CONTROL OF INDICATORS OF IRON ORES MAGNETIC CONCENTRATION","authors":"N. V. Osipova","doi":"10.17073/0368-0797-2018-5-372-377","DOIUrl":"https://doi.org/10.17073/0368-0797-2018-5-372-377","url":null,"abstract":"The paper presents the current state of the problems of automation and control data of wet magnetic concentration for iron ore mining and processing plants. Data on the measurement errors of modern analyzers and material composition of the pulp are considered. The possibility of using Kalman filter in order to obtain the most accurate information about the content of valuable component in concentrate and tailings of magnetic separator products is shown. The mathematical description of the dynamics of concentration indicators is given in state coordinates in the form of differential equations system. The author has selected maximum allowable and nominal values of the water flow in the separator bath and the rotation frequency of its drum as well as the corresponding data for the mass fraction of iron in magnetite concentrate and tailings, based on the reference information. With MATLAB program of computer simulation the nonlinear static characteristics were composed, reflecting the dependence of technological parameters of the magnetic concentration from control actions. The linearization dynamic model of the system is held using expansion in Taylor series in the neighborhood of the points, corresponding to a nominal operation mode. The transfer functions of control valve of water flow rate of induction motor rotating the drum were calculated. Standard deviations of control parameters affecting the separation process were determined. The calculated ratio are obtained for determining the covariance matrices of the system noise, describing dynamics of indicators of magnetic concentration, and the noise of their measurement by devices that control the content of magnetite iron in concentrate and tails. The presented algorithm of estimating the coordinates of the Kalman filter state consists of two stages: prediction of the system state and adjustment of the state vector. Simulation results of the MATLAB programming environment are presented in the form of time diagrams reflecting the dynamics of technological indicators of concentration, the evaluation of the Kalman filter and measurement error. The system has been considered in case of random changes of control actions. At the end of the article, the results are summed up, where it is reported that the Kalman filter should be used in tasks of automation and control of the iron ore concentration process.","PeriodicalId":35527,"journal":{"name":"Izvestiya Vysshikh Uchebnykh Zavedenij. Chernaya Metallurgiya","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2018-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82666716","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 : 2018-06-01DOI: 10.17073/0368-0797-2018-5-385-392
S. Snitko, A. V. Yakovchenko, A. Sotnikov
Ensuring the stability of the dimensions of the stamped-rolled railway wheels, the rational power modes of the press operation and durability of the metal deformation tool parts, as well as reduction of the initial billets mass, are actual scientific and technical tasks. This durability largely determines the costs associated with the choice of steel grade for dies, technology of their manufacture and process lubrication. In the present work, based on the results of finite element modeling, the analysis of the influence of stamping schemes of wheel billets on the power modes of operation of a forming press and on wear of the deformation tool was made in relation to modern press rolling lines. It is shown that the stamping schemes, which provide for the regulated distribution of metal between the central and peripheral parts of the billet delivered to the stamps, are characterized by a rational power mode of the forming press. The average force in this case is 63 – 70 % of the average force when stamping out of the billets, sagged by smooth slabs. Elimination of premature filling of the hub contributes to a decrease in the average (by the upper and lower stamps) of the wear of molding dies by 20 – 24 %. It was established that in the process of metal reduction in the disk zone, as the earlier formation of the resistance to flow of metal from the side of the molding ring is formed, the smaller slip of the deformable metal relative to the surface of the molding dies is in the zones of their most intense wear (the transition from the disk to the rim) and, as a consequence, less wear amount appears. It has also been found that the metal deformation scheme in molding dies ensuring filling of the flange during axial metal reduction in the rim zone, decrease the metal slippage relatively to the surface of the molding dies at the zones of transition from the disc to the rim. The additional decrease of wear in this case is 27 – 33 %. Ensuring the dimensions stability of the stamped-rolled railway wheels is possible on the basis of stamping schemes, providing a regulated distribution of metal between the central and peripheral parts of the billet and its self-centering in molding dies. This will reduce the weight of the initial billet by 7 – 10 kg.
{"title":"INFLUENCE OF WHEEL BILLET STAMPING SCHEMES ON POWER MODES OF FORMING PRESS OPERATION AND ON WEAR OF THE DEFORMATION TOOL","authors":"S. Snitko, A. V. Yakovchenko, A. Sotnikov","doi":"10.17073/0368-0797-2018-5-385-392","DOIUrl":"https://doi.org/10.17073/0368-0797-2018-5-385-392","url":null,"abstract":"Ensuring the stability of the dimensions of the stamped-rolled railway wheels, the rational power modes of the press operation and durability of the metal deformation tool parts, as well as reduction of the initial billets mass, are actual scientific and technical tasks. This durability largely determines the costs associated with the choice of steel grade for dies, technology of their manufacture and process lubrication. In the present work, based on the results of finite element modeling, the analysis of the influence of stamping schemes of wheel billets on the power modes of operation of a forming press and on wear of the deformation tool was made in relation to modern press rolling lines. It is shown that the stamping schemes, which provide for the regulated distribution of metal between the central and peripheral parts of the billet delivered to the stamps, are characterized by a rational power mode of the forming press. The average force in this case is 63 – 70 % of the average force when stamping out of the billets, sagged by smooth slabs. Elimination of premature filling of the hub contributes to a decrease in the average (by the upper and lower stamps) of the wear of molding dies by 20 – 24 %. It was established that in the process of metal reduction in the disk zone, as the earlier formation of the resistance to flow of metal from the side of the molding ring is formed, the smaller slip of the deformable metal relative to the surface of the molding dies is in the zones of their most intense wear (the transition from the disk to the rim) and, as a consequence, less wear amount appears. It has also been found that the metal deformation scheme in molding dies ensuring filling of the flange during axial metal reduction in the rim zone, decrease the metal slippage relatively to the surface of the molding dies at the zones of transition from the disc to the rim. The additional decrease of wear in this case is 27 – 33 %. Ensuring the dimensions stability of the stamped-rolled railway wheels is possible on the basis of stamping schemes, providing a regulated distribution of metal between the central and peripheral parts of the billet and its self-centering in molding dies. This will reduce the weight of the initial billet by 7 – 10 kg.","PeriodicalId":35527,"journal":{"name":"Izvestiya Vysshikh Uchebnykh Zavedenij. Chernaya Metallurgiya","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2018-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72569825","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 : 2018-06-01DOI: 10.17073/0368-0797-2018-5-393-398
P. Kuznetsov, V. Klimov, D. Kirilenko, M. Yagovkina, E. A. Samodelki
Amorphous and nanocrystal magnetic soft Fe-based alloys are widely used for the shielding materials production, which are effective in the wide range of magnetic and electromagnetic fields. These alloys are obtained in ribbons by an ultra-quick quenching of the melt flow on the high-speed rotating refrigerator-disk. During the amorphous ribbons production process, melted in the high-frequency inductor metal is fed through the dye on the surface of the quenching disk, wherein the surface layers, contacted with the refrigerator-disk, of the forming amorphous ribbon are cooled quicker than the top ones, which are not in contact with the refrigerator-disk. As the result on the “contact” side of the ribbon the residual compression stresses can occur, wherein on the “free” side – the tension stresses. All these can lead to the structure anisotropy along the ribbon thickness, therefore also to the properties anisotropy during the further heat treatment. In the present paper, the results of the TEM structure analysis (planar geometry and transversal cut geometry) along the ribbon thickness of the AMAG200 alloy (Fe – Nb – Cu – Si – B system), obtained by the spinning method, are presented. The relation between the structure changes in the amorphous AMAG-200 alloy (Fe – Nb – Cu – Si – B system), which occurred during the process of the controlled crystallization, with the structure features of the amorphous ribbon, obtained by the ultra-quick quenching of the melt (with the cooling speed up to 106 K/s) is determined, explaining the structure anisotropy along the ribbon thickness. It is stated that the heat treatment under 530 °С forms high magnetic properties and lowers the destruction energy by the formation of the optimal amorphous-nanocrystallline structure in part of grains volume fraction and size. Using the SEM the fracture appearance analysis was performed, connected to the structure obtained during the ultra-quick quenching from the melt and after the heat treatment under 530 °С. It is stated that the fracture surface at the as-build state provide viscous type and after heat treatment-completely brittle type.
{"title":"STRUCTURE FEATURES OF THE Fe –Cu–Nb–Si–B BASED NANOCRYSTALLINE ALLOY RIBBON PRODUCED BY THE MELT SPINNING METHOD","authors":"P. Kuznetsov, V. Klimov, D. Kirilenko, M. Yagovkina, E. A. Samodelki","doi":"10.17073/0368-0797-2018-5-393-398","DOIUrl":"https://doi.org/10.17073/0368-0797-2018-5-393-398","url":null,"abstract":"Amorphous and nanocrystal magnetic soft Fe-based alloys are widely used for the shielding materials production, which are effective in the wide range of magnetic and electromagnetic fields. These alloys are obtained in ribbons by an ultra-quick quenching of the melt flow on the high-speed rotating refrigerator-disk. During the amorphous ribbons production process, melted in the high-frequency inductor metal is fed through the dye on the surface of the quenching disk, wherein the surface layers, contacted with the refrigerator-disk, of the forming amorphous ribbon are cooled quicker than the top ones, which are not in contact with the refrigerator-disk. As the result on the “contact” side of the ribbon the residual compression stresses can occur, wherein on the “free” side – the tension stresses. All these can lead to the structure anisotropy along the ribbon thickness, therefore also to the properties anisotropy during the further heat treatment. In the present paper, the results of the TEM structure analysis (planar geometry and transversal cut geometry) along the ribbon thickness of the AMAG200 alloy (Fe – Nb – Cu – Si – B system), obtained by the spinning method, are presented. The relation between the structure changes in the amorphous AMAG-200 alloy (Fe – Nb – Cu – Si – B system), which occurred during the process of the controlled crystallization, with the structure features of the amorphous ribbon, obtained by the ultra-quick quenching of the melt (with the cooling speed up to 106 K/s) is determined, explaining the structure anisotropy along the ribbon thickness. It is stated that the heat treatment under 530 °С forms high magnetic properties and lowers the destruction energy by the formation of the optimal amorphous-nanocrystallline structure in part of grains volume fraction and size. Using the SEM the fracture appearance analysis was performed, connected to the structure obtained during the ultra-quick quenching from the melt and after the heat treatment under 530 °С. It is stated that the fracture surface at the as-build state provide viscous type and after heat treatment-completely brittle type.","PeriodicalId":35527,"journal":{"name":"Izvestiya Vysshikh Uchebnykh Zavedenij. Chernaya Metallurgiya","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2018-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80393381","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 : 2018-06-01DOI: 10.17073/0368-0797-2018-5-339-347
М. Х. Зиатдинов, И. М. Шатохин, Леопольд Игоревич Леонтьев
The article presents research findings in the development of a specialized SHS technology for composite ferrous alloys for steel melting and blast furnace iron-making. To resolve the principle goal of creating metallurgical production lines it was developed a new approach to practical implementation of the SHS method – a metallurgical SHS process. The metallurgical version of SHS is based on using different metallurgical alloys as the main raw stock; those include dust-type wastes of ferrite alloys production. In this case, the process of synthesis by combustion is implemented via exothermic exchange reactions. Here, composite materials form; they are based on inorganic compositions bound with iron and/or an alloy based on iron. It has been shown that depending on the aggregate state of source reagents, metallurgical SHS processes can be gasless, gasabsorbing or gas-yielding. Combustion modes for these processes largely differ. To arrange for metallurgical SHS process in weakly exothermic systems, one can use different versions of the thermal bonding principle. The authors have investigated self-propagating high-temperature synthesis of nitrided ferrovanadium and ferrochrome. It has been shown that the phase composition of the source alloy has strong impact on the consistent behaviors of the combustion flow and the combustion mechanism of ferrovanadium (if combustion is taking place in nitrogen atmosphere). In the course of nitriding σ-(Fe – V), process activation takes place; the activation is related to the transformation of the intermetallide into α-solid solution when the phase transition temperature is reached (~1200 °C). The composition structure of ferrovanadium nitride products is formed by the confluence of solid-liquid droplet-particles that consist of molten Fe and solid vanadium nitride. A 3-phase mechanism of ferrochrome interaction with nitrogen facilitates the achievement of a high degree of nitriding. It was shown that the combustion rates of ferrochrome (and chrome) during nitriding in coflow filtration mode increase as the nitrogen flow rate is increased. Here, the degree of ferrochrome nitriding during forced filtration (4.7 – 7.5 % N) is much less than that during non-forced filtration (8.8 – 14.2 % N).
{"title":"ТЕХНОЛОГИЯ CВС КОМПОЗИЦИОННЫХ ФЕРРОСПЛАВОВ ЧАСТЬ I. МЕТАЛЛУРГИЧЕСКИЙ СВС ПРОЦЕСС. СИНТЕЗ НИТРИДОВ ФЕРРОВАНАДИЯ И ФЕРРОХРОМА","authors":"М. Х. Зиатдинов, И. М. Шатохин, Леопольд Игоревич Леонтьев","doi":"10.17073/0368-0797-2018-5-339-347","DOIUrl":"https://doi.org/10.17073/0368-0797-2018-5-339-347","url":null,"abstract":"The article presents research findings in the development of a specialized SHS technology for composite ferrous alloys for steel melting and blast furnace iron-making. To resolve the principle goal of creating metallurgical production lines it was developed a new approach to practical implementation of the SHS method – a metallurgical SHS process. The metallurgical version of SHS is based on using different metallurgical alloys as the main raw stock; those include dust-type wastes of ferrite alloys production. In this case, the process of synthesis by combustion is implemented via exothermic exchange reactions. Here, composite materials form; they are based on inorganic compositions bound with iron and/or an alloy based on iron. It has been shown that depending on the aggregate state of source reagents, metallurgical SHS processes can be gasless, gasabsorbing or gas-yielding. Combustion modes for these processes largely differ. To arrange for metallurgical SHS process in weakly exothermic systems, one can use different versions of the thermal bonding principle. The authors have investigated self-propagating high-temperature synthesis of nitrided ferrovanadium and ferrochrome. It has been shown that the phase composition of the source alloy has strong impact on the consistent behaviors of the combustion flow and the combustion mechanism of ferrovanadium (if combustion is taking place in nitrogen atmosphere). In the course of nitriding σ-(Fe – V), process activation takes place; the activation is related to the transformation of the intermetallide into α-solid solution when the phase transition temperature is reached (~1200 °C). The composition structure of ferrovanadium nitride products is formed by the confluence of solid-liquid droplet-particles that consist of molten Fe and solid vanadium nitride. A 3-phase mechanism of ferrochrome interaction with nitrogen facilitates the achievement of a high degree of nitriding. It was shown that the combustion rates of ferrochrome (and chrome) during nitriding in coflow filtration mode increase as the nitrogen flow rate is increased. Here, the degree of ferrochrome nitriding during forced filtration (4.7 – 7.5 % N) is much less than that during non-forced filtration (8.8 – 14.2 % N).","PeriodicalId":35527,"journal":{"name":"Izvestiya Vysshikh Uchebnykh Zavedenij. Chernaya Metallurgiya","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2018-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77145414","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 : 2018-06-01DOI: 10.17073/0368-0797-2018-5-348-356
T. Koinov, S. M. Bel’skii, Y. A. Mukhin, V. B. Chuprov
Based on the Jourdain variation principle, a mathematical model of the process of free widening in hot rolling of thin sheet metal is developed. The principle applies to rigid-plastic materials and for the cinematically admissible area of speeds. As a functional of the variational equation, sum of the powers of internal resistances, frictional forces, shear forces, front and back tension was used. When solving the Jourdain variational equation for the case of rolling with tension, the Ritz method was applied. The Jourdain variational equation was transformed into a system of homogeneous equations, the left side of each represented a derivative with respect to a varying parameter. Varying parameters were the exponent of the kinematic condition, general widening in the plastic deformation zone and the widening in its neutral section. The developed model allows to study the distribution of the widening on length of the deformation zone depending on the parameters of rolling process and sheet metal. To test the adequacy of the developed free-widening model, experimental studies were carried out on a two-roll cold rolling mill. Lead samples were rolled, the measured widening values of which coincided with the theoretical calculated with an accuracy of less than 10%. Cold rolling of lead samples simulates hot rolling. Theoretical analysis of the influence of tension on the process of free widening when applying tension is consistent with the practical results presented in the literature. It is shown that the unevenness of tensile stresses in the input and output sections of the deformation zone arising from the application of tension causes the appearance of additional powers in the power balance equation, leading to a decrease in magnitude of the widening. The resulting unevenness of the tensile stresses can be used to control magnitude of the widening in thin-sheet rolling. In turn, unevenness of the tensile stresses along the width of rolled strip can be increased or decreased by means of the bending forces of work rolls of the rolling stand. The article presents a scheme for controlling the value of the rolling band widening during hot rolling with the help of bending forces of work rolls.
{"title":"INFLUENCE OF BENDING EFFORTS OF WORKING ROLLS ON WIDENING OF THE THIN STEEL STRIP DURING HOT ROLLING","authors":"T. Koinov, S. M. Bel’skii, Y. A. Mukhin, V. B. Chuprov","doi":"10.17073/0368-0797-2018-5-348-356","DOIUrl":"https://doi.org/10.17073/0368-0797-2018-5-348-356","url":null,"abstract":"Based on the Jourdain variation principle, a mathematical model of the process of free widening in hot rolling of thin sheet metal is developed. The principle applies to rigid-plastic materials and for the cinematically admissible area of speeds. As a functional of the variational equation, sum of the powers of internal resistances, frictional forces, shear forces, front and back tension was used. When solving the Jourdain variational equation for the case of rolling with tension, the Ritz method was applied. The Jourdain variational equation was transformed into a system of homogeneous equations, the left side of each represented a derivative with respect to a varying parameter. Varying parameters were the exponent of the kinematic condition, general widening in the plastic deformation zone and the widening in its neutral section. The developed model allows to study the distribution of the widening on length of the deformation zone depending on the parameters of rolling process and sheet metal. To test the adequacy of the developed free-widening model, experimental studies were carried out on a two-roll cold rolling mill. Lead samples were rolled, the measured widening values of which coincided with the theoretical calculated with an accuracy of less than 10%. Cold rolling of lead samples simulates hot rolling. Theoretical analysis of the influence of tension on the process of free widening when applying tension is consistent with the practical results presented in the literature. It is shown that the unevenness of tensile stresses in the input and output sections of the deformation zone arising from the application of tension causes the appearance of additional powers in the power balance equation, leading to a decrease in magnitude of the widening. The resulting unevenness of the tensile stresses can be used to control magnitude of the widening in thin-sheet rolling. In turn, unevenness of the tensile stresses along the width of rolled strip can be increased or decreased by means of the bending forces of work rolls of the rolling stand. The article presents a scheme for controlling the value of the rolling band widening during hot rolling with the help of bending forces of work rolls.","PeriodicalId":35527,"journal":{"name":"Izvestiya Vysshikh Uchebnykh Zavedenij. Chernaya Metallurgiya","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2018-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88987222","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 : 2018-06-01DOI: 10.17073/0368-0797-2018-5-413-415
T. Malysheva, S. A. Pisarev, A. R. Makavetskas, Yu. Yu. Fishchenko
Recently, the demand for iron ore concentrates of the Kovdor deposit has been maintained, despite the complexity of their use for the production of man-made raw materials. Magnetite of Kovdor ore has a heterogeneous structure and its iron does not participate in melt formation processes during sintering of agglomerates. Therefore, up to the basicity of 2.0, a silicate glass phase is a binder of ore grains of the finished product. With the increase in basicity above 2.0, the mineral composition and microstructure of the agglomerates change. Magnetite is oxidized to hematite, an alumino-siliciferite appears on the hematite contact with the high-calcium melt, the residual melt crystallizes to form a titanium-containing silicate.
{"title":"ON THE USE OF KOVDOR IRON ORE IN SINTERING PROCESS","authors":"T. Malysheva, S. A. Pisarev, A. R. Makavetskas, Yu. Yu. Fishchenko","doi":"10.17073/0368-0797-2018-5-413-415","DOIUrl":"https://doi.org/10.17073/0368-0797-2018-5-413-415","url":null,"abstract":"Recently, the demand for iron ore concentrates of the Kovdor deposit has been maintained, despite the complexity of their use for the production of man-made raw materials. Magnetite of Kovdor ore has a heterogeneous structure and its iron does not participate in melt formation processes during sintering of agglomerates. Therefore, up to the basicity of 2.0, a silicate glass phase is a binder of ore grains of the finished product. With the increase in basicity above 2.0, the mineral composition and microstructure of the agglomerates change. Magnetite is oxidized to hematite, an alumino-siliciferite appears on the hematite contact with the high-calcium melt, the residual melt crystallizes to form a titanium-containing silicate.","PeriodicalId":35527,"journal":{"name":"Izvestiya Vysshikh Uchebnykh Zavedenij. Chernaya Metallurgiya","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2018-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79824862","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 : 2018-06-01DOI: 10.17073/0368-0797-2018-5-416-417
G. Orlov, A. A. Malanov, A. G. Orlov
The results of numerical experiments on studying of influence of technological errors on the vertical and horizontal forces of rolling are given. A full factorial computational experiment was performed by varying factors: initial wall thickness variation of pipes, feed and friction factor. The regression equations were obtained by the vertical and horizontal forces from these factors. It was found that the force values obtained when the maximum values of the factors are much higher than the values obtained at minimum values of factors: the vertical force varies by more than 2 times, and the axial force – more than 8 times. It was concluded that the errors of setup rolling parameters can cause a multiple increase in the forces of rolling, especially, in the horizontal component. Therefore, for stable rolling mills operation the observance of procedures discipline and control the initial wall thickness variation of pipes are necessary.
{"title":"EFFECT OF TECHNOLOGICAL ERRORS ON FORCE PARAMETERS OF PIPES COLD ROLLING","authors":"G. Orlov, A. A. Malanov, A. G. Orlov","doi":"10.17073/0368-0797-2018-5-416-417","DOIUrl":"https://doi.org/10.17073/0368-0797-2018-5-416-417","url":null,"abstract":"The results of numerical experiments on studying of influence of technological errors on the vertical and horizontal forces of rolling are given. A full factorial computational experiment was performed by varying factors: initial wall thickness variation of pipes, feed and friction factor. The regression equations were obtained by the vertical and horizontal forces from these factors. It was found that the force values obtained when the maximum values of the factors are much higher than the values obtained at minimum values of factors: the vertical force varies by more than 2 times, and the axial force – more than 8 times. It was concluded that the errors of setup rolling parameters can cause a multiple increase in the forces of rolling, especially, in the horizontal component. Therefore, for stable rolling mills operation the observance of procedures discipline and control the initial wall thickness variation of pipes are necessary.","PeriodicalId":35527,"journal":{"name":"Izvestiya Vysshikh Uchebnykh Zavedenij. Chernaya Metallurgiya","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2018-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83127144","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 : 2018-06-01DOI: 10.17073/0368-0797-2018-5-364-371
А. М. Михайленко, Данил Леонидович Шварц
Based on the system approach and on the experience accumulated at theoretical data, design and industrial development of bar rolling, the Chair “Metal Forming” of Ural Federal University develops the universal “Concept of optimum calibration”. The general ideology of roll pass design optimization is stated in article “The concept of optimal bar roll pass design. Report 1. Basic statements”. In the article “The concept of optimal bar roll pass design. Report 2. Calibers space” the structure, appointment and maintenance of the information block reflecting so-called “calibers space” are considered. According to the general concept of optimization, the following task that needs to be solved is the problem of creation of information block so-called “space of schemes of roll pass design” which will be used further as the first space of optimization. The concept “space of schemes of roll pass design of a bar-rolling mill” is considered as the space containing all possible virtual schemes of rolling of a concrete profile on the concrete rolling mill. For formation of the space of schemes of rail calibrations it is necessary to generate separate virtual schemes and to consistently fill this space with them. Thus, the space of calibrations schemes is formed of separate unique calibrations schemes. For formation of this space from separate calibers, it is offered to use the specialized algorithms which are “generators of schemes of roll pass design”. As an example, the structure of the generator prepared for creation of such space for rolling of railway rails is considered. It is revealed that all known rail calibrations can be presented in the form of essentially the same block structure which is used as the central element of the schemes generator of rail calibrations. Usage of described and similar generators in relation to rolling process of a concrete profile on the concrete rolling mill allows obtaining spaces of acceptable schemes of calibrations. Such spaces are necessary for the subsequent optimizing procedures for search of the best calibration scheme from all possible calibrations. The considered approach for creation of calibrations schemes space can be used during creation of computer-aided engineering systems and optimization of calibrations of rolling rolls.
{"title":"КОНЦЕПЦИЯ ОПТИМАЛЬНОЙ КАЛИБРОВКИ СОРТОПРОКАТНЫХ ВАЛКОВ. СООБЩЕНИЕ 3. ПРОСТРАНСТВО СХЕМ КАЛИБРОВОК","authors":"А. М. Михайленко, Данил Леонидович Шварц","doi":"10.17073/0368-0797-2018-5-364-371","DOIUrl":"https://doi.org/10.17073/0368-0797-2018-5-364-371","url":null,"abstract":"Based on the system approach and on the experience accumulated at theoretical data, design and industrial development of bar rolling, the Chair “Metal Forming” of Ural Federal University develops the universal “Concept of optimum calibration”. The general ideology of roll pass design optimization is stated in article “The concept of optimal bar roll pass design. Report 1. Basic statements”. In the article “The concept of optimal bar roll pass design. Report 2. Calibers space” the structure, appointment and maintenance of the information block reflecting so-called “calibers space” are considered. According to the general concept of optimization, the following task that needs to be solved is the problem of creation of information block so-called “space of schemes of roll pass design” which will be used further as the first space of optimization. The concept “space of schemes of roll pass design of a bar-rolling mill” is considered as the space containing all possible virtual schemes of rolling of a concrete profile on the concrete rolling mill. For formation of the space of schemes of rail calibrations it is necessary to generate separate virtual schemes and to consistently fill this space with them. Thus, the space of calibrations schemes is formed of separate unique calibrations schemes. For formation of this space from separate calibers, it is offered to use the specialized algorithms which are “generators of schemes of roll pass design”. As an example, the structure of the generator prepared for creation of such space for rolling of railway rails is considered. It is revealed that all known rail calibrations can be presented in the form of essentially the same block structure which is used as the central element of the schemes generator of rail calibrations. Usage of described and similar generators in relation to rolling process of a concrete profile on the concrete rolling mill allows obtaining spaces of acceptable schemes of calibrations. Such spaces are necessary for the subsequent optimizing procedures for search of the best calibration scheme from all possible calibrations. The considered approach for creation of calibrations schemes space can be used during creation of computer-aided engineering systems and optimization of calibrations of rolling rolls.","PeriodicalId":35527,"journal":{"name":"Izvestiya Vysshikh Uchebnykh Zavedenij. Chernaya Metallurgiya","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2018-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76755221","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 : 2018-06-01DOI: 10.17073/0368-0797-2018-5-399-406
E. Smirnov, V. Sklyar, O. E. Smirnov, V. Belevitin, R. E. Pivovarov
{"title":"RESEARCH OF THE BEHAVIOR OF MACROSTRUCTURE DEFECTS OF THE PRE-DEFORMED CONTINUOUS CAST BILLETS DURING ROLLING","authors":"E. Smirnov, V. Sklyar, O. E. Smirnov, V. Belevitin, R. E. Pivovarov","doi":"10.17073/0368-0797-2018-5-399-406","DOIUrl":"https://doi.org/10.17073/0368-0797-2018-5-399-406","url":null,"abstract":"","PeriodicalId":35527,"journal":{"name":"Izvestiya Vysshikh Uchebnykh Zavedenij. Chernaya Metallurgiya","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2018-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75378809","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 : 2018-06-01DOI: 10.17073/0368-0797-2018-5-357-363
I. A. Levitskii, A. Radyuk, A. Titlyanov, T. Sidorova
. The use of natural gas reduces the amount of coke to produce pig iron. The flow of hot blast pushes natural gas to the surface of blowing channel in the conventional tuyere. Natural gas is poorly mixed with natural gas. This causes incomplete natural gas combus-363 tion and pyro lysis. Therefore, the problem of the completeness of combustion of natural gas is relevant. One way to improve the mixing of natural gas and hot blast is the gas pipe in the blow channel. However, dynamics and change of the thermal state of the tuyere are understudied for this option. The possibility of ignition of natural gas inside tuyeres must also be taken into account. The authors have in-vestigated the infl uence of the method of natural gas supplying on gas dynamics and heat transfer in air tuyere of a blast furnace with the help of modeling in ANSYS Fluent 15.0.7. Simplifying assumptions were adopted. Only fluid inside the blowing channel is considered as the modeling zone, and the processes of heat transfer to the water of cooling system are considered in the extended boundary conditions. A simplified diagram of the compu tational domain was created in DesignModeler and a computational mesh – in AnsysMeshing. The boundary conditions were set for blowing, natural gas, and also for the border of the fluid with copper walls. The calculations were carried out for half of the tuyere. It is shown that under the given conditions of flow of air and natural gas, combustion inside tuyere with extended to mid-channel gas blowing nozzle does not occur, and natural gas is mixed with the hot air. Improving the mixing of natural gas and hot air, one side, reduces heat flow at the exit of the blowing channel and the average temperature of the gas mixture, on the other side, creates conditions for complete combustion of natural gas outside the tuyere.
{"title":"INFLUENCE OF THE METHOD OF NATURAL GAS SUPPLYING ON GAS DYNAMICS AND HEAT TRANSFER IN AIR TUYERE OF BLAST FURNACE","authors":"I. A. Levitskii, A. Radyuk, A. Titlyanov, T. Sidorova","doi":"10.17073/0368-0797-2018-5-357-363","DOIUrl":"https://doi.org/10.17073/0368-0797-2018-5-357-363","url":null,"abstract":". The use of natural gas reduces the amount of coke to produce pig iron. The flow of hot blast pushes natural gas to the surface of blowing channel in the conventional tuyere. Natural gas is poorly mixed with natural gas. This causes incomplete natural gas combus-363 tion and pyro lysis. Therefore, the problem of the completeness of combustion of natural gas is relevant. One way to improve the mixing of natural gas and hot blast is the gas pipe in the blow channel. However, dynamics and change of the thermal state of the tuyere are understudied for this option. The possibility of ignition of natural gas inside tuyeres must also be taken into account. The authors have in-vestigated the infl uence of the method of natural gas supplying on gas dynamics and heat transfer in air tuyere of a blast furnace with the help of modeling in ANSYS Fluent 15.0.7. Simplifying assumptions were adopted. Only fluid inside the blowing channel is considered as the modeling zone, and the processes of heat transfer to the water of cooling system are considered in the extended boundary conditions. A simplified diagram of the compu tational domain was created in DesignModeler and a computational mesh – in AnsysMeshing. The boundary conditions were set for blowing, natural gas, and also for the border of the fluid with copper walls. The calculations were carried out for half of the tuyere. It is shown that under the given conditions of flow of air and natural gas, combustion inside tuyere with extended to mid-channel gas blowing nozzle does not occur, and natural gas is mixed with the hot air. Improving the mixing of natural gas and hot air, one side, reduces heat flow at the exit of the blowing channel and the average temperature of the gas mixture, on the other side, creates conditions for complete combustion of natural gas outside the tuyere.","PeriodicalId":35527,"journal":{"name":"Izvestiya Vysshikh Uchebnykh Zavedenij. Chernaya Metallurgiya","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2018-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76334252","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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