Pub Date : 2018-07-28DOI: 10.17073/0368-0797-2018-7-564-571
E. К. Mukhambetgaliev, V. E. Roshchin, S. Baisanov
Calculations of analytical expressions of Fe – Si – Al – Mn quaternary metal system and phase compositions of complex alumosilicomanganese alloy are presented in the article. Analytical expressions were obtained by the derivation of transformation equations that show any secondary system through the primary components of the base system. The location of the melt given composition was determined from positive values of coefficients of the equations of certain polytope calculated by Heath equation. Chemical composition of the complex alumosilicomanganese alloy obtained under semi-industrial conditions corresponds to the tetrahedron FeAl3 – Al – Si – Mn11Si19 with the volume equal to V = 0,216811. It was established that compositions of alumosilicomanganese obtained from coals of the Karaganda coal basin, in contrast to the AMS alloy from Ekibastuz coals, tend to be in the region of tetrahedra with a relatively large volume. The alloy compositions modeled by such large-volume tetrahedrons are more stable and technologically predictable. Practical application of the results of the thermodynamic-diagram analysis (TDA) to the compositions of different grades of alumosilicomanganese reduces to finding of elementary tetrahedra within which their compositions are limited, and the normative distribution of primary phases between secondary compounds for them is equal to 100 % of the considered tetrahedron. Based on the normative distribution of the primary phases between the compounds (secondary phases) located on vertices of the Fe – Si – Al – Mn tetrahedron, a metallurgical evaluation of the melts can be made. This will subsequently allow to determine the phase composition of metal products at smelting of various grades of alumosilicomanganese and to limit the residual content of silicon and aluminum in them while using the latter in the recovery of manganese from manganese ore, as well as silicon and aluminum from high-ash coal. The derived analytical expressions for estimating the type and number of secondary phases of Fe – Si – Al – Mn system formed in it are universal and can be used both at smelting of various grades of alumosilicomanganese and in assessing the compositions of ferrosilicoaluminum and ferrosilicomanganese.
{"title":"ANALYTICAL EXPRESSIONS FOR Fe – Si – Al – Mn METAL SYSTEM AND PHASE COMPOSITION OF ALUMOSILICOMANGANESE","authors":"E. К. Mukhambetgaliev, V. E. Roshchin, S. Baisanov","doi":"10.17073/0368-0797-2018-7-564-571","DOIUrl":"https://doi.org/10.17073/0368-0797-2018-7-564-571","url":null,"abstract":"Calculations of analytical expressions of Fe – Si – Al – Mn quaternary metal system and phase compositions of complex alumosilicomanganese alloy are presented in the article. Analytical expressions were obtained by the derivation of transformation equations that show any secondary system through the primary components of the base system. The location of the melt given composition was determined from positive values of coefficients of the equations of certain polytope calculated by Heath equation. Chemical composition of the complex alumosilicomanganese alloy obtained under semi-industrial conditions corresponds to the tetrahedron FeAl3 – Al – Si – Mn11Si19 with the volume equal to V = 0,216811. It was established that compositions of alumosilicomanganese obtained from coals of the Karaganda coal basin, in contrast to the AMS alloy from Ekibastuz coals, tend to be in the region of tetrahedra with a relatively large volume. The alloy compositions modeled by such large-volume tetrahedrons are more stable and technologically predictable. Practical application of the results of the thermodynamic-diagram analysis (TDA) to the compositions of different grades of alumosilicomanganese reduces to finding of elementary tetrahedra within which their compositions are limited, and the normative distribution of primary phases between secondary compounds for them is equal to 100 % of the considered tetrahedron. Based on the normative distribution of the primary phases between the compounds (secondary phases) located on vertices of the Fe – Si – Al – Mn tetrahedron, a metallurgical evaluation of the melts can be made. This will subsequently allow to determine the phase composition of metal products at smelting of various grades of alumosilicomanganese and to limit the residual content of silicon and aluminum in them while using the latter in the recovery of manganese from manganese ore, as well as silicon and aluminum from high-ash coal. The derived analytical expressions for estimating the type and number of secondary phases of Fe – Si – Al – Mn system formed in it are universal and can be used both at smelting of various grades of alumosilicomanganese and in assessing the compositions of ferrosilicoaluminum and ferrosilicomanganese.","PeriodicalId":35527,"journal":{"name":"Izvestiya Vysshikh Uchebnykh Zavedenij. Chernaya Metallurgiya","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2018-07-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81732757","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 : 2018-07-28DOI: 10.17073/0368-0797-2018-6-466-469
A. G. Nikitin, A. Abramov, V. V. Garyashin
The magnitude decrease of the dynamic loads that arise during the operation of machines in general and metallurgical ones in particular, is one of the main tasks of general problem of increasing their reliability and durability. The analysis of work of lever mechanisms of jaw crusher with internal degrees of freedom conditioned by presence of clearances in hinges, was made. It has shown that presence of unstable forces of locomotive masses inertia during work of oscillating crank drive results in breakage of pin surfaces in joint of piston-rod with a crank, and in subsequent change of working surfaces of this kinematics pair, followed by hitting of the masses of movable links and in generation of considerable dynamic load, providing the reason of breakages of details of executive mechanism and the source of resilient vibration (vibrations) and harmful acoustic vibration generation. With the purpose of removal of influence of clearances in hinges on the origin of additional dynamic forces it is necessary to reveal regularities of impulse loads appearance. Regularities of such loads appearance in crank-type mechanisms with clearances in joints of kinematics pairs, caused by contact fault as a result of change in working surfaces contact, can be determined by kinetic static analysis. Analysis of work of crank-type hinge with clearance of oscillating crank drive of jaw crusher was conducted. Based on the analysis results it was determined, that contact fault in joint of crank-piston-rod kinema tics pair elements is conditioned by change of sign of reaction force. Clearance overtravel in a crank-type hinge takes place when both links are on one line. Determination of mechanism links positions, at which there is interconnection of crank-type hinge contact surfaces, allows to use mechanisms rationally for selection of clearances with resilient elements that during all work cycle of oscillating crank drive choose clearance in crank-type joint and prevent additional dynamic load occurrence. That promotes reliability of jaw crusher operation in whole.
{"title":"MATHEMATICAL MODEL OF CRANK-TYPE JOINT CLEARANCE OVERTRAVEL ASSESSMENT IN OSCILLATING CRANK DRIVE OF JAW CRUSHER","authors":"A. G. Nikitin, A. Abramov, V. V. Garyashin","doi":"10.17073/0368-0797-2018-6-466-469","DOIUrl":"https://doi.org/10.17073/0368-0797-2018-6-466-469","url":null,"abstract":"The magnitude decrease of the dynamic loads that arise during the operation of machines in general and metallurgical ones in particular, is one of the main tasks of general problem of increasing their reliability and durability. The analysis of work of lever mechanisms of jaw crusher with internal degrees of freedom conditioned by presence of clearances in hinges, was made. It has shown that presence of unstable forces of locomotive masses inertia during work of oscillating crank drive results in breakage of pin surfaces in joint of piston-rod with a crank, and in subsequent change of working surfaces of this kinematics pair, followed by hitting of the masses of movable links and in generation of considerable dynamic load, providing the reason of breakages of details of executive mechanism and the source of resilient vibration (vibrations) and harmful acoustic vibration generation. With the purpose of removal of influence of clearances in hinges on the origin of additional dynamic forces it is necessary to reveal regularities of impulse loads appearance. Regularities of such loads appearance in crank-type mechanisms with clearances in joints of kinematics pairs, caused by contact fault as a result of change in working surfaces contact, can be determined by kinetic static analysis. Analysis of work of crank-type hinge with clearance of oscillating crank drive of jaw crusher was conducted. Based on the analysis results it was determined, that contact fault in joint of crank-piston-rod kinema tics pair elements is conditioned by change of sign of reaction force. Clearance overtravel in a crank-type hinge takes place when both links are on one line. Determination of mechanism links positions, at which there is interconnection of crank-type hinge contact surfaces, allows to use mechanisms rationally for selection of clearances with resilient elements that during all work cycle of oscillating crank drive choose clearance in crank-type joint and prevent additional dynamic load occurrence. That promotes reliability of jaw crusher operation in whole.","PeriodicalId":35527,"journal":{"name":"Izvestiya Vysshikh Uchebnykh Zavedenij. Chernaya Metallurgiya","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2018-07-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81012448","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 : 2018-07-28DOI: 10.17073/0368-0797-2018-7-557-563
G. S. Podgorodetskii, V. Gorbunov, E. А. Agapov, T. V. Erokhov, O. N. Kozlova
For existing and already constructed coal TPP plants, known methods of utilization of fly ash and slag wastes (FASW) may be in demand when all emerging environmental and economic risks are taken into account. But for the new power generating source when choosing coal combustion technology, it is necessary to increase the significance of the environmental component of the project more essentially. It is known that the most promising technologies for coal combustion, which increase environmental safety exactly by burning, are technologies based on a circulating fluidized bed. These technologies can significantly reduce sulfur and nitrogen oxide emissions behind the boiler, but the solution to the problem of flay ash and slag waste remains at the same level. It is proposed to solve the problem of FASW utilization during the implementation of new energy projects or when replacing the decommissioning capacities of coal generation by replacing the method of coal combustion in a stream or fluidized bed with methods of burning solid fuel in a bubbling slag melt. The descriptions and schemes of these methods are given. The comparison of the main qualitative technical and ecological parameters of pulverized coal combustion and technologies of coal combustion in slag melt is presented. The development of coal generation is expected in two main areas: coal combustion with increasing steam parameters and gas generation with a combined cycle of electricity generation: steam and gas, based on the gasification of solid fuels. These directions will allow achieving electric efficiency of steam-power plants from 30 – 36 %, up to 44 – 45 % on supercritical steam parameters, and using a combined steam-gas cycle up to 50 – 55 %. A technological scheme of gasification of coal in a slag melt is proposed, which increases the electrical efficiency of the installation. The ecological and economic efficiency of the gasification method for solid fuel and the simplicity of the production of slag products by casting are shown. The quality of cast slagstone products is much higher than similar cement-sand products with the addition of fly ash, and the ease of transition from one casting mold to another allows quickly responding to market demands.
{"title":"CHALLENGES AND OPPORTUNITIES OF UTILIZATION OF ASH AND SLAG WASTE OF TPP (THERMAL POWER PLANT). PART 2","authors":"G. S. Podgorodetskii, V. Gorbunov, E. А. Agapov, T. V. Erokhov, O. N. Kozlova","doi":"10.17073/0368-0797-2018-7-557-563","DOIUrl":"https://doi.org/10.17073/0368-0797-2018-7-557-563","url":null,"abstract":"For existing and already constructed coal TPP plants, known methods of utilization of fly ash and slag wastes (FASW) may be in demand when all emerging environmental and economic risks are taken into account. But for the new power generating source when choosing coal combustion technology, it is necessary to increase the significance of the environmental component of the project more essentially. It is known that the most promising technologies for coal combustion, which increase environmental safety exactly by burning, are technologies based on a circulating fluidized bed. These technologies can significantly reduce sulfur and nitrogen oxide emissions behind the boiler, but the solution to the problem of flay ash and slag waste remains at the same level. It is proposed to solve the problem of FASW utilization during the implementation of new energy projects or when replacing the decommissioning capacities of coal generation by replacing the method of coal combustion in a stream or fluidized bed with methods of burning solid fuel in a bubbling slag melt. The descriptions and schemes of these methods are given. The comparison of the main qualitative technical and ecological parameters of pulverized coal combustion and technologies of coal combustion in slag melt is presented. The development of coal generation is expected in two main areas: coal combustion with increasing steam parameters and gas generation with a combined cycle of electricity generation: steam and gas, based on the gasification of solid fuels. These directions will allow achieving electric efficiency of steam-power plants from 30 – 36 %, up to 44 – 45 % on supercritical steam parameters, and using a combined steam-gas cycle up to 50 – 55 %. A technological scheme of gasification of coal in a slag melt is proposed, which increases the electrical efficiency of the installation. The ecological and economic efficiency of the gasification method for solid fuel and the simplicity of the production of slag products by casting are shown. The quality of cast slagstone products is much higher than similar cement-sand products with the addition of fly ash, and the ease of transition from one casting mold to another allows quickly responding to market demands.","PeriodicalId":35527,"journal":{"name":"Izvestiya Vysshikh Uchebnykh Zavedenij. Chernaya Metallurgiya","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2018-07-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75402259","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 : 2018-07-28DOI: 10.17073/0368-0797-2018-7-551-556
A. Filippov, G. Pachurin, N. A. Kuz’min, Yu. I. Mat¬veev, V. Deev
Metal products obtained by cold heading from rolled metal are used in all branches of mechanical engineering. Its quality is estimated by the required chemical composition and plasticity, the absence of a dispersion of mechanical characteristics along the entire length, the absence of internal and surface defects. The competitive advantage of metalware is the result of optimization during all technological processes: from rolled metal smelting to heading of finished metalware. At the same time, to reduce costs and to achieve the required quality of metalware, an important condition is to ensure safety and to reduce the energy intensity and labor input of its manufacturing process. An important controlling role in this technological chain is the preparation of the material for its cold volume forging. High-strength fasteners, obtained in conditions of cold heading, are most often obtained from chromium steels. Recently, alternative boron-containing steels have been actively introduced. However, because of the possible formation of boron oxides and nitrides, which lead to a decrease in hardenability, they exhibit instability of thermal hardening during thermohardening of metal products. In addition, the rolled metal of chromium steels, as a rule, is cheaper by 12 – 16 %. And as the fact that foreign deliveries of such steels are associated with additional costs, the fasteners produced from boron-containing steel are obtained with even higher increase in value, which again shows the favor of chromium steels. The standard mechanical characteristics were obtained as well as the destruction criteria of 40Kh rolled steel, subjected to patenting in a nylon bath with different temperatures and subsequent drawing with different degrees of deformation during cobbing. The optimum mode of preparation of structure parameters and mechanical characteristics of rolled products before the operation of metalware cold volume forging was identified: patenting (temperature of salt bath of 400 °С) and drawing (deformation degree in the range of 5 – 10 %). It was established that treatment under this mode ensures the obtaining of the required quality of rolled products and is more preferable than the one that operates in production.
{"title":"EVALUATION OF QUALITY OF ROLLED STEEL FOR COLD VOLUME FORGING","authors":"A. Filippov, G. Pachurin, N. A. Kuz’min, Yu. I. Mat¬veev, V. Deev","doi":"10.17073/0368-0797-2018-7-551-556","DOIUrl":"https://doi.org/10.17073/0368-0797-2018-7-551-556","url":null,"abstract":"Metal products obtained by cold heading from rolled metal are used in all branches of mechanical engineering. Its quality is estimated by the required chemical composition and plasticity, the absence of a dispersion of mechanical characteristics along the entire length, the absence of internal and surface defects. The competitive advantage of metalware is the result of optimization during all technological processes: from rolled metal smelting to heading of finished metalware. At the same time, to reduce costs and to achieve the required quality of metalware, an important condition is to ensure safety and to reduce the energy intensity and labor input of its manufacturing process. An important controlling role in this technological chain is the preparation of the material for its cold volume forging. High-strength fasteners, obtained in conditions of cold heading, are most often obtained from chromium steels. Recently, alternative boron-containing steels have been actively introduced. However, because of the possible formation of boron oxides and nitrides, which lead to a decrease in hardenability, they exhibit instability of thermal hardening during thermohardening of metal products. In addition, the rolled metal of chromium steels, as a rule, is cheaper by 12 – 16 %. And as the fact that foreign deliveries of such steels are associated with additional costs, the fasteners produced from boron-containing steel are obtained with even higher increase in value, which again shows the favor of chromium steels. The standard mechanical characteristics were obtained as well as the destruction criteria of 40Kh rolled steel, subjected to patenting in a nylon bath with different temperatures and subsequent drawing with different degrees of deformation during cobbing. The optimum mode of preparation of structure parameters and mechanical characteristics of rolled products before the operation of metalware cold volume forging was identified: patenting (temperature of salt bath of 400 °С) and drawing (deformation degree in the range of 5 – 10 %). It was established that treatment under this mode ensures the obtaining of the required quality of rolled products and is more preferable than the one that operates in production.","PeriodicalId":35527,"journal":{"name":"Izvestiya Vysshikh Uchebnykh Zavedenij. Chernaya Metallurgiya","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2018-07-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85776089","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 : 2018-07-28DOI: 10.17073/0368-0797-2018-6-478-484
V. V. Zimin, I. Burkova, V. V. Mit’kov, A. Zimin
Planning of pilot testing is among important problems of creation of Enterprise resource planning. Pilot (experimental) projects are intended for testing of the main functions of the created system by limited number of “advanced” users. A key task when planning pilot testing is determination of its volume. If the volume of the pilot project is small, then essentially important functions of system can be not checked, and the probability of detection of essential mistakes at full introduction will be high. If the volume is big, then amount of works on implementation of the pilot project considerably increases, and there will be no necessary speed and flexibility of testing of the main functions, because of which pilot testing is organized, and its efficiency will be close to efficiency of full introduction. The article describes mathematical problem definition of pilot testing scoping which relies on results of the solution of formation problems of a portfolio of IT services and creation scheduling of Enterprise resource planning of the large metallurgical company. The solutions for the considered task are sets of the services and communications which are subject to check between them satisfying to the set restriction for volume of the resources allocated for testing realization, and delivering an optimum to the set criterion. The procedure of the task solution is based on network programming method which relies on structural and similar network representation of criterion and restrictions. The procedure and an example of the solution of the studied task in which separate estimated tasks are solved by method of dichotomizing programming are shown. The received approximate solutions of an objective can be improved by means of the solution of a dual problem of network programming. For the purpose of finding of initial task global optimum, the method of branches and borders can be used in which the criterions of function of the found approximate solutions are applied as border values. The considered task can be generalized for preferences of the consumers of IT service concerning need of check of services various communications. These preferences can be considered by introduction of “scales” of the corresponding communications. The general scheme of the solution of a task at the same time doesn’t change.
{"title":"SCOPING OF PILOT TESTING OF ENTERPRISE RESOURCE PLANNING","authors":"V. V. Zimin, I. Burkova, V. V. Mit’kov, A. Zimin","doi":"10.17073/0368-0797-2018-6-478-484","DOIUrl":"https://doi.org/10.17073/0368-0797-2018-6-478-484","url":null,"abstract":" Planning of pilot testing is among important problems of creation of Enterprise resource planning. Pilot (experimental) projects are intended for testing of the main functions of the created system by limited number of “advanced” users. A key task when planning pilot testing is determination of its volume. If the volume of the pilot project is small, then essentially important functions of system can be not checked, and the probability of detection of essential mistakes at full introduction will be high. If the volume is big, then amount of works on implementation of the pilot project considerably increases, and there will be no necessary speed and flexibility of testing of the main functions, because of which pilot testing is organized, and its efficiency will be close to efficiency of full introduction. The article describes mathematical problem definition of pilot testing scoping which relies on results of the solution of formation problems of a portfolio of IT services and creation scheduling of Enterprise resource planning of the large metallurgical company. The solutions for the considered task are sets of the services and communications which are subject to check between them satisfying to the set restriction for volume of the resources allocated for testing realization, and delivering an optimum to the set criterion. The procedure of the task solution is based on network programming method which relies on structural and similar network representation of criterion and restrictions. The procedure and an example of the solution of the studied task in which separate estimated tasks are solved by method of dichotomizing programming are shown. The received approximate solutions of an objective can be improved by means of the solution of a dual problem of network programming. For the purpose of finding of initial task global optimum, the method of branches and borders can be used in which the criterions of function of the found approximate solutions are applied as border values. The considered task can be generalized for preferences of the consumers of IT service concerning need of check of services various communications. These preferences can be considered by introduction of “scales” of the corresponding communications. The general scheme of the solution of a task at the same time doesn’t change.","PeriodicalId":35527,"journal":{"name":"Izvestiya Vysshikh Uchebnykh Zavedenij. Chernaya Metallurgiya","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2018-07-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83913097","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 : 2018-07-28DOI: 10.17073/0368-0797-2018-6-423-430
Y. Yaroshenko, Yu. I. Lipunov, A. B. Smakhanov, M. Stolyarova
The paper presents the results of mathematical modeling and experimental researches executed during the development of the techno logy of differential water-air cooling of bearing rings made of 52100 (EN1.3505) steel produced by JSC “Vologda Bearing Plant”. Overlapping the mathematical model of temperature variation curves across the bearing cross-section on the thermokinetic diagram of the decomposition of supercooled austenite calculated according to the mathematical model developed by JSC VNIIMT has shown that a required microstructure of the heat-treated metal is achieved in a wide range of differentiated water-air cooling modes. Experimental studies of heat-strengthening of bearing rings by water-air jets were carried out on a specially assembled experimental industrial device with a cooling system equipped with mixers and collectors with flat-jet nozzles of the original design that ensure the stability of the torch and the uniformity of spraying the water-air mixture over a wide range of flow rates and water and air pressure. The thermal hardening of the rings carried out at various cooling regimes, followed by the determination of the mechanical properties and structural characteristics of the steel, has confirmed that the water-air cooling technology achieves the required structural and mechanical characteristics of the bearing rings and is a competitive, environmentally friendly alternative to the technology of volume quenching in oil tank.
{"title":"APPLICATION OF WATER-AIR COOLING TECHNOLOGIES FOR HEAT TREATMENT OF BEARING RINGS","authors":"Y. Yaroshenko, Yu. I. Lipunov, A. B. Smakhanov, M. Stolyarova","doi":"10.17073/0368-0797-2018-6-423-430","DOIUrl":"https://doi.org/10.17073/0368-0797-2018-6-423-430","url":null,"abstract":"The paper presents the results of mathematical modeling and experimental researches executed during the development of the techno logy of differential water-air cooling of bearing rings made of 52100 (EN1.3505) steel produced by JSC “Vologda Bearing Plant”. Overlapping the mathematical model of temperature variation curves across the bearing cross-section on the thermokinetic diagram of the decomposition of supercooled austenite calculated according to the mathematical model developed by JSC VNIIMT has shown that a required microstructure of the heat-treated metal is achieved in a wide range of differentiated water-air cooling modes. Experimental studies of heat-strengthening of bearing rings by water-air jets were carried out on a specially assembled experimental industrial device with a cooling system equipped with mixers and collectors with flat-jet nozzles of the original design that ensure the stability of the torch and the uniformity of spraying the water-air mixture over a wide range of flow rates and water and air pressure. The thermal hardening of the rings carried out at various cooling regimes, followed by the determination of the mechanical properties and structural characteristics of the steel, has confirmed that the water-air cooling technology achieves the required structural and mechanical characteristics of the bearing rings and is a competitive, environmentally friendly alternative to the technology of volume quenching in oil tank.","PeriodicalId":35527,"journal":{"name":"Izvestiya Vysshikh Uchebnykh Zavedenij. Chernaya Metallurgiya","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2018-07-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78659261","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 : 2018-07-28DOI: 10.17073/0368-0797-2018-7-510-519
A. V. Belonosov, O. Chikova, N. Zaitseva
The authors have investigated microstructure and crystal structure of the steel samples of 9Kh2MF and 8Kh3SMFA steel with laser surfacing. The samples were taken from working shafts of reverse rolling mill in conditions of OJSC «Uralmashzavod». Brewing surface cracks in rolls with the use of laser is considered as an effective method of parts restoring in small-scale production. The research was carried out to control the quality of steel products with laser surfacing. Quality control of working rolls of rolling mills with laser surfacing is aimed at identifying the defects of metallurgical origin (nonmetallic inclusions, discontinuities, regions with heterogeneity of chemical composition) in zones of surfacing and thermal influence and is performed by ultrasonic method. Metallographic study of the microstructure and crystal structure of steel samples with laser surfacing was necessary to develop an ultrasonic testing technique. The main way to detect defects of metallurgical origin in steels is scanning electron microscopy with functions of micro-X-ray spectral analysis (EDS-analysis) and diffraction of backscattered electrons (EBSD-analysis). The metallographic study was carried out using a scanning electron microscope Carl Zeiss AURIGA CrossBeam equipped with analytical systems for studying the elemental surface composition by X-ray spectral analysis (EDS) and the crystal structure of the surface by diffraction of backscattered electrons (EBSD). As a result of metallographic examination, steel-laser welded samples taken from the working rollers of the reverse rolling mill were found to have defects of metallurgical origin along the surfacing boundary. The size of microinhomogeneities for 9Kh2MF steel is 10 – 50 μm; the elemental composition includes Mn, Si and O. The size of microinhomogeneities for 8Kh3SMFA steel is 1 – 3 μm, and the elemental composition includes Mn, Cr and Mo. It was established that metal on melting is less textured and has more homogeneous acoustic characteristics than base metal, it must be taken into account at ultrasonic quality control of steel products with laser surfacing. At ultrasonic inspection of laser-surfaced working rolls, we recommend setting the signal fixation level with reflectivity equivalent to the flat-bottom hole diameter of 1.5 mm.
{"title":"EXAMINING THE STRUCTURE OF MILL ROLLS METAL WITH LASER SURFACING FOR THEIR QUALITY CONTROL","authors":"A. V. Belonosov, O. Chikova, N. Zaitseva","doi":"10.17073/0368-0797-2018-7-510-519","DOIUrl":"https://doi.org/10.17073/0368-0797-2018-7-510-519","url":null,"abstract":"The authors have investigated microstructure and crystal structure of the steel samples of 9Kh2MF and 8Kh3SMFA steel with laser surfacing. The samples were taken from working shafts of reverse rolling mill in conditions of OJSC «Uralmashzavod». Brewing surface cracks in rolls with the use of laser is considered as an effective method of parts restoring in small-scale production. The research was carried out to control the quality of steel products with laser surfacing. Quality control of working rolls of rolling mills with laser surfacing is aimed at identifying the defects of metallurgical origin (nonmetallic inclusions, discontinuities, regions with heterogeneity of chemical composition) in zones of surfacing and thermal influence and is performed by ultrasonic method. Metallographic study of the microstructure and crystal structure of steel samples with laser surfacing was necessary to develop an ultrasonic testing technique. The main way to detect defects of metallurgical origin in steels is scanning electron microscopy with functions of micro-X-ray spectral analysis (EDS-analysis) and diffraction of backscattered electrons (EBSD-analysis). The metallographic study was carried out using a scanning electron microscope Carl Zeiss AURIGA CrossBeam equipped with analytical systems for studying the elemental surface composition by X-ray spectral analysis (EDS) and the crystal structure of the surface by diffraction of backscattered electrons (EBSD). As a result of metallographic examination, steel-laser welded samples taken from the working rollers of the reverse rolling mill were found to have defects of metallurgical origin along the surfacing boundary. The size of microinhomogeneities for 9Kh2MF steel is 10 – 50 μm; the elemental composition includes Mn, Si and O. The size of microinhomogeneities for 8Kh3SMFA steel is 1 – 3 μm, and the elemental composition includes Mn, Cr and Mo. It was established that metal on melting is less textured and has more homogeneous acoustic characteristics than base metal, it must be taken into account at ultrasonic quality control of steel products with laser surfacing. At ultrasonic inspection of laser-surfaced working rolls, we recommend setting the signal fixation level with reflectivity equivalent to the flat-bottom hole diameter of 1.5 mm.","PeriodicalId":35527,"journal":{"name":"Izvestiya Vysshikh Uchebnykh Zavedenij. Chernaya Metallurgiya","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2018-07-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75249740","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 : 2018-07-28DOI: 10.17073/0368-0797-2018-7-503-509
M. R. Filonov
Summing up the results of scientific research activity for 2017, we can confidently say that NUST MISIS, based on the scientific potential and experience of its teaching and research staff, has achieved even more substantial gains in the field of fundamental and applied research. Through the development of laboratories, invitation of internationally recognized researchers to the university, and participation in ambitious international scientific projects, the university continues every year to conduct even more research and development in disciplines that are both conventional and new for NUST MISIS. This article presents the main results of the research and technology and innovation efforts of the National University of Science and Technology MISIS (NUST MISIS) for 2017. The issues of inclusion in international ratings, university financing, results of the researchers’ publishing activities, as well as the results of scientific and innovation efforts, have been covered here in detail.
{"title":"RESULTS OF SCIENTIFIC RESEARCH ACTIVITY OF THE NATIONAL UNIVERSITY OF SCIENCE AND TECHNOLOGY MISIS (NUST MISIS) FOR 2017","authors":"M. R. Filonov","doi":"10.17073/0368-0797-2018-7-503-509","DOIUrl":"https://doi.org/10.17073/0368-0797-2018-7-503-509","url":null,"abstract":"Summing up the results of scientific research activity for 2017, we can confidently say that NUST MISIS, based on the scientific potential and experience of its teaching and research staff, has achieved even more substantial gains in the field of fundamental and applied research. Through the development of laboratories, invitation of internationally recognized researchers to the university, and participation in ambitious international scientific projects, the university continues every year to conduct even more research and development in disciplines that are both conventional and new for NUST MISIS. This article presents the main results of the research and technology and innovation efforts of the National University of Science and Technology MISIS (NUST MISIS) for 2017. The issues of inclusion in international ratings, university financing, results of the researchers’ publishing activities, as well as the results of scientific and innovation efforts, have been covered here in detail. ","PeriodicalId":35527,"journal":{"name":"Izvestiya Vysshikh Uchebnykh Zavedenij. Chernaya Metallurgiya","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2018-07-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73032410","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 : 2018-07-28DOI: 10.17073/0368-0797-2018-7-520-526
S. Eron’ko, V. I. Zolotukhin, M. Tkachev, D. A. Pro¬votorov, E. V. Oshovskaya
The analysis results of trends and modern techniques of research in the field of steel continuous casting are highlighted which are aimed at finding and eliminating of factors that have a negative impact on the surface quality of continuous cast billets. It is shown that the existing concept of creating quick change systems of submerged nozzles, which are used on the slab CCM, leads to the formation at the each stream of machine during serial casting of 20 heates of substandard portion of the billet with 30 – 40 m of length, formed as a result of unstable hydrodynamic conditions in the mold. The research results are given for the physical model of changes of trajectory and speed of the metal flows into the CCM mold, which are related with submerged nozzles replacement in the process of serial casting of steel. Recommendations to reduce duration of the negative impact of this factor on the conditions of cast billet formation are offered. Using control-measuring system with strain gauge transducer, it was found that the fluid flows velocity difference at the opposite narrow walls of the mold model, causing a violation of the thermal conditions of crust formation of continuous casting billet, in the case of once-through submerged nozzles can reach 2.0 – 2.3 and for non-pressure hollow-bottom nozzles with two lateral holes separated by divider – 1.2 – 4.0. Information about the trajectory symmetry breaking of circulation circuits of melt flows in the mold, caused by conducting of operation of outworn submerged nozzle replacing, also was obtained using high speed video materials. During the research the visualization of water flows trajectories, which simulated the molten steel in the mold model, was provided by introduction of air through a channel of model of stopper-monoblock of the tundish, so that the input of argon during casting was simulated. The obtained information allowed to develop a new principle of construction of system of submerged nozzles quick change which consists the combined and parallel implementation of individual stages of refractories replacement by its structural elements (manipulator, teeming and pushing devices). It allowed to reduce the time required to replace a outworn submerged nozzle and to increase the yield during the production of slab billets on CCM.
{"title":"MODEL STUDIES OF HYDRODYNAMIC CHANGES OF STEEL FLOWS IN MOLD OF SLAB CCM DURING SUBMERGED NOZZLES REPLACEMENT","authors":"S. Eron’ko, V. I. Zolotukhin, M. Tkachev, D. A. Pro¬votorov, E. V. Oshovskaya","doi":"10.17073/0368-0797-2018-7-520-526","DOIUrl":"https://doi.org/10.17073/0368-0797-2018-7-520-526","url":null,"abstract":"The analysis results of trends and modern techniques of research in the field of steel continuous casting are highlighted which are aimed at finding and eliminating of factors that have a negative impact on the surface quality of continuous cast billets. It is shown that the existing concept of creating quick change systems of submerged nozzles, which are used on the slab CCM, leads to the formation at the each stream of machine during serial casting of 20 heates of substandard portion of the billet with 30 – 40 m of length, formed as a result of unstable hydrodynamic conditions in the mold. The research results are given for the physical model of changes of trajectory and speed of the metal flows into the CCM mold, which are related with submerged nozzles replacement in the process of serial casting of steel. Recommendations to reduce duration of the negative impact of this factor on the conditions of cast billet formation are offered. Using control-measuring system with strain gauge transducer, it was found that the fluid flows velocity difference at the opposite narrow walls of the mold model, causing a violation of the thermal conditions of crust formation of continuous casting billet, in the case of once-through submerged nozzles can reach 2.0 – 2.3 and for non-pressure hollow-bottom nozzles with two lateral holes separated by divider – 1.2 – 4.0. Information about the trajectory symmetry breaking of circulation circuits of melt flows in the mold, caused by conducting of operation of outworn submerged nozzle replacing, also was obtained using high speed video materials. During the research the visualization of water flows trajectories, which simulated the molten steel in the mold model, was provided by introduction of air through a channel of model of stopper-monoblock of the tundish, so that the input of argon during casting was simulated. The obtained information allowed to develop a new principle of construction of system of submerged nozzles quick change which consists the combined and parallel implementation of individual stages of refractories replacement by its structural elements (manipulator, teeming and pushing devices). It allowed to reduce the time required to replace a outworn submerged nozzle and to increase the yield during the production of slab billets on CCM.","PeriodicalId":35527,"journal":{"name":"Izvestiya Vysshikh Uchebnykh Zavedenij. Chernaya Metallurgiya","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2018-07-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73127000","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 : 2018-07-28DOI: 10.17073/0368-0797-2018-7-527-535
M. Ziatdinov, I. M. Shatokhin, L. Leont’ev
Consistent patterns in the combustion of ferrosilicium in nitrogen are rather similar to those of metal silicon. As the concentration of silicon in initial ferrosilicium is increased, the intensity of its interaction with nitrogen increases as well, resulting in a significant growth of the combustion rate. The concentration of nitrogen in the combustion products here increases as well. In the entire investigated range of initial parameters (nitrogen pressure, powder fineness, burden mix), the main phase in the combustion products is β-Si3N4. No considerable amounts of α-Si3N4 have been observed. In practical applications, the use of FS75 and FS90 ferrosilicium is optimal for producing fire-resistant materials, while FS65 and FS75 (being the purest alloy grades) are optimal for obtaining alloying steel compositions. Introducing iron into the (Ti – B) ( T ad = 3190 K) system significantly narrows down the concentration limits of combustion. ((Fe – B) + Ti) mixture with 16.9 % B alloy burns in a narrow range of Ti:B concentrations close to 0.86. When a ferroboron-titanium mixture burns, an increase in the initial temperature significantly expands the synthesis concentration limits. In all the cases, an increase in the initial temperature leads to a significant increase in the combustion rate. Heating up to T 0 ≥ 300 °C allows for involving mixtures with more coarse titanium powders ( r av. Ti ≥ 0.4 mm) into the SHS process. The synthesis is implemented in a wide range of B:Ti ratios. By burning such mixtures one can obtain alloys with 6 – 14 % B and 30 – 60 % Ti. Specialized industrial equipment has been built: a series of SHS reactors with the operation volume of 0.06, 0.15 and 0.3 m3 for the serial production of manufacturing items based on hard-melting inorganic compositions (nitrides, borides, silicides, etc.) for metallurgical applications. Industrial SHS production of composite materials based on oxygenless compositions has been set up.
{"title":"SHS TECHNOLOGY OF COMPOSITION FERROALLOYS. PART II. SYNTHESIS OF FERROSILICON NITRIDE AND FERROTITANIUM BORIDE","authors":"M. Ziatdinov, I. M. Shatokhin, L. Leont’ev","doi":"10.17073/0368-0797-2018-7-527-535","DOIUrl":"https://doi.org/10.17073/0368-0797-2018-7-527-535","url":null,"abstract":"Consistent patterns in the combustion of ferrosilicium in nitrogen are rather similar to those of metal silicon. As the concentration of silicon in initial ferrosilicium is increased, the intensity of its interaction with nitrogen increases as well, resulting in a significant growth of the combustion rate. The concentration of nitrogen in the combustion products here increases as well. In the entire investigated range of initial parameters (nitrogen pressure, powder fineness, burden mix), the main phase in the combustion products is β-Si3N4. No considerable amounts of α-Si3N4 have been observed. In practical applications, the use of FS75 and FS90 ferrosilicium is optimal for producing fire-resistant materials, while FS65 and FS75 (being the purest alloy grades) are optimal for obtaining alloying steel compositions. Introducing iron into the (Ti – B) ( T ad = 3190 K) system significantly narrows down the concentration limits of combustion. ((Fe – B) + Ti) mixture with 16.9 % B alloy burns in a narrow range of Ti:B concentrations close to 0.86. When a ferroboron-titanium mixture burns, an increase in the initial temperature significantly expands the synthesis concentration limits. In all the cases, an increase in the initial temperature leads to a significant increase in the combustion rate. Heating up to T 0 ≥ 300 °C allows for involving mixtures with more coarse titanium powders ( r av. Ti ≥ 0.4 mm) into the SHS process. The synthesis is implemented in a wide range of B:Ti ratios. By burning such mixtures one can obtain alloys with 6 – 14 % B and 30 – 60 % Ti. Specialized industrial equipment has been built: a series of SHS reactors with the operation volume of 0.06, 0.15 and 0.3 m3 for the serial production of manufacturing items based on hard-melting inorganic compositions (nitrides, borides, silicides, etc.) for metallurgical applications. Industrial SHS production of composite materials based on oxygenless compositions has been set up.","PeriodicalId":35527,"journal":{"name":"Izvestiya Vysshikh Uchebnykh Zavedenij. Chernaya Metallurgiya","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2018-07-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77588040","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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