Анна Стовпченко - Academia.edu (original) (raw)
Papers by Анна Стовпченко
Energies
This article is devoted to the following issues: calculating the values of temperatures obtained ... more This article is devoted to the following issues: calculating the values of temperatures obtained by simulating welding heating and the subsequent implementation of the welding process at the given mode parameters made it possible to obtain a welded joint of the rotor with an improved initial structure and increased mechanical properties, hydrogen resistance and durability by up to 10–15%; simulating welding heating in the areas of fusion, the overheating and normalization of the HAZ and the formation of austenite grains; specified welding heating creates the conditions for the formation of new products of austenite decomposition in the form of sorbitol in the area of the incomplete recrystallization of the HAZ. In air and gaseous hydrogen, the destruction of the combined joints took place on the weld metal, as well as on the fusion areas, the overheating and the incomplete recrystallization of the HAZ of 20H3NMFA steel as the base metal. Structural materials have a relatively low st...
Journal of Materials Research and Technology
Ironmaking & Steelmaking, 2022
Sovremennaâ èlektrometallurgiâ, 2020
Archives of Materials Science and Engineering, 2018
Purpose: To develop novel ESR based process for composite ingot with shallow transition zone betw... more Purpose: To develop novel ESR based process for composite ingot with shallow transition zone between layers in order to produce efficient heavy-weight rotors for steam turbines. Design/methodology/approach: The nowadays heavy-weight rotors for steam turbines for power plants are monoblock or two or more layer in length composite part facilitating operation in different zones withstanding various loads and working medium. However, the joining of various steel in composite rotors by welding has low productivity. The ESR now is recognised as the best available technology for the big-diameter and mass forgings for power generating machines, including rotor ones. The ESR affords the most favourable conditions of solidification resulting in homogenous low-segregation ingot with smooth surface and high-quality structure. The step ahead is the ESR for composite. Findings: The two-layer model ingot had produced from steel grades 12Cr13 and 35NiCrMoV12-5 were manufactured using the electrosla...
Sovremennaâ èlektrometallurgiâя, 2018
Зроблено огляд тенденцій розвитку залізничного транспорту і пов'язаних з ними змін умов експлуата... more Зроблено огляд тенденцій розвитку залізничного транспорту і пов'язаних з ними змін умов експлуатації та виникнення дефектів, що скорочують строк служби рейок. Зростання швидкості руху пасажирських потягів і збільшення навантаження на вісь при перевезенні вантажу вимагає покращення якості рейок і властивостей сталей, з яких їх виробляють. Збільшення інтенсивності знакоперемінних контактних навантажень, нагрів при тривалому гальмуванні та корозійні фактори викликають пошкодження рейок. Більшість дефектів рейок, що призводять до виходу їх з ладу, мають контактно-втомне походження і їх утворення часто пов'язано з металургійною якістю сталі, покращення якої потребує технологічних вдосконалень вздовж всього циклу виробництва рейок. Бібліогр. 25, іл. 1. К л ю ч о в і с л о в а : залізничні рейки; швидкість руху; навантаження на вісь; умови експлуатації; дефекти втомного походження
Nauka ta innovacii, 2019
Introduction. The development of railway transport is a necessary factor in the national developm... more Introduction. The development of railway transport is a necessary factor in the national development and European integration of Ukraine. Problem Statement. Nowadays, over 80% of rail tracks in the national railways does not meet the requirements for bearing high-speed and heavy-load trains and needs to be replaced. At present, Ukrainian Railways corporation buys rails in foreign countries, which requires significant foreign exchange costs, and therefore the manufacture of high-quality mainstream and switch point rails in our country becomes an urgent need. Purpose. To develop innovative options for organizing the production of premium rails in Ukraine. Materials and Methods. Rail steel. Experimental melting and metallographic studies (using the optical and electron microscopy methods). Results. A high homogeneity (high purity of boundaries and dispersion of primary grains, small inter-lamellar distance of perlite), enhanced properties of the rail metal ensured by conventional electroslag remelting (ESR), and similar characteristic of ingot steel produced by ESR in the current-supplying mold with twice as fast speed of formation have been experimentally proved. Experiments with high-speed ESR and test of fluoride slag in the mold on real continuous casting machine has created the technological framework for a hybrid process of continuous casting with electroslag heating of the meniscus in current-supplying mold (CC + ESR). Conclusions. ESR enables reducing the minimum hump rate of casting, improving the density and uniformity of the metal in the axial zone, and maintaining a high quality of the ingot surface. Promising options of technological schemes of waste rail ESR for obtaining the ingots with cross section close to the rail profile have been developed and proposed. Using several modern ESR furnaces with special design will enable satisfying needs of Ukrainian Railways corporation in highquality main and switch point rails. K e y w o r d s : railway, main rail, switch rail, rail steel, CC, ESR, hybrid process, and recycling of used rails. Nowadays, in many countries, the development of transport infrastructure is a priority and a driving force for national economic development. In accordance with the ambitious goals of the Na-tio nal Transport Strategy Drive Ukraine 2030 for the period up to 2030 [1], the development of transport is mentioned among the key factors for Uk raine's national development and European in tegration. The strategy foresees the creation of conditions for the introduction of high-speed
ISIJ International, 2018
Bimetallic composite roll has been given more and more attentions because of its superiority in p... more Bimetallic composite roll has been given more and more attentions because of its superiority in playing the advantages performance of the internal and external materials at the same time. In the present study, a 2D quasi-steady state mathematical model of the electroslag cladding technology for producing bimetallic composite roll was developed by the Fluent software with the UDS and UDF function. Characteristics of the electromagnetic field, flow field and temperature field of the composite roll system have been numerically simulated and the laboratory scale experiments with the different power supply circuits were also developed to provide a verification of the mathematical models. The results indicate that: simulation results of the temperature distribution in the composite roll were well verified by the corresponding experiments. With the using of current supplying mold (CSM ®), the improved conductive circuit is more beneficial to improve the distributions of current density and Joule heat in the slag pool and keep the high temperature zone away from the roll core surface than the conventional conductive circuit. On one hand, it makes the roll core be no longer as a pole of the electroslag process and the temperature adjustment of the slag pool become more flexible. On the other hand, it leads to a partial micro-melting of the roll core surface which is beneficial to form a metallurgical bonding and effectively avoid the mechanical mixing of the liquid metal between the roll core and composite layer, so, it can improve the comprehensive performance of bimetallic composite roll.
Ironmaking & Steelmaking, 2018
A new slag susceptible to self-disintegration in the solid state due to formation of dicalcium si... more A new slag susceptible to self-disintegration in the solid state due to formation of dicalcium silicate (2CaOSiO 2) was developed. This compound reduces the thermodynamic activity of silica in a slag and, consequently, decreases silicon reduction and its transition to metal in the electroslag remelting process.
Ironmaking & Steelmaking, 2018
The paper is devoted to comparison of electroslag remelting (ESR) with consumable electrode and e... more The paper is devoted to comparison of electroslag remelting (ESR) with consumable electrode and electroslag refining with liquid metal (ESR LM) processes. The possibility of rearrangement of the heat contributions coming from the consumable electrode and current supplying mould (nonconsumable electrode, CSM) makes the core of the ESR process organisation in the CSM. The usage of liquid metal instead of consumable electrodes allows to reduce liquid bath temperature and volume in order to provide low segregation ingot. The formal assessment of physico-chemical conditions and experimental measurements of desulphurisation have shown the same level of refining ability of both processes. Replacing the classic ESR by the ESR LM is a prospective way to produce high-quality ingots from sophisticated and hard-to-deform materials, whereas manufacturing of the consumable electrodes is technically problematic and costly.
Metals, 2018
In the present study, a new electroslag cladding method by using of the advanced current supplyin... more In the present study, a new electroslag cladding method by using of the advanced current supplying mold technology was used for manufacturing the high speed steel (HSS)/ductile cast iron (DCI) composite roll. The graphite morphology, matrix microstructure, elements distribution, carbides morphology, and carbides composition have been investigated by means of optical microscope (OM), scanning electron microscope (SEM), and energy dispersive spectroscopy (EDS). With increasing distance from the HSS side, a transition of graphite morphology from naught to existence and from small and dispersed to large and nonuniform was obtained at the interface. It was closely related to the fact that graphite in DCI participated in the phase change and the roll core surface and its nearby positions was heated to a high temperature by the liquid slag during the whole electroslag cladding process. Due to the combined effects of melting and elements diffusion, a significant migration of the alloying elements have occurred through the line scan analysis. Based on this, different types of carbides with the morphology and composition were found at the bonding interface. In addition, no obvious slag inclusions, porosity, shrinkage and other defects at the bonding interface were found. Results of the tensile test also illustrated that the bonding interface had a good quality and it could fully meet the requirements of the roll.
Journal of Achievements in Materials and Manufacturing Engineering, 2018
Purpose: The main task of this work was the developing of new compositions of the ESR slag that w... more Purpose: The main task of this work was the developing of new compositions of the ESR slag that would keep the required amount of easily oxidizable elements in the superalloys and have the favourable physicochemical properties. Design/methodology/approach: Thermo-dynamic modeling was applied to estimate of oxidation effect of the slags on the Inconel 718 superalloy. Slag properties (viscosity, electrical conductivity and melting points) were measured by standard methodics. Findings: The effect of slags chemistry on the preservation of the active elements (aluminium, titanium) content in the superalloy while ESR remelting was studied. Physical properties of the several compositions of the slag are prospective for ESR of alloys with high content of active elements were measured. Research limitations/implications: The results of this work allowing development of a new compositions of the slags for ESR of the specific grades of the steel and alloys and making selection of the most effec...
steel research international, 2013
Electroslag casting with liquid metal (ESC LM) using current conductive ring has been developed. ... more Electroslag casting with liquid metal (ESC LM) using current conductive ring has been developed. This technology is different from classical electroslag remelting (ESR) process. No consumable electrode is needed in the process. Liquid metal after refining is introduced into the mold directly. Current conductive ring instead of consumable electrode is the conductive unit for heating slag pool for the first time. Short collar mold and continuous withdrawal mechanism like continuous casting process are employed in the process. Conductive path of ESC LM process using current conductive ring is transformer → current conductive ring → liquid slag → molten steel → solid ingot → base plate → transformer. A mathematical model of electroslag casting process with liquid metal is developed for understanding the technology. Thermal field, voltage, and current density distributions in the system have been simulated, which are similar but different from conventional ESR process. Results of industrial trial indicate that there is no obvious macrosegregation and cracks in the industrial ingots produced by these methods. Ingot quality is equivalent to the conventional electroslag ingot. In addition, the production efficiency of ESC LM process is obvious higher than conventional ESR operation.
Proceedings of the 2013 International Symposium on Liquid Metal Processing and Casting, 2013
High Nitrogen Steels with nitrogen contents above atmospheric solubility are usually melted using... more High Nitrogen Steels with nitrogen contents above atmospheric solubility are usually melted using an advanced P-ESR process under elevated pressure. The nitrogen pick up can be controlled by Si3N4 or nitrogen gas. This paper provide a comparison of alloying by nitrogen gas by ASR vs P-ESR process in terms of processing and nitrogen distribution. In two series of ASR and P-ESR separate trials the nitrogen content was increased at remelting in nitrogen atmosphere practically twice in spite of big difference in nitrogen pressure. Comparison of P-ESR and ASR processes abilities in steel alloying by nitrogen from gas phase shown quite close results that gives us reasons for experiments continuation.
Krane/Proceedings, 2013
In this paper development of both ESR technology and equipment for hollow ingot manufacture revie... more In this paper development of both ESR technology and equipment for hollow ingot manufacture review and analysis are presented. The real complications of hollow ingot manufacture and some tendentious issues which restrict process dissemination are discussed. An actual data of modern manufacture of as-cast pipes for heat and power engineering by traditional ESR with consumable electrode are given. Results of microstructure and nonmetal inclusion investigations have shown the high quality of as-cast ESR pipes. On the basis of these results the possibility to produce huge ESR hollows (up 5000 mm in dia) with final goal drastically to reduce setting ratio on forged shells and rings or even replace it by ESR hollows as-cast is grounded. Two new ESR technologies — consumable electrodes change and liquid metal usage — have passed pilot tests for heavy hollow production and shown very prospective results to be presented.
Krane/Proceedings, 2013
A new electroslag remelting (ESR) technology for hollow ingot manufacture was recently commercial... more A new electroslag remelting (ESR) technology for hollow ingot manufacture was recently commercialized due to the cooperation between Northeastern University of China and Elmet-Roll engineering company (Ukraine). The usage of T-shape current supplying mould (CSM) and ingot withdrawing system as well as the change of consumable multi electrode (electrodes) are the main features of performed process. Using the new process the 20t ESR hollow ingots (hollows) with perfect quality of surfaces and defect-free macrostructure were manufactured. Any visible defects in the external and internal surface of hollow ingot including all areas of electrodes changes were not found. It becomes to be possible due to non-stop supply of electric current via CSM from second transformer. Both the high cleanness and fine as-cast microstructure of hollow ingots were proved. Simulation of slag flow and heat transfer at ESR process was developed by using the ANSYS software. The model has been verified by measuring of geometry of liquid metal pool was revealed in macrostructure of 650/450mm hollow ingots.
Le Centre pour la Communication Scientifique Directe - HAL - Diderot, Jun 13, 2018
International audienc
2,2020 (125), 2020
Objective. The results of the analysis of advanced technologies of electroslag remelting are pres... more Objective. The results of the analysis of advanced technologies of electroslag remelting are presented. Results It is shown that ESR today is the main and most challenging in obtaining of high quality metal. Protection of the melting chamber and the electrode from the atmosphere by inert gas (IESR) or melting under pressure (PESR) prevents oxidation, which is especially important during remelting of the steels and alloys with high content of easily oxidizable elements. Refusal to use a consumable electrode in the classical ESR in favor of liquid metal, provided by the use of current-suppling mold, is an effective solution to the problem of its manufacture (manufacturing price reaches 40-60% of the cost of ingot production, and in some cases impossible) and reduce energy costs. Scientific novelty. During ESR LM, there is a decrease in temperature of slag and overheating of metal in comparison with classical ESR , the volume of liquid metal bath decreases that followed by improving co...
FIELD: metallurgy. SUBSTANCE: tubular blank is filled with a mix consisting of grains of fluxing ... more FIELD: metallurgy. SUBSTANCE: tubular blank is filled with a mix consisting of grains of fluxing stone powder and grains of modifying components with the mass contents 5-40% from grains of fluxing stone powder. The strength of grains of modifying components is selected 30% less than the strength of grains of fluxing stone powder. Before deforming the tubular blank is sealed. The tubular blank is deformed with decrease of its diameter down to the size corresponding to the following relation: D d = 10 − 500 , where D - diameter of the tubular blank, d - outside diameter of the flux cored wire, meanwhile the tubular blank before deforming is sealed. EFFECT: improvement of quality of the flux cored wire by achieving of uniformity of density of the powder filler along the length of the flux cored wire and improvement of properties of the flux cored wire due to forming in the powder filler of nano-sized grains of modifying components.
Energies
This article is devoted to the following issues: calculating the values of temperatures obtained ... more This article is devoted to the following issues: calculating the values of temperatures obtained by simulating welding heating and the subsequent implementation of the welding process at the given mode parameters made it possible to obtain a welded joint of the rotor with an improved initial structure and increased mechanical properties, hydrogen resistance and durability by up to 10–15%; simulating welding heating in the areas of fusion, the overheating and normalization of the HAZ and the formation of austenite grains; specified welding heating creates the conditions for the formation of new products of austenite decomposition in the form of sorbitol in the area of the incomplete recrystallization of the HAZ. In air and gaseous hydrogen, the destruction of the combined joints took place on the weld metal, as well as on the fusion areas, the overheating and the incomplete recrystallization of the HAZ of 20H3NMFA steel as the base metal. Structural materials have a relatively low st...
Journal of Materials Research and Technology
Ironmaking & Steelmaking, 2022
Sovremennaâ èlektrometallurgiâ, 2020
Archives of Materials Science and Engineering, 2018
Purpose: To develop novel ESR based process for composite ingot with shallow transition zone betw... more Purpose: To develop novel ESR based process for composite ingot with shallow transition zone between layers in order to produce efficient heavy-weight rotors for steam turbines. Design/methodology/approach: The nowadays heavy-weight rotors for steam turbines for power plants are monoblock or two or more layer in length composite part facilitating operation in different zones withstanding various loads and working medium. However, the joining of various steel in composite rotors by welding has low productivity. The ESR now is recognised as the best available technology for the big-diameter and mass forgings for power generating machines, including rotor ones. The ESR affords the most favourable conditions of solidification resulting in homogenous low-segregation ingot with smooth surface and high-quality structure. The step ahead is the ESR for composite. Findings: The two-layer model ingot had produced from steel grades 12Cr13 and 35NiCrMoV12-5 were manufactured using the electrosla...
Sovremennaâ èlektrometallurgiâя, 2018
Зроблено огляд тенденцій розвитку залізничного транспорту і пов'язаних з ними змін умов експлуата... more Зроблено огляд тенденцій розвитку залізничного транспорту і пов'язаних з ними змін умов експлуатації та виникнення дефектів, що скорочують строк служби рейок. Зростання швидкості руху пасажирських потягів і збільшення навантаження на вісь при перевезенні вантажу вимагає покращення якості рейок і властивостей сталей, з яких їх виробляють. Збільшення інтенсивності знакоперемінних контактних навантажень, нагрів при тривалому гальмуванні та корозійні фактори викликають пошкодження рейок. Більшість дефектів рейок, що призводять до виходу їх з ладу, мають контактно-втомне походження і їх утворення часто пов'язано з металургійною якістю сталі, покращення якої потребує технологічних вдосконалень вздовж всього циклу виробництва рейок. Бібліогр. 25, іл. 1. К л ю ч о в і с л о в а : залізничні рейки; швидкість руху; навантаження на вісь; умови експлуатації; дефекти втомного походження
Nauka ta innovacii, 2019
Introduction. The development of railway transport is a necessary factor in the national developm... more Introduction. The development of railway transport is a necessary factor in the national development and European integration of Ukraine. Problem Statement. Nowadays, over 80% of rail tracks in the national railways does not meet the requirements for bearing high-speed and heavy-load trains and needs to be replaced. At present, Ukrainian Railways corporation buys rails in foreign countries, which requires significant foreign exchange costs, and therefore the manufacture of high-quality mainstream and switch point rails in our country becomes an urgent need. Purpose. To develop innovative options for organizing the production of premium rails in Ukraine. Materials and Methods. Rail steel. Experimental melting and metallographic studies (using the optical and electron microscopy methods). Results. A high homogeneity (high purity of boundaries and dispersion of primary grains, small inter-lamellar distance of perlite), enhanced properties of the rail metal ensured by conventional electroslag remelting (ESR), and similar characteristic of ingot steel produced by ESR in the current-supplying mold with twice as fast speed of formation have been experimentally proved. Experiments with high-speed ESR and test of fluoride slag in the mold on real continuous casting machine has created the technological framework for a hybrid process of continuous casting with electroslag heating of the meniscus in current-supplying mold (CC + ESR). Conclusions. ESR enables reducing the minimum hump rate of casting, improving the density and uniformity of the metal in the axial zone, and maintaining a high quality of the ingot surface. Promising options of technological schemes of waste rail ESR for obtaining the ingots with cross section close to the rail profile have been developed and proposed. Using several modern ESR furnaces with special design will enable satisfying needs of Ukrainian Railways corporation in highquality main and switch point rails. K e y w o r d s : railway, main rail, switch rail, rail steel, CC, ESR, hybrid process, and recycling of used rails. Nowadays, in many countries, the development of transport infrastructure is a priority and a driving force for national economic development. In accordance with the ambitious goals of the Na-tio nal Transport Strategy Drive Ukraine 2030 for the period up to 2030 [1], the development of transport is mentioned among the key factors for Uk raine's national development and European in tegration. The strategy foresees the creation of conditions for the introduction of high-speed
ISIJ International, 2018
Bimetallic composite roll has been given more and more attentions because of its superiority in p... more Bimetallic composite roll has been given more and more attentions because of its superiority in playing the advantages performance of the internal and external materials at the same time. In the present study, a 2D quasi-steady state mathematical model of the electroslag cladding technology for producing bimetallic composite roll was developed by the Fluent software with the UDS and UDF function. Characteristics of the electromagnetic field, flow field and temperature field of the composite roll system have been numerically simulated and the laboratory scale experiments with the different power supply circuits were also developed to provide a verification of the mathematical models. The results indicate that: simulation results of the temperature distribution in the composite roll were well verified by the corresponding experiments. With the using of current supplying mold (CSM ®), the improved conductive circuit is more beneficial to improve the distributions of current density and Joule heat in the slag pool and keep the high temperature zone away from the roll core surface than the conventional conductive circuit. On one hand, it makes the roll core be no longer as a pole of the electroslag process and the temperature adjustment of the slag pool become more flexible. On the other hand, it leads to a partial micro-melting of the roll core surface which is beneficial to form a metallurgical bonding and effectively avoid the mechanical mixing of the liquid metal between the roll core and composite layer, so, it can improve the comprehensive performance of bimetallic composite roll.
Ironmaking & Steelmaking, 2018
A new slag susceptible to self-disintegration in the solid state due to formation of dicalcium si... more A new slag susceptible to self-disintegration in the solid state due to formation of dicalcium silicate (2CaOSiO 2) was developed. This compound reduces the thermodynamic activity of silica in a slag and, consequently, decreases silicon reduction and its transition to metal in the electroslag remelting process.
Ironmaking & Steelmaking, 2018
The paper is devoted to comparison of electroslag remelting (ESR) with consumable electrode and e... more The paper is devoted to comparison of electroslag remelting (ESR) with consumable electrode and electroslag refining with liquid metal (ESR LM) processes. The possibility of rearrangement of the heat contributions coming from the consumable electrode and current supplying mould (nonconsumable electrode, CSM) makes the core of the ESR process organisation in the CSM. The usage of liquid metal instead of consumable electrodes allows to reduce liquid bath temperature and volume in order to provide low segregation ingot. The formal assessment of physico-chemical conditions and experimental measurements of desulphurisation have shown the same level of refining ability of both processes. Replacing the classic ESR by the ESR LM is a prospective way to produce high-quality ingots from sophisticated and hard-to-deform materials, whereas manufacturing of the consumable electrodes is technically problematic and costly.
Metals, 2018
In the present study, a new electroslag cladding method by using of the advanced current supplyin... more In the present study, a new electroslag cladding method by using of the advanced current supplying mold technology was used for manufacturing the high speed steel (HSS)/ductile cast iron (DCI) composite roll. The graphite morphology, matrix microstructure, elements distribution, carbides morphology, and carbides composition have been investigated by means of optical microscope (OM), scanning electron microscope (SEM), and energy dispersive spectroscopy (EDS). With increasing distance from the HSS side, a transition of graphite morphology from naught to existence and from small and dispersed to large and nonuniform was obtained at the interface. It was closely related to the fact that graphite in DCI participated in the phase change and the roll core surface and its nearby positions was heated to a high temperature by the liquid slag during the whole electroslag cladding process. Due to the combined effects of melting and elements diffusion, a significant migration of the alloying elements have occurred through the line scan analysis. Based on this, different types of carbides with the morphology and composition were found at the bonding interface. In addition, no obvious slag inclusions, porosity, shrinkage and other defects at the bonding interface were found. Results of the tensile test also illustrated that the bonding interface had a good quality and it could fully meet the requirements of the roll.
Journal of Achievements in Materials and Manufacturing Engineering, 2018
Purpose: The main task of this work was the developing of new compositions of the ESR slag that w... more Purpose: The main task of this work was the developing of new compositions of the ESR slag that would keep the required amount of easily oxidizable elements in the superalloys and have the favourable physicochemical properties. Design/methodology/approach: Thermo-dynamic modeling was applied to estimate of oxidation effect of the slags on the Inconel 718 superalloy. Slag properties (viscosity, electrical conductivity and melting points) were measured by standard methodics. Findings: The effect of slags chemistry on the preservation of the active elements (aluminium, titanium) content in the superalloy while ESR remelting was studied. Physical properties of the several compositions of the slag are prospective for ESR of alloys with high content of active elements were measured. Research limitations/implications: The results of this work allowing development of a new compositions of the slags for ESR of the specific grades of the steel and alloys and making selection of the most effec...
steel research international, 2013
Electroslag casting with liquid metal (ESC LM) using current conductive ring has been developed. ... more Electroslag casting with liquid metal (ESC LM) using current conductive ring has been developed. This technology is different from classical electroslag remelting (ESR) process. No consumable electrode is needed in the process. Liquid metal after refining is introduced into the mold directly. Current conductive ring instead of consumable electrode is the conductive unit for heating slag pool for the first time. Short collar mold and continuous withdrawal mechanism like continuous casting process are employed in the process. Conductive path of ESC LM process using current conductive ring is transformer → current conductive ring → liquid slag → molten steel → solid ingot → base plate → transformer. A mathematical model of electroslag casting process with liquid metal is developed for understanding the technology. Thermal field, voltage, and current density distributions in the system have been simulated, which are similar but different from conventional ESR process. Results of industrial trial indicate that there is no obvious macrosegregation and cracks in the industrial ingots produced by these methods. Ingot quality is equivalent to the conventional electroslag ingot. In addition, the production efficiency of ESC LM process is obvious higher than conventional ESR operation.
Proceedings of the 2013 International Symposium on Liquid Metal Processing and Casting, 2013
High Nitrogen Steels with nitrogen contents above atmospheric solubility are usually melted using... more High Nitrogen Steels with nitrogen contents above atmospheric solubility are usually melted using an advanced P-ESR process under elevated pressure. The nitrogen pick up can be controlled by Si3N4 or nitrogen gas. This paper provide a comparison of alloying by nitrogen gas by ASR vs P-ESR process in terms of processing and nitrogen distribution. In two series of ASR and P-ESR separate trials the nitrogen content was increased at remelting in nitrogen atmosphere practically twice in spite of big difference in nitrogen pressure. Comparison of P-ESR and ASR processes abilities in steel alloying by nitrogen from gas phase shown quite close results that gives us reasons for experiments continuation.
Krane/Proceedings, 2013
In this paper development of both ESR technology and equipment for hollow ingot manufacture revie... more In this paper development of both ESR technology and equipment for hollow ingot manufacture review and analysis are presented. The real complications of hollow ingot manufacture and some tendentious issues which restrict process dissemination are discussed. An actual data of modern manufacture of as-cast pipes for heat and power engineering by traditional ESR with consumable electrode are given. Results of microstructure and nonmetal inclusion investigations have shown the high quality of as-cast ESR pipes. On the basis of these results the possibility to produce huge ESR hollows (up 5000 mm in dia) with final goal drastically to reduce setting ratio on forged shells and rings or even replace it by ESR hollows as-cast is grounded. Two new ESR technologies — consumable electrodes change and liquid metal usage — have passed pilot tests for heavy hollow production and shown very prospective results to be presented.
Krane/Proceedings, 2013
A new electroslag remelting (ESR) technology for hollow ingot manufacture was recently commercial... more A new electroslag remelting (ESR) technology for hollow ingot manufacture was recently commercialized due to the cooperation between Northeastern University of China and Elmet-Roll engineering company (Ukraine). The usage of T-shape current supplying mould (CSM) and ingot withdrawing system as well as the change of consumable multi electrode (electrodes) are the main features of performed process. Using the new process the 20t ESR hollow ingots (hollows) with perfect quality of surfaces and defect-free macrostructure were manufactured. Any visible defects in the external and internal surface of hollow ingot including all areas of electrodes changes were not found. It becomes to be possible due to non-stop supply of electric current via CSM from second transformer. Both the high cleanness and fine as-cast microstructure of hollow ingots were proved. Simulation of slag flow and heat transfer at ESR process was developed by using the ANSYS software. The model has been verified by measuring of geometry of liquid metal pool was revealed in macrostructure of 650/450mm hollow ingots.
Le Centre pour la Communication Scientifique Directe - HAL - Diderot, Jun 13, 2018
International audienc
2,2020 (125), 2020
Objective. The results of the analysis of advanced technologies of electroslag remelting are pres... more Objective. The results of the analysis of advanced technologies of electroslag remelting are presented. Results It is shown that ESR today is the main and most challenging in obtaining of high quality metal. Protection of the melting chamber and the electrode from the atmosphere by inert gas (IESR) or melting under pressure (PESR) prevents oxidation, which is especially important during remelting of the steels and alloys with high content of easily oxidizable elements. Refusal to use a consumable electrode in the classical ESR in favor of liquid metal, provided by the use of current-suppling mold, is an effective solution to the problem of its manufacture (manufacturing price reaches 40-60% of the cost of ingot production, and in some cases impossible) and reduce energy costs. Scientific novelty. During ESR LM, there is a decrease in temperature of slag and overheating of metal in comparison with classical ESR , the volume of liquid metal bath decreases that followed by improving co...
FIELD: metallurgy. SUBSTANCE: tubular blank is filled with a mix consisting of grains of fluxing ... more FIELD: metallurgy. SUBSTANCE: tubular blank is filled with a mix consisting of grains of fluxing stone powder and grains of modifying components with the mass contents 5-40% from grains of fluxing stone powder. The strength of grains of modifying components is selected 30% less than the strength of grains of fluxing stone powder. Before deforming the tubular blank is sealed. The tubular blank is deformed with decrease of its diameter down to the size corresponding to the following relation: D d = 10 − 500 , where D - diameter of the tubular blank, d - outside diameter of the flux cored wire, meanwhile the tubular blank before deforming is sealed. EFFECT: improvement of quality of the flux cored wire by achieving of uniformity of density of the powder filler along the length of the flux cored wire and improvement of properties of the flux cored wire due to forming in the powder filler of nano-sized grains of modifying components.