Pub Date : 2023-06-06DOI: 10.17073/0368-0797-2023-2-148-153
B. B. Musurzaeva
This paper studies the kinetics of structure formation of an iron-bronze composite containing solid lubricants. Depending on the compacting pressure and sintering temperature, binary and complex phases are detected in the iron-bronze structure. The presence of solid lubricants in the composition of the composite material significantly reduces interaction of the liquid (bronze) and solid (iron) phases during sintering. Talc and graphite, which are heat–resistant at a sintering temperature of 850 – 1150 °C, were used as solid lubricants. The presence of talc, located on the surface of compressed particles of iron, copper, tin and graphite, significantly reduces the effect of their interaction. At the same time, the micro-talc particles envelop them, and its thermal stability retains this state up to high temperatures (approximately 900 °C). It was established that there is no perlite in the microstructure of iron-bronze sintered at a temperature of 850 °C. This can be explained by the talc adsorbing ability on the surface of iron particles which prevents diffusion of carbon into the iron crystal lattice. An increase in the sintering temperature up to 1000 °C leads to the formation of perlite in the iron-bronze structure, while the amount of perlite predominates over ferrite. This indicates the partial burnout of talc from the surface of iron particles and the opening of diffusion paths to carbon. At a sintering temperature of 1150 °C, perlite and a grid of light inclusions are formed in the microstructure of the iron-bronze samples. According to the results of electron microprobe analysis, the light inclusions are solid solutions of variable compositions such as Fe – Cu – Sn, Cu – Fe – Sn, Cu – Sn – Fe. In order to confirm these assumptions, a phase X-ray diffraction analysis was performed. Diffraction patterns of these samples are represented by reflections of iron and copper crystals. The absence of diffraction effects (characteristic of tin crystals) is conditioned by tin solubility in the copper lattice. This is due to the low melting point of tin (232 °C) and its ionic radius, which allows isomorphically replacing of copper and iron ions with tin ions (their difference is less than 15 %).
本文研究了含固体润滑剂的铁青铜复合材料的结构形成动力学。根据压实压力和烧结温度的不同，铁青铜结构中存在二元相和复相。复合材料组成中固体润滑剂的存在显著降低了烧结过程中液体(青铜)和固体(铁)相的相互作用。滑石和石墨在850 - 1150℃的烧结温度下耐热，被用作固体润滑剂。滑石的存在，位于铁、铜、锡和石墨的压缩颗粒表面，显著降低了它们相互作用的影响。同时，微滑石颗粒包裹着它们，其热稳定性在高温(约900°C)下保持这种状态。结果表明，850℃烧结铁青铜的显微组织中不存在珍珠岩。这可以用滑石在铁颗粒表面的吸附能力来解释，这种吸附能力可以防止碳扩散到铁晶格中。当烧结温度升高到1000℃时，铁青铜组织中会形成珍珠岩，但珍珠岩的数量多于铁素体。这表明滑石从铁颗粒表面部分烧坏，向碳扩散路径打开。在1150℃的烧结温度下，铁青铜样品的微观结构中形成了珍珠岩和轻夹杂物网格。电子探针分析结果表明，轻夹杂物为Fe - Cu - Sn、Cu - Fe - Sn、Cu - Sn - Fe等不同组分的固溶体。为了证实这些假设，进行了相x射线衍射分析。这些样品的衍射图样由铁和铜晶体的反射来表示。没有衍射效应(锡晶体的特征)是由锡在铜晶格中的溶解度决定的。这是由于锡的低熔点(232°C)和它的离子半径，这使得铜和铁离子可以同构地替换为锡离子(它们的差异小于15%)。
{"title":"Microstructure and elemental analysis of iron-based powder composite materials","authors":"B. B. Musurzaeva","doi":"10.17073/0368-0797-2023-2-148-153","DOIUrl":"https://doi.org/10.17073/0368-0797-2023-2-148-153","url":null,"abstract":"This paper studies the kinetics of structure formation of an iron-bronze composite containing solid lubricants. Depending on the compacting pressure and sintering temperature, binary and complex phases are detected in the iron-bronze structure. The presence of solid lubricants in the composition of the composite material significantly reduces interaction of the liquid (bronze) and solid (iron) phases during sintering. Talc and graphite, which are heat–resistant at a sintering temperature of 850 – 1150 °C, were used as solid lubricants. The presence of talc, located on the surface of compressed particles of iron, copper, tin and graphite, significantly reduces the effect of their interaction. At the same time, the micro-talc particles envelop them, and its thermal stability retains this state up to high temperatures (approximately 900 °C). It was established that there is no perlite in the microstructure of iron-bronze sintered at a temperature of 850 °C. This can be explained by the talc adsorbing ability on the surface of iron particles which prevents diffusion of carbon into the iron crystal lattice. An increase in the sintering temperature up to 1000 °C leads to the formation of perlite in the iron-bronze structure, while the amount of perlite predominates over ferrite. This indicates the partial burnout of talc from the surface of iron particles and the opening of diffusion paths to carbon. At a sintering temperature of 1150 °C, perlite and a grid of light inclusions are formed in the microstructure of the iron-bronze samples. According to the results of electron microprobe analysis, the light inclusions are solid solutions of variable compositions such as Fe – Cu – Sn, Cu – Fe – Sn, Cu – Sn – Fe. In order to confirm these assumptions, a phase X-ray diffraction analysis was performed. Diffraction patterns of these samples are represented by reflections of iron and copper crystals. The absence of diffraction effects (characteristic of tin crystals) is conditioned by tin solubility in the copper lattice. This is due to the low melting point of tin (232 °C) and its ionic radius, which allows isomorphically replacing of copper and iron ions with tin ions (their difference is less than 15 %).","PeriodicalId":14630,"journal":{"name":"Izvestiya. Ferrous Metallurgy","volume":"2537 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-06-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86583666","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 : 2023-06-06DOI: 10.17073/0368-0797-2023-2-177-183
G. Brover, E. E. Shcherbakova
The article presents the metal-physical studies results of the structure formation effects in surface layers in the hard alloys of the WC–Co system under extreme thermal and deformation effects of pulsed laser radiation. It is shown that the structural organization and properties of hard alloys VK6, VK8, VK10 upon radiation treatment with a power density of 175 MW/m2 are determined by state of the zones which are formed around carbide inclusions due to the various kinds of stresses appearance at the “carbide-bond” composition boundaries, including thermostrictive and phase stresses. The result is dissolution of the carbides boundary zones due to contact melting, which is accompanied by mutual mass transfer of atoms at the boundaries in the “carbide-bond” system with the possible formation of a thin amorphous-like super hard shell. These processes make it possible to create compositions in hard alloys with a set of differentiated properties specified by varying the laser treatment process parameters and composition of the starting materials. After laser alloying with a radiation power density of 200 MW/m2, temperature gradients and thermal stresses appearing in the surface layers of hard alloys with coatings (cobalt, nickel) contribute to convective mixing of the molten coating components and their penetration into the hard alloy to a depth of more than 20 μm. Simultaneously, despite the extremely short laser pulse time (10–3 s), mass transfer of tungsten, carbon and titanium atoms from the melted boundary zones of carbides to the adjacent bond zones with their hardening is possible in the irradiated zones. It was established that after high-temperature laser heating, carbides, in contrast to the initial ones, achieve a globular shape of grains. They are dispersed, and stoichiometric characteristics change in the local zones bordering the bond (the complex type carbide CoxWyCz is formed). As a result, due to these processes, the surface layers’ viscosity of hard alloys and the irradiated products performance increase. Compared to non-irradiated samples of hard alloy, the ultimate strength increases by 15 %, strength and durability – by 30 – 40 %.
{"title":"Structural organization and properties of surface layers of WC–Co hard alloys after pulsed laser processing","authors":"G. Brover, E. E. Shcherbakova","doi":"10.17073/0368-0797-2023-2-177-183","DOIUrl":"https://doi.org/10.17073/0368-0797-2023-2-177-183","url":null,"abstract":"The article presents the metal-physical studies results of the structure formation effects in surface layers in the hard alloys of the WC–Co system under extreme thermal and deformation effects of pulsed laser radiation. It is shown that the structural organization and properties of hard alloys VK6, VK8, VK10 upon radiation treatment with a power density of 175 MW/m2 are determined by state of the zones which are formed around carbide inclusions due to the various kinds of stresses appearance at the “carbide-bond” composition boundaries, including thermostrictive and phase stresses. The result is dissolution of the carbides boundary zones due to contact melting, which is accompanied by mutual mass transfer of atoms at the boundaries in the “carbide-bond” system with the possible formation of a thin amorphous-like super hard shell. These processes make it possible to create compositions in hard alloys with a set of differentiated properties specified by varying the laser treatment process parameters and composition of the starting materials. After laser alloying with a radiation power density of 200 MW/m2, temperature gradients and thermal stresses appearing in the surface layers of hard alloys with coatings (cobalt, nickel) contribute to convective mixing of the molten coating components and their penetration into the hard alloy to a depth of more than 20 μm. Simultaneously, despite the extremely short laser pulse time (10–3 s), mass transfer of tungsten, carbon and titanium atoms from the melted boundary zones of carbides to the adjacent bond zones with their hardening is possible in the irradiated zones. It was established that after high-temperature laser heating, carbides, in contrast to the initial ones, achieve a globular shape of grains. They are dispersed, and stoichiometric characteristics change in the local zones bordering the bond (the complex type carbide CoxWyCz is formed). As a result, due to these processes, the surface layers’ viscosity of hard alloys and the irradiated products performance increase. Compared to non-irradiated samples of hard alloy, the ultimate strength increases by 15 %, strength and durability – by 30 – 40 %.","PeriodicalId":14630,"journal":{"name":"Izvestiya. Ferrous Metallurgy","volume":"20 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-06-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80288317","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 : 2023-06-06DOI: 10.17073/0368-0797-2023-2-215-221
N. Nemchinova, A. Tyutrin, A. Zaitseva
The paper presents the results of refining silicon of metallurgical grades based on leaching of impurities with inorganic acids. Silicon samples were studied by metallographic and X-ray fluorescent methods of analysis, as well as X-ray spectral microanalysis. To improve the quality of this alloying element, we carried out experimental work on its hydrometallurgical purification with solutions of various acids (10 % H2SO4 , HCl, HNO3 , 4 % HF) and their mixtures. Values of changes in the Gibbs energy were calculated for reactions of interaction with reagents of the main impurity inclusions recorded in the studied silicon samples (FeSi2 , Fe2Si, FeSi, AlFeSi, AlFeSi2 , Al3FeSi2 , FeSi2Ti, FeAlTiSi, TiSi2 , Ca2Si). The experiments were carried out on silicon samples with a particle size of –200 μm with constant stirring by a magnetic stirrer at a temperature of 60 °С, duration 1 h and L:S = 5:1. Determination of concentration of the impurity elements in the solution after leaching was made by the atomic emission method of analysis. When hydrofluoric acid is used as a solvent, the best results are obtained for purification of iron, aluminum, and titanium (concentration in solution, mg/dm3, respectively: 2380, 831, 145). The maximum concentration of calcium in the solution (147 mg/dm3 ) was achieved by hydrochloric acid treatment of fine silicon. The most effective for transferring impurities into solution is a mixture of sulfuric and hydrofluoric acids at a ratio of 1:1. Using a mixture of H2SO4 and HCl as a solvent (at a ratio of 1:3) made it possible to achieve sufficiently high mass concentrations of impurity elements in the leaching solution. The degree of silicon purification from iron was 33.32 %, aluminum – 54.64 %, calcium – 65.77 %, titanium – 15.64 %.
{"title":"Hydrometallurgical refining of metallurgical silicon","authors":"N. Nemchinova, A. Tyutrin, A. Zaitseva","doi":"10.17073/0368-0797-2023-2-215-221","DOIUrl":"https://doi.org/10.17073/0368-0797-2023-2-215-221","url":null,"abstract":"The paper presents the results of refining silicon of metallurgical grades based on leaching of impurities with inorganic acids. Silicon samples were studied by metallographic and X-ray fluorescent methods of analysis, as well as X-ray spectral microanalysis. To improve the quality of this alloying element, we carried out experimental work on its hydrometallurgical purification with solutions of various acids (10 % H2SO4 , HCl, HNO3 , 4 % HF) and their mixtures. Values of changes in the Gibbs energy were calculated for reactions of interaction with reagents of the main impurity inclusions recorded in the studied silicon samples (FeSi2 , Fe2Si, FeSi, AlFeSi, AlFeSi2 , Al3FeSi2 , FeSi2Ti, FeAlTiSi, TiSi2 , Ca2Si). The experiments were carried out on silicon samples with a particle size of –200 μm with constant stirring by a magnetic stirrer at a temperature of 60 °С, duration 1 h and L:S = 5:1. Determination of concentration of the impurity elements in the solution after leaching was made by the atomic emission method of analysis. When hydrofluoric acid is used as a solvent, the best results are obtained for purification of iron, aluminum, and titanium (concentration in solution, mg/dm3, respectively: 2380, 831, 145). The maximum concentration of calcium in the solution (147 mg/dm3 ) was achieved by hydrochloric acid treatment of fine silicon. The most effective for transferring impurities into solution is a mixture of sulfuric and hydrofluoric acids at a ratio of 1:1. Using a mixture of H2SO4 and HCl as a solvent (at a ratio of 1:3) made it possible to achieve sufficiently high mass concentrations of impurity elements in the leaching solution. The degree of silicon purification from iron was 33.32 %, aluminum – 54.64 %, calcium – 65.77 %, titanium – 15.64 %.","PeriodicalId":14630,"journal":{"name":"Izvestiya. Ferrous Metallurgy","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-06-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88597947","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: 10.17073/0368-0797-2023-1-35-42
I. Pyshmintsev, A. Gizatullin, N. Devyaterikova, K. Laev, A. Tsvetkov, A. A. Al’khimenko, N. Shaposhnikov, M. Kurakin
To assess resistance to hydrogen embrittlement caused by the presence of hydrogen in the transported product, and, accordingly, suitability of pipes for hydrogen transport, the base metal of large-diameter pipes of X52 strength class manufactured by JSC “ChelPipe” (part of the PJSC “TMK” group of companies) was studied. The work included the study of pure gaseous hydrogen effect under pressure up to 10 MPa on change in mechanical characteristics of the base metal of large-diameter pipes (LDP) during preliminary hydrogen charging for various time periods in a stationary autoclave under pressure, and during simultaneous loading with a slow strain rate (SSRT) under expected operating conditions. Results of the X52 LDP metal study show that there is no significant impact on the effect of gaseous hydrogen under pressure for up to 144 hours on mechanical characteristics of the base metal determined by static uniaxial tension (decrease in ductile characteristics does not exceed 9 %). During SSRT at a rate of not more than 1·10–6 s–1 in pure gaseous hydrogen environment under a pressure of 10 MPa, the change in strength and ductile characteristics does not exceed 13 % in comparison with reference tests in nitrogen environment under the same pressure. The results obtained allow us to consider that the base metal of low-alloy pipe steel with ferrite-perlite microstructure of X52 strength class is sufficiently resistant to hydrogen embrittlement. Final confirmation of the possibility to use LDP made from steel under study will be the results of further qualification tests, including the study of the weld metal and heat-affected zone properties.
{"title":"Preliminary assessment of the possibility to use large-diameter pipes of Х52 steel for transportation of pure gaseous hydrogen under pressure","authors":"I. Pyshmintsev, A. Gizatullin, N. Devyaterikova, K. Laev, A. Tsvetkov, A. A. Al’khimenko, N. Shaposhnikov, M. Kurakin","doi":"10.17073/0368-0797-2023-1-35-42","DOIUrl":"https://doi.org/10.17073/0368-0797-2023-1-35-42","url":null,"abstract":"To assess resistance to hydrogen embrittlement caused by the presence of hydrogen in the transported product, and, accordingly, suitability of pipes for hydrogen transport, the base metal of large-diameter pipes of X52 strength class manufactured by JSC “ChelPipe” (part of the PJSC “TMK” group of companies) was studied. The work included the study of pure gaseous hydrogen effect under pressure up to 10 MPa on change in mechanical characteristics of the base metal of large-diameter pipes (LDP) during preliminary hydrogen charging for various time periods in a stationary autoclave under pressure, and during simultaneous loading with a slow strain rate (SSRT) under expected operating conditions. Results of the X52 LDP metal study show that there is no significant impact on the effect of gaseous hydrogen under pressure for up to 144 hours on mechanical characteristics of the base metal determined by static uniaxial tension (decrease in ductile characteristics does not exceed 9 %). During SSRT at a rate of not more than 1·10–6 s–1 in pure gaseous hydrogen environment under a pressure of 10 MPa, the change in strength and ductile characteristics does not exceed 13 % in comparison with reference tests in nitrogen environment under the same pressure. The results obtained allow us to consider that the base metal of low-alloy pipe steel with ferrite-perlite microstructure of X52 strength class is sufficiently resistant to hydrogen embrittlement. Final confirmation of the possibility to use LDP made from steel under study will be the results of further qualification tests, including the study of the weld metal and heat-affected zone properties.","PeriodicalId":14630,"journal":{"name":"Izvestiya. Ferrous Metallurgy","volume":"238 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74879833","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: 10.17073/0368-0797-2023-1-50-56
V. Gromov, K. Aksenova, Y. Ivanov, R. V. Kuznetsov, V. Kormyshev
The defective substructure of polycrystalline bodies causes substructural hardening and mechanical properties. Perlite, which is the main structural component of rails, undergoes a significant transformation during deformation, which is accompanied by a number of processes. In this paper, the methods of modern physical materials science were used to study and analyze the defective substructure of perlite of lamellar morphology and the properties of rail steel subjected to destruction under deformation conditions by single-axis stretching of flat samples. It was established that the ultimate strength varies from 1247 to 1335 MPa, and the relative deformation to failure – from 0.69 to 0.75. The formation of three zones of the fracture surface was observed: fibrous, radial and shear zones. Their shape and sizes were analyzed. Deformation of rail steel is accompanied by destruction of cementite plates of perlite colonies and repeated release of nanoscale particles of tertiary cementite approximately 8.3 nm in size in the volume of ferrite plates. The main mechanisms of destruction of cementite plates are cutting and dissolution. The dislocation substructure is represented by a chaotic distribution of dislocations and their clusters. The scalar density of dislocations in ferrite increases from 3.2·1010 cm–2 in the initial state to 7.9·1010 cm–2 when it is destroyed. Deformation is accompanied by formation of internal stress fields, manifested in the form of bending extinction contours. The sources of stress fields are the interface of cementite and ferrite plates, as well as grain boundaries. Fragmentation of ferrite and cementite plates was revealed. The average size of cementite fragments is 9.3 nm. In fracture zone of the rail steel sample, rotation of perlite grains was noted, indicating the presence of a rotational mode of deformation. Electron microscopic images of cementite plates show a change in the contrast, which may be associated with the formation of Cottrell’s atmospheres.
{"title":"Transformation of fine structure of lamellar pearlite under deformation of rail steel","authors":"V. Gromov, K. Aksenova, Y. Ivanov, R. V. Kuznetsov, V. Kormyshev","doi":"10.17073/0368-0797-2023-1-50-56","DOIUrl":"https://doi.org/10.17073/0368-0797-2023-1-50-56","url":null,"abstract":"The defective substructure of polycrystalline bodies causes substructural hardening and mechanical properties. Perlite, which is the main structural component of rails, undergoes a significant transformation during deformation, which is accompanied by a number of processes. In this paper, the methods of modern physical materials science were used to study and analyze the defective substructure of perlite of lamellar morphology and the properties of rail steel subjected to destruction under deformation conditions by single-axis stretching of flat samples. It was established that the ultimate strength varies from 1247 to 1335 MPa, and the relative deformation to failure – from 0.69 to 0.75. The formation of three zones of the fracture surface was observed: fibrous, radial and shear zones. Their shape and sizes were analyzed. Deformation of rail steel is accompanied by destruction of cementite plates of perlite colonies and repeated release of nanoscale particles of tertiary cementite approximately 8.3 nm in size in the volume of ferrite plates. The main mechanisms of destruction of cementite plates are cutting and dissolution. The dislocation substructure is represented by a chaotic distribution of dislocations and their clusters. The scalar density of dislocations in ferrite increases from 3.2·1010 cm–2 in the initial state to 7.9·1010 cm–2 when it is destroyed. Deformation is accompanied by formation of internal stress fields, manifested in the form of bending extinction contours. The sources of stress fields are the interface of cementite and ferrite plates, as well as grain boundaries. Fragmentation of ferrite and cementite plates was revealed. The average size of cementite fragments is 9.3 nm. In fracture zone of the rail steel sample, rotation of perlite grains was noted, indicating the presence of a rotational mode of deformation. Electron microscopic images of cementite plates show a change in the contrast, which may be associated with the formation of Cottrell’s atmospheres. ","PeriodicalId":14630,"journal":{"name":"Izvestiya. Ferrous Metallurgy","volume":"21 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86279436","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: 10.17073/0368-0797-2023-1-97-104
I. V. Bakin, A. Shapovalov, A. V. Kalyaskin, M. Kuznetsov
Increasingly rigid requirements in terms of the steel products quality are forcing the technical experts of metallurgical production to look for new solutions to stabilize the steel quality. Much attention is paid to ladle treatment technologies and selection well-minded composition of modifiers, which makes it possible to reduce steel contamination by non-metallic inclusions. To solve this problem, complex modifiers containing both calcium and other alkaline-earth metals (barium and strontium) are used. The paper presents the results of the pilot scale tests of steel ladle treatment by complex modifiers with alkaline-earth metals (Si, Ca, Ba) in steel production with increased requirements to non-metallic inclusions in conditions of electric furnace steelmaking shop of JSC “Ural Steel”. During experimental work it was possible to reduce the maximum contamination score profile rolled steel from pipe steel grades for brittle silicates (GOST 1778) from 4.0 to 1.5 – 2.5, for non-deforming silicates from 4.0 to 3.0 – 3.5. The substitution of SK40 grade silicocalcium for experimental modifiers led to an improvement in the strength properties of rolled products, both in tensile tests and in impact bending tests at low temperatures. The indicated impact was observed in all variants of consumption the experimental master alloys. It is noted that with an increasing in the consumption of master alloys, the positive effect on the steel mechanical properties enhanced. It was established that the replacement of silicocalcium with experimental variants of master alloys made it possible to increase the calcium recovery by an average of 1.6 times when using Si – Ca – Ba, and by an average of 2.4 times when using Si – Ca – Ba – Sr. The use of complex modifiers made it possible to obtain the target value of residual calcium in the sample at significantly lower calcium consumption.
人们对钢铁产品质量的要求越来越严格，迫使冶金生产技术专家寻找新的解决方案来稳定钢铁质量。重视钢包处理技术和合理选择改性剂组合，使减少非金属夹杂物对钢的污染成为可能。为了解决这个问题，使用了含有钙和其他碱土金属(钡和锶)的复合改性剂。本文介绍了在乌拉尔钢铁公司电炉炼钢车间对非金属夹杂物要求提高的情况下，用碱土金属(Si、Ca、Ba)复合改性剂处理钢包的中试结果。在实验工作中，有可能将脆性硅酸盐(GOST 1778)的最大污染分数从管材钢等级从4.0降低到1.5 - 2.5，对于不变形硅酸盐从4.0降低到3.0 - 3.5。用SK40级硅钙代替实验改性剂，在拉伸试验和低温冲击弯曲试验中，轧制产品的强度性能都得到了改善。在实验母合金的所有消耗变量中都观察到所指示的影响。结果表明，随着中间合金用量的增加，中间合金对钢力学性能的积极作用增强。成立的替代硅钙合金与实验变量的主合金成为可能增加1.6倍的平均钙复苏当使用Si - Ca Ba和平均的2.4倍在使用Si - Ca Ba Sr。复合改性剂的使用可以在显著降低钙消耗的情况下获得样品中残余钙的目标值。
{"title":"Impact of barium and strontium on calcium recovery level in ladle treatment of steel by complex modifiers with alkaline-earth metals","authors":"I. V. Bakin, A. Shapovalov, A. V. Kalyaskin, M. Kuznetsov","doi":"10.17073/0368-0797-2023-1-97-104","DOIUrl":"https://doi.org/10.17073/0368-0797-2023-1-97-104","url":null,"abstract":"Increasingly rigid requirements in terms of the steel products quality are forcing the technical experts of metallurgical production to look for new solutions to stabilize the steel quality. Much attention is paid to ladle treatment technologies and selection well-minded composition of modifiers, which makes it possible to reduce steel contamination by non-metallic inclusions. To solve this problem, complex modifiers containing both calcium and other alkaline-earth metals (barium and strontium) are used. The paper presents the results of the pilot scale tests of steel ladle treatment by complex modifiers with alkaline-earth metals (Si, Ca, Ba) in steel production with increased requirements to non-metallic inclusions in conditions of electric furnace steelmaking shop of JSC “Ural Steel”. During experimental work it was possible to reduce the maximum contamination score profile rolled steel from pipe steel grades for brittle silicates (GOST 1778) from 4.0 to 1.5 – 2.5, for non-deforming silicates from 4.0 to 3.0 – 3.5. The substitution of SK40 grade silicocalcium for experimental modifiers led to an improvement in the strength properties of rolled products, both in tensile tests and in impact bending tests at low temperatures. The indicated impact was observed in all variants of consumption the experimental master alloys. It is noted that with an increasing in the consumption of master alloys, the positive effect on the steel mechanical properties enhanced. It was established that the replacement of silicocalcium with experimental variants of master alloys made it possible to increase the calcium recovery by an average of 1.6 times when using Si – Ca – Ba, and by an average of 2.4 times when using Si – Ca – Ba – Sr. The use of complex modifiers made it possible to obtain the target value of residual calcium in the sample at significantly lower calcium consumption.","PeriodicalId":14630,"journal":{"name":"Izvestiya. Ferrous Metallurgy","volume":"27 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79254822","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: 10.17073/0368-0797-2023-1-43-49
Y. Goikhenberg, D. S. Polukhin, D. Zherebtsov, E. G. Bodrov
The authors studied the structure, properties and corrosion resistance in various acids of nickel-phosphorus coatings with dispersed silicon carbides after crystallization annealing under various modes. Temperatures of the beginning of crystallization after heating at speeds of 1, 5, 20 °С/min and the percentage of crystalline phases formed under isothermal conditions (nickel phosphide Ni3P and nickel) were determined. High microhardness of more than 1000 HV is achieved in a composite nickel-phosphorus coating with dispersed particles of silicon carbides during prolonged low-temperature annealing, accompanied by crystallization with formation of already insignificant (10 %) amounts of Ni3P. The revealed dispersed Ni3P located both in the body and along boundaries of the grain, make the main contribution to the increment of microhardness. The yield strength and ultimate strength of coatings increase during crystallization annealing by only 12 – 15 MPa, and the elongation drops to zero, which is due to the formation of brittle Ni3P compounds. Annealing with short soaking at crystallization temperatures leads to the fact that silicon carbides exhibit a barrier effect, reducing the intensity of formation of crystalline Ni3P and corrosion resistance, while long soaking at lower crystallization temperatures forms about 70 % Ni3P, contributing to consistently high hardness and improved corrosion resistance. Corrosion resistance of composite coatings Ni-P + silicon carbides, regardless of the heat treatment modes, is maximum in acetic and orthophosphoric acids at 70 % nickel phosphide and minimum in nitric acid and its mixtures with other acids.
{"title":"Influence of silicon carbides on the structure and properties of composite nickel-phosphorus coating","authors":"Y. Goikhenberg, D. S. Polukhin, D. Zherebtsov, E. G. Bodrov","doi":"10.17073/0368-0797-2023-1-43-49","DOIUrl":"https://doi.org/10.17073/0368-0797-2023-1-43-49","url":null,"abstract":"The authors studied the structure, properties and corrosion resistance in various acids of nickel-phosphorus coatings with dispersed silicon carbides after crystallization annealing under various modes. Temperatures of the beginning of crystallization after heating at speeds of 1, 5, 20 °С/min and the percentage of crystalline phases formed under isothermal conditions (nickel phosphide Ni3P and nickel) were determined. High microhardness of more than 1000 HV is achieved in a composite nickel-phosphorus coating with dispersed particles of silicon carbides during prolonged low-temperature annealing, accompanied by crystallization with formation of already insignificant (10 %) amounts of Ni3P. The revealed dispersed Ni3P located both in the body and along boundaries of the grain, make the main contribution to the increment of microhardness. The yield strength and ultimate strength of coatings increase during crystallization annealing by only 12 – 15 MPa, and the elongation drops to zero, which is due to the formation of brittle Ni3P compounds. Annealing with short soaking at crystallization temperatures leads to the fact that silicon carbides exhibit a barrier effect, reducing the intensity of formation of crystalline Ni3P and corrosion resistance, while long soaking at lower crystallization temperatures forms about 70 % Ni3P, contributing to consistently high hardness and improved corrosion resistance. Corrosion resistance of composite coatings Ni-P + silicon carbides, regardless of the heat treatment modes, is maximum in acetic and orthophosphoric acids at 70 % nickel phosphide and minimum in nitric acid and its mixtures with other acids.","PeriodicalId":14630,"journal":{"name":"Izvestiya. Ferrous Metallurgy","volume":"15 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78913591","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: 10.17073/0368-0797-2023-1-112-118
I. B. Abdukodirov, A. V. Vargin, I. A. Levitskii
Slab heating before hot rolling is necessary for obtaining required metal ductility. The most effective for this purpose are furnaces with walking beams that provide heat supply to all sides of the slab. However, the areas of slabs lower surfaces, contacting with water-cooled beams, are shielded from the radiation of the furnace lower heating zones and take the heat from the beams.To study the inhomogeneity of the slab temperature field and its dependence on the peculiarities of their transport system design, a mathematical model of slab heating in a furnace with walking beams was developed and programmatically implemented, based on numerical solution of a three-dimensional heat conduction problem with piecewise defined boundary conditions on the lower surface. For the open areas of the slab bottom surface, the same boundary conditions were set as on the top surface; and for the areas of contact with the beams, modified boundary conditions were set, taking into account the duration of this contact. For the numerical solution of the system of difference equations, the line-by-line method was applied, which allows us to obtain a system with a three-diagonal matrix of coefficients. The calculations carried out in the approximation of adiabaticity of the contact areas of the slab with the beams during the contact period allowed us to obtain temperature fields for different slab sections. As a result, a significant irregularity of temperature field of the slab lower surface was revealed, affecting the irregularity of temperature field of the entire slab. The developed program for calculating and visualizing the results can be used to study the temperature field of the slab under various heating modes if there is experimental information that allows one to clarify the tuning parameters of the model.
{"title":"Mathematical model of slab heating in a furnace with walking beams","authors":"I. B. Abdukodirov, A. V. Vargin, I. A. Levitskii","doi":"10.17073/0368-0797-2023-1-112-118","DOIUrl":"https://doi.org/10.17073/0368-0797-2023-1-112-118","url":null,"abstract":"Slab heating before hot rolling is necessary for obtaining required metal ductility. The most effective for this purpose are furnaces with walking beams that provide heat supply to all sides of the slab. However, the areas of slabs lower surfaces, contacting with water-cooled beams, are shielded from the radiation of the furnace lower heating zones and take the heat from the beams.To study the inhomogeneity of the slab temperature field and its dependence on the peculiarities of their transport system design, a mathematical model of slab heating in a furnace with walking beams was developed and programmatically implemented, based on numerical solution of a three-dimensional heat conduction problem with piecewise defined boundary conditions on the lower surface. For the open areas of the slab bottom surface, the same boundary conditions were set as on the top surface; and for the areas of contact with the beams, modified boundary conditions were set, taking into account the duration of this contact. For the numerical solution of the system of difference equations, the line-by-line method was applied, which allows us to obtain a system with a three-diagonal matrix of coefficients. The calculations carried out in the approximation of adiabaticity of the contact areas of the slab with the beams during the contact period allowed us to obtain temperature fields for different slab sections. As a result, a significant irregularity of temperature field of the slab lower surface was revealed, affecting the irregularity of temperature field of the entire slab. The developed program for calculating and visualizing the results can be used to study the temperature field of the slab under various heating modes if there is experimental information that allows one to clarify the tuning parameters of the model.","PeriodicalId":14630,"journal":{"name":"Izvestiya. Ferrous Metallurgy","volume":"24 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76483664","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: 10.17073/0368-0797-2023-1-80-85
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: 10.17073/0368-0797-2023-1-127-132
F. Bahfie, A. Manaf, W. Astuti, F. Nurjaman, S. Suharto, U. Herlina, W. A. Adi, Maykel Manawan
The selective reduction process generates products in the form of concentrates and tailing/by-products. There is high percentage of iron and other elements in the tailings that are not extracted in selective reduction process. Properties of by-products of selective reduction were investigated using X-ray diffraction (XRD), inductively coupled plasma optical emission spectroscopy (ICP–OES), ultraviolet-visible (UV–VIS), and scanning electron microscopy energy dispersion spectroscopy (SEM–EDS). Based on the results of this study, the properties of iron-sulfur, iron-magnesium-aluminium, and silica phases in the tailings can be interpreted experimentally. For future research, it can be the reference for such processes as acid and base leaching. Pure iron extracted from tailings can be used for metal fuel in the future. The tailings composition data will help future researchers to find optimal processes for the tailings.
{"title":"Composition of tailings after selective reduction of laterite","authors":"F. Bahfie, A. Manaf, W. Astuti, F. Nurjaman, S. Suharto, U. Herlina, W. A. Adi, Maykel Manawan","doi":"10.17073/0368-0797-2023-1-127-132","DOIUrl":"https://doi.org/10.17073/0368-0797-2023-1-127-132","url":null,"abstract":"The selective reduction process generates products in the form of concentrates and tailing/by-products. There is high percentage of iron and other elements in the tailings that are not extracted in selective reduction process. Properties of by-products of selective reduction were investigated using X-ray diffraction (XRD), inductively coupled plasma optical emission spectroscopy (ICP–OES), ultraviolet-visible (UV–VIS), and scanning electron microscopy energy dispersion spectroscopy (SEM–EDS). Based on the results of this study, the properties of iron-sulfur, iron-magnesium-aluminium, and silica phases in the tailings can be interpreted experimentally. For future research, it can be the reference for such processes as acid and base leaching. Pure iron extracted from tailings can be used for metal fuel in the future. The tailings composition data will help future researchers to find optimal processes for the tailings.","PeriodicalId":14630,"journal":{"name":"Izvestiya. Ferrous Metallurgy","volume":"154 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79479868","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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