Guomin Han, Hongbo Li, Yujin Liu, J. Zhang, N. Kong, Zhiyuan Hu, Lei Liu
In tandem cold rolling, the control of the temperature of high-grade non-oriented silicon steel is a difficult problem for its large deformation resistance and the preheating procedure before rolling. And it is complicated to calculate the total temperature rise of rolling deformation zone due to the comprehensive influence of the plastic deformation heat, the friction heat and the contact heat loss. So, to precisely calculate the total temperature rise, firstly, based on the four classical cold rolling force formulas, the initial total temperature rise calculation models are established correspondingly by theoretically analyzing the temperature rise of deformation heat, the temperature rise of friction heat and the temperature drop of contact heat loss; then, the model based on the improved Lian rolling force formula is adopted, which leads to calculated best matching the measured temperature; finally, considering the complex formula calculation of the initial model, based on the influences of different rolling parameters on the total temperature rise, a simplified model for convenient calculation is proposed by the nonlinear regression analysis of the initial model calculation results and main rolling parameters, which is convenient for the actual application by the field technicians.
{"title":"A simplified mathematical model for total temperature rise calculation in non-oriented silicon steel cold rolling deformation zone","authors":"Guomin Han, Hongbo Li, Yujin Liu, J. Zhang, N. Kong, Zhiyuan Hu, Lei Liu","doi":"10.1051/metal/2021095","DOIUrl":"https://doi.org/10.1051/metal/2021095","url":null,"abstract":"In tandem cold rolling, the control of the temperature of high-grade non-oriented silicon steel is a difficult problem for its large deformation resistance and the preheating procedure before rolling. And it is complicated to calculate the total temperature rise of rolling deformation zone due to the comprehensive influence of the plastic deformation heat, the friction heat and the contact heat loss. So, to precisely calculate the total temperature rise, firstly, based on the four classical cold rolling force formulas, the initial total temperature rise calculation models are established correspondingly by theoretically analyzing the temperature rise of deformation heat, the temperature rise of friction heat and the temperature drop of contact heat loss; then, the model based on the improved Lian rolling force formula is adopted, which leads to calculated best matching the measured temperature; finally, considering the complex formula calculation of the initial model, based on the influences of different rolling parameters on the total temperature rise, a simplified model for convenient calculation is proposed by the nonlinear regression analysis of the initial model calculation results and main rolling parameters, which is convenient for the actual application by the field technicians.","PeriodicalId":18527,"journal":{"name":"Metallurgical Research & Technology","volume":"4 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2021-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90960995","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Hebin Wang, D. Hong, L. Hou, Li Shen, P. Ou, LiFang Qiu, Zhi-gang Wang, Hong-jin Zhao
The microstructure and properties of niobium-containing AISI M3:2 high speed steels (HSSs) fabricated by spray forming and traditional casting have been investigated. The results show that fine and uniformly-distributed grains without macrosegregation appeared in the as-deposited HSSs that differ from those of as-cast HSSs. Nb mostly appears in primary MC carbides, whereas it contributes less to the formation of M6C carbides. The high stabilization of Nb-rich MC carbides can pin the grain boundaries during high-temperature austenitizing process, thus conferring a fine grains and raising the content of dissolved alloying elements. Enhanced precipitation strengthening and fine dispersion of NbC carbides throughout the matrix contribute to the high hardness and red hardness of Nb-containing HSS.
{"title":"Effect of niobium and austenitizing temperature on the microstructures and properties of spray-deposited AISI M3:2 high speed steel","authors":"Hebin Wang, D. Hong, L. Hou, Li Shen, P. Ou, LiFang Qiu, Zhi-gang Wang, Hong-jin Zhao","doi":"10.1051/metal/2021097","DOIUrl":"https://doi.org/10.1051/metal/2021097","url":null,"abstract":"The microstructure and properties of niobium-containing AISI M3:2 high speed steels (HSSs) fabricated by spray forming and traditional casting have been investigated. The results show that fine and uniformly-distributed grains without macrosegregation appeared in the as-deposited HSSs that differ from those of as-cast HSSs. Nb mostly appears in primary MC carbides, whereas it contributes less to the formation of M6C carbides. The high stabilization of Nb-rich MC carbides can pin the grain boundaries during high-temperature austenitizing process, thus conferring a fine grains and raising the content of dissolved alloying elements. Enhanced precipitation strengthening and fine dispersion of NbC carbides throughout the matrix contribute to the high hardness and red hardness of Nb-containing HSS.","PeriodicalId":18527,"journal":{"name":"Metallurgical Research & Technology","volume":"1 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2021-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86379320","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The significant impact of ultra-rapid heating continuous annealing on microstructure and mechanical properties of Al substituted Si dual phase steel under hot-dip galvanized process was studied. The heating rate of 300 °C/s, and different annealing temperatures in the range of 750 °C to 810 °C were explored. The study indicated that the yield and tensile strengths are increased with the increase of intercritical annealing temperature during rapid heating continuous annealing. When the annealing temperature was 780 °C, the steel exhibited good comprehensive properties with yield strength of 574.9 MPa, tensile strength up to 1009 MPa, total elongation of 18.5%. This is attributed to refined microstructure, appropriate proportion of phases, high density of dislocations and finely distributed NbC precipitates. Furthermore, the variations in strength, elongation and strain-hardening behavior of the steel with thermomechanical parameters and the inherent mechanism for strengthening were further discussed in relation to the microstructural features.
{"title":"Significant impact of intercritical annealing temperature on microstructure and mechanical properties of Al substituted Si dual phase steel under ultra-rapid heating","authors":"Y. Deng, R. Misra","doi":"10.1051/metal/2021051","DOIUrl":"https://doi.org/10.1051/metal/2021051","url":null,"abstract":"The significant impact of ultra-rapid heating continuous annealing on microstructure and mechanical properties of Al substituted Si dual phase steel under hot-dip galvanized process was studied. The heating rate of 300 °C/s, and different annealing temperatures in the range of 750 °C to 810 °C were explored. The study indicated that the yield and tensile strengths are increased with the increase of intercritical annealing temperature during rapid heating continuous annealing. When the annealing temperature was 780 °C, the steel exhibited good comprehensive properties with yield strength of 574.9 MPa, tensile strength up to 1009 MPa, total elongation of 18.5%. This is attributed to refined microstructure, appropriate proportion of phases, high density of dislocations and finely distributed NbC precipitates. Furthermore, the variations in strength, elongation and strain-hardening behavior of the steel with thermomechanical parameters and the inherent mechanism for strengthening were further discussed in relation to the microstructural features.","PeriodicalId":18527,"journal":{"name":"Metallurgical Research & Technology","volume":"4 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2021-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76875428","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
To destabilize as-cast microstructure of 20 wt.% chromium white iron, cyclic annealing involving repeated austenitization for short duration of 0.6 h at 900, 950, 1000, 1050 and 1100 °C followed by forced air cooling is conducted as an alternative to continuous annealing requiring austenitization for longer period of 4–6 h at the said temperatures followed by furnace cooling. Continuous austenitization destabilizes the austenite matrix through precipitation of secondary carbides and transforms the alloy depleted austenite to pearlite on furnace cooling, thereby reducing the as-cast hardness from HV 669 to HV466. In contrast, repeated austenitization not only destabilizes the austenite matrix through precipitation of secondary carbides followed by its transformation to martensite on forced air cooling, but also causes disintegration of longer eutectic carbides to shorter segments with subsequent increase in hardness to as high as HV 890. Notched impact toughness after both continuous and cyclic annealing remains uniformly at 12.0 J as compared to as-cast value of 6.0 J. Besides, an unexpected rise in abrasive wear resistance after cyclic annealing treatment makes the alloy superior than that obtained by continuous annealing treatment as practiced in industries.
{"title":"Cyclic annealing versus continuous annealing of 20 wt.% chromium white cast iron","authors":"S. S. Mandal, D. Mondal, K. Ghosh","doi":"10.1051/metal/2021044","DOIUrl":"https://doi.org/10.1051/metal/2021044","url":null,"abstract":"To destabilize as-cast microstructure of 20 wt.% chromium white iron, cyclic annealing involving repeated austenitization for short duration of 0.6 h at 900, 950, 1000, 1050 and 1100 °C followed by forced air cooling is conducted as an alternative to continuous annealing requiring austenitization for longer period of 4–6 h at the said temperatures followed by furnace cooling. Continuous austenitization destabilizes the austenite matrix through precipitation of secondary carbides and transforms the alloy depleted austenite to pearlite on furnace cooling, thereby reducing the as-cast hardness from HV 669 to HV466. In contrast, repeated austenitization not only destabilizes the austenite matrix through precipitation of secondary carbides followed by its transformation to martensite on forced air cooling, but also causes disintegration of longer eutectic carbides to shorter segments with subsequent increase in hardness to as high as HV 890. Notched impact toughness after both continuous and cyclic annealing remains uniformly at 12.0 J as compared to as-cast value of 6.0 J. Besides, an unexpected rise in abrasive wear resistance after cyclic annealing treatment makes the alloy superior than that obtained by continuous annealing treatment as practiced in industries.","PeriodicalId":18527,"journal":{"name":"Metallurgical Research & Technology","volume":"232 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2021-06-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77075718","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The particle distribution in pre-reduction rotary kiln directly affects the reduction process of iron ore, and in-depth understanding of the mixing behavior is helpful to improve the product quality and productivity. The present work focused on the mixed dynamics of multi-component and multi-size systems in rotary kiln using discrete element method (DEM). We first confirmed that the final particle distribution and mixing degree are independent of the initial particle distribution, and then further discussed the influence of the key operating parameters such as rotating speed, average size ratio and filling degree on mixing behavior. The size segregation pattern of three components shows that the large particles segregated to the outer region, while the small particles were concentrated in the core region, forming an annular distribution with different particle sizes. Furthermore, the results also indicate that the rotational speed and fill degree show strong influence on the mixing time and have little influence on the mixing quality. Conversely, the average size ratio significantly affects on the mixing quality. The particle segregation is suppressed and the coal and iron ore particles are well mixed together for the whole bed when the average size of coal particles is smaller than that of iron ore particle. The findings of this work provide a reference for controlling and optimizing the particle mixing process in pre-reduction rotary kiln.
{"title":"Analyses of multi-size particle mixing behavior in an ore pre-reduction rotary kiln by discrete element method","authors":"Chenghong Liu, Xueyong Ding","doi":"10.1051/metal/2021038","DOIUrl":"https://doi.org/10.1051/metal/2021038","url":null,"abstract":"The particle distribution in pre-reduction rotary kiln directly affects the reduction process of iron ore, and in-depth understanding of the mixing behavior is helpful to improve the product quality and productivity. The present work focused on the mixed dynamics of multi-component and multi-size systems in rotary kiln using discrete element method (DEM). We first confirmed that the final particle distribution and mixing degree are independent of the initial particle distribution, and then further discussed the influence of the key operating parameters such as rotating speed, average size ratio and filling degree on mixing behavior. The size segregation pattern of three components shows that the large particles segregated to the outer region, while the small particles were concentrated in the core region, forming an annular distribution with different particle sizes. Furthermore, the results also indicate that the rotational speed and fill degree show strong influence on the mixing time and have little influence on the mixing quality. Conversely, the average size ratio significantly affects on the mixing quality. The particle segregation is suppressed and the coal and iron ore particles are well mixed together for the whole bed when the average size of coal particles is smaller than that of iron ore particle. The findings of this work provide a reference for controlling and optimizing the particle mixing process in pre-reduction rotary kiln.","PeriodicalId":18527,"journal":{"name":"Metallurgical Research & Technology","volume":"22 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2021-06-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90651273","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In this study, the effect of mechanical soft reduction on carbon segregation in the continuous casting of 300 × 400 mm 42CrMo alloy structural steel blooms was comparatively investigated by adjusting the casting speed, which was systematically optimized through numerical simulation. When the casting speed is 0.60 m · min−1, during the soft reduction process, the central solidification structure of the bloom becomes dense, and carbon segregation is improved. Moreover, the distribution of carbon in the samples before and after rolling was analyzed. Combined with the soft reduction process, the uniformity of carbon across the cross section of the bloom /bar distinctly improved for casting speeds of 0.50 m · min−1, 0.55 m · min−1 and 0.60 m · min−1, this was predominantly reflected in the core areas. The effective segregation length proportion of the bloom and rolled bar is approximately 40%. This phenomenon fully verifies the heredity characteristics of the elements in the rolling process.
{"title":"Improvement of carbon segregation in cast bloom and heredity in hot-rolled bar","authors":"Mengyun Zhang, Y. Bao, Li-hua Zhao, Xin Li","doi":"10.1051/metal/2021072","DOIUrl":"https://doi.org/10.1051/metal/2021072","url":null,"abstract":"In this study, the effect of mechanical soft reduction on carbon segregation in the continuous casting of 300 × 400 mm 42CrMo alloy structural steel blooms was comparatively investigated by adjusting the casting speed, which was systematically optimized through numerical simulation. When the casting speed is 0.60 m · min−1, during the soft reduction process, the central solidification structure of the bloom becomes dense, and carbon segregation is improved. Moreover, the distribution of carbon in the samples before and after rolling was analyzed. Combined with the soft reduction process, the uniformity of carbon across the cross section of the bloom /bar distinctly improved for casting speeds of 0.50 m · min−1, 0.55 m · min−1 and 0.60 m · min−1, this was predominantly reflected in the core areas. The effective segregation length proportion of the bloom and rolled bar is approximately 40%. This phenomenon fully verifies the heredity characteristics of the elements in the rolling process.","PeriodicalId":18527,"journal":{"name":"Metallurgical Research & Technology","volume":"18 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79958083","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Lithium is the lightest of all metals and the third element in the periodic table. Recent years, lithium salts have become an important input for the energy industry. Lithium carbonate and hydroxides are the basic building blocks of Li-ion battery production. The usage areas of lithium compounds are not limited to only energy; they are also utilized in heavy-duty machines, in the aluminum industry, in nuclear power plants and for glass, ceramics, frit, and coatings in industrial sectors. Lithium has also been found to be very useful in the development of harder, smoother, and more resistant low-temperature glasses, glazes, and enamels. It is also used in very-low-melting-point vitreous compositions like aluminum enamels, colors, fluxes, and glass-seals. The use of lithium also helps in the development of low-expansion bodies, glazes, and glasses. In this study, it is intended to explore the adherence forces in the steel sheet application of different amounts of lithium in enamel frit composition and to examine surface characteristics such as ease of cleaning, gloss, and color. For chemical characterization, X-ray fluorescence (XRF) spectrometry and color measurements were done with a Minolta CM-700d spectrometer device. Bond adherence tests were performed in accordance with the TS EN 10209 standard.
锂是所有金属中最轻的，也是元素周期表中的第三个元素。近年来，锂盐已成为能源工业的重要投入品。碳酸锂和氢氧化物是锂离子电池生产的基本组成部分。锂化合物的使用领域不仅限于能源;它们还用于重型机械，铝工业，核电站以及工业部门的玻璃，陶瓷，水果和涂料。锂也被发现在开发更硬、更光滑、更耐低温的玻璃、釉料和搪瓷方面非常有用。它也用于非常低熔点的玻璃组合物，如铝搪瓷，颜色，助焊剂和玻璃密封件。锂的使用也有助于低膨胀体、釉料和玻璃的开发。在本研究中，旨在探讨不同数量的锂在搪瓷熔块成分中对钢板的粘附力的影响，并研究表面特性，如易于清洁，光泽度和颜色。为了进行化学表征，使用美能达CM-700d光谱仪进行x射线荧光(XRF)光谱和颜色测量。粘接测试按照TS EN 10209标准进行。
{"title":"Influence of lithium amount on vitreous enamel properties","authors":"A. M. Erayvaz, E. Derun","doi":"10.1051/METAL/2021028","DOIUrl":"https://doi.org/10.1051/METAL/2021028","url":null,"abstract":"Lithium is the lightest of all metals and the third element in the periodic table. Recent years, lithium salts have become an important input for the energy industry. Lithium carbonate and hydroxides are the basic building blocks of Li-ion battery production. The usage areas of lithium compounds are not limited to only energy; they are also utilized in heavy-duty machines, in the aluminum industry, in nuclear power plants and for glass, ceramics, frit, and coatings in industrial sectors. Lithium has also been found to be very useful in the development of harder, smoother, and more resistant low-temperature glasses, glazes, and enamels. It is also used in very-low-melting-point vitreous compositions like aluminum enamels, colors, fluxes, and glass-seals. The use of lithium also helps in the development of low-expansion bodies, glazes, and glasses. In this study, it is intended to explore the adherence forces in the steel sheet application of different amounts of lithium in enamel frit composition and to examine surface characteristics such as ease of cleaning, gloss, and color. For chemical characterization, X-ray fluorescence (XRF) spectrometry and color measurements were done with a Minolta CM-700d spectrometer device. Bond adherence tests were performed in accordance with the TS EN 10209 standard.","PeriodicalId":18527,"journal":{"name":"Metallurgical Research & Technology","volume":"23 1","pages":"306"},"PeriodicalIF":1.1,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85625328","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The objectives of the paper were twofold. The first was exploring possibility of fast and reliable modelling of phase transformations during cooling of steels, accounting for the evolution of the carbon concentration in the austenite. Existing discrete models require long computing times and their application to optimization of industrial processes is limited. Therefore, a model based on the modified JMAK equation was proposed. Control of the carbon concentration in the austenite during ferritic and bainitic transformations allowed to predict incomplete austenite transformation and occurrence of the retained austenite. Moreover, prediction of the onset of pearlitic transformation after the bainitic was possible. The model was validated by comparison the predictions with the results of physical simulations. Numerical simulations for various industrial processes were performed. Problem of the difference in the incubation time between isothermal and constant cooling rate tests was raised.
{"title":"Mean field model of phase transformations in steels during cooling, which predicts evolution of carbon concentration in the austenite","authors":"D. Bachniak, R. Kuziak, D. Szeliga, M. Pietrzyk","doi":"10.1051/metal/2021046","DOIUrl":"https://doi.org/10.1051/metal/2021046","url":null,"abstract":"The objectives of the paper were twofold. The first was exploring possibility of fast and reliable modelling of phase transformations during cooling of steels, accounting for the evolution of the carbon concentration in the austenite. Existing discrete models require long computing times and their application to optimization of industrial processes is limited. Therefore, a model based on the modified JMAK equation was proposed. Control of the carbon concentration in the austenite during ferritic and bainitic transformations allowed to predict incomplete austenite transformation and occurrence of the retained austenite. Moreover, prediction of the onset of pearlitic transformation after the bainitic was possible. The model was validated by comparison the predictions with the results of physical simulations. Numerical simulations for various industrial processes were performed. Problem of the difference in the incubation time between isothermal and constant cooling rate tests was raised.","PeriodicalId":18527,"journal":{"name":"Metallurgical Research & Technology","volume":"59 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82446946","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Sandwich materials made of two aluminum sheets and a crumpled aluminum core have been manufactured for the first time using a reproducible process. This very specific core aims to drastically improve the elasticity performance indexes of the sandwich. The structure has been studied mainly in bending.
{"title":"Sandwich materials with a crumpled aluminium core","authors":"O. Bouaziz, Rabeb Bouafif, Roxanne Massion","doi":"10.1051/METAL/2021014","DOIUrl":"https://doi.org/10.1051/METAL/2021014","url":null,"abstract":"Sandwich materials made of two aluminum sheets and a crumpled aluminum core have been manufactured for the first time using a reproducible process. This very specific core aims to drastically improve the elasticity performance indexes of the sandwich. The structure has been studied mainly in bending.","PeriodicalId":18527,"journal":{"name":"Metallurgical Research & Technology","volume":"60 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74345808","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Zhonghua Sheng, Lianghua Feng, Kun Liu, Bin Yang, Kong Lingzhong
There are two problems to be solved in the numerical simulation of the top blown oxygen vacuum refining process. (1) The two-equation turbulence models underpredict the turbulence mixing shear process for high-temperature gradient jet flows. (2) The high compressibility of the jet in a low vacuum environment. In this study, the SST k-ω turbulence model is modified by the composite function of the compressibility factor and the total temperature gradient. Based on the experimental model of the Kotani vacuum jet, the modified turbulence model was used to simulate the supersonic jet behavior of oxygen lance at different ambient temperatures. The reliability of the model is verified by the semi-empirical formula of Ito and Muchi. The simulation results show that the entrainment rate is an important inducing factor. The potential core length and the supersonic core length at the temperature of 1800 K are 2.5 times and 2.0 times that at the temperature of 285 K, respectively. Besides, based on the ejection model established by Ricou and Spalding, the calculation formula of turbulence entrainment rate at different ambient temperatures is obtained. This research work will benefit greatly to the supersonic jet behavior in Vacuum Refining.
{"title":"Modeling of supersonic jet behavior in the vacuum refining process","authors":"Zhonghua Sheng, Lianghua Feng, Kun Liu, Bin Yang, Kong Lingzhong","doi":"10.1051/METAL/2021004","DOIUrl":"https://doi.org/10.1051/METAL/2021004","url":null,"abstract":"There are two problems to be solved in the numerical simulation of the top blown oxygen vacuum refining process. (1) The two-equation turbulence models underpredict the turbulence mixing shear process for high-temperature gradient jet flows. (2) The high compressibility of the jet in a low vacuum environment. In this study, the SST k-ω turbulence model is modified by the composite function of the compressibility factor and the total temperature gradient. Based on the experimental model of the Kotani vacuum jet, the modified turbulence model was used to simulate the supersonic jet behavior of oxygen lance at different ambient temperatures. The reliability of the model is verified by the semi-empirical formula of Ito and Muchi. The simulation results show that the entrainment rate is an important inducing factor. The potential core length and the supersonic core length at the temperature of 1800 K are 2.5 times and 2.0 times that at the temperature of 285 K, respectively. Besides, based on the ejection model established by Ricou and Spalding, the calculation formula of turbulence entrainment rate at different ambient temperatures is obtained. This research work will benefit greatly to the supersonic jet behavior in Vacuum Refining.","PeriodicalId":18527,"journal":{"name":"Metallurgical Research & Technology","volume":"34 1","pages":"114"},"PeriodicalIF":1.1,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73090159","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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