Pub Date : 2018-10-24DOI: 10.17073/0368-0797-2018-8-631-637
G. Poletaev, I. Zorya, Roman Rakitin
The interaction of hydrogen atoms with nanocrystalline palladium and nickel in the work was studied by the molecular dynamics method. The nanocrystalline structure of palladium and nickel was created in the model by crystallization from the liquid state at the presence of several specially introduced crystalline embryos. After solidification, the calculation blocks, in addition to the crystalline phase, contained grain boundaries and triple junctions of grain boundaries. The interactions of metal atoms with each other were described by the multi-particle Cleri-Rosato potential constructed in the framework of the tight-binding model. Morse potentials were used to describe the interactions of hydrogen atoms with metal atoms and with each other. The parameters of Morse potentials were calculated from the experimental data of theabsorption energy, the activation energy of the above-barrier diffusion of hydrogen in a metal (at normal and high temperatures), the binding energy with a vacancy, dilatation. According to the results obtained in the present work, at a high concentration of hydrogen (the concentration of 10% from the metal atoms was considered), the hydrogen atoms combine into aggregates, which are formed predominantly near the surface of the metal. The aggregates contained, as a rule, several dozen hydrogen atoms and had low diffusion activity. The binding energy of hydrogen atoms with these aggregates was greater than with the metal crystal lattice or grain boundaries in it. In palladium, hydrogen aggregates were formed farther from the surface than in nickel. Apparently, this is due not so much to the relatively low energy of hydrogen absorption by palladium (–0.1 eV) in comparison with nickel (0.16 eV), but rather to the difference in lattice parameters of the metals under consideration: 3.89 Å for Pd and 3.524 Å for Ni. For the same reason, conspicuously, hydrogen aggregates in a pure crystal lattice were more often observed in Pd than in Ni. In Ni, aggregates, as a rule, were formed in defect areas containing an excess free volume: near the free surface, in grain boundaries and in triple junctions.
{"title":"INTERACTION OF HYDROGEN IMPURITY WITH NANOCRYSTALLINE PALLADIUM AND NICKEL","authors":"G. Poletaev, I. Zorya, Roman Rakitin","doi":"10.17073/0368-0797-2018-8-631-637","DOIUrl":"https://doi.org/10.17073/0368-0797-2018-8-631-637","url":null,"abstract":"The interaction of hydrogen atoms with nanocrystalline palladium and nickel in the work was studied by the molecular dynamics method. The nanocrystalline structure of palladium and nickel was created in the model by crystallization from the liquid state at the presence of several specially introduced crystalline embryos. After solidification, the calculation blocks, in addition to the crystalline phase, contained grain boundaries and triple junctions of grain boundaries. The interactions of metal atoms with each other were described by the multi-particle Cleri-Rosato potential constructed in the framework of the tight-binding model. Morse potentials were used to describe the interactions of hydrogen atoms with metal atoms and with each other. The parameters of Morse potentials were calculated from the experimental data of theabsorption energy, the activation energy of the above-barrier diffusion of hydrogen in a metal (at normal and high temperatures), the binding energy with a vacancy, dilatation. According to the results obtained in the present work, at a high concentration of hydrogen (the concentration of 10% from the metal atoms was considered), the hydrogen atoms combine into aggregates, which are formed predominantly near the surface of the metal. The aggregates contained, as a rule, several dozen hydrogen atoms and had low diffusion activity. The binding energy of hydrogen atoms with these aggregates was greater than with the metal crystal lattice or grain boundaries in it. In palladium, hydrogen aggregates were formed farther from the surface than in nickel. Apparently, this is due not so much to the relatively low energy of hydrogen absorption by palladium (–0.1 eV) in comparison with nickel (0.16 eV), but rather to the difference in lattice parameters of the metals under consideration: 3.89 Å for Pd and 3.524 Å for Ni. For the same reason, conspicuously, hydrogen aggregates in a pure crystal lattice were more often observed in Pd than in Ni. In Ni, aggregates, as a rule, were formed in defect areas containing an excess free volume: near the free surface, in grain boundaries and in triple junctions.","PeriodicalId":35527,"journal":{"name":"Izvestiya Vysshikh Uchebnykh Zavedenij. Chernaya Metallurgiya","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2018-10-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86263849","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 : 2018-10-24DOI: 10.17073/0368-0797-2018-8-589-595
A. V. Afanas’ev, A. A. Mel’nikov, M. I. Vas’kov, D. N. Bel’kov
The paper presents the results of metallographic studies of stresscorrosion defects (SCC defects) detected on the output gas pipeline of the compressor station. The diagnostics statistics of defects in such pipelines and the data on the effectiveness evaluation of various diagnostic tools during the diagnosis of SCC are given. A presumptive steel grade corresponding to the pipeline metal was identified. The species and morphology of cracks are described. Their character of development is defined. To detect traces of the influence of metallurgical impurities and the external environment on the defects development, a spectrometry of corrosion products and base metal was made. The authors have made the maps of elements distribution over the sample controlled surface. The absence of influence of nonmetallic sulphide inclusions on the development of metal destruction in this is described for the particular case of SCC. It is shown that the sulfur content in corrosion products does not exceed the sulfur content in the sample metal. In some samples, reduced sulfur content can be observed, with the exception of local sites with nonmetallic sulphide inclusions. Electronic images were obtained, which show that these nonmetallic inclusions (in this case) are not sources of cracking development. The results of cyclic tests of samples cut from the pipeline and containing cracks are given. The choice of the cyclic test mode was carried out in accordance with the analysis of the compressor station operating mode for the current year of operation. According to the data received, pipe materials with defects at their initial stage of development have shown considerable durability under test loads. The samples with cracks have withstood from 1.6·106 to 7.5·106 loading cycles under conditions of cyclic transverse bending in the same test plane in the absence of a corrosive medium. In a real gas pipeline under normal operation conditions, the number of such cycles does not exceed 120 – 200 per year, therefore, it can be concluded that the pipeline with defects in their initial stage of development has a significant residual life, provided that its metal wall is reliably protected from effects of corrosive environment.
{"title":"CYCLIC TESTS OF STRESS-CORROSION CRACKS OF STEEL GAS PIPELINE PIPES IN THE ABSENCE OF CORROSIVE ENVIRONMENT","authors":"A. V. Afanas’ev, A. A. Mel’nikov, M. I. Vas’kov, D. N. Bel’kov","doi":"10.17073/0368-0797-2018-8-589-595","DOIUrl":"https://doi.org/10.17073/0368-0797-2018-8-589-595","url":null,"abstract":"The paper presents the results of metallographic studies of stresscorrosion defects (SCC defects) detected on the output gas pipeline of the compressor station. The diagnostics statistics of defects in such pipelines and the data on the effectiveness evaluation of various diagnostic tools during the diagnosis of SCC are given. A presumptive steel grade corresponding to the pipeline metal was identified. The species and morphology of cracks are described. Their character of development is defined. To detect traces of the influence of metallurgical impurities and the external environment on the defects development, a spectrometry of corrosion products and base metal was made. The authors have made the maps of elements distribution over the sample controlled surface. The absence of influence of nonmetallic sulphide inclusions on the development of metal destruction in this is described for the particular case of SCC. It is shown that the sulfur content in corrosion products does not exceed the sulfur content in the sample metal. In some samples, reduced sulfur content can be observed, with the exception of local sites with nonmetallic sulphide inclusions. Electronic images were obtained, which show that these nonmetallic inclusions (in this case) are not sources of cracking development. The results of cyclic tests of samples cut from the pipeline and containing cracks are given. The choice of the cyclic test mode was carried out in accordance with the analysis of the compressor station operating mode for the current year of operation. According to the data received, pipe materials with defects at their initial stage of development have shown considerable durability under test loads. The samples with cracks have withstood from 1.6·106 to 7.5·106 loading cycles under conditions of cyclic transverse bending in the same test plane in the absence of a corrosive medium. In a real gas pipeline under normal operation conditions, the number of such cycles does not exceed 120 – 200 per year, therefore, it can be concluded that the pipeline with defects in their initial stage of development has a significant residual life, provided that its metal wall is reliably protected from effects of corrosive environment.","PeriodicalId":35527,"journal":{"name":"Izvestiya Vysshikh Uchebnykh Zavedenij. Chernaya Metallurgiya","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2018-10-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72623603","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 : 2018-10-24DOI: 10.17073/0368-0797-2018-8-644-648
M. P. Revun, V. Zinchenko, V. Ivanov, A. Cheprasov
Using local systems of automatic control of temperature and surplus pressure of heating in the working volume of flaming thermal furnace of chamber type, settings, as a rule, are selected separately without the account of their interconnection. At the same time in control of expense of fuel and air not only temperature but also pressure changes in the working chamber of furnace, that, in turn, is accompanied by change of gaseous exchange with a medium and renders substantial influence temperature in a working chamber. All this is accompanied by substantial excessive consumption of gaseous fuel, and, as a result, by the rise of costs of metal heat treatment. Using heating chart with the constant volume of products of burning in the furnaces of such type, the control of its heat power is in combining charges of different components of gaseous fuel at condition of providing of the given temperature in the working volume. According to the principle of Bellman dynamic programming, optimization of control for the cycle of metal heat treatment was provided by choice of the applied fuel which is optimal on a cost composition for every period of quantum. The present cost of fuel serves as the linear function of middle charges of its separate components in periods of quantum and finding of its minimum value for every discrete moment of time, presented as a decision of task of the linear programming. The determination algorithm for optimal values of charges of gaseous fuel separate components was worked out, as well as for the expense of surplus air, used as controlling influences for the automatic systems of adjusting of temperature and surplus pressure of heating medium in the working volume of furnaces. The functional cart of automatic control system is provided, which implementation allows not only optimization of heating technology by cost of separate fuel components, but also provision of the control autonomy of temperature and surplus pressure of heating medium in the working chamber of furnaces of chamber type by means of self-adjustment. In real-time control process is executed with optimization of cost of separate components of fuel self-adjustment of the system.
{"title":"OPTIMIZATION OF HEATING OPERATION CONTROL IN CHAMBER-TYPE THERMAL FURNACE","authors":"M. P. Revun, V. Zinchenko, V. Ivanov, A. Cheprasov","doi":"10.17073/0368-0797-2018-8-644-648","DOIUrl":"https://doi.org/10.17073/0368-0797-2018-8-644-648","url":null,"abstract":"Using local systems of automatic control of temperature and surplus pressure of heating in the working volume of flaming thermal furnace of chamber type, settings, as a rule, are selected separately without the account of their interconnection. At the same time in control of expense of fuel and air not only temperature but also pressure changes in the working chamber of furnace, that, in turn, is accompanied by change of gaseous exchange with a medium and renders substantial influence temperature in a working chamber. All this is accompanied by substantial excessive consumption of gaseous fuel, and, as a result, by the rise of costs of metal heat treatment. Using heating chart with the constant volume of products of burning in the furnaces of such type, the control of its heat power is in combining charges of different components of gaseous fuel at condition of providing of the given temperature in the working volume. According to the principle of Bellman dynamic programming, optimization of control for the cycle of metal heat treatment was provided by choice of the applied fuel which is optimal on a cost composition for every period of quantum. The present cost of fuel serves as the linear function of middle charges of its separate components in periods of quantum and finding of its minimum value for every discrete moment of time, presented as a decision of task of the linear programming. The determination algorithm for optimal values of charges of gaseous fuel separate components was worked out, as well as for the expense of surplus air, used as controlling influences for the automatic systems of adjusting of temperature and surplus pressure of heating medium in the working volume of furnaces. The functional cart of automatic control system is provided, which implementation allows not only optimization of heating technology by cost of separate fuel components, but also provision of the control autonomy of temperature and surplus pressure of heating medium in the working chamber of furnaces of chamber type by means of self-adjustment. In real-time control process is executed with optimization of cost of separate components of fuel self-adjustment of the system.","PeriodicalId":35527,"journal":{"name":"Izvestiya Vysshikh Uchebnykh Zavedenij. Chernaya Metallurgiya","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2018-10-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79863695","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 : 2018-10-24DOI: 10.17073/0368-0797-2018-8-638-643
A. Brover, G. Brover
Experimental studies of laser-irradiated layers in a magnetic field (MF) have shown a non-trivial morphology of the surface of handling zone of material in case of reflow. Twisting of a thin layer of liquid metal is observed, irradiated area is getting a crescent appearance, definitely strictly oriented in relation to magnetic flux. This is probably due to the effect of Righi-Leduc, as well as the action of Lorentz forces, which deflect the electrons flow. As a result, there is significant mixing of metal in the irradiation zone, chemical composition equalization, which positively affects the strength properties of the products. One of the important consequences of the MF-effect on the results of laser processing is the phenomenon of magnetostriction. In laser irradiation without MF slide lines were observed on the pre-polished surface patterns resulting from the emerging thermal and structural stresses. By analyzing the topography of irradiated surfaces using modern analysis techniques and computer image processing, it was established that irradiation in MF in conditions of magnetostriction decreases the stress level in irradiated areas and reduces the risk of cracking. The results of temperature measurements at the irradiated spot on cooling stage allow establishing that the cooling rate during laser processing in a MF is considerably higher than without the field. It affects the processes of phase and structural transformations. At laser heating in MF microheterogenic austenite is supercooled with great speed to temperatures of martensite transformation. After that its transformation begins, the sequence of which is determined by the level of local saturation, degree of deformation and is controlled by temperature. The first crystals of martensite are formed in the least saturated areas of austenite, and a very high speed (thousands or tens of thousands of °С/s) of the transformation process beginning γ → α prevents martensite self tempering, which partially can occur when the temperature decreases further due to transformation spread on the remaining volume of austenite, grabbing areas of different saturation. As a result, along with the “fresh-formed” martensite in the areas of laser quenching the martensite is formed, in which segregation of carbon or even ε-carbide may occur and residual austenite with high carbon intensity are formed. Released dispersed carbides contribute to obtaining a sufficiently high hardness values of metals irradiated in a MF.
{"title":"INFLUENCE OF CONSTANT MAGNETIC FIELD ON STRUCTURE FORMATION IN STEELS AT HIGH-SPEED LASER PROCESSING","authors":"A. Brover, G. Brover","doi":"10.17073/0368-0797-2018-8-638-643","DOIUrl":"https://doi.org/10.17073/0368-0797-2018-8-638-643","url":null,"abstract":"Experimental studies of laser-irradiated layers in a magnetic field (MF) have shown a non-trivial morphology of the surface of handling zone of material in case of reflow. Twisting of a thin layer of liquid metal is observed, irradiated area is getting a crescent appearance, definitely strictly oriented in relation to magnetic flux. This is probably due to the effect of Righi-Leduc, as well as the action of Lorentz forces, which deflect the electrons flow. As a result, there is significant mixing of metal in the irradiation zone, chemical composition equalization, which positively affects the strength properties of the products. One of the important consequences of the MF-effect on the results of laser processing is the phenomenon of magnetostriction. In laser irradiation without MF slide lines were observed on the pre-polished surface patterns resulting from the emerging thermal and structural stresses. By analyzing the topography of irradiated surfaces using modern analysis techniques and computer image processing, it was established that irradiation in MF in conditions of magnetostriction decreases the stress level in irradiated areas and reduces the risk of cracking. The results of temperature measurements at the irradiated spot on cooling stage allow establishing that the cooling rate during laser processing in a MF is considerably higher than without the field. It affects the processes of phase and structural transformations. At laser heating in MF microheterogenic austenite is supercooled with great speed to temperatures of martensite transformation. After that its transformation begins, the sequence of which is determined by the level of local saturation, degree of deformation and is controlled by temperature. The first crystals of martensite are formed in the least saturated areas of austenite, and a very high speed (thousands or tens of thousands of °С/s) of the transformation process beginning γ → α prevents martensite self tempering, which partially can occur when the temperature decreases further due to transformation spread on the remaining volume of austenite, grabbing areas of different saturation. As a result, along with the “fresh-formed” martensite in the areas of laser quenching the martensite is formed, in which segregation of carbon or even ε-carbide may occur and residual austenite with high carbon intensity are formed. Released dispersed carbides contribute to obtaining a sufficiently high hardness values of metals irradiated in a MF.","PeriodicalId":35527,"journal":{"name":"Izvestiya Vysshikh Uchebnykh Zavedenij. Chernaya Metallurgiya","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2018-10-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84774102","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 : 2018-10-24DOI: 10.17073/0368-0797-2018-8-606-612
V. I. Odinokov, E. A. Dmitriev, A. I. Evstigneev
Flow of liquid melt in the crystallizer is a little-studied process. Analytical solutions of melt flow in general case refer to complex mathematical problems, therefore numerical methods are used to model it. The purpose of this work is to use numerical method proposed by Professor V.I. Odinokov, based on finite-difference representation of the initial system of equations. This method has been successfully used in mechanics of continuous media, in foundry industry in mathematical modeling of strained deformed state of shell molds on investment models,as well as in other technological works, which indicates its universality. In the present study, the object of research is hydrodynamic flows of liquid metal during steel casting into a rectangular section mold when fed from a submerged nozzle with eccentric holes, and the result is a spatial mathematical model describing the flows of liquid metal in the crystallizer. To simulate the processes occurring in the crystallizer, the software complex “Odyssey” was used. The theoretical calculation is based on fundamental equations of hydrodynamics and approved numericalmethod. Solution of differential equations system formulatedin the work was carried out numerically. Investigated area was divided into elements of finite dimensions, for each element the resulting system of equations was written in the difference form. The result of the solution is velocity field of metal flow in crystallizer volume. To solve the system of algebraic equations obtained, a numerical scheme and a calculation algorithm were developed. Based on developed numerical scheme and algorithm, a computation program was compiled in Fortran-4. Mathematical model makes it possible to vary geometric dimensions of the crystallizer and cross-section of metal exit openings from the immersion nozzle, and it can also help to understand the flow pattern of the cast metal that affects heat dissipation of crystallizer walls and to find the optimal parameters for liquid metal outlet from the gravy glass at various casting modes. As an example it is given calculation of steel casting into a rectangular mold with a height of 100 cm and a section of 2000×40 (cm) in plan. Casting was carried out from immersion nozzle eccentrically in both sides in a horizontal plane. The calculation results are presented in graphical form. The movement of liquid metal flows is shown, their magnitudes and intensity are determined.
{"title":"MATHEMATICAL MODELING OF METAL FLOW IN CRYSTALLIZER AT ITS SUPPLY FROM SUBMERSIBLE NOZZLE WITH ECCENTRIC HOLES","authors":"V. I. Odinokov, E. A. Dmitriev, A. I. Evstigneev","doi":"10.17073/0368-0797-2018-8-606-612","DOIUrl":"https://doi.org/10.17073/0368-0797-2018-8-606-612","url":null,"abstract":"Flow of liquid melt in the crystallizer is a little-studied process. Analytical solutions of melt flow in general case refer to complex mathematical problems, therefore numerical methods are used to model it. The purpose of this work is to use numerical method proposed by Professor V.I. Odinokov, based on finite-difference representation of the initial system of equations. This method has been successfully used in mechanics of continuous media, in foundry industry in mathematical modeling of strained deformed state of shell molds on investment models,as well as in other technological works, which indicates its universality. In the present study, the object of research is hydrodynamic flows of liquid metal during steel casting into a rectangular section mold when fed from a submerged nozzle with eccentric holes, and the result is a spatial mathematical model describing the flows of liquid metal in the crystallizer. To simulate the processes occurring in the crystallizer, the software complex “Odyssey” was used. The theoretical calculation is based on fundamental equations of hydrodynamics and approved numericalmethod. Solution of differential equations system formulatedin the work was carried out numerically. Investigated area was divided into elements of finite dimensions, for each element the resulting system of equations was written in the difference form. The result of the solution is velocity field of metal flow in crystallizer volume. To solve the system of algebraic equations obtained, a numerical scheme and a calculation algorithm were developed. Based on developed numerical scheme and algorithm, a computation program was compiled in Fortran-4. Mathematical model makes it possible to vary geometric dimensions of the crystallizer and cross-section of metal exit openings from the immersion nozzle, and it can also help to understand the flow pattern of the cast metal that affects heat dissipation of crystallizer walls and to find the optimal parameters for liquid metal outlet from the gravy glass at various casting modes. As an example it is given calculation of steel casting into a rectangular mold with a height of 100 cm and a section of 2000×40 (cm) in plan. Casting was carried out from immersion nozzle eccentrically in both sides in a horizontal plane. The calculation results are presented in graphical form. The movement of liquid metal flows is shown, their magnitudes and intensity are determined. ","PeriodicalId":35527,"journal":{"name":"Izvestiya Vysshikh Uchebnykh Zavedenij. Chernaya Metallurgiya","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2018-10-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88287003","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 : 2018-10-23DOI: 10.17073/0368-0797-2018-8-657-661
A. Aleksandrov, V. Dashevskii, L. I. Leont’ev
Thermodynamic analysis of the effect of silicon on the solubility of oxygen in Fe – Co – Cr melts has been carried out at 1873 K. Silicon has a sufficiently high deoxidizing ability in Fe – Co – Cr melts. Silicon at low contents practically does not affect the concentration of oxygen in the melt, which is determined by the chromium content. With a higher content of silicon after changing the mechanism of interaction process of chromium and silicon with oxygen, when silicon already determines the solubility of oxygen in the melt, the oxygen concentration decreases.
在1873 K时，对硅对Fe - Co - Cr熔体中氧溶解度的影响进行了热力学分析。硅在Fe - Co - Cr熔体中具有足够高的脱氧能力。低含量的硅实际上不影响熔体中氧的浓度，这是由铬含量决定的。随着硅含量的增加，铬、硅与氧的相互作用机理发生改变后，当硅已经决定了氧在熔体中的溶解度时，氧浓度降低。
{"title":"THERMODYNAMICS OF OXYGEN SOLUTIONS IN SILICON-CONTAINING Fe – Co – Cr MELTS","authors":"A. Aleksandrov, V. Dashevskii, L. I. Leont’ev","doi":"10.17073/0368-0797-2018-8-657-661","DOIUrl":"https://doi.org/10.17073/0368-0797-2018-8-657-661","url":null,"abstract":"Thermodynamic analysis of the effect of silicon on the solubility of oxygen in Fe – Co – Cr melts has been carried out at 1873 K. Silicon has a sufficiently high deoxidizing ability in Fe – Co – Cr melts. Silicon at low contents practically does not affect the concentration of oxygen in the melt, which is determined by the chromium content. With a higher content of silicon after changing the mechanism of interaction process of chromium and silicon with oxygen, when silicon already determines the solubility of oxygen in the melt, the oxygen concentration decreases.","PeriodicalId":35527,"journal":{"name":"Izvestiya Vysshikh Uchebnykh Zavedenij. Chernaya Metallurgiya","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2018-10-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75995448","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 : 2018-10-21DOI: 10.17073/0368-0797-2019-9-708-713
A. Mukhtar, M. K. Mukhymbekova, A. Makashev, V. N. Savin
Oolitic brown clay iron ores are of prime economic importance because of their enormous stocks in the world. However, their use in metallurgical production is very severely limited at the present time because of the high content of phosphorus in them. The process of phosphorus extracting from these ores almost cannot be realized by the known enrichment methods, since phosphorus presents in oolites in the emulsionated and impregnated state, without forming the independent minerals in this case. Therefore, using of ores of the given type is very limited. Growth of the world steel production at this time has considerably increased demand for iron ore, for that reason in the last decades in the world there were made considerable efforts on creation of new manufacturing schemes of brown clay iron ores obtaining standard iron ore concentrates. Considerable reduction of rich and easily beneficiated iron ores in Kazakhstan results in necessity to attract in metallurgical production the huge resources of the easily extracted ooli tic brown clay iron ores of Lissakovsk, Ayat, Priaral, and other fields with the iron content from 35 to 40 % and phosphorus up to 1 %. The technology of thermomagnetic beneficiation is represented as the most self-sustainable and acceptable dephosphorizing technology of brown limonites. The essence of the technology consists in the reproduction by liquid hydrocarbon reducer (LHR), mesmerizing roasting of the concentrate, magnetic concentration of the roasted raw material receiving the magnetic concentrate with the subsequent dephosphorizing of the obtained concentrate by the acid leaching method. The technology was tested in pilot conditions by representative samplings of the Lissakovsk concentrate and the ores of Ayat and Kokbulak fields.
{"title":"Thermomagnetic concentration and dephosphorizing of brown clay iron ore and concentrates","authors":"A. Mukhtar, M. K. Mukhymbekova, A. Makashev, V. N. Savin","doi":"10.17073/0368-0797-2019-9-708-713","DOIUrl":"https://doi.org/10.17073/0368-0797-2019-9-708-713","url":null,"abstract":"Oolitic brown clay iron ores are of prime economic importance because of their enormous stocks in the world. However, their use in metallurgical production is very severely limited at the present time because of the high content of phosphorus in them. The process of phosphorus extracting from these ores almost cannot be realized by the known enrichment methods, since phosphorus presents in oolites in the emulsionated and impregnated state, without forming the independent minerals in this case. Therefore, using of ores of the given type is very limited. Growth of the world steel production at this time has considerably increased demand for iron ore, for that reason in the last decades in the world there were made considerable efforts on creation of new manufacturing schemes of brown clay iron ores obtaining standard iron ore concentrates. Considerable reduction of rich and easily beneficiated iron ores in Kazakhstan results in necessity to attract in metallurgical production the huge resources of the easily extracted ooli tic brown clay iron ores of Lissakovsk, Ayat, Priaral, and other fields with the iron content from 35 to 40 % and phosphorus up to 1 %. The technology of thermomagnetic beneficiation is represented as the most self-sustainable and acceptable dephosphorizing technology of brown limonites. The essence of the technology consists in the reproduction by liquid hydrocarbon reducer (LHR), mesmerizing roasting of the concentrate, magnetic concentration of the roasted raw material receiving the magnetic concentrate with the subsequent dephosphorizing of the obtained concentrate by the acid leaching method. The technology was tested in pilot conditions by representative samplings of the Lissakovsk concentrate and the ores of Ayat and Kokbulak fields.","PeriodicalId":35527,"journal":{"name":"Izvestiya Vysshikh Uchebnykh Zavedenij. Chernaya Metallurgiya","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2018-10-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75610054","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 : 2018-10-21DOI: 10.17073/0368-0797-2019-9-683-688
A. Budnikov, B. Romantsev, E. Kharitonov
The problem of determining the maximum diameter of working rolls is typical for screw rolling mills that have more than two working rolls. Precise determination of the working roll diameter is especially important for three-roll mills, which are widely used in such industries as rolling and calibration, and radial-shear rolling mills operating at large feeding and rolling angles. Typically, the diameter of working rolls is determined in a constructive way or using 3D modeling. These methods are quite complex, require special skills, and do not allow investigation of the influence of main tuning mill factors such as feeding and rolling angles. There is a calculated method for determining the diameter of the roll barrel for a three-roll mill, but it is applicable for mills working at feeding angles of up to 10 degrees and rolling angles of 4 – 7 degrees. In conditions of radial-shear rolling, this method is not used, since it does not take into account the influence of feeding and rolling angles on which the conditions of the deformation process, manufacturability and quality of the products depend. The article considers a more general method for determining the diameter of working rolls of three or more rolling mills, taking into account their rotation at the feeding and rolling angles. The relationship between diameter of the rolls, their number, minimum diameter of the deformation center, the feeding and rolling angles are shown, which makes it possible to evaluate the structural capabilities of both three and four-roll rolling mills. The results of the presented work make it possible to expand the possibilities for further studies of the technology and equipment of three-roll screw rolling mills for the production of solid and hollow products using completely new deformation modes for the processes of rolling out hollow products of their reduction as well as radial shearing rolling. Importantly, it is possible to supplement existing knowledge about the change in geometry of deformation center, and also to predict geometric parameters of the working rolls of the projected multi-roll mills for given rolled products sizes.
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Pub Date : 2018-10-21DOI: 10.17073/0368-0797-2019-9-695-701
E. К. Mukhambetgaliev, A. B. Esenzhulov, V. E. Roshchin
The article presents theoretical and technological foundations for the production of complex alumosilicomanganese alloy (ASM) from high-silicon manganese ore, Karaganda high-ash coals and Teniz-Korzhunkol coal basins (Borly and Saryadyr coal deposits), Tekturmas deposit quartzite and long-flame coal of Shubarkol field. Based on the reference data and calculated thermodynamic data (for compounds with unknown thermodynamic data), a mathematical model of the phase structure was constructed by conducting a thermodynamic-diagram analysis of four-component Fe – Si – Al – Mn system. The compositions of alumosilicomanganese obtained from the coals of Karaganda and Teniz-Korzhunkol coal basins, in contrast to ASM alloy from Ekibastuz coals, are shifted in the region of tetrahedra with relatively large volumes. This fact indicates their increased stability and technological predictability. The results of the series of experimental tests carried out in an ore-thermal furnace has shown the possibility of obtaining an ASM alloy with controlled chemical composition using high-ash coals of Borly and Saryadyr fields, the substandard high-silica manganese ore of Zapadny Kamys field, addition of long-flame coal from Shubarkol deposit and quartzite of Tekturmas deposit to the mix by continuous slag-free process. Chemical composition of the alloy was regulated by addition of manganese ore to the sample of charge materials. A complex alloy was obtained with the following chemical composition (% by mass): 32 – 53 % of Si; 15.5 – 25.0 % of Al; 12 – 32 % of Mn; 8 – 20 % of Fe; 0.02 – 0.05 % of P; 0.2 – 0.5 % of C. The resulting metal does not crumble into powder when stored. This is ensured by low phosphorus content and high aluminum content of more than 10 %. Phase components of the experimental alloy were determined. The use of dumping high-ash coals, substandard manganese ores and the complete elimination of coke use ensure a low cost of the alloy. It is proposed to use this alloy for deoxidation and alloying of steel, and also as a reducing agent in the production of refined ferromanganese grades.
{"title":"Production of complex alloy from high-silicon manganese ore and high-ash coals of Kazakhstan","authors":"E. К. Mukhambetgaliev, A. B. Esenzhulov, V. E. Roshchin","doi":"10.17073/0368-0797-2019-9-695-701","DOIUrl":"https://doi.org/10.17073/0368-0797-2019-9-695-701","url":null,"abstract":"The article presents theoretical and technological foundations for the production of complex alumosilicomanganese alloy (ASM) from high-silicon manganese ore, Karaganda high-ash coals and Teniz-Korzhunkol coal basins (Borly and Saryadyr coal deposits), Tekturmas deposit quartzite and long-flame coal of Shubarkol field. Based on the reference data and calculated thermodynamic data (for compounds with unknown thermodynamic data), a mathematical model of the phase structure was constructed by conducting a thermodynamic-diagram analysis of four-component Fe – Si – Al – Mn system. The compositions of alumosilicomanganese obtained from the coals of Karaganda and Teniz-Korzhunkol coal basins, in contrast to ASM alloy from Ekibastuz coals, are shifted in the region of tetrahedra with relatively large volumes. This fact indicates their increased stability and technological predictability. The results of the series of experimental tests carried out in an ore-thermal furnace has shown the possibility of obtaining an ASM alloy with controlled chemical composition using high-ash coals of Borly and Saryadyr fields, the substandard high-silica manganese ore of Zapadny Kamys field, addition of long-flame coal from Shubarkol deposit and quartzite of Tekturmas deposit to the mix by continuous slag-free process. Chemical composition of the alloy was regulated by addition of manganese ore to the sample of charge materials. A complex alloy was obtained with the following chemical composition (% by mass): 32 – 53 % of Si; 15.5 – 25.0 % of Al; 12 – 32 % of Mn; 8 – 20 % of Fe; 0.02 – 0.05 % of P; 0.2 – 0.5 % of C. The resulting metal does not crumble into powder when stored. This is ensured by low phosphorus content and high aluminum content of more than 10 %. Phase components of the experimental alloy were determined. The use of dumping high-ash coals, substandard manganese ores and the complete elimination of coke use ensure a low cost of the alloy. It is proposed to use this alloy for deoxidation and alloying of steel, and also as a reducing agent in the production of refined ferromanganese grades.","PeriodicalId":35527,"journal":{"name":"Izvestiya Vysshikh Uchebnykh Zavedenij. Chernaya Metallurgiya","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2018-10-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77688993","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 : 2018-10-21DOI: 10.17073/0368-0797-2019-9-721-730
L. M. Simonyan
Nowadays there are different points of view about the cause of global climate change. The current warming, according to one version, is related to the greenhouse effect, i.e. with increasing concentrations of greenhouse gases (mainly carbon dioxide, CO2) in the atmosphere. It is believed that the uncontrolled growth of greenhouse gases in the atmosphere may lead to negative consequences. The position of UNFCCC and IPCC proposing accounting of greenhouse gases is of recommendatory nature. In particular, an inventory of greenhouse gases can be produced, taking into account the particularities of national development. The main objective of the greenhouse gas inventory is defining reserves to reduce them. Main anthropogenic sources of CO2formation in the Russian Federation are reviewed. Comparative indicators of CO2emissions in different sectors of production are provided. The methodology for greenhouse gases in Russia is considered, in particular with respect to the steel industry. The analysis has shown that official methods to assess CO2emissions into the atmosphere are mainly Base and Sectoral approaches and Level 2 method. Detailed approach and Level 3 method are used for a limited number of metallurgical processing. Part of the CO2emissions from ferrous metallurgy, in particular the emissions from the production of blast furnace coke, is accounted in the energy sector. According to the inventory estimation, total anthropogenic CO2emissions on the territory of RF have decreased and amounted in 2015 75 % from the level of 1990: compared to 1990, the CO2emissions of the steel industry also decreased. Estimated share of the ferrous metallurgy in anthropogenic emissions of CO2compared to 1990 (4.0 %) has increased and amounted to 4.8 % in 2015.
{"title":"Analysis of the methodology for determining CO2 emissions on the territory of the Russian Federation in respect to the ferrous metallurgy","authors":"L. M. Simonyan","doi":"10.17073/0368-0797-2019-9-721-730","DOIUrl":"https://doi.org/10.17073/0368-0797-2019-9-721-730","url":null,"abstract":"Nowadays there are different points of view about the cause of global climate change. The current warming, according to one version, is related to the greenhouse effect, i.e. with increasing concentrations of greenhouse gases (mainly carbon dioxide, CO2) in the atmosphere. It is believed that the uncontrolled growth of greenhouse gases in the atmosphere may lead to negative consequences. The position of UNFCCC and IPCC proposing accounting of greenhouse gases is of recommendatory nature. In particular, an inventory of greenhouse gases can be produced, taking into account the particularities of national development. The main objective of the greenhouse gas inventory is defining reserves to reduce them. Main anthropogenic sources of CO2formation in the Russian Federation are reviewed. Comparative indicators of CO2emissions in different sectors of production are provided. The methodology for greenhouse gases in Russia is considered, in particular with respect to the steel industry. The analysis has shown that official methods to assess CO2emissions into the atmosphere are mainly Base and Sectoral approaches and Level 2 method. Detailed approach and Level 3 method are used for a limited number of metallurgical processing. Part of the CO2emissions from ferrous metallurgy, in particular the emissions from the production of blast furnace coke, is accounted in the energy sector. According to the inventory estimation, total anthropogenic CO2emissions on the territory of RF have decreased and amounted in 2015 75 % from the level of 1990: compared to 1990, the CO2emissions of the steel industry also decreased. Estimated share of the ferrous metallurgy in anthropogenic emissions of CO2compared to 1990 (4.0 %) has increased and amounted to 4.8 % in 2015.","PeriodicalId":35527,"journal":{"name":"Izvestiya Vysshikh Uchebnykh Zavedenij. Chernaya Metallurgiya","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2018-10-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77086548","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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