Pub Date : 2023-03-01DOI: 10.17073/0368-0797-2023-1-105-111
E. L. Vorozheva, K. Smetanin, V. Kislitsa, D. Kudashov
The authors determined the level of zonal and dendritic segregation in slabs poured by thin-slab technology. The calculated variation coefficients of the content of basic and impurity chemical elements over the slab cross-section do not exceed 10 %, zonal segregation is low. The manganese content measured with the area occupied by the dendritic axes and the interstitial spaces showed the level of dendritic segregation. The manganese concentration varies from 0.6 to 1.1 %, respectively. It was established that the use of dynamic soft compression during solidification makes it possible to grind the primary dendritic structure to form additional centers during the phase transformation of δ-ferrite into austenite. Dimensions of the initial austenitic grains formed taking into account the primary dendritic structure are 3 times smaller in a thin slab than in a slab with a thickness of more than 200 mm. Transformations of the dendritic structure during compression show high workability necessary for the formation of uniform austenitic grains in the fullering before finishing rolling. The study has not confirmed the hypothesis that bainite of coarse morphology in the microstructure of hot-rolled products is formed in segregation areas. The hereditary influence of the primary dendritic structure on the structure formation during rolling was revealed. The manganese concentration varies between the bainite and the “neighboring” structure from 0.68 to 1.01 %, similar to the level of the initial dendritic segregation. Difference in the content of chemical elements affects the processes of recrystallization of austenitic grains during high-temperature rough rolling. Bainite was formed within the framework of chemically “depleted” large austenitic grains that are stable during phase transformation.
{"title":"Metallographic study on the structural features of thin slab and rolled products made from it","authors":"E. L. Vorozheva, K. Smetanin, V. Kislitsa, D. Kudashov","doi":"10.17073/0368-0797-2023-1-105-111","DOIUrl":"https://doi.org/10.17073/0368-0797-2023-1-105-111","url":null,"abstract":"The authors determined the level of zonal and dendritic segregation in slabs poured by thin-slab technology. The calculated variation coefficients of the content of basic and impurity chemical elements over the slab cross-section do not exceed 10 %, zonal segregation is low. The manganese content measured with the area occupied by the dendritic axes and the interstitial spaces showed the level of dendritic segregation. The manganese concentration varies from 0.6 to 1.1 %, respectively. It was established that the use of dynamic soft compression during solidification makes it possible to grind the primary dendritic structure to form additional centers during the phase transformation of δ-ferrite into austenite. Dimensions of the initial austenitic grains formed taking into account the primary dendritic structure are 3 times smaller in a thin slab than in a slab with a thickness of more than 200 mm. Transformations of the dendritic structure during compression show high workability necessary for the formation of uniform austenitic grains in the fullering before finishing rolling. The study has not confirmed the hypothesis that bainite of coarse morphology in the microstructure of hot-rolled products is formed in segregation areas. The hereditary influence of the primary dendritic structure on the structure formation during rolling was revealed. The manganese concentration varies between the bainite and the “neighboring” structure from 0.68 to 1.01 %, similar to the level of the initial dendritic segregation. Difference in the content of chemical elements affects the processes of recrystallization of austenitic grains during high-temperature rough rolling. Bainite was formed within the framework of chemically “depleted” large austenitic grains that are stable during phase transformation.","PeriodicalId":14630,"journal":{"name":"Izvestiya. Ferrous Metallurgy","volume":"2 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84350061","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 : 2023-03-01DOI: 10.17073/0368-0797-2023-1-89-96
A. Vusikhis, L. I. Leont’ev, R. Gulyaeva, S. Sergeeva, S. Tyushnyakov
Metallurgical companies in the Urals account for 50 – 60 % of local raw materials. Its deficit is compensated by the use of materials imported from Central Russia, the Kola Peninsula and Kazakhstan. Replacing them with the local raw materials would increase the competitiveness of metal produced in the Urals, so the question of assessing the possibility of replacing imported raw materials with local ones is very relevant. Such raw materials could be siderite ores from the Bakal deposit. They are not in demand by metallurgists because of their low iron content and high magnesium content. With growth of siderites in a charge the magnesium oxide content in slag increases that influences its viscosity and makes it difficult or impossible to smelt using more than 20 % of siderites. The use of boron oxide has been suggested to liquefy the slag. The synthetic slag containing 26.8 % CaO, 38.1 % SiO2 , 11.8 % Al2O3 , 23.6 % MgO, simulating composition of slag from MMK blast-furnace smelting with the addition of 30 % of burnt siderites is short and unstable. The temperature corresponding to the slag viscosity at the blast furnace outlet (0.5 Pa·s) is 1390 °C and the temperature corresponding to the melting point (viscosity 2.5 Pa·s) is 1367 °C. If boric anhydride is added to such a slag, it becomes long and stable. In the melts, when the proportion of B2O3 is increased from 0 to 12 %, the temperature at which the slag viscosity is 0.5 Pa·s and 2.5 Pa·s decreases to 1260 °C, and 1100 °C, respectively. This makes it possible to significantly increase the siderite content in blast furnace charge.
{"title":"Effect of B2O3 on viscosity of high-magnesia blast furnace slag","authors":"A. Vusikhis, L. I. Leont’ev, R. Gulyaeva, S. Sergeeva, S. Tyushnyakov","doi":"10.17073/0368-0797-2023-1-89-96","DOIUrl":"https://doi.org/10.17073/0368-0797-2023-1-89-96","url":null,"abstract":"Metallurgical companies in the Urals account for 50 – 60 % of local raw materials. Its deficit is compensated by the use of materials imported from Central Russia, the Kola Peninsula and Kazakhstan. Replacing them with the local raw materials would increase the competitiveness of metal produced in the Urals, so the question of assessing the possibility of replacing imported raw materials with local ones is very relevant. Such raw materials could be siderite ores from the Bakal deposit. They are not in demand by metallurgists because of their low iron content and high magnesium content. With growth of siderites in a charge the magnesium oxide content in slag increases that influences its viscosity and makes it difficult or impossible to smelt using more than 20 % of siderites. The use of boron oxide has been suggested to liquefy the slag. The synthetic slag containing 26.8 % CaO, 38.1 % SiO2 , 11.8 % Al2O3 , 23.6 % MgO, simulating composition of slag from MMK blast-furnace smelting with the addition of 30 % of burnt siderites is short and unstable. The temperature corresponding to the slag viscosity at the blast furnace outlet (0.5 Pa·s) is 1390 °C and the temperature corresponding to the melting point (viscosity 2.5 Pa·s) is 1367 °C. If boric anhydride is added to such a slag, it becomes long and stable. In the melts, when the proportion of B2O3 is increased from 0 to 12 %, the temperature at which the slag viscosity is 0.5 Pa·s and 2.5 Pa·s decreases to 1260 °C, and 1100 °C, respectively. This makes it possible to significantly increase the siderite content in blast furnace charge.","PeriodicalId":14630,"journal":{"name":"Izvestiya. Ferrous Metallurgy","volume":"7 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90821832","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 : 2023-03-01DOI: 10.17073/0368-0797-2023-1-57-61
K. Akimov, K. V. Ivanov, M. G. Figurko, V. Ovcharenko
In the work the possibility of improving the strength properties of Ni3Al intermetallic compound by reducing its average grain size was studied using the example of microhardness. The authors investigated the effect of reaction mixture deformation during self-propagating high-temperature synthesis (SHS) on the grain size and microhardness of Ni3Al intermetallic compound. SHS extrusion was carried out on the experimental stand, which allows continuous monitoring of synthesis parameters. It was established that one of the key factors affecting the characteristics of the grain structure and microhardness is degree of the synthesis product deformation. An increase in diameter of the extrusion hole from 3 to 5 mm leads to an increase in the maximum linear displacement of the press plunger due to active output of the material through a hole of the larger diameter. The above assumes a decrease in the material resistance to deformation when pressure is applied and an increase in degree of the material deformation inside the die and its decrease in the extruded material. Furthermore, the average grain size of Ni3Al remaining in the mold volume after synthesis decreases by 40 % (from 7 to 5 μm), and the material that passed through the extrusion hole increases by 2 times (from 3 to 6 µm). Compared to Ni3Al obtained by SHS compaction, the average grain size of the extruded intermetallic compound is 5.6 times smaller (from 17 to 3 μm). A decrease in the average grain size of extruded Ni3Al leads to an increase in microhardness by 600 MPa. The results obtained make it possible to develop recommendations for producing intermetallic compounds and alloys based on them with a fine grain size and high microhardness.
{"title":"Formation of grain structure and microhardness of Ni3Al intermetallic compound as a result of SHS extrusion","authors":"K. Akimov, K. V. Ivanov, M. G. Figurko, V. Ovcharenko","doi":"10.17073/0368-0797-2023-1-57-61","DOIUrl":"https://doi.org/10.17073/0368-0797-2023-1-57-61","url":null,"abstract":"In the work the possibility of improving the strength properties of Ni3Al intermetallic compound by reducing its average grain size was studied using the example of microhardness. The authors investigated the effect of reaction mixture deformation during self-propagating high-temperature synthesis (SHS) on the grain size and microhardness of Ni3Al intermetallic compound. SHS extrusion was carried out on the experimental stand, which allows continuous monitoring of synthesis parameters. It was established that one of the key factors affecting the characteristics of the grain structure and microhardness is degree of the synthesis product deformation. An increase in diameter of the extrusion hole from 3 to 5 mm leads to an increase in the maximum linear displacement of the press plunger due to active output of the material through a hole of the larger diameter. The above assumes a decrease in the material resistance to deformation when pressure is applied and an increase in degree of the material deformation inside the die and its decrease in the extruded material. Furthermore, the average grain size of Ni3Al remaining in the mold volume after synthesis decreases by 40 % (from 7 to 5 μm), and the material that passed through the extrusion hole increases by 2 times (from 3 to 6 µm). Compared to Ni3Al obtained by SHS compaction, the average grain size of the extruded intermetallic compound is 5.6 times smaller (from 17 to 3 μm). A decrease in the average grain size of extruded Ni3Al leads to an increase in microhardness by 600 MPa. The results obtained make it possible to develop recommendations for producing intermetallic compounds and alloys based on them with a fine grain size and high microhardness.","PeriodicalId":14630,"journal":{"name":"Izvestiya. Ferrous Metallurgy","volume":"49 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88533433","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 : 2023-03-01DOI: 10.17073/0368-0797-2023-1-62-69
L. Trishkina, A. Klopotov, A. Potekaev, T. Cherkasova, V. Borodin
Development and successes of the physical science of strength and durability allow us to formulate the main aspects of dislocation physics. In this paper, the current state of this issue is considered within the framework of a multilevel approach – patterns of dislocations accumulation in the material after deformation with various degrees. The main mechanism of hardening of a metallic polycrystal is the dislocations accumulation in its grains, and the main parameter of hardening is the average scalar density of dislocations. The scalar dislocation density is divided into components: the density of statistically stored (ρS ) and the density of geometrically necessary (ρG ) dislocations. Transmission diffraction electron microscopy (TEM) is used to study the stages of development of types of dislocation substructure (DSS) in Cu – Mn alloys depending on concentration of the alloying element during active plastic deformation. Polycrystalline alloys were studied in a wide concentration range: from 0.4 to 25 % Mn (at.). A number of dislocation substructure parameters were measured using the images obtained on an electron microscope: the average scalar density of dislocations , the density of statistically stored (ρS ) and geometrically necessary (ρG ) dislocations, the curvature-torsion of the crystal lattice (χ), the density of microstrips (Рstrips ), the density of ragged sub-boundaries (Мrag.bound. ). The authors established the effect of the sequence of DSS types transformations with an increase in the degree of deformation and the second element quantity on formation of the type of substructure and its parameters. Influence of concentration of the second element and the grain size on the average scalar density of dislocations and its components was experimentally determined. The presence of disorientations in the substructure during deformation is based on the measurement of these parameters by the TEM method.
{"title":"Substructure parameters in deformed Cu – Mn alloys with a FCC lattice","authors":"L. Trishkina, A. Klopotov, A. Potekaev, T. Cherkasova, V. Borodin","doi":"10.17073/0368-0797-2023-1-62-69","DOIUrl":"https://doi.org/10.17073/0368-0797-2023-1-62-69","url":null,"abstract":"Development and successes of the physical science of strength and durability allow us to formulate the main aspects of dislocation physics. In this paper, the current state of this issue is considered within the framework of a multilevel approach – patterns of dislocations accumulation in the material after deformation with various degrees. The main mechanism of hardening of a metallic polycrystal is the dislocations accumulation in its grains, and the main parameter of hardening is the average scalar density of dislocations. The scalar dislocation density is divided into components: the density of statistically stored (ρS ) and the density of geometrically necessary (ρG ) dislocations. Transmission diffraction electron microscopy (TEM) is used to study the stages of development of types of dislocation substructure (DSS) in Cu – Mn alloys depending on concentration of the alloying element during active plastic deformation. Polycrystalline alloys were studied in a wide concentration range: from 0.4 to 25 % Mn (at.). A number of dislocation substructure parameters were measured using the images obtained on an electron microscope: the average scalar density of dislocations , the density of statistically stored (ρS ) and geometrically necessary (ρG ) dislocations, the curvature-torsion of the crystal lattice (χ), the density of microstrips (Рstrips ), the density of ragged sub-boundaries (Мrag.bound. ). The authors established the effect of the sequence of DSS types transformations with an increase in the degree of deformation and the second element quantity on formation of the type of substructure and its parameters. Influence of concentration of the second element and the grain size on the average scalar density of dislocations and its components was experimentally determined. The presence of disorientations in the substructure during deformation is based on the measurement of these parameters by the TEM method.","PeriodicalId":14630,"journal":{"name":"Izvestiya. Ferrous Metallurgy","volume":"37 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81671131","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 : 2023-03-01DOI: 10.17073/0368-0797-2023-1-119-126
А. S. Leont’ev, I. Rybenko
Due to the world trade development, metallurgical plants have a great variability in preparation of the production plan. At EVRAZ West Siberian Metallurgical Combine JSC (JSC “EVRAZ ZSMK”), the charge is optimized from 110 components only in terms of agglomeration and blast furnace production. The product range consists of more than 2000 units and varies from month to month. Usually, the production plan is optimized only within individual redevelopments. The purpose of optimization is to minimize the cost of conversion and to maximize production. The article describes development and implementation of a mathematical modeling system of production of the entire metallurgical plant on the example of JSC “EVRAZ ZSMK”. In contrast to the existing conversion modeling systems, the goal of the system is a one-time end-to-end optimization of all the plant’s conversions. The ultimate goal is to maximize the profit of the entire plant. During the operation of the new system in 2019 – 2020, high labor costs were found during the work of the users. For example, more than 10,000 test iterations of calculations were performed for the release of 60 plans for the year and calculation of 30 economic cases. A form of work statistics was developed and analyzed, which showed the following main problems: unsolvability of the model due to the input of mathematically incorrect data; repeated calculations of economic cases to isolate and interpret individual changed factors of the plan from the budget; errors at the data verification stage due to incorrect chemical composition of elements or incorrect model settings for a specific period of work. To eliminate the shortcomings of the system, the authors developed the validation systems for input data at the stage before and after calculations, sensitivity analysis and factor calculation modules and automatic chemical composition filling system. Also the possibility of retraining the model on historical data was added.
{"title":"Experience in using and improving the usability of mathematical modeling system of production at a metallurgical enterprise","authors":"А. S. Leont’ev, I. Rybenko","doi":"10.17073/0368-0797-2023-1-119-126","DOIUrl":"https://doi.org/10.17073/0368-0797-2023-1-119-126","url":null,"abstract":"Due to the world trade development, metallurgical plants have a great variability in preparation of the production plan. At EVRAZ West Siberian Metallurgical Combine JSC (JSC “EVRAZ ZSMK”), the charge is optimized from 110 components only in terms of agglomeration and blast furnace production. The product range consists of more than 2000 units and varies from month to month. Usually, the production plan is optimized only within individual redevelopments. The purpose of optimization is to minimize the cost of conversion and to maximize production. The article describes development and implementation of a mathematical modeling system of production of the entire metallurgical plant on the example of JSC “EVRAZ ZSMK”. In contrast to the existing conversion modeling systems, the goal of the system is a one-time end-to-end optimization of all the plant’s conversions. The ultimate goal is to maximize the profit of the entire plant. During the operation of the new system in 2019 – 2020, high labor costs were found during the work of the users. For example, more than 10,000 test iterations of calculations were performed for the release of 60 plans for the year and calculation of 30 economic cases. A form of work statistics was developed and analyzed, which showed the following main problems: unsolvability of the model due to the input of mathematically incorrect data; repeated calculations of economic cases to isolate and interpret individual changed factors of the plan from the budget; errors at the data verification stage due to incorrect chemical composition of elements or incorrect model settings for a specific period of work. To eliminate the shortcomings of the system, the authors developed the validation systems for input data at the stage before and after calculations, sensitivity analysis and factor calculation modules and automatic chemical composition filling system. Also the possibility of retraining the model on historical data was added.","PeriodicalId":14630,"journal":{"name":"Izvestiya. Ferrous Metallurgy","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75325559","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 : 2023-03-01DOI: 10.17073/0368-0797-2023-1-86-88
N. Babailov, Y. Loginov, L. I. Polyanskii
The paper considers the geometry of cracks in the volume of briquettes made of a slag-forming material widely used in ferrous metallurgy – magnesium oxide MgO. The authors present the results of measuring the geometry and location of cracks in the volume of briquettes obtained by roller briquetting. The possibility of cracks in the volume of briquettes is a technological feature of roll briquetting. This defect affects the strength of the briquettes, as well as the yield (and productivity) in the process of briquetting on roller briquetting machines. The number and angle of inclination of cracks relative to the direction of briquetting are determined from photographs of the briquette side surface using graphic programs.
{"title":"Cracking in magnesium oxide briquettes","authors":"N. Babailov, Y. Loginov, L. I. Polyanskii","doi":"10.17073/0368-0797-2023-1-86-88","DOIUrl":"https://doi.org/10.17073/0368-0797-2023-1-86-88","url":null,"abstract":"The paper considers the geometry of cracks in the volume of briquettes made of a slag-forming material widely used in ferrous metallurgy – magnesium oxide MgO. The authors present the results of measuring the geometry and location of cracks in the volume of briquettes obtained by roller briquetting. The possibility of cracks in the volume of briquettes is a technological feature of roll briquetting. This defect affects the strength of the briquettes, as well as the yield (and productivity) in the process of briquetting on roller briquetting machines. The number and angle of inclination of cracks relative to the direction of briquetting are determined from photographs of the briquette side surface using graphic programs.","PeriodicalId":14630,"journal":{"name":"Izvestiya. Ferrous Metallurgy","volume":"275 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78449213","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 : 2023-03-01DOI: 10.17073/0368-0797-2023-1-70-79
A. Zinyagin, A. Muntin, M. O. Kryuchkova
The study of resistance to deformation of various steel grades is one of the key issues for the adequate operation of automation systems, which makes it possible to obtain rolled products with the required accuracy in terms of geometric characteristics. In addition, knowledge of deformation resistance is important in the design of rolling mill equipment. In the literature, the values of deformation resistance in the overwhelming majority of cases are given in the form of coefficients of various equations (for example, Hensel-Spittel). However, these formulas often have limitations in the range of technological parameters where they give an acceptable result. It should also be considered that dozens of steel grades are produced at modern rolling mills, and their chemical composition can vary over a wide range depending on the final thickness of rolled products, customer requirements, or based on economic considerations (the most advantageous alloying composition). The study of the rheological properties of such a quantity of materials in the laboratory is expensive, long-term, and labor-intensive, and the literature sources do not provide completeness of the data. The article shows that, using data from industrial rolling mills and machine learning methods, it is possible to obtain information about the rheology of the material with satisfactory accuracy, which makes it possible to avoid laboratory studies. Carrying out such studies is possible due to the high saturation of modern rolling mills with various sensors and measuring instruments. Comparison of the results from industrial data was carried out with the values of the deformation resistance obtained on the Gleeble machine. Based on this comparison, the model was trained based on gradient boosting to take into account the features of the technological process in industrial production.
{"title":"Study of pipe steel resistance to deformation in laboratory conditions and on the data from industrial rolling with the use of machine learning tools","authors":"A. Zinyagin, A. Muntin, M. O. Kryuchkova","doi":"10.17073/0368-0797-2023-1-70-79","DOIUrl":"https://doi.org/10.17073/0368-0797-2023-1-70-79","url":null,"abstract":"The study of resistance to deformation of various steel grades is one of the key issues for the adequate operation of automation systems, which makes it possible to obtain rolled products with the required accuracy in terms of geometric characteristics. In addition, knowledge of deformation resistance is important in the design of rolling mill equipment. In the literature, the values of deformation resistance in the overwhelming majority of cases are given in the form of coefficients of various equations (for example, Hensel-Spittel). However, these formulas often have limitations in the range of technological parameters where they give an acceptable result. It should also be considered that dozens of steel grades are produced at modern rolling mills, and their chemical composition can vary over a wide range depending on the final thickness of rolled products, customer requirements, or based on economic considerations (the most advantageous alloying composition). The study of the rheological properties of such a quantity of materials in the laboratory is expensive, long-term, and labor-intensive, and the literature sources do not provide completeness of the data. The article shows that, using data from industrial rolling mills and machine learning methods, it is possible to obtain information about the rheology of the material with satisfactory accuracy, which makes it possible to avoid laboratory studies. Carrying out such studies is possible due to the high saturation of modern rolling mills with various sensors and measuring instruments. Comparison of the results from industrial data was carried out with the values of the deformation resistance obtained on the Gleeble machine. Based on this comparison, the model was trained based on gradient boosting to take into account the features of the technological process in industrial production.","PeriodicalId":14630,"journal":{"name":"Izvestiya. Ferrous Metallurgy","volume":"190 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77305015","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 : 2023-02-20DOI: 10.17073/0368-0797-2023-1-27-34
M. E. Goshkoderya, T. Bobkova, S. P. Bogdanov, A. V. Krasikov, M. Staritsyn, A. A. Kashirina
The present work considers the results on synthesis of composite clad powder systems with the “core-shell” type of structure for spraying wear-resistant metal-ceramic coatings. Powders of highly hard TiB2 and HfB2 borides were used as a core for the synthesis of a composite powder, and titanium was used to create coating on their surface. The cladding layer is synthesized by the iodine transport method. Powder cladding uses the method of detecting one component on another gas transport path, the agent of which is contact iodine. The deposition of composite clad powders of the TiB2 /Ti and HfB2 /Ti systems is implemented by the microplasma method, which, in contrast to the classical plasma deposition, makes it possible to dissolve transformations in composite powders due to thermal action. In the study of transverse microsections of sprayed coatings, it was found that during microplasma spraying, titanium is saturated with oxygen, forming a titanium dioxide phase, as a result of which the clad composite powder of systems TiB2 /Ti and HfB2 /Ti are converted into coatings from systems TiB2 (TiB)/Ti(TiO2 ) and HfB2 /Ti(TiO2 ). Features of the composition in terms of coating thickness were revealed. The study of hardness shows that the integral value of microhardness for a coating based on titanium diboride is 1300 HV. Coating based on hafnium diboride has integral microhardness of about 1600 HV. When checking the wear resistance, pairs with TiB2 (TiB)/Ti(TiO2 ) and HfB2 /Ti(TiO2 ) coatings were mated with a counterbody from the 45Kh sample without coatings and together with each other. Despite the lower microhardness, the most wear-resistant is coating of TiB2 (TiB)/Ti(TiO2 ) system.
{"title":"Spraying wear-resistant coatings from clad powders TiB2/Ti and HfB2/Ti","authors":"M. E. Goshkoderya, T. Bobkova, S. P. Bogdanov, A. V. Krasikov, M. Staritsyn, A. A. Kashirina","doi":"10.17073/0368-0797-2023-1-27-34","DOIUrl":"https://doi.org/10.17073/0368-0797-2023-1-27-34","url":null,"abstract":"The present work considers the results on synthesis of composite clad powder systems with the “core-shell” type of structure for spraying wear-resistant metal-ceramic coatings. Powders of highly hard TiB2 and HfB2 borides were used as a core for the synthesis of a composite powder, and titanium was used to create coating on their surface. The cladding layer is synthesized by the iodine transport method. Powder cladding uses the method of detecting one component on another gas transport path, the agent of which is contact iodine. The deposition of composite clad powders of the TiB2 /Ti and HfB2 /Ti systems is implemented by the microplasma method, which, in contrast to the classical plasma deposition, makes it possible to dissolve transformations in composite powders due to thermal action. In the study of transverse microsections of sprayed coatings, it was found that during microplasma spraying, titanium is saturated with oxygen, forming a titanium dioxide phase, as a result of which the clad composite powder of systems TiB2 /Ti and HfB2 /Ti are converted into coatings from systems TiB2 (TiB)/Ti(TiO2 ) and HfB2 /Ti(TiO2 ). Features of the composition in terms of coating thickness were revealed. The study of hardness shows that the integral value of microhardness for a coating based on titanium diboride is 1300 HV. Coating based on hafnium diboride has integral microhardness of about 1600 HV. When checking the wear resistance, pairs with TiB2 (TiB)/Ti(TiO2 ) and HfB2 /Ti(TiO2 ) coatings were mated with a counterbody from the 45Kh sample without coatings and together with each other. Despite the lower microhardness, the most wear-resistant is coating of TiB2 (TiB)/Ti(TiO2 ) system.","PeriodicalId":14630,"journal":{"name":"Izvestiya. Ferrous Metallurgy","volume":"141 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-02-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86184091","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 : 2023-02-20DOI: 10.17073/0368-0797-2023-1-8-26
M. Kostina, L. Rigina, V. S. Kostina, A. Kudryashov, R. S. Fedortsov
Martensitic stainless steels with 13 % Cr are widely used in many industries due to their high level of mechanical properties and acceptable corrosion resistance. The paper consolidates information about the guaranteed level of properties and the heat treatment conditions necessary for its implementation. The properties after the treatment proposed by the researchers are compared with the known properties for industrial metal. Dependences of hardness of the hardened steels of 13Cr type with 0.20 – 0.5 % C on austenitization temperature and accompanying changes in the structure were analyzed, the temperatures providing maximum hardening and the temperatures at which the steel ceases to harden were identified. Influence of the austenitization duration, heating and cooling rates on the steels properties is described. The review considers mechanical properties and corrosion resistance after quenching, quenching and tempering in relation to the structural-phase states of steels. It is shown in detail how the type of secondary phases during tempering, their quantity and distribution affect the corrosion resistance of steels with 13 % Cr. It increases with an increase in the heating temperature during austenitization and decreases with an increase in tempering temperature due to precipitation of Cr23C6 carbides and depletion of the matrix in chromium to concentrations below 12 %. The tempering temperature of 500 – 550 °C is recognized as the worst: due to the intense precipitation of carbides, the steel is not passivated, the corrosion rate is maximal. For steels of 20Kh13 type, low tempering quenching (for a combination of high strength, good corrosion resistance and satisfactory ductility) or, more often, high tempering at ~(650 – 700) °C (good ductility, satisfactory corrosion resistance) is recommended. For steels of 40Kh13 type, a temperature of ~700 °C is not recommended due to the increased concentration of carbides and insufficient corrosion resistance. Examples are given of increasing the wear resistance of steels of 40Kh13 type due to surface treatments, from nitriding to laser and plasma surface hardening.
{"title":"Corrosion-resistant steels based on Fe – ~13 % Cr: Heat treatment, corrosion- and wear resistance. Review","authors":"M. Kostina, L. Rigina, V. S. Kostina, A. Kudryashov, R. S. Fedortsov","doi":"10.17073/0368-0797-2023-1-8-26","DOIUrl":"https://doi.org/10.17073/0368-0797-2023-1-8-26","url":null,"abstract":"Martensitic stainless steels with 13 % Cr are widely used in many industries due to their high level of mechanical properties and acceptable corrosion resistance. The paper consolidates information about the guaranteed level of properties and the heat treatment conditions necessary for its implementation. The properties after the treatment proposed by the researchers are compared with the known properties for industrial metal. Dependences of hardness of the hardened steels of 13Cr type with 0.20 – 0.5 % C on austenitization temperature and accompanying changes in the structure were analyzed, the temperatures providing maximum hardening and the temperatures at which the steel ceases to harden were identified. Influence of the austenitization duration, heating and cooling rates on the steels properties is described. The review considers mechanical properties and corrosion resistance after quenching, quenching and tempering in relation to the structural-phase states of steels. It is shown in detail how the type of secondary phases during tempering, their quantity and distribution affect the corrosion resistance of steels with 13 % Cr. It increases with an increase in the heating temperature during austenitization and decreases with an increase in tempering temperature due to precipitation of Cr23C6 carbides and depletion of the matrix in chromium to concentrations below 12 %. The tempering temperature of 500 – 550 °C is recognized as the worst: due to the intense precipitation of carbides, the steel is not passivated, the corrosion rate is maximal. For steels of 20Kh13 type, low tempering quenching (for a combination of high strength, good corrosion resistance and satisfactory ductility) or, more often, high tempering at ~(650 – 700) °C (good ductility, satisfactory corrosion resistance) is recommended. For steels of 40Kh13 type, a temperature of ~700 °C is not recommended due to the increased concentration of carbides and insufficient corrosion resistance. Examples are given of increasing the wear resistance of steels of 40Kh13 type due to surface treatments, from nitriding to laser and plasma surface hardening.","PeriodicalId":14630,"journal":{"name":"Izvestiya. Ferrous Metallurgy","volume":"516 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-02-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77124096","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 : 2022-12-31DOI: 10.17073/0368-0797-2022-12-904-912
A. Zimin, I. Burkova, V. V. Zimin
The improvement of management mechanisms for the formation and calendar planning of development programs is the most important direction for improving the productivity (achievement of goals) and efficiency (reduction of the amount of resources consumed) of the activities of metallurgical companies. Currently, it is necessary to ensure the mobilization of companies’ assets to solve the tasks of their sustainable development. The task of forming a program for the development of a metallurgical enterprise (company) is considered. The program includes several different areas of development: improvement of existing business processes (sales, supply, production, repair of equipment, etc.), production technologies of various stages (production of coke, agglomerate, cast iron, steel, rolled products), implementation of digital transformation tasks, etc. Each of the directions of the development program contains projects described by effect, size of investments, changes in the expenditure items of operating budget related to the costs of operating those systems and processes that the project is aimed at improving, as well as an indicator describing the risk of project implementation. One of the directions of the development program may include multi-purpose projects, the implementation of which leads not only to changes in its own performance indicators, but also to changes in the performance indicators of projects of other (non-multi-purpose) directions of such development program. The case is considered when management of the development program includes the management of the overall budget and achievement of overall goal of the program (the maximum effect from implementation of all projects). At the same time, project risk management and changes in the operating budget are implemented at the level of project portfolio management of individual program areas (there are no restrictions on risks and changes in the operating budget common to the development program). The stated formalizations of the problems, their decomposition and composition schemes, and the developed procedures for solving individual subtasks are based on the provisions and methods of the theories of system analysis and a new section of discrete mathematics (network programming).
{"title":"Formation of development programs with multi-purpose projects at ferrous metallurgy enterprises","authors":"A. Zimin, I. Burkova, V. V. Zimin","doi":"10.17073/0368-0797-2022-12-904-912","DOIUrl":"https://doi.org/10.17073/0368-0797-2022-12-904-912","url":null,"abstract":"The improvement of management mechanisms for the formation and calendar planning of development programs is the most important direction for improving the productivity (achievement of goals) and efficiency (reduction of the amount of resources consumed) of the activities of metallurgical companies. Currently, it is necessary to ensure the mobilization of companies’ assets to solve the tasks of their sustainable development. The task of forming a program for the development of a metallurgical enterprise (company) is considered. The program includes several different areas of development: improvement of existing business processes (sales, supply, production, repair of equipment, etc.), production technologies of various stages (production of coke, agglomerate, cast iron, steel, rolled products), implementation of digital transformation tasks, etc. Each of the directions of the development program contains projects described by effect, size of investments, changes in the expenditure items of operating budget related to the costs of operating those systems and processes that the project is aimed at improving, as well as an indicator describing the risk of project implementation. One of the directions of the development program may include multi-purpose projects, the implementation of which leads not only to changes in its own performance indicators, but also to changes in the performance indicators of projects of other (non-multi-purpose) directions of such development program. The case is considered when management of the development program includes the management of the overall budget and achievement of overall goal of the program (the maximum effect from implementation of all projects). At the same time, project risk management and changes in the operating budget are implemented at the level of project portfolio management of individual program areas (there are no restrictions on risks and changes in the operating budget common to the development program). The stated formalizations of the problems, their decomposition and composition schemes, and the developed procedures for solving individual subtasks are based on the provisions and methods of the theories of system analysis and a new section of discrete mathematics (network programming).","PeriodicalId":14630,"journal":{"name":"Izvestiya. Ferrous Metallurgy","volume":"15 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83536204","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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