Pub Date : 2023-03-01DOI: 10.17073/0368-0797-2023-1-80-85
M. Kaplan, A. Gorbenko, A. Ivannikov, S. V. Konushkin, A. V. Mikhailova, A. Kirsankin, A. S. Baikin, K. V. Sergienko, E. O. Nasakina, A. Kolmakov, M. A. Sevost’yanov
At present, powder with spherical particles from corrosion-resistant steels is used in such widespread additive methods as selective laser melting, selective laser sintering, direct laser sintering, electron beam melting, and others. Each of these methods places high demands on the characteristics of the spherical particles of stainless steel powder. This article is devoted to the production of a spherical powder by plasma spraying of a wire with diameter of 1 mm from corrosion-resistant steel 03Kh17N10M2 and the study of powder characteristics on its suitability for the use in additive methods. The authors developed the technology for obtaining a spherical powder and studied the influence of spraying modes on the yield of fraction less than 160 μm, suitable for additive methods. With an increase in power and gas flow, the yield of fraction less than 160 μm increases and reaches more than 70 %. The resulting powder has high fluidity (17.6 ± 1 s), bulk density (4.15 ± 0.1 g/cm3 ) and density after tapping (4.36 ± 0.2 g/cm3 ) and is suitable for use in additive production. Influence of the spherical powder fraction on the fluidity, bulk density and density after tapping was also studied. The best characteristics were obtained for the –90 μm fraction: fluidity 16.64 ± 1 s, bulk density 4.16 ± 0.1 g/cm3 and density after tapping 4.38 ± 0.2 g/cm3. These figures meet the requirements for powders used in additive manufacturing, namely, the fluidity of 50 g of powder is less than 30 s and the bulk density is more than 3 g/cm3.
{"title":"Investigation of spherical powder obtained by plasma spraying of wire from corrosion-resistant steel 03Kh17N10M2","authors":"M. Kaplan, A. Gorbenko, A. Ivannikov, S. V. Konushkin, A. V. Mikhailova, A. Kirsankin, A. S. Baikin, K. V. Sergienko, E. O. Nasakina, A. Kolmakov, M. A. Sevost’yanov","doi":"10.17073/0368-0797-2023-1-80-85","DOIUrl":"https://doi.org/10.17073/0368-0797-2023-1-80-85","url":null,"abstract":"At present, powder with spherical particles from corrosion-resistant steels is used in such widespread additive methods as selective laser melting, selective laser sintering, direct laser sintering, electron beam melting, and others. Each of these methods places high demands on the characteristics of the spherical particles of stainless steel powder. This article is devoted to the production of a spherical powder by plasma spraying of a wire with diameter of 1 mm from corrosion-resistant steel 03Kh17N10M2 and the study of powder characteristics on its suitability for the use in additive methods. The authors developed the technology for obtaining a spherical powder and studied the influence of spraying modes on the yield of fraction less than 160 μm, suitable for additive methods. With an increase in power and gas flow, the yield of fraction less than 160 μm increases and reaches more than 70 %. The resulting powder has high fluidity (17.6 ± 1 s), bulk density (4.15 ± 0.1 g/cm3 ) and density after tapping (4.36 ± 0.2 g/cm3 ) and is suitable for use in additive production. Influence of the spherical powder fraction on the fluidity, bulk density and density after tapping was also studied. The best characteristics were obtained for the –90 μm fraction: fluidity 16.64 ± 1 s, bulk density 4.16 ± 0.1 g/cm3 and density after tapping 4.38 ± 0.2 g/cm3. These figures meet the requirements for powders used in additive manufacturing, namely, the fluidity of 50 g of powder is less than 30 s and the bulk density is more than 3 g/cm3.","PeriodicalId":14630,"journal":{"name":"Izvestiya. Ferrous Metallurgy","volume":"54 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74823060","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: 10.17073/0368-0797-2023-1-8-26
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}
Pub Date : 2022-12-31DOI: 10.17073/0368-0797-2022-12-879-886
E. E. Deryugin, N. Narkevich, Yu. F. Gomorova
The paper studies the influence of boundary conditions and the loading rate on the strain behavior and fracture of Cr – Mn – C – N austenitic steel in the cast state without additional heat treatment. Regularities of steel strain and fracture were analyzed on the basis of three-point bending test data of square-section samples with and without a notch, placed with a rib on supports. In addition to the initial stage of the steel elastic strain, this unconventional arrangement of the sample on supports enabled the detection of two more stages of strain development under the effect of an external applied force: the stage of nonlinear strain and the stage of discontinuous strain preceding the moment of sample failure. As the loading rate increases, it was demonstrated that the fracture resistance and the extent of the nonlin-ear strain stage of the sample with a notch increases, and the extent of the discontinuous strain stage decreases. The sample without a notch has a prolonged nonlinear strain stage and exhibits maximum strength in the absence of the discontinuous stage. The end of the nonlinear strain stage corresponds to the moment of sample failure. A characteristic property of cast steel under the given loading conditions is that the fracture of the sample is brittle, despite the prolonged stage of non-linear strain. Structural metallographic and diffractometric studies have shown that in all tests the steel fracture is brittle with-out traces of plastic yield. The nonlinear strain stage of steel is determined not by dislocation plastic yield, but by the mechanism of γ → αʹ transformation in austenitic interlayers between nitride and car-bide particles under the effect of an external applied force. The discontinuous strain stage of steel is associated with the process of stable crack propagation across the sample.
研究了边界条件和加载速率对铸态Cr - Mn - C - N奥氏体钢应变行为和断口的影响。根据带肋支承的带缺口和不带缺口的方形截面试样三点弯曲试验数据，分析了钢的应变和断裂规律。除了钢弹性应变的初始阶段外，这种非传统的支撑试样排列方式还可以检测到在外力作用下的另外两个应变发展阶段:非线性应变阶段和试样失效前的不连续应变阶段。结果表明，随着加载速率的增加，带缺口试样的断裂抗力和非线性穗应变阶段增大，不连续应变阶段减小;没有缺口的试样具有延长的非线性应变阶段，在没有不连续阶段时表现出最大的强度。非线性应变阶段的结束对应于试样的破坏时刻。在给定的加载条件下，铸钢的一个特征是试样的断裂是脆性的，尽管非线性应变阶段延长了。组织金相和衍射研究表明，在所有的测试中，钢的断裂是脆的，没有塑性屈服的痕迹。钢的非线性应变阶段不是由位错塑性屈服决定的，而是由外力作用下氮化物与车相颗粒之间奥氏体层γ→α→相变机制决定的。钢的不连续应变阶段与裂纹在试样上的稳定扩展过程有关。
{"title":"Deformation and fracture of Cr – Mn – C – N steel in as-cast condition","authors":"E. E. Deryugin, N. Narkevich, Yu. F. Gomorova","doi":"10.17073/0368-0797-2022-12-879-886","DOIUrl":"https://doi.org/10.17073/0368-0797-2022-12-879-886","url":null,"abstract":"The paper studies the influence of boundary conditions and the loading rate on the strain behavior and fracture of Cr – Mn – C – N austenitic steel in the cast state without additional heat treatment. Regularities of steel strain and fracture were analyzed on the basis of three-point bending test data of square-section samples with and without a notch, placed with a rib on supports. In addition to the initial stage of the steel elastic strain, this unconventional arrangement of the sample on supports enabled the detection of two more stages of strain development under the effect of an external applied force: the stage of nonlinear strain and the stage of discontinuous strain preceding the moment of sample failure. As the loading rate increases, it was demonstrated that the fracture resistance and the extent of the nonlin-ear strain stage of the sample with a notch increases, and the extent of the discontinuous strain stage decreases. The sample without a notch has a prolonged nonlinear strain stage and exhibits maximum strength in the absence of the discontinuous stage. The end of the nonlinear strain stage corresponds to the moment of sample failure. A characteristic property of cast steel under the given loading conditions is that the fracture of the sample is brittle, despite the prolonged stage of non-linear strain. Structural metallographic and diffractometric studies have shown that in all tests the steel fracture is brittle with-out traces of plastic yield. The nonlinear strain stage of steel is determined not by dislocation plastic yield, but by the mechanism of γ → αʹ transformation in austenitic interlayers between nitride and car-bide particles under the effect of an external applied force. The discontinuous strain stage of steel is associated with the process of stable crack propagation across the sample.","PeriodicalId":14630,"journal":{"name":"Izvestiya. Ferrous Metallurgy","volume":"27 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83318771","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: 10.17073/0368-0797-2022-12-851-860
L. Korotkova, A. Korotkov
The authors analyzed the state of tool production in Russia. The main manufacturing companies and the main brands of materials used in the production of domestic tools are highlighted. Powder high-speed steels are practically not used in the domestic market, but they are widely distributed in the foreign market of tool steels due to their significant advantages in terms of basic and technological properties (including the possibility of using high-carbon and high-alloy high-speed steels). There is a new group of economically alloyed tungsten-free high-speed steels with a high content of carbon and vanadium, which are practically impossible to manufacture and apply in our traditional technology due to low technological properties. The authors give recommendations on the technology of manufacturing such steels by powder metallurgy and on the modes of their heat treatment. The paper studies a set of properties of these steels, including: basic mechanical properties (hardness, bending strength, toughness, and heat resistance), basic technological properties (pressure, cutting, grinding) and operational properties (evaluated by tool durability during turning). Structural and phase compositions of the steels and their influence on the basic and technological properties were investigated. The compaction mode affects the density of the billets. The paper presents distribution of alloying elements in the microstructure of powder high-speed steel and results of their relative grindability. Also the durability of tools was tested. There are significant advantages of high-carbon high-vanadium high-speed steels, especially in terms of technological properties, compared with traditional high-speed steels. It is possible to produce high-alloy tool steels using inexpensive carbide-forming alloying elements. The steels under consideration can be used to manufacture a wide range of tools, including hot-forming die tools. The use of powder technology opens up the prospect of developing universal economically alloyed powder tool steels.
{"title":"Influence of production technology of powder high-speed steels on the complex of formed properties","authors":"L. Korotkova, A. Korotkov","doi":"10.17073/0368-0797-2022-12-851-860","DOIUrl":"https://doi.org/10.17073/0368-0797-2022-12-851-860","url":null,"abstract":"The authors analyzed the state of tool production in Russia. The main manufacturing companies and the main brands of materials used in the production of domestic tools are highlighted. Powder high-speed steels are practically not used in the domestic market, but they are widely distributed in the foreign market of tool steels due to their significant advantages in terms of basic and technological properties (including the possibility of using high-carbon and high-alloy high-speed steels). There is a new group of economically alloyed tungsten-free high-speed steels with a high content of carbon and vanadium, which are practically impossible to manufacture and apply in our traditional technology due to low technological properties. The authors give recommendations on the technology of manufacturing such steels by powder metallurgy and on the modes of their heat treatment. The paper studies a set of properties of these steels, including: basic mechanical properties (hardness, bending strength, toughness, and heat resistance), basic technological properties (pressure, cutting, grinding) and operational properties (evaluated by tool durability during turning). Structural and phase compositions of the steels and their influence on the basic and technological properties were investigated. The compaction mode affects the density of the billets. The paper presents distribution of alloying elements in the microstructure of powder high-speed steel and results of their relative grindability. Also the durability of tools was tested. There are significant advantages of high-carbon high-vanadium high-speed steels, especially in terms of technological properties, compared with traditional high-speed steels. It is possible to produce high-alloy tool steels using inexpensive carbide-forming alloying elements. The steels under consideration can be used to manufacture a wide range of tools, including hot-forming die tools. The use of powder technology opens up the prospect of developing universal economically alloyed powder tool steels.","PeriodicalId":14630,"journal":{"name":"Izvestiya. Ferrous Metallurgy","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84206515","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: 10.17073/0368-0797-2022-12-895-903
G. G. Mikhailov, L. Makrovets, I. V. Bakin
The use of complex strontium-containing alloys with alkaline-earth metals for steel out-of-furnace treatment makes it possible to increase the efficiency of the refining process and steel modifying. In this work based on the binary phase diagrams of SrO – CaO, SrO – Al2O3 , Al2O3 – CaO binary systems and data on possibility of the solid solution formation, the phase diagram of the SrO – Al2O3 – CaO system is modeled in the temperature range 1600 – 2600 °С. When constructing liquidus lines, the theories of perfect solutions (for solid solutions of strontium and calcium aluminates), regular solutions (for solid solutions of oxides) and irregular ionic solutions (for oxide melt) were used to calculate the activity of components. Thermodynamic analysis of the Fe – Sr – Ca – Al – O system was carried out as applied to the refining steel processes with alloys containing calcium and strontium at a temperature of 1600 °C. The simulation results showed that in in the process of refining the aluminium-deoxidized steel, a complex mechanism of interaction of active elements with oxygen will be realized. The interaction of calcium and strontium with oxygen occurs both for elements dissolved in iron and along the boundary of the gas phase containing calcium and strontium with the liquid iron melt. As a result of the interaction of calcium and strontium with oxygen in the presence of aluminium (0.05 %), the probability of formation of liquid oxide melts SrO – Al2O3 – CaO is high, which greatly facilitates the removal of reaction products from the melt. The resulting non-metallic inclusions are most likely to be complex calcium and strontium aluminates, which, due to the presence of strontium, are easily assimilated by slag. The formation of undesirable corundum inclusions during metal processing with complex alloys containing strontium and calcium is unlikely.
将含锶复合合金与碱土金属用于钢的炉外处理，可以提高炼钢工艺和钢的改性效率。在这个工作的基础上,“二元相图的SrO” 曹,地面读数 氧化铝,氧化铝 —— 曹二元系统和数据的可能性固溶体的形成,“相图的SrO” - 氧化铝 曹系统建模在温度范围1600 - 2600°С。在构造液相线时，采用完美溶液理论(适用于锶和铝酸钙的固溶体)、规则溶液理论(适用于氧化物的固溶体)和不规则离子溶液理论(适用于氧化物熔体)计算组分的活度。对Fe - Sr - Ca - Al - - O体系在1600℃含钙锶合金炼钢过程中进行了热力学分析。模拟结果表明，在铝脱氧钢精炼过程中，活性元素与氧相互作用的复杂机制将得以实现。钙和锶与氧的相互作用既发生在溶解在铁中的元素中，也发生在含钙和锶的气相与液态铁熔体的边界上。在铝的存在下(0.05%)，由于钙、锶与氧的相互作用，形成液态氧化物熔体SrO - Al2O3 - CaO的概率很高，这极大地促进了熔体中反应产物的去除。所产生的非金属夹杂物很可能是复合的钙和锶铝酸盐，由于锶的存在，很容易被炉渣同化。在含有锶和钙的复杂合金的金属加工过程中，不太可能形成不良的刚玉夹杂物。
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Pub Date : 2022-11-22DOI: 10.17073/0368-0797-2022-11-758-768
S. Zhilin, N. Bogdanova, O. N. Komarov
The growth in metal intensity of industrial production and the volume of consumption of finished metal products determine the relevance of development and research of energy efficient technological processes aimed at reducing costs by reducing the number of operations while maintaining product performance. In mechanical engineering, the problem of obtaining blanks with increased dimensional and geometric accuracy and complex configuration is solved by using a common method of investment casting. Expansion of the use of such technological approach to produce blanks in mechanical engineering is hindered by a number of physical phenomena associated with the thermal expansion of investment and ceramic materials, which leads to an increase in the product final cost. A significant number of defect-forming factors can be eliminated by applying an innovative solution consisting in the formation of porous removable models by compacting mixtures based on waxy materials. This solves the problem of material shrinkage and increases the crack resistance of ceramic molds, which significantly reduces the share of machining in the overall volume of technological operations. Technical tests of the new method have revealed the reason why the machining of castings cannot be completely eliminated at present. The problem mainly lies in elastic response of compacted material of the model mixture, which, in some cases, affects the increase in the compacts size. This paper considers the effect of initial packing of spherical-shaped elements simulating one- and two-component model mixtures on the stress-strain state of a powder body subjected to unilateral compaction in a rigid cylindrical matrix to technologically justified density values. The results of the experiment are presented in the form of stress-strain relations. Preferable conditions of compact formation with minimal values of elastic response of the compacted material are considered.
{"title":"Experimental simulation of volumetric compacts formation from spherical waxy elements","authors":"S. Zhilin, N. Bogdanova, O. N. Komarov","doi":"10.17073/0368-0797-2022-11-758-768","DOIUrl":"https://doi.org/10.17073/0368-0797-2022-11-758-768","url":null,"abstract":"The growth in metal intensity of industrial production and the volume of consumption of finished metal products determine the relevance of development and research of energy efficient technological processes aimed at reducing costs by reducing the number of operations while maintaining product performance. In mechanical engineering, the problem of obtaining blanks with increased dimensional and geometric accuracy and complex configuration is solved by using a common method of investment casting. Expansion of the use of such technological approach to produce blanks in mechanical engineering is hindered by a number of physical phenomena associated with the thermal expansion of investment and ceramic materials, which leads to an increase in the product final cost. A significant number of defect-forming factors can be eliminated by applying an innovative solution consisting in the formation of porous removable models by compacting mixtures based on waxy materials. This solves the problem of material shrinkage and increases the crack resistance of ceramic molds, which significantly reduces the share of machining in the overall volume of technological operations. Technical tests of the new method have revealed the reason why the machining of castings cannot be completely eliminated at present. The problem mainly lies in elastic response of compacted material of the model mixture, which, in some cases, affects the increase in the compacts size. This paper considers the effect of initial packing of spherical-shaped elements simulating one- and two-component model mixtures on the stress-strain state of a powder body subjected to unilateral compaction in a rigid cylindrical matrix to technologically justified density values. The results of the experiment are presented in the form of stress-strain relations. Preferable conditions of compact formation with minimal values of elastic response of the compacted material are considered.","PeriodicalId":14630,"journal":{"name":"Izvestiya. Ferrous Metallurgy","volume":"31 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-11-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73290997","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 : 2022-11-22DOI: 10.17073/0368-0797-2022-11-814-823
S. B. Gamanyuk, D. Rutskii, N. A. Zyuban, M. Kirilichev, M. Nikitin, D. Gurulev
The article presents the results of evaluation of the impact of teeming method and rate on solidification and formation of the axial zone of large ingots. The research is based on a physical simulation. With this aim a laboratory-scale plant (a crystallization mould) was designed and built which enabled to visualize and monitor solidification and structural formation of the model ingots. Sodium thiosulphate (crystal hyposulphite) – Na2S2O3·5H2O was used as a modeling solution. Matching of the processes in the model and in real industrial conditions of ingot teeming was assessed with similarity criteria obtained on the basis of the dimension theory with consideration of the physical and chemical processes in the ingot during its teeming and crystallization. Two methods – downhill casting and uphill casting – were used to teem the melt into the mould. During teeming the geometry and technological parameters of the model ingots remained unchanged while the teeming rate was altered. Length and medium width of the model ingot axial zone were measured. The thermal profiling of the surface of the mould model was monitored over the entire period of solidification to evaluate the thermal field alteration while the ingot was teemed and crystallized. Thermal imaging processing made it possible to observe temperature changes of the surface of the model mould from top to bottom for downhill cast ingots teemed at different rates. The results obtained demonstrate that teeming rate has a noticeable impact on the axial zone length. It was established that a decreased rate leads to an increased directionality of crystallization and improvement of the ingot axial zone structure.
{"title":"Application of physical simulation to evaluate the impact of teeming method and rate on axial zone formation of large ingots","authors":"S. B. Gamanyuk, D. Rutskii, N. A. Zyuban, M. Kirilichev, M. Nikitin, D. Gurulev","doi":"10.17073/0368-0797-2022-11-814-823","DOIUrl":"https://doi.org/10.17073/0368-0797-2022-11-814-823","url":null,"abstract":"The article presents the results of evaluation of the impact of teeming method and rate on solidification and formation of the axial zone of large ingots. The research is based on a physical simulation. With this aim a laboratory-scale plant (a crystallization mould) was designed and built which enabled to visualize and monitor solidification and structural formation of the model ingots. Sodium thiosulphate (crystal hyposulphite) – Na2S2O3·5H2O was used as a modeling solution. Matching of the processes in the model and in real industrial conditions of ingot teeming was assessed with similarity criteria obtained on the basis of the dimension theory with consideration of the physical and chemical processes in the ingot during its teeming and crystallization. Two methods – downhill casting and uphill casting – were used to teem the melt into the mould. During teeming the geometry and technological parameters of the model ingots remained unchanged while the teeming rate was altered. Length and medium width of the model ingot axial zone were measured. The thermal profiling of the surface of the mould model was monitored over the entire period of solidification to evaluate the thermal field alteration while the ingot was teemed and crystallized. Thermal imaging processing made it possible to observe temperature changes of the surface of the model mould from top to bottom for downhill cast ingots teemed at different rates. The results obtained demonstrate that teeming rate has a noticeable impact on the axial zone length. It was established that a decreased rate leads to an increased directionality of crystallization and improvement of the ingot axial zone structure.","PeriodicalId":14630,"journal":{"name":"Izvestiya. Ferrous Metallurgy","volume":"259 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-11-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76796695","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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