Pub Date : 2020-01-01DOI: 10.37904/metal.2020.3458
M. Voron, Y. Kostetsky, Marina Fon Pruss
The work is dedicated to obtaining a complex Al-Mn-Fe master alloy for precise alloying high-manganese steels with aluminum high content as well as for making additions during aluminum alloys production. The addition of aluminum large quantity to steel during steelmaking is an especially difficult task, because of the low density and melting temperature of aluminum. A complex Al-Mn-Fe master alloy with more high density and melting temperature then aluminum may be proposed as an alternative for metal aluminum at precise steel alloying. Such master alloy also may be useful for preparing traditional cast aluminum alloys and special creep-resistant Al-based alloys. In this investigation, the master alloy was prepared via electron-beam casting technology (EBCT) with using cheap raw materials like ferromanganese and aluminum scrap. It was established there is a possibility to obtain an alloy with a high content of main components and low content of carbon due to the process peculiarities. The prepared master alloy Al-17Mn-4Fe has a density of 3.8 g/cm3 and a specific structure, that contains phases with a significantly higher melting point than pure aluminum.
{"title":"GETTING A COMPLEX MASTER ALLOY FOR ALLOYING HIGH-MANGANESE STEELS AND CAST ALUMINUM ALLOYS","authors":"M. Voron, Y. Kostetsky, Marina Fon Pruss","doi":"10.37904/metal.2020.3458","DOIUrl":"https://doi.org/10.37904/metal.2020.3458","url":null,"abstract":"The work is dedicated to obtaining a complex Al-Mn-Fe master alloy for precise alloying high-manganese steels with aluminum high content as well as for making additions during aluminum alloys production. The addition of aluminum large quantity to steel during steelmaking is an especially difficult task, because of the low density and melting temperature of aluminum. A complex Al-Mn-Fe master alloy with more high density and melting temperature then aluminum may be proposed as an alternative for metal aluminum at precise steel alloying. Such master alloy also may be useful for preparing traditional cast aluminum alloys and special creep-resistant Al-based alloys. In this investigation, the master alloy was prepared via electron-beam casting technology (EBCT) with using cheap raw materials like ferromanganese and aluminum scrap. It was established there is a possibility to obtain an alloy with a high content of main components and low content of carbon due to the process peculiarities. The prepared master alloy Al-17Mn-4Fe has a density of 3.8 g/cm3 and a specific structure, that contains phases with a significantly higher melting point than pure aluminum.","PeriodicalId":21337,"journal":{"name":"Revue De Metallurgie-cahiers D Informations Techniques","volume":"7 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89513763","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 : 2020-01-01DOI: 10.37904/metal.2020.3489
Alexey Korhunov, E. Medvedeva, P. Ivekeeva, Dmitrii Konstantiov
The article presents the finite-element modeling results of stranding, reduction, straightening and mechanicalthermal treatment (MTT) of prestressing strand (PSC strand). Computer models took into account the distribution of residual stresses formed at the preliminary stage of wire drawing. During the simulation, the effect of MTT on the internal stresses of the wires was studied: residual stresses after the drawing process and additional stresses after the stranding. All studied methods demonstrated a positive effect not only from the point of eliminating internal stresses, but also from the point of view of their favorable redistribution. The reduction of PSC strand in a monolith tool with strain degree 1-3% allows to minimize tensile stresses on the surface of the wires and save compressive stresses in the center of the wires. The straightening by a group of 5 rolls made it possible to reduce the tension of outer wires twice. The MTT application, combining the effects of various physical nature, made it possible to control over a wide range the redistribution of residual stresses in the wires after high strain degrees and the additional stresses created during the stranding, which affect the preservation of the geometric parameters of the PSC strand. The study showed that to eliminate longitudinal residual stresses, the magnitude of the tension in the MTT is the most important parameter. Therefore, with a minimum value of tension, the residual stresses are not redistributed either in the central or in the surface layers, regardless of the temperature of the MTT. However, with tension above 70 kN and a temperature of 380-400°C, the residual stresses in the center and on the surface of the wires are balanced or almost completely eliminated.
{"title":"FEM research of internal stresses evolution in the prestressing strand production","authors":"Alexey Korhunov, E. Medvedeva, P. Ivekeeva, Dmitrii Konstantiov","doi":"10.37904/metal.2020.3489","DOIUrl":"https://doi.org/10.37904/metal.2020.3489","url":null,"abstract":"The article presents the finite-element modeling results of stranding, reduction, straightening and mechanicalthermal treatment (MTT) of prestressing strand (PSC strand). Computer models took into account the distribution of residual stresses formed at the preliminary stage of wire drawing. During the simulation, the effect of MTT on the internal stresses of the wires was studied: residual stresses after the drawing process and additional stresses after the stranding. All studied methods demonstrated a positive effect not only from the point of eliminating internal stresses, but also from the point of view of their favorable redistribution. The reduction of PSC strand in a monolith tool with strain degree 1-3% allows to minimize tensile stresses on the surface of the wires and save compressive stresses in the center of the wires. The straightening by a group of 5 rolls made it possible to reduce the tension of outer wires twice. The MTT application, combining the effects of various physical nature, made it possible to control over a wide range the redistribution of residual stresses in the wires after high strain degrees and the additional stresses created during the stranding, which affect the preservation of the geometric parameters of the PSC strand. The study showed that to eliminate longitudinal residual stresses, the magnitude of the tension in the MTT is the most important parameter. Therefore, with a minimum value of tension, the residual stresses are not redistributed either in the central or in the surface layers, regardless of the temperature of the MTT. However, with tension above 70 kN and a temperature of 380-400°C, the residual stresses in the center and on the surface of the wires are balanced or almost completely eliminated.","PeriodicalId":21337,"journal":{"name":"Revue De Metallurgie-cahiers D Informations Techniques","volume":"310 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79956808","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 : 2020-01-01DOI: 10.37904/metal.2020.3544
K. Kreislová, L. Turek, L. Mindos
There are shown some case studies when the defects in coatings (hot dip galvanised and duplex coatings with powder paints) were caused by hydrogen charging into matrix of substrate steel. Steel was exposed into hydrochloric acid and then the zinc coatings had been formed at higher temperature. The evidence of hydrogen recombination and its molecules ́ diffusion from coating layers is shown on cross-sections. The hydrogen release caused the defects on subsequently powder coated galvanized plates, too.
{"title":"The effect of hydrogen charging on the quality of zinc and powder paint coatings","authors":"K. Kreislová, L. Turek, L. Mindos","doi":"10.37904/metal.2020.3544","DOIUrl":"https://doi.org/10.37904/metal.2020.3544","url":null,"abstract":"There are shown some case studies when the defects in coatings (hot dip galvanised and duplex coatings with powder paints) were caused by hydrogen charging into matrix of substrate steel. Steel was exposed into hydrochloric acid and then the zinc coatings had been formed at higher temperature. The evidence of hydrogen recombination and its molecules ́ diffusion from coating layers is shown on cross-sections. The hydrogen release caused the defects on subsequently powder coated galvanized plates, too.","PeriodicalId":21337,"journal":{"name":"Revue De Metallurgie-cahiers D Informations Techniques","volume":"122 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72530602","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 : 2020-01-01DOI: 10.37904/metal.2020.3645
Tomáš Malčic, P. Besta
This paper deals with the optimization of storage and retrieval operations in the expedition warehouse of the metallurgical company. First, the problem of warehouse management in the metallurgical industry is defined. In the literature review, the approaches, methods, and results from studies of different authors are presented. In the main part of the paper, the idea of application of the principles and methods from the automotive industry in the metallurgical industry is described. For this purpose, the differences between the logistics processes in these two industries are described. Implementation of multicriteria inventory management for optimization of storage location assignment and subsequently the order picking is proposed. Conclusions from this paper will serve as a foundation for future work centered around the design of multicriteria support tools for decisionmaking processes related to storage and retrieval operations.
{"title":"Multicriteria Inventory classification in the expedition warehouse of the metallurgical company","authors":"Tomáš Malčic, P. Besta","doi":"10.37904/metal.2020.3645","DOIUrl":"https://doi.org/10.37904/metal.2020.3645","url":null,"abstract":"This paper deals with the optimization of storage and retrieval operations in the expedition warehouse of the metallurgical company. First, the problem of warehouse management in the metallurgical industry is defined. In the literature review, the approaches, methods, and results from studies of different authors are presented. In the main part of the paper, the idea of application of the principles and methods from the automotive industry in the metallurgical industry is described. For this purpose, the differences between the logistics processes in these two industries are described. Implementation of multicriteria inventory management for optimization of storage location assignment and subsequently the order picking is proposed. Conclusions from this paper will serve as a foundation for future work centered around the design of multicriteria support tools for decisionmaking processes related to storage and retrieval operations.","PeriodicalId":21337,"journal":{"name":"Revue De Metallurgie-cahiers D Informations Techniques","volume":"93 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84756940","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 : 2020-01-01DOI: 10.37904/metal.2020.3608
P. A. Prokofev, N. Kolchugina, K. Skotnicová, G. Burkhanov, M. Zheleznyi, N. Dormidontov, A. Bakulina, T. Čegan, J. Juřica
The application of powder blending procedure shows promise in manufacturing Nd-Fe-B magnets; in this case, hydrides, oxides, intermetallic compounds, etc. are used as one of the mixture components. The application of these additions allows one to increase the hysteretic characteristics of Nd-Fe-B magnets at the expense of realized grain-boundary diffusion and grain-boundary structuring processes since these characteristics of the magnets are highly sensitive to their microstructure, composition of phases, and distribution of alloy components as well. This study is focused on the possibility of using the Pr3Co0.6Cu0.4Hx composition as the addition to the powder mixture for manufacturing Nd-Fe-B magnets and on the processes occurred during hydrogen treatment of the addition. The base alloy having the composition Nd-24.0, Pr-6.5, Dy-0.5, B-1.0, Al0.2, Fe-balance was prepared by strip-casting and subjected to hydrogen decrepitation at 270 °C for 1 h. The Pr3Co0.6Cu0.4 alloy was prepared by arc melting in an argon atmosphere and subjected to homogenizing annealing at 600 °C for 90 h and subsequent hydrogenation under the conditions used for the strip-cast alloy. The phase composition of Pr3Co0.6Cu0.4Hx was studied by X-ray diffraction analysis, DTA, scanning electron microscopy, and electron microprobe analysis. The Pr3Co0.6Cu0.4Hx composition was shown to undergo the hydrogenolysis with the formation of PrHx hydride (or hydrogen solid solution in Pr), Co+Cu fine mixture, and PrCu compound. The behavior of the additions in manufacturing sintered permanent magnets is analyzed from the viewpoint of the grain-boundary structuring effect of the addition. The sintered magnet prepared from the hydrogenated mixture Nd-Fe-B strip-cast alloy + Pr3(Co,Cu) compound exhibits the following hysteretic parameters: Br = 1.35 T, jHc = 1008 kA/m, and (BH)max = 349 kJ/m3.
{"title":"Sintered permanent magnets prepared from hydrogenated (Nd-Fe-b strip-cast alloy + pr3(Co,cu) compound) mixture","authors":"P. A. Prokofev, N. Kolchugina, K. Skotnicová, G. Burkhanov, M. Zheleznyi, N. Dormidontov, A. Bakulina, T. Čegan, J. Juřica","doi":"10.37904/metal.2020.3608","DOIUrl":"https://doi.org/10.37904/metal.2020.3608","url":null,"abstract":"The application of powder blending procedure shows promise in manufacturing Nd-Fe-B magnets; in this case, hydrides, oxides, intermetallic compounds, etc. are used as one of the mixture components. The application of these additions allows one to increase the hysteretic characteristics of Nd-Fe-B magnets at the expense of realized grain-boundary diffusion and grain-boundary structuring processes since these characteristics of the magnets are highly sensitive to their microstructure, composition of phases, and distribution of alloy components as well. This study is focused on the possibility of using the Pr3Co0.6Cu0.4Hx composition as the addition to the powder mixture for manufacturing Nd-Fe-B magnets and on the processes occurred during hydrogen treatment of the addition. The base alloy having the composition Nd-24.0, Pr-6.5, Dy-0.5, B-1.0, Al0.2, Fe-balance was prepared by strip-casting and subjected to hydrogen decrepitation at 270 °C for 1 h. The Pr3Co0.6Cu0.4 alloy was prepared by arc melting in an argon atmosphere and subjected to homogenizing annealing at 600 °C for 90 h and subsequent hydrogenation under the conditions used for the strip-cast alloy. The phase composition of Pr3Co0.6Cu0.4Hx was studied by X-ray diffraction analysis, DTA, scanning electron microscopy, and electron microprobe analysis. The Pr3Co0.6Cu0.4Hx composition was shown to undergo the hydrogenolysis with the formation of PrHx hydride (or hydrogen solid solution in Pr), Co+Cu fine mixture, and PrCu compound. The behavior of the additions in manufacturing sintered permanent magnets is analyzed from the viewpoint of the grain-boundary structuring effect of the addition. The sintered magnet prepared from the hydrogenated mixture Nd-Fe-B strip-cast alloy + Pr3(Co,Cu) compound exhibits the following hysteretic parameters: Br = 1.35 T, jHc = 1008 kA/m, and (BH)max = 349 kJ/m3.","PeriodicalId":21337,"journal":{"name":"Revue De Metallurgie-cahiers D Informations Techniques","volume":"24 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83484878","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 : 2020-01-01DOI: 10.37904/metal.2020.3631
J. Švadlena, K. C. Strachotová, T. Prošek, M. Kouřil
The corrosivity of indoor atmospheres is usually evaluated according to the ISO 11844-1 standard, utilizing specimens of different metals. However, the sensitivity of this setup is not sufficient to the presence of specific organic pollutants, such as acetic and formic acid or formaldehyde. In this study, lead metal specimens were added as complementary specimens in the series of exposures including various museums and cultural sites. Temperature and relative humidity were monitored and adsorbent tubes were deployed for estimation of the content of the organic compound. For comparison and verification, lead specimens were exposed in laboratory conditions with controlled levels of acetic acid, which is supposed to be the main cause of the increase in lead corrosion rates. The results show that the use of lead specimens can provide valuable data about the corrosivity of the atmosphere due to its sensitivity to the presence of the carboxylic acids. This can be particularly important information for indoor storage conditions in museums and depositories. However, a proper method to evaluate the lead corrosion rates is necessary.
{"title":"Evaluation of corrosivity of indoor museum atmospheres using lead specimens","authors":"J. Švadlena, K. C. Strachotová, T. Prošek, M. Kouřil","doi":"10.37904/metal.2020.3631","DOIUrl":"https://doi.org/10.37904/metal.2020.3631","url":null,"abstract":"The corrosivity of indoor atmospheres is usually evaluated according to the ISO 11844-1 standard, utilizing specimens of different metals. However, the sensitivity of this setup is not sufficient to the presence of specific organic pollutants, such as acetic and formic acid or formaldehyde. In this study, lead metal specimens were added as complementary specimens in the series of exposures including various museums and cultural sites. Temperature and relative humidity were monitored and adsorbent tubes were deployed for estimation of the content of the organic compound. For comparison and verification, lead specimens were exposed in laboratory conditions with controlled levels of acetic acid, which is supposed to be the main cause of the increase in lead corrosion rates. The results show that the use of lead specimens can provide valuable data about the corrosivity of the atmosphere due to its sensitivity to the presence of the carboxylic acids. This can be particularly important information for indoor storage conditions in museums and depositories. However, a proper method to evaluate the lead corrosion rates is necessary.","PeriodicalId":21337,"journal":{"name":"Revue De Metallurgie-cahiers D Informations Techniques","volume":"27 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83546123","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 : 2020-01-01DOI: 10.37904/metal.2020.3554
Š. Syrovátka, J. Martan
One of the main benefits of ultrashort laser micromachining is the possibility of preparing various surface structures, including a diversity of shapes and dimensions. The goal of this paper was to fabricate hydrophobic surface structures and to study coherency between the wettability and antibacterial properties of these structures for their further ways of application. The picosecond laser with a galvanometer scanner was used in the experiment for the fabrication of several types of surface structures. The next part of the experiment was testing of fabricated structures. Their wettability and antibacterial properties were tested and analyzed during several months. Tests showed that the fabrication of surface structures changed the wettability of the tested samples (the samples became more hydrophobic) and also showed that these structures affect their bacterial properties.
{"title":"Hydrophobic and antibacterial properties of laser micromachined steel surfaces","authors":"Š. Syrovátka, J. Martan","doi":"10.37904/metal.2020.3554","DOIUrl":"https://doi.org/10.37904/metal.2020.3554","url":null,"abstract":"One of the main benefits of ultrashort laser micromachining is the possibility of preparing various surface structures, including a diversity of shapes and dimensions. The goal of this paper was to fabricate hydrophobic surface structures and to study coherency between the wettability and antibacterial properties of these structures for their further ways of application. The picosecond laser with a galvanometer scanner was used in the experiment for the fabrication of several types of surface structures. The next part of the experiment was testing of fabricated structures. Their wettability and antibacterial properties were tested and analyzed during several months. Tests showed that the fabrication of surface structures changed the wettability of the tested samples (the samples became more hydrophobic) and also showed that these structures affect their bacterial properties.","PeriodicalId":21337,"journal":{"name":"Revue De Metallurgie-cahiers D Informations Techniques","volume":"18 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87495180","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 : 2020-01-01DOI: 10.37904/metal.2020.3657
Ehsaan-Reza Bagherian
{"title":"analysis of Jigless Spot Welding Process ParameterS","authors":"Ehsaan-Reza Bagherian","doi":"10.37904/metal.2020.3657","DOIUrl":"https://doi.org/10.37904/metal.2020.3657","url":null,"abstract":"","PeriodicalId":21337,"journal":{"name":"Revue De Metallurgie-cahiers D Informations Techniques","volume":"34 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72984541","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 : 2020-01-01DOI: 10.37904/metal.2020.3584
M. Dyčka, M. Juliš, L. Klakurková, L. Dyčková, P. Gejdoš
In this article, the intensity of mold metal reactions between ceramic shell and magnesium alloy AZ91E is studied. The two possible protective gasses used for melt protection are studied SF6 (sulphur hexafluoride) and 3M NOVEC 612. The scanning electron microscopy (SEM) with X-ray spectroscopy (EDS) were used for the analyses of the mold-metal reaction products on the interface between the magnesium alloy and the ceramic shell. Penetration of AZ91E into the ceramic shell was observed, thickness of mold-metal reaction products layer ranged from 0 μm to 80 μm. The intensity of mold metal reaction is much higher on the outer surface than on the inner surface of the casting. The thicker layer of the fine zircon particles as the first layer of ceramic shell seems to lower the mold metal reactions intensity to minimum. While using SF6, the penetration of AZ91E into ceramic shell was observed, the corroded layer consists of Al-enriched phase with higher content of oxygen. The use of 3M NOVEC 612 as the protective gas led to formation of continuous MgO layer between the ceramic shell and the magnesium alloy, thickness of this layer was up to 60 μm depending on the ceramic shell composition in the close surrounding area.
{"title":"mold metal reactions of magnesium alloy az91E using sf6 and 3m novec 612 as protective gasses in investment casting technology","authors":"M. Dyčka, M. Juliš, L. Klakurková, L. Dyčková, P. Gejdoš","doi":"10.37904/metal.2020.3584","DOIUrl":"https://doi.org/10.37904/metal.2020.3584","url":null,"abstract":"In this article, the intensity of mold metal reactions between ceramic shell and magnesium alloy AZ91E is studied. The two possible protective gasses used for melt protection are studied SF6 (sulphur hexafluoride) and 3M NOVEC 612. The scanning electron microscopy (SEM) with X-ray spectroscopy (EDS) were used for the analyses of the mold-metal reaction products on the interface between the magnesium alloy and the ceramic shell. Penetration of AZ91E into the ceramic shell was observed, thickness of mold-metal reaction products layer ranged from 0 μm to 80 μm. The intensity of mold metal reaction is much higher on the outer surface than on the inner surface of the casting. The thicker layer of the fine zircon particles as the first layer of ceramic shell seems to lower the mold metal reactions intensity to minimum. While using SF6, the penetration of AZ91E into ceramic shell was observed, the corroded layer consists of Al-enriched phase with higher content of oxygen. The use of 3M NOVEC 612 as the protective gas led to formation of continuous MgO layer between the ceramic shell and the magnesium alloy, thickness of this layer was up to 60 μm depending on the ceramic shell composition in the close surrounding area.","PeriodicalId":21337,"journal":{"name":"Revue De Metallurgie-cahiers D Informations Techniques","volume":"103 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78374520","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}
Lian-yun Jiang, Zhen Tao, G. Yuan, Huang Jinbo, Wei Yaoyu, Li Heng, Wang Ping
The grains in the center of the heavy steel plate can be refined by the snake/gradient temperature rolling, and the deformation penetration, the microstructure, and the properties of the steel plate will be improved. The existing rolling mechanical models are not suitable for the snake/gradient temperature rolling, so it is necessary to establish the mechanical parameters model of the snake/gradient temperature rolling to instruct production. The yield criterion of rolled material was modified based on the idea of equivalent flow stress. The element stress analyses were carried out based on the uniform normal stress and nonuniform shear stress in the vertical sides of each slab. Then the equilibrium equation of the unit pressure based on the slab method was established on this basis. The deformation region was divided into three layers (the top layer, the bottom layer, and the central layer) and maximum four zones (back slip zone, front slip zone, cross shear zone, and reverse deflection zone) according to the temperature distribution and position of the neutral point, and then the 12 zones were formed during the snake/gradient temperature rolling. The boundary conditions of the existence of the back slip zone, the front slip zone, and the cross shear zone were established according to the relationship between the threading angle and the neutral angle. The accurate mechanical parameters model of the rolling force and rolling torque of the snake/gradient temperature rolling with the same roll diameters was set up on this basis. The ANSYS software has been used in the rolling process simulation by many scholars, and the calculating precision has been verified. So the rolling processes were simulated by the ANSYS software to validate the model precision. The results show that the maximum relative deviation of the rolling force analytic model is less than 7% compared with the numerical method, and the maximum relative deviation of the rolling torque analytic model is less than 11% compared with the measured results. The mechanical parameters model can accurately predict the rolling force and rolling torque during the snake/gradient temperature rolling with the same roll diameters, so as to provide a theoretical basis for the design of rolling mill and the setup of the process parameters.
{"title":"The mechanical parameters modeling of heavy steel plate snake/gradient temperature rolling with the same roll diameters","authors":"Lian-yun Jiang, Zhen Tao, G. Yuan, Huang Jinbo, Wei Yaoyu, Li Heng, Wang Ping","doi":"10.1051/metal/2020019","DOIUrl":"https://doi.org/10.1051/metal/2020019","url":null,"abstract":"The grains in the center of the heavy steel plate can be refined by the snake/gradient temperature rolling, and the deformation penetration, the microstructure, and the properties of the steel plate will be improved. The existing rolling mechanical models are not suitable for the snake/gradient temperature rolling, so it is necessary to establish the mechanical parameters model of the snake/gradient temperature rolling to instruct production. The yield criterion of rolled material was modified based on the idea of equivalent flow stress. The element stress analyses were carried out based on the uniform normal stress and nonuniform shear stress in the vertical sides of each slab. Then the equilibrium equation of the unit pressure based on the slab method was established on this basis. The deformation region was divided into three layers (the top layer, the bottom layer, and the central layer) and maximum four zones (back slip zone, front slip zone, cross shear zone, and reverse deflection zone) according to the temperature distribution and position of the neutral point, and then the 12 zones were formed during the snake/gradient temperature rolling. The boundary conditions of the existence of the back slip zone, the front slip zone, and the cross shear zone were established according to the relationship between the threading angle and the neutral angle. The accurate mechanical parameters model of the rolling force and rolling torque of the snake/gradient temperature rolling with the same roll diameters was set up on this basis. The ANSYS software has been used in the rolling process simulation by many scholars, and the calculating precision has been verified. So the rolling processes were simulated by the ANSYS software to validate the model precision. The results show that the maximum relative deviation of the rolling force analytic model is less than 7% compared with the numerical method, and the maximum relative deviation of the rolling torque analytic model is less than 11% compared with the measured results. The mechanical parameters model can accurately predict the rolling force and rolling torque during the snake/gradient temperature rolling with the same roll diameters, so as to provide a theoretical basis for the design of rolling mill and the setup of the process parameters.","PeriodicalId":21337,"journal":{"name":"Revue De Metallurgie-cahiers D Informations Techniques","volume":"15 1","pages":"301"},"PeriodicalIF":0.0,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74940109","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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