Fengjun Chang, Liangjun Li, R. Xu, Yufen Wang, Xudong Cui
In order to prevent molten steel reoxidation in the tundish during continuous casting, argon injection into the shroud is applied. The injected argon bubbles in molten steel may change the molten steel flow pattern in the tundish. Consequently, the ratios of dead zone, plunger zone and well-mixed zone would change. Also, the motion of inclusions in the molten steel of tundish would change resulting from argon injection. The current word developed a coupling multiphase flow mathematical model. Basing on the developed model, the present work has researched the influences of argon injection on the molten steel flow pattern, inclusion motion characteristics in the tundish.
{"title":"Optimization of argon injection into shroud of tundish during continuous casting: a numerical study","authors":"Fengjun Chang, Liangjun Li, R. Xu, Yufen Wang, Xudong Cui","doi":"10.1051/metal/2021087","DOIUrl":"https://doi.org/10.1051/metal/2021087","url":null,"abstract":"In order to prevent molten steel reoxidation in the tundish during continuous casting, argon injection into the shroud is applied. The injected argon bubbles in molten steel may change the molten steel flow pattern in the tundish. Consequently, the ratios of dead zone, plunger zone and well-mixed zone would change. Also, the motion of inclusions in the molten steel of tundish would change resulting from argon injection. The current word developed a coupling multiphase flow mathematical model. Basing on the developed model, the present work has researched the influences of argon injection on the molten steel flow pattern, inclusion motion characteristics in the tundish.","PeriodicalId":18527,"journal":{"name":"Metallurgical Research & Technology","volume":"1 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78347083","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}
J. Diao, J. Lei, Yi-Yu Qiu, Deman Liu, Hong-Yi Li, B. Xie, Gang Li
In this paper, a series of nitriding experiments were carried out to investigate the phase evolution and element migration in the nitriding process. The results show that it undergoes a low temperature reducing stage firstly. High valent vanadium oxides are reduced to V2 O3 between room temperature and 770 °C. In Ar atmosphere, V2 O3 reacts with C to form VC in the temperature interval of 770 °C∼1080 °C. In N2 atmosphere, V2 O3 reacts directly with N2 and C to form VN in the interval of 670 °C∼1050 °C. During 1050 °C∼1270 °C, part of the VN obtained in the previous reaction stage will react with C to form VC. High temperature is beneficial to the removal of impurity element sulfur. The volatilization of alkali metal elements in the pellet mainly occurs between 670 °C and 1270 °C. However, there are about 20% of sodium and potassium remain in the nitriding product. The volatile alkali metal vapor would react with other gases at the furnace cover to form a white sediment and deposits on the cover. The sediment mainly consists of Na2 CO3 , K2 CO3 , Na2 SO4 , K2 SO4 , KCl, etc.
{"title":"Study on the phase evolution and element migration of vanadium oxide during the nitridation process","authors":"J. Diao, J. Lei, Yi-Yu Qiu, Deman Liu, Hong-Yi Li, B. Xie, Gang Li","doi":"10.1051/METAL/2021027","DOIUrl":"https://doi.org/10.1051/METAL/2021027","url":null,"abstract":"In this paper, a series of nitriding experiments were carried out to investigate the phase evolution and element migration in the nitriding process. The results show that it undergoes a low temperature reducing stage firstly. High valent vanadium oxides are reduced to V2 O3 between room temperature and 770 °C. In Ar atmosphere, V2 O3 reacts with C to form VC in the temperature interval of 770 °C∼1080 °C. In N2 atmosphere, V2 O3 reacts directly with N2 and C to form VN in the interval of 670 °C∼1050 °C. During 1050 °C∼1270 °C, part of the VN obtained in the previous reaction stage will react with C to form VC. High temperature is beneficial to the removal of impurity element sulfur. The volatilization of alkali metal elements in the pellet mainly occurs between 670 °C and 1270 °C. However, there are about 20% of sodium and potassium remain in the nitriding product. The volatile alkali metal vapor would react with other gases at the furnace cover to form a white sediment and deposits on the cover. The sediment mainly consists of Na2 CO3 , K2 CO3 , Na2 SO4 , K2 SO4 , KCl, etc.","PeriodicalId":18527,"journal":{"name":"Metallurgical Research & Technology","volume":"63 1","pages":"309"},"PeriodicalIF":1.1,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85198875","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}
R. Uzun, Ü. Başkaya, Z. Çetin, Y. Kılıç, O. Gündüz, Adem Bakkaloğlu
In this study, the effect of varying strain levels on hydrogen permeability properties were investigated. Distinct strain levels (10% and 40%) were carried out on the deep drawing test samples by using Marciniak die to simulate the forming process. Amount of strain on deep drawn material was calculated by GOM’s ARAMIS 3D deformation measurement system. Hydrogen diffusion coefficient and permeation time were calculated by using Helios II system. Light optical microscope (LOM) and scanning electron microscopy (SEM) were used for microstructure characterization. Automated inclusion/precipitation analysis was performed by Thermoscientific Explorer-4. By this study, it is aimed to understand the hydrogen permeation properties of ultra-low carbon IF steel material with varying strain values. Finally, it was determined that number of inclusion/precipitation per mm2 was significantly increased as a function of strain ratio, which improves hydrogen permeation properties.
{"title":"Effect of strain ratio on hydrogen permeability properties of low carbon enamel steel","authors":"R. Uzun, Ü. Başkaya, Z. Çetin, Y. Kılıç, O. Gündüz, Adem Bakkaloğlu","doi":"10.1051/metal/2021053","DOIUrl":"https://doi.org/10.1051/metal/2021053","url":null,"abstract":"In this study, the effect of varying strain levels on hydrogen permeability properties were investigated. Distinct strain levels (10% and 40%) were carried out on the deep drawing test samples by using Marciniak die to simulate the forming process. Amount of strain on deep drawn material was calculated by GOM’s ARAMIS 3D deformation measurement system. Hydrogen diffusion coefficient and permeation time were calculated by using Helios II system. Light optical microscope (LOM) and scanning electron microscopy (SEM) were used for microstructure characterization. Automated inclusion/precipitation analysis was performed by Thermoscientific Explorer-4. By this study, it is aimed to understand the hydrogen permeation properties of ultra-low carbon IF steel material with varying strain values. Finally, it was determined that number of inclusion/precipitation per mm2 was significantly increased as a function of strain ratio, which improves hydrogen permeation properties.","PeriodicalId":18527,"journal":{"name":"Metallurgical Research & Technology","volume":"46 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79347567","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, a coupled three-dimensional model of the billet continuous casting mold process was developed to investigate the characteristics of the macroscopic transmission behaviors under different mold electromagnetic stirring (M-EMS) parameters. The mold curvature was also considered during the modeling of electromagnetic and flow fields. The results indicate that the macroscopic physical quantities had nonsymmetrical distributions in the mold because of the mold curvature. However, the influence of mold curvature on the electromagnetic force could be ignored. The horizontal swirling flow caused by the M-EMS became stronger as the current density increased, which enhanced the dissipation of the molten steel superheat and promoted the growth of the solidification shell. However, the flushing of the bias hot jet slowed the growth of the local solidified shell. Meanwhile, the washing effect of the melt flow on the solidification front caused the solute element content near the billet surface to fluctuate. In addition, the distribution of the solute element content became more uneven in the strand transverse direction as the current density increased.
{"title":"Numerical simulation of the flow, solidification, and solute transport in a billet mold under electromagnetic stirring","authors":"Yaoguang Li, Yan-hui Sun, X. Bai","doi":"10.1051/METAL/2021015","DOIUrl":"https://doi.org/10.1051/METAL/2021015","url":null,"abstract":"In this study, a coupled three-dimensional model of the billet continuous casting mold process was developed to investigate the characteristics of the macroscopic transmission behaviors under different mold electromagnetic stirring (M-EMS) parameters. The mold curvature was also considered during the modeling of electromagnetic and flow fields. The results indicate that the macroscopic physical quantities had nonsymmetrical distributions in the mold because of the mold curvature. However, the influence of mold curvature on the electromagnetic force could be ignored. The horizontal swirling flow caused by the M-EMS became stronger as the current density increased, which enhanced the dissipation of the molten steel superheat and promoted the growth of the solidification shell. However, the flushing of the bias hot jet slowed the growth of the local solidified shell. Meanwhile, the washing effect of the melt flow on the solidification front caused the solute element content near the billet surface to fluctuate. In addition, the distribution of the solute element content became more uneven in the strand transverse direction as the current density increased.","PeriodicalId":18527,"journal":{"name":"Metallurgical Research & Technology","volume":"67 1","pages":"221"},"PeriodicalIF":1.1,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80658911","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 corrosion behaviors of the hot-pressed Mg-Sn-Zn-Al-Mn magnesium alloys with the addition of Al in different proportions have been investigated. Paraffin coating technique was applied to Mg powders before production. After debinding at 300 °C, the sintering process was applied at 610 °C under 50 MPa pressure for 70 min. All of the alloys were immersed in Hank’s solution for 10-days. The results indicated that the corrosion properties of the alloys were affected by the production method (hot pressing) and alloying element addition. After immersion, magnesium hydroxide (Mg(OH)2), hydroxyapatite (HA), and Mg-Al hydrotalcite structures were determined by the X-ray diffraction (XRD) analysis on the surfaces of Mg-Sn-Zn-Al-Mn alloys. The Mg-Al hydrotalcite protective layer was effective in preventing corrosion. Superior corrosion properties (weight loss: 1.2%, total volume of evolved H2 gas: 4 ml/cm2, corrosion rate: 0.39 mm/year) were obtained from TZAM5420 alloy (5 wt.%Sn, 4 wt.%Zn, 2 wt.%Al, 0.2 wt.%Mn).
研究了不同比例的Al对热压Mg-Sn-Zn-Al-Mn镁合金的腐蚀行为。在生产前对镁粉采用石蜡包覆技术。300℃脱脂后，在610℃50 MPa压力下烧结70 min。所有合金都在汉克的溶液中浸泡了10天。结果表明，合金的腐蚀性能受生产方法(热压)和合金元素添加的影响。通过x射线衍射(XRD)分析了浸泡后Mg- sn - zn - al - mn合金表面的氢氧化镁(Mg(OH)2)、羟基磷灰石(HA)和Mg- al水滑石的结构。镁铝水滑石保护层具有良好的防腐效果。采用TZAM5420合金(5 wt. 5)，获得了优异的腐蚀性能(失重:1.2%，析出H2气体总量:4 ml/cm2，腐蚀速率:0.39 mm/年)。%Sn, 4 wt。%Zn, 2wt。%Al, 0.2 wt.%Mn)。
{"title":"A novel Mg-Sn-Zn-Al-Mn magnesium alloy with superior corrosion properties","authors":"Ali Erçetin","doi":"10.1051/metal/2021064","DOIUrl":"https://doi.org/10.1051/metal/2021064","url":null,"abstract":"The corrosion behaviors of the hot-pressed Mg-Sn-Zn-Al-Mn magnesium alloys with the addition of Al in different proportions have been investigated. Paraffin coating technique was applied to Mg powders before production. After debinding at 300 °C, the sintering process was applied at 610 °C under 50 MPa pressure for 70 min. All of the alloys were immersed in Hank’s solution for 10-days. The results indicated that the corrosion properties of the alloys were affected by the production method (hot pressing) and alloying element addition. After immersion, magnesium hydroxide (Mg(OH)2), hydroxyapatite (HA), and Mg-Al hydrotalcite structures were determined by the X-ray diffraction (XRD) analysis on the surfaces of Mg-Sn-Zn-Al-Mn alloys. The Mg-Al hydrotalcite protective layer was effective in preventing corrosion. Superior corrosion properties (weight loss: 1.2%, total volume of evolved H2 gas: 4 ml/cm2, corrosion rate: 0.39 mm/year) were obtained from TZAM5420 alloy (5 wt.%Sn, 4 wt.%Zn, 2 wt.%Al, 0.2 wt.%Mn).","PeriodicalId":18527,"journal":{"name":"Metallurgical Research & Technology","volume":"35 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81076964","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}
Tongsheng Zhang, Li Rensheng, Wanlin Wang, Shi-fan Dai, Peisheng Lv, Tiang-tang Yan
Pipeline steel is widely used in various industries, and the sulfur content and inclusions in steel have a significant impact on performance, which determines whether the steel quality is qualified. The experiments were carried out to explore the sulfur content and inclusion evolution of pipeline steel which was deoxidized by Si–Mn–Al with “EAF-LF-VD-T-CC”. The samples of molten steel and slag were taken during the process of LF-VD-Tundish after EAF tapping. The kinetics model was established to simulate the desulfuration process of molten steel in actual production, obtaining a result which the error is within 3 ppm. It can be summarized that proper calcium treatment can transform the inclusion into a liquid inclusion, the value of [Ca] ranges from 25 to 45 ppm. Too high and lower calcium treatment can cause the compositions of inclusions to deviate from the liquid phase area, while too low calcium treatment will increase the overall size and density of the inclusions. In addition, the evolution of inclusion in steel at refining temperature and during solidification process was comprehensively calculated, considering all types of inclusions such as calcium oxide, magnesium oxide, aluminum oxide, calcium sulfide, spinel, calcium aluminate and liquid inclusion. The thermodynamic calculations are in good agreement with experimental results, which can predict the formation of the inclusions in Si–Mn–Al deoxidized pipeline steel.
{"title":"Research on the variation of the inclusion and sulfur content in Pipeline steel","authors":"Tongsheng Zhang, Li Rensheng, Wanlin Wang, Shi-fan Dai, Peisheng Lv, Tiang-tang Yan","doi":"10.1051/METAL/2021010","DOIUrl":"https://doi.org/10.1051/METAL/2021010","url":null,"abstract":"Pipeline steel is widely used in various industries, and the sulfur content and inclusions in steel have a significant impact on performance, which determines whether the steel quality is qualified. The experiments were carried out to explore the sulfur content and inclusion evolution of pipeline steel which was deoxidized by Si–Mn–Al with “EAF-LF-VD-T-CC”. The samples of molten steel and slag were taken during the process of LF-VD-Tundish after EAF tapping. The kinetics model was established to simulate the desulfuration process of molten steel in actual production, obtaining a result which the error is within 3 ppm. It can be summarized that proper calcium treatment can transform the inclusion into a liquid inclusion, the value of [Ca] ranges from 25 to 45 ppm. Too high and lower calcium treatment can cause the compositions of inclusions to deviate from the liquid phase area, while too low calcium treatment will increase the overall size and density of the inclusions. In addition, the evolution of inclusion in steel at refining temperature and during solidification process was comprehensively calculated, considering all types of inclusions such as calcium oxide, magnesium oxide, aluminum oxide, calcium sulfide, spinel, calcium aluminate and liquid inclusion. The thermodynamic calculations are in good agreement with experimental results, which can predict the formation of the inclusions in Si–Mn–Al deoxidized pipeline steel.","PeriodicalId":18527,"journal":{"name":"Metallurgical Research & Technology","volume":"89 1","pages":"214"},"PeriodicalIF":1.1,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81232349","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 mechanical properties including Vickers hardness, tensile properties and fatigue crack growth rate and also, the microstructure of pure copper severely deformed by the ECAP in different temperatures, were studied in the present work. The equal channel angular pressing (ECAP) is a process applied to make fine grains microstructure. On the other hand, high temperature provides an opportunity for recrystallization of materials and reduces required force for ECAP at the same time. In this paper we have tried to find optimized temperature to perform ECAP effectively and reduce required force. The results indicated that the grains size can reduce from 18.2 to 2.7 µm by ECAP process. This study shows that because of the recrystallization phenomenon and reducing the effect of stress concentration and increasing the number of grain boundaries, the fatigue crack growth rate can decrease significantly. Also, it was found that the major improvement in tensile properties in all the temperature conditions and due to the applied simple shear to the copper, all the ECAPed specimens have demonstrated an enhanced hardness and resistance to fatigue crack growth. Although, these improvements decrease when the temperature increases. Finally, the SEM images of the fatigue fraction sections revealed three areas including, crack initiation, stable crack growth, and final fracture zone. It seems that the final fracture appeared to be a ductile fracture in the ECAP copper sample.
{"title":"Influence of process temperature on fatigue crack growth rate of copper in equal channel angular pressing","authors":"Kaveh Abbasi, M. Vakili-Azghandi, A. Shirazi","doi":"10.1051/metal/2021062","DOIUrl":"https://doi.org/10.1051/metal/2021062","url":null,"abstract":"The mechanical properties including Vickers hardness, tensile properties and fatigue crack growth rate and also, the microstructure of pure copper severely deformed by the ECAP in different temperatures, were studied in the present work. The equal channel angular pressing (ECAP) is a process applied to make fine grains microstructure. On the other hand, high temperature provides an opportunity for recrystallization of materials and reduces required force for ECAP at the same time. In this paper we have tried to find optimized temperature to perform ECAP effectively and reduce required force. The results indicated that the grains size can reduce from 18.2 to 2.7 µm by ECAP process. This study shows that because of the recrystallization phenomenon and reducing the effect of stress concentration and increasing the number of grain boundaries, the fatigue crack growth rate can decrease significantly. Also, it was found that the major improvement in tensile properties in all the temperature conditions and due to the applied simple shear to the copper, all the ECAPed specimens have demonstrated an enhanced hardness and resistance to fatigue crack growth. Although, these improvements decrease when the temperature increases. Finally, the SEM images of the fatigue fraction sections revealed three areas including, crack initiation, stable crack growth, and final fracture zone. It seems that the final fracture appeared to be a ductile fracture in the ECAP copper sample.","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":"81681869","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}
Research on plasma transferred arc (PTA) coatings has increased contemplation due to its augmented appropriateness which results from the advanced materials used in applications like mining, petroleum and power plant sectors. This article further broadens the research scope of investigation, by influencing metallurgical and processing aspects in accordance with the significance of microstructural changes. Martensitic formation with coarser structure, carbide phase formation and fine interdendritic eutectic matrix are the significant metallurgical aspects for an improved surface characteristic. Welding current, powder feed rate and travel speed, are the significant processing variables to achieve the microstructural changes like uniform dendritic growth, finer grain size, etc. The addition of alloying elements and heat treatment are the most observed processing conditions for the formation of precipitates and carbide phases. A schematic summary, the significance of processing variables, processing conditions and process modelling and simulation on metallurgical aspects have been enumerated in this paper. Further, critical comments and findings from in-depth review have also been discussed for the future scope. Hence, this review will be helpful to ascertain the relation among the microstructural evolution, the applicability of microscopic tools and the mechanical properties for the forthcoming researchers and the industrial persons.
{"title":"Overview of metallurgical studies on weld deposited surface by plasma transferred arc technique","authors":"V. Kalyankar, H. Naik","doi":"10.1051/METAL/2020088","DOIUrl":"https://doi.org/10.1051/METAL/2020088","url":null,"abstract":"Research on plasma transferred arc (PTA) coatings has increased contemplation due to its augmented appropriateness which results from the advanced materials used in applications like mining, petroleum and power plant sectors. This article further broadens the research scope of investigation, by influencing metallurgical and processing aspects in accordance with the significance of microstructural changes. Martensitic formation with coarser structure, carbide phase formation and fine interdendritic eutectic matrix are the significant metallurgical aspects for an improved surface characteristic. Welding current, powder feed rate and travel speed, are the significant processing variables to achieve the microstructural changes like uniform dendritic growth, finer grain size, etc. The addition of alloying elements and heat treatment are the most observed processing conditions for the formation of precipitates and carbide phases. A schematic summary, the significance of processing variables, processing conditions and process modelling and simulation on metallurgical aspects have been enumerated in this paper. Further, critical comments and findings from in-depth review have also been discussed for the future scope. Hence, this review will be helpful to ascertain the relation among the microstructural evolution, the applicability of microscopic tools and the mechanical properties for the forthcoming researchers and the industrial persons.","PeriodicalId":18527,"journal":{"name":"Metallurgical Research & Technology","volume":"25 1","pages":"111"},"PeriodicalIF":1.1,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85922265","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 research, using iron-oxide fines (average size: 2.5 μm) and biochar fines (average size: 50.0 μm), the biochar composite briquette (BCB) for blast furnace (BF) application was prepared by cold briquetting followed by heat treatment. The preparing conditions were optimized regarding its cold crushing strength. Anti-pulverization capability, reaction development, and structure evolution of the optimally-designed BCB under simulated BF conditions were then examined. Results of optimizing BCB preparation conditions showed that a heating temperature of 1073 K was optimal for preparing the BCB. The optimally-designed BCB contained 11.10 wt.% carbon, 72.21 wt.% Fe3 O4 , 11.25 wt.% FeO, and 0.77 wt.% Fe, 6.44 wt.% gangue, and had a cold crushing strength of 1800 N/briquette. Results of BCB behavior under simulated BF conditions showed that the cold crushing strength after partial reaction of the BCB ranged from 1500 N/briquette to 5500 N/briquette and its maximum volume shrinkage degree was 0.45. The high anti-pulverization capability of the BCB was supported by the slag matrix or the iron network. Under the simulated BF conditions, the BCB underwent five stages of reduction by atmosphere, partial self-reduction and reduction by atmosphere, full self-reduction, partial self-reduction and gasification by atmosphere, and gasification by atmosphere. It is inferred from the experimental findings that, by charging the BCB in BF, an increase of top gas utilization efficiency could be realized, and a favorable influence on lowering the temperature level of the thermal reserve zone could be obtained.
{"title":"Preparation of high-strength biochar composite briquette for blast furnace ironmaking","authors":"Zi Yu, Zhu Liu, Huiqing Tang, Q. Xue","doi":"10.1051/METAL/2020083","DOIUrl":"https://doi.org/10.1051/METAL/2020083","url":null,"abstract":"In this research, using iron-oxide fines (average size: 2.5 μm) and biochar fines (average size: 50.0 μm), the biochar composite briquette (BCB) for blast furnace (BF) application was prepared by cold briquetting followed by heat treatment. The preparing conditions were optimized regarding its cold crushing strength. Anti-pulverization capability, reaction development, and structure evolution of the optimally-designed BCB under simulated BF conditions were then examined. Results of optimizing BCB preparation conditions showed that a heating temperature of 1073 K was optimal for preparing the BCB. The optimally-designed BCB contained 11.10 wt.% carbon, 72.21 wt.% Fe3 O4 , 11.25 wt.% FeO, and 0.77 wt.% Fe, 6.44 wt.% gangue, and had a cold crushing strength of 1800 N/briquette. Results of BCB behavior under simulated BF conditions showed that the cold crushing strength after partial reaction of the BCB ranged from 1500 N/briquette to 5500 N/briquette and its maximum volume shrinkage degree was 0.45. The high anti-pulverization capability of the BCB was supported by the slag matrix or the iron network. Under the simulated BF conditions, the BCB underwent five stages of reduction by atmosphere, partial self-reduction and reduction by atmosphere, full self-reduction, partial self-reduction and gasification by atmosphere, and gasification by atmosphere. It is inferred from the experimental findings that, by charging the BCB in BF, an increase of top gas utilization efficiency could be realized, and a favorable influence on lowering the temperature level of the thermal reserve zone could be obtained.","PeriodicalId":18527,"journal":{"name":"Metallurgical Research & Technology","volume":"30 1","pages":"109"},"PeriodicalIF":1.1,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78785844","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}
Yaou Shen, K. Zhao, Zheng Kong, Yu-zhu Zhang, Yan Shi, Y. Qi
In view of the influence of tuyere layout change on velocity field in oxy-coal combustor-melter-separator furnace, three-dimensional numerical simulation method was used to compare the distribution of velocity field in the furnace under different tuyere layout. The purpose is to explore the influence of the velocity distribution on the molten pool flow in the process of multi-tuyere injection. It is shown that the maximum velocity of the upper and lower tuyeres is 60 m/s and 50 m/s. And the change of tuyere has a significant effect on the velocity distribution in the molten pool, and the sudden change of velocity near the tuyere will trigger a certain scale of gyratory zone. In addition, the change of tuyere arrangement will result in the concentration of velocity distribution in the molten pool and the increase of flow dead zone, while the change of tuyere spacing will not only promote the increase of flow dead zone, but also reduce the velocity distribution area.
{"title":"Three-dimensional numerical simulation of velocity field distribution in an oxy-coal combustor-melter-separator furnace","authors":"Yaou Shen, K. Zhao, Zheng Kong, Yu-zhu Zhang, Yan Shi, Y. Qi","doi":"10.1051/metal/2021066","DOIUrl":"https://doi.org/10.1051/metal/2021066","url":null,"abstract":"In view of the influence of tuyere layout change on velocity field in oxy-coal combustor-melter-separator furnace, three-dimensional numerical simulation method was used to compare the distribution of velocity field in the furnace under different tuyere layout. The purpose is to explore the influence of the velocity distribution on the molten pool flow in the process of multi-tuyere injection. It is shown that the maximum velocity of the upper and lower tuyeres is 60 m/s and 50 m/s. And the change of tuyere has a significant effect on the velocity distribution in the molten pool, and the sudden change of velocity near the tuyere will trigger a certain scale of gyratory zone. In addition, the change of tuyere arrangement will result in the concentration of velocity distribution in the molten pool and the increase of flow dead zone, while the change of tuyere spacing will not only promote the increase of flow dead zone, but also reduce the velocity distribution area.","PeriodicalId":18527,"journal":{"name":"Metallurgical Research & Technology","volume":"19 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78911090","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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