Chute accidents frequently occur during blast furnace operation. Worn or even fractured chutes can seriously affect the movement of the charge, subsequently impacting the burden distribution in the blast furnace. Therefore, it is necessary to investigate the influence of different types of chutes on burden distribution. In this paper, a model of a serial-hopper bell-less top system was established and the burden distribution through different chutes was calculated using EDM. The results of the calculations are as follows: wear liner reduces the average velocity of the charge at the chute outlet and the charge platform moves closer to the center of the blast furnace; the greater the fractured length, the greater the average velocity at the chute outlet and the easier it is for particles to accumulate in the center of the blast furnace; the velocity of the charge in the perforated chute is smaller than that the intact chute, and the hole size has limited effect on the velocity of the set position. Particle size and volume of blast furnace edge are reduced.
{"title":"DEM study of the effect of different chute conditions on burden distribution during charging process blast furnace","authors":"Xiaoman Cheng, S. Cheng","doi":"10.1051/metal/2023026","DOIUrl":"https://doi.org/10.1051/metal/2023026","url":null,"abstract":"Chute accidents frequently occur during blast furnace operation. Worn or even fractured chutes can seriously affect the movement of the charge, subsequently impacting the burden distribution in the blast furnace. Therefore, it is necessary to investigate the influence of different types of chutes on burden distribution. In this paper, a model of a serial-hopper bell-less top system was established and the burden distribution through different chutes was calculated using EDM. The results of the calculations are as follows: wear liner reduces the average velocity of the charge at the chute outlet and the charge platform moves closer to the center of the blast furnace; the greater the fractured length, the greater the average velocity at the chute outlet and the easier it is for particles to accumulate in the center of the blast furnace; the velocity of the charge in the perforated chute is smaller than that the intact chute, and the hole size has limited effect on the velocity of the set position. Particle size and volume of blast furnace edge are reduced.","PeriodicalId":370509,"journal":{"name":"Metallurgical Research & Technology","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129260788","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}
With the emergence of entropy alloys, the scientific community has been persuaded to explore its joining issues for some stimulating and un-explored engineering applications. Currently, CoCrNi Medium-entropy alloy (MEA) is considered to be an excellent cryogenic material which can retain highest strength and ductility even at cryogenic temperature (i.e. 77 K). With such extravagant properties, authors compelled to explore the joining issues of this alloy. Therefore, the motivation of this research was to examine the weldability of CoCrNi MEA with the commercially available SUS 304 stainless steel using different interlayers. This research work was mainly concerned to investigate the effect of Ni, Cu, and Nb interlayers on bond formation and interface reaction during vacuum diffusion welding process. Results clinched that Ni-interlayered joints were free from the formation of Intermetallic Compounds (IMCs) and offered maximum shear strength (425.5 MPa). Cu-interlayered joints displayed the formation of Cr-C IMCs at Cu-SUS interface while Nb-Co, Nb-Ni and Nb-Cr-Ni phases were formed at Nb-MEA side. Formation of microvoids, cracks and presence of IMCs was observed in Nb-interlayered welded samples which caused lowest shear strength (238.12 MPa). Energy dispersive X-ray (EDX) and electron probe micro analysis (EPMA) were used to examine the diffusion thickness, diffusivities of constituent elements and other microstructural features across the welded joints. Scanning electron microscopy (SEM) scans and X-ray diffraction (XRD) was also executed on fractured surfaces to comprehend the joint formation mechanism.
{"title":"Diffusion welding of CoCrNi Medium-entropy alloy (MEA) and SUS 304 stainless steel using different interlayers","authors":"M. Samiuddin, Jinglong Li, Xianjun Sun, J. Xiong","doi":"10.1051/metal/2022019","DOIUrl":"https://doi.org/10.1051/metal/2022019","url":null,"abstract":"With the emergence of entropy alloys, the scientific community has been persuaded to explore its joining issues for some stimulating and un-explored engineering applications. Currently, CoCrNi Medium-entropy alloy (MEA) is considered to be an excellent cryogenic material which can retain highest strength and ductility even at cryogenic temperature (i.e. 77 K). With such extravagant properties, authors compelled to explore the joining issues of this alloy. Therefore, the motivation of this research was to examine the weldability of CoCrNi MEA with the commercially available SUS 304 stainless steel using different interlayers. This research work was mainly concerned to investigate the effect of Ni, Cu, and Nb interlayers on bond formation and interface reaction during vacuum diffusion welding process. Results clinched that Ni-interlayered joints were free from the formation of Intermetallic Compounds (IMCs) and offered maximum shear strength (425.5 MPa). Cu-interlayered joints displayed the formation of Cr-C IMCs at Cu-SUS interface while Nb-Co, Nb-Ni and Nb-Cr-Ni phases were formed at Nb-MEA side. Formation of microvoids, cracks and presence of IMCs was observed in Nb-interlayered welded samples which caused lowest shear strength (238.12 MPa). Energy dispersive X-ray (EDX) and electron probe micro analysis (EPMA) were used to examine the diffusion thickness, diffusivities of constituent elements and other microstructural features across the welded joints. Scanning electron microscopy (SEM) scans and X-ray diffraction (XRD) was also executed on fractured surfaces to comprehend the joint formation mechanism.","PeriodicalId":370509,"journal":{"name":"Metallurgical Research & Technology","volume":"30 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114424603","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}
Due to the great difference of coke properties used in blast furnaces, how to reasonably evaluate coke has become a hotspot. In this study, the non-isothermal gasification behaviors and kinetics of cokes with different reactivity are studied, which provides theoretical basis for reasonable coke evaluation. The coke reactivity index of coke A, B and C are 24.75%, 30.80% and 41.25%, respectively. The FWO method is used to calculate the kinetic parameters. The results show that coke reactivity has little influence on gasification reaction starting temperature at lower heating rate. The starting temperature decrease gradually with coke reactivity at higher heating rate. Under the same conditions, the alkali index and microcrystalline structure of cokes can better characterize the coke reactivity. The gasification mechanism does not change with coke reactivity. The reaction is divided into two stages. In the early stage, the average apparent activation energy E of coke powder A, B and C are 211.52 kJ/mol, 214.96 kJ/mol 208.99 kJ/mol, respectively. The optimal mechanism models are all F model, in which the integral form is G(α) = (1–α)−1–1. In the later stage, the average E of coke powder A, B and C are 226.89 kJ/mol, 207.53 kJ/mol and 192.12 kJ/mol, respectively. The optimal models are all A1 model, in which the integral form is G(α) = –ln(1–α).
{"title":"Behaviors and kinetics of non-isothermal gasification reaction of cokes with different reactivity","authors":"Ruijun Yan, Zhenggen Liu, M. Chu, Peijun Liu","doi":"10.1051/metal/2022089","DOIUrl":"https://doi.org/10.1051/metal/2022089","url":null,"abstract":"Due to the great difference of coke properties used in blast furnaces, how to reasonably evaluate coke has become a hotspot. In this study, the non-isothermal gasification behaviors and kinetics of cokes with different reactivity are studied, which provides theoretical basis for reasonable coke evaluation. The coke reactivity index of coke A, B and C are 24.75%, 30.80% and 41.25%, respectively. The FWO method is used to calculate the kinetic parameters. The results show that coke reactivity has little influence on gasification reaction starting temperature at lower heating rate. The starting temperature decrease gradually with coke reactivity at higher heating rate. Under the same conditions, the alkali index and microcrystalline structure of cokes can better characterize the coke reactivity. The gasification mechanism does not change with coke reactivity. The reaction is divided into two stages. In the early stage, the average apparent activation energy E of coke powder A, B and C are 211.52 kJ/mol, 214.96 kJ/mol 208.99 kJ/mol, respectively. The optimal mechanism models are all F model, in which the integral form is G(α) = (1–α)−1–1. In the later stage, the average E of coke powder A, B and C are 226.89 kJ/mol, 207.53 kJ/mol and 192.12 kJ/mol, respectively. The optimal models are all A1 model, in which the integral form is G(α) = –ln(1–α).","PeriodicalId":370509,"journal":{"name":"Metallurgical Research & Technology","volume":"29 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126840855","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}
Good profile is one of the important control objectives in hot rolling of aluminum plate. However, M-shaped profile defect often appears for wide aluminum plate and W-shaped profile defect often appears for narrow aluminum plate. In order to reveal the formation mechanism of the two typical profile defects, the evaluation indexes of the M-shaped profile defect and W-shaped profile defect are proposed, and the roll-plate coupling deformation model and the roll thermal expansion model are established. The effects of rolling force, bending force and work roll thermal expansion on the profile are analyzed using these models. The results show that the rolling force and bending force has little effect on M-shaped profile defect, and the main reason for this problem is the uneven thermal expansion of work roll. Meanwhile, the W-shaped profile defect is produced under the combined action of the roll thermal expansion and large roll deflection, and the roll thermal expansion is the necessary condition for the formation of W-shaped profile defect. The greater the thermal crown of the roll, the smaller the rolling force and the greater the bending force, the more obvious the W-shaped profile defect. Based on the above conclusions, industrial tests were carried out. By increasing the cooling flow in the middle of the roll, the frequency of M-shaped profile defect decreases from 29.4% to 9.0%. Meanwhile, by increasing the positive shifting of CVC rolls, reducing the bending force, and decreasing the cooling flow of work roll at the edge of the plate, the frequency of W-shaped profile defect decreases from 42.1% to 14.1%. The profiles of the hot rolled aluminum plates are effectively improved by the developed control strategies.
{"title":"Formation mechanism and control strategy of M-shaped and W-shaped profile defects in hot rolling of aluminum plate","authors":"Chaoan Liu, Hairui Wu, Anrui He, Wenhao Han, Bo-en Ma, Huixia Zhang","doi":"10.1051/metal/2022110","DOIUrl":"https://doi.org/10.1051/metal/2022110","url":null,"abstract":"Good profile is one of the important control objectives in hot rolling of aluminum plate. However, M-shaped profile defect often appears for wide aluminum plate and W-shaped profile defect often appears for narrow aluminum plate. In order to reveal the formation mechanism of the two typical profile defects, the evaluation indexes of the M-shaped profile defect and W-shaped profile defect are proposed, and the roll-plate coupling deformation model and the roll thermal expansion model are established. The effects of rolling force, bending force and work roll thermal expansion on the profile are analyzed using these models. The results show that the rolling force and bending force has little effect on M-shaped profile defect, and the main reason for this problem is the uneven thermal expansion of work roll. Meanwhile, the W-shaped profile defect is produced under the combined action of the roll thermal expansion and large roll deflection, and the roll thermal expansion is the necessary condition for the formation of W-shaped profile defect. The greater the thermal crown of the roll, the smaller the rolling force and the greater the bending force, the more obvious the W-shaped profile defect. Based on the above conclusions, industrial tests were carried out. By increasing the cooling flow in the middle of the roll, the frequency of M-shaped profile defect decreases from 29.4% to 9.0%. Meanwhile, by increasing the positive shifting of CVC rolls, reducing the bending force, and decreasing the cooling flow of work roll at the edge of the plate, the frequency of W-shaped profile defect decreases from 42.1% to 14.1%. The profiles of the hot rolled aluminum plates are effectively improved by the developed control strategies.","PeriodicalId":370509,"journal":{"name":"Metallurgical Research & Technology","volume":"58 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126550805","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}
Asaithambi Suresh, Abhinav Soni, V. K. Chandaliya, A. Tiwary, Pritesh Garg, B. Sagar, P. Choudhary, B. Seal, D. Kumar, P. S. Dash, R. Singh, Mantu Patra
The gasification characteristics of metallurgical coke plays an important role in controlling the thermal balance of blast furnace. In this work, the gasification reaction kinetics of nut coke was enhanced using catalytic materials to improve the reaction efficiency of blast furnace. The starting temperature of nut coke gasification was reduced by 100 °C using the solid waste materials (lime fines and iron oxide dust) that are generated internally from an integrated steel plant. Analysis of catalyst doped nut coke showed that the coke reactivity index (CRI) improved by 5–6 points over the normal nut coke. The catalyst doping facility with catalyst slurry preparation tank, slurry transfer pump, basket filter and spray header fitted with nozzles was developed to produce the catalyst doped nut coke on large scale. The plant trial was conducted in a commercial blast furnace for a month-long duration by replacing the normal nut coke with catalyst doped nut coke. As a result, the reduction of 4 kg carbon rate per ton of hot metal production was achieved through this methodology. Also, slight improvement was observed in the gas utilization efficiency of blast furnace when catalyst doped nut coke was used.
{"title":"Reduction of carbon rate in blast furnace by using catalyst doped nut coke","authors":"Asaithambi Suresh, Abhinav Soni, V. K. Chandaliya, A. Tiwary, Pritesh Garg, B. Sagar, P. Choudhary, B. Seal, D. Kumar, P. S. Dash, R. Singh, Mantu Patra","doi":"10.1051/metal/2022013","DOIUrl":"https://doi.org/10.1051/metal/2022013","url":null,"abstract":"The gasification characteristics of metallurgical coke plays an important role in controlling the thermal balance of blast furnace. In this work, the gasification reaction kinetics of nut coke was enhanced using catalytic materials to improve the reaction efficiency of blast furnace. The starting temperature of nut coke gasification was reduced by 100 °C using the solid waste materials (lime fines and iron oxide dust) that are generated internally from an integrated steel plant. Analysis of catalyst doped nut coke showed that the coke reactivity index (CRI) improved by 5–6 points over the normal nut coke. The catalyst doping facility with catalyst slurry preparation tank, slurry transfer pump, basket filter and spray header fitted with nozzles was developed to produce the catalyst doped nut coke on large scale. The plant trial was conducted in a commercial blast furnace for a month-long duration by replacing the normal nut coke with catalyst doped nut coke. As a result, the reduction of 4 kg carbon rate per ton of hot metal production was achieved through this methodology. Also, slight improvement was observed in the gas utilization efficiency of blast furnace when catalyst doped nut coke was used.","PeriodicalId":370509,"journal":{"name":"Metallurgical Research & Technology","volume":"34 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125050684","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}
This research aims to explore the forming quality of Laser Cladding NiCrCoAlY. The small changes in process parameters on the geometric characteristics of cladding layer was investigated. Mathematical models were established based on the linear regression analysis, and the influence of process parameters on the geometric morphology was obtained through the sensitivity analysis. The results show that the mathematical models have remarkable fitting accuracy. The laser power is positively correlated with clad height, width, and dilution rate; while the scanning speed is negatively correlated with clad height and width but positively with dilution rate. The powder feeding voltage has a positive correlation with clad height and a negative with clad width and dilution rate. In addition, the clad height has the greatest negative sensitivity to scanning speed, while the clad width is most sensitive to laser power and nearly insensitive to powder feeding voltage, which indicates that the clad width cannot be controlled effectively by powder feeding voltage. The dilution rate is most sensitive to laser power. The findings of this research provide a characteristic diagram of sensitivity for the geometric characteristics of laser cladding NiCrCoAlY, and also provide a theoretical basis for the further effective control on the forming quality of cladding layer.
{"title":"Sensitivity analysis of the process parameters of laser cladding NiCrCoAlY","authors":"Q. Cao, G. Lian, Changrong Chen, Meiyan Feng","doi":"10.1051/metal/2022015","DOIUrl":"https://doi.org/10.1051/metal/2022015","url":null,"abstract":"This research aims to explore the forming quality of Laser Cladding NiCrCoAlY. The small changes in process parameters on the geometric characteristics of cladding layer was investigated. Mathematical models were established based on the linear regression analysis, and the influence of process parameters on the geometric morphology was obtained through the sensitivity analysis. The results show that the mathematical models have remarkable fitting accuracy. The laser power is positively correlated with clad height, width, and dilution rate; while the scanning speed is negatively correlated with clad height and width but positively with dilution rate. The powder feeding voltage has a positive correlation with clad height and a negative with clad width and dilution rate. In addition, the clad height has the greatest negative sensitivity to scanning speed, while the clad width is most sensitive to laser power and nearly insensitive to powder feeding voltage, which indicates that the clad width cannot be controlled effectively by powder feeding voltage. The dilution rate is most sensitive to laser power. The findings of this research provide a characteristic diagram of sensitivity for the geometric characteristics of laser cladding NiCrCoAlY, and also provide a theoretical basis for the further effective control on the forming quality of cladding layer.","PeriodicalId":370509,"journal":{"name":"Metallurgical Research & Technology","volume":"9 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123199301","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}
Bensheng Huang, Xiao Hong, Peng Chen, Tianning Li, Xia Luo, Lingzhi Chen, Ge Liu
In order to improve the wear resistance and corrosion resistance of sucker rod surface, Ni-based self-lubricating composite coating with Y2O3 was successfully prepared on 35CrMo steel substrate by high frequency induction heating cladding technology. The coating structure is uniform and dense, and there are no obvious defects such as pores and cracks. The microstructure of the coating layer was studied by means of metallographic microscope, scanning electron microscope and X-ray diffractometer. The hardness, wear resistance and corrosion resistance of the coating layer were tested by microhardness testers, friction and wear testers and electrochemical workstations. The results show that the main phases of the composite coating are γ- (Ni, Fe), Ni3Fe, CrB, TiC and Cr23C6. When the addition amount of Y2O3 is 2%, the average microhardness of the composite coating is the highest, which is 805.1 HV0.2; under the same wear conditions, the wear resistance of 2% Y2O3 composite coating is the best. The average friction coefficient and wear loss are reduced by 16.27% and 20.35% respectively compared with the composite coating without rare earth, and 37.55% and 48.02% respectively compared with the substrate. The wear mechanism of the composite coating is mainly severe adhesive wear, and there is a small amount of oxidation wear. With the increase of Y2O3 content, the self-corrosion potential of the composite coating fluctuates in a small range, and its self-corrosion current density decreases first and then increases. The self-corrosion potential of the composite coating containing 2% Y2O3 is more positive (–0.4316 V), and the self-corrosion current density is the smallest (3.9579 µA · cm−2), and its corrosion resistance is the best.
{"title":"Effect of Y2O3 content on microstructure and properties of Ni-based self-lubricating composite coating","authors":"Bensheng Huang, Xiao Hong, Peng Chen, Tianning Li, Xia Luo, Lingzhi Chen, Ge Liu","doi":"10.1051/metal/2023056","DOIUrl":"https://doi.org/10.1051/metal/2023056","url":null,"abstract":"In order to improve the wear resistance and corrosion resistance of sucker rod surface, Ni-based self-lubricating composite coating with Y2O3 was successfully prepared on 35CrMo steel substrate by high frequency induction heating cladding technology. The coating structure is uniform and dense, and there are no obvious defects such as pores and cracks. The microstructure of the coating layer was studied by means of metallographic microscope, scanning electron microscope and X-ray diffractometer. The hardness, wear resistance and corrosion resistance of the coating layer were tested by microhardness testers, friction and wear testers and electrochemical workstations. The results show that the main phases of the composite coating are γ- (Ni, Fe), Ni3Fe, CrB, TiC and Cr23C6. When the addition amount of Y2O3 is 2%, the average microhardness of the composite coating is the highest, which is 805.1 HV0.2; under the same wear conditions, the wear resistance of 2% Y2O3 composite coating is the best. The average friction coefficient and wear loss are reduced by 16.27% and 20.35% respectively compared with the composite coating without rare earth, and 37.55% and 48.02% respectively compared with the substrate. The wear mechanism of the composite coating is mainly severe adhesive wear, and there is a small amount of oxidation wear. With the increase of Y2O3 content, the self-corrosion potential of the composite coating fluctuates in a small range, and its self-corrosion current density decreases first and then increases. The self-corrosion potential of the composite coating containing 2% Y2O3 is more positive (–0.4316 V), and the self-corrosion current density is the smallest (3.9579 µA · cm−2), and its corrosion resistance is the best.","PeriodicalId":370509,"journal":{"name":"Metallurgical Research & Technology","volume":"34 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126340837","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}
H. Zhong, M. Jiang, Kanghao Wang, Xinhua Wang, Shuai Liu, Jinxing Jiang
The formation and evolution of non-metallic inclusions in X70MS pipeline steel during LF-RH-CC process were investigated by industrial trials, and the evolution mechanism of non-metallic inclusions was analyzed and discussed with thermodynamic calculations. The results show that after RH vacuum refining, the inclusions in molten steel are mainly spherical CaO-MgO-Al2O3 and CaO-Al2O3. After calcium treatment, the inclusions are transformed into spherical CaS-CaO-Al2O3 and CaO-CaS with finer size. During calcium treatment, it is difficult for [Ca] and [S] in the molten steel to react directly to form CaS, and CaS is mainly generated at the edge of liquid calcium aluminate. When w[Al] in molten steel is 0.032%, w[Ca] is controlled above 0.0035%, which is more favorable to avoid the generation of liquid calcium aluminate. Calcium treatment to the tundish reaches the casting liquid level, the molten steel occurred a continuous reoxidation, reoxidation of inclusions composition transformation is mainly determined by the [Ca] and T[O] contents of the molten steel, this process inclusions are transformed from CaO-CaS to liquid CaO-MgO-Al2O3. During cooling and solidification of the molten steel, the CaS content in inclusions increases sharply, the CaO content decreases sharply, and the changes in inclusions are mainly affected by the reaction between the molten steel and the inclusions and the precipitation of new phases.
{"title":"Formation and evolution of non-metallic inclusions in X70MS pipeline steel during LF-RH-CC process","authors":"H. Zhong, M. Jiang, Kanghao Wang, Xinhua Wang, Shuai Liu, Jinxing Jiang","doi":"10.1051/metal/2022078","DOIUrl":"https://doi.org/10.1051/metal/2022078","url":null,"abstract":"The formation and evolution of non-metallic inclusions in X70MS pipeline steel during LF-RH-CC process were investigated by industrial trials, and the evolution mechanism of non-metallic inclusions was analyzed and discussed with thermodynamic calculations. The results show that after RH vacuum refining, the inclusions in molten steel are mainly spherical CaO-MgO-Al2O3 and CaO-Al2O3. After calcium treatment, the inclusions are transformed into spherical CaS-CaO-Al2O3 and CaO-CaS with finer size. During calcium treatment, it is difficult for [Ca] and [S] in the molten steel to react directly to form CaS, and CaS is mainly generated at the edge of liquid calcium aluminate. When w[Al] in molten steel is 0.032%, w[Ca] is controlled above 0.0035%, which is more favorable to avoid the generation of liquid calcium aluminate. Calcium treatment to the tundish reaches the casting liquid level, the molten steel occurred a continuous reoxidation, reoxidation of inclusions composition transformation is mainly determined by the [Ca] and T[O] contents of the molten steel, this process inclusions are transformed from CaO-CaS to liquid CaO-MgO-Al2O3. During cooling and solidification of the molten steel, the CaS content in inclusions increases sharply, the CaO content decreases sharply, and the changes in inclusions are mainly affected by the reaction between the molten steel and the inclusions and the precipitation of new phases.","PeriodicalId":370509,"journal":{"name":"Metallurgical Research & Technology","volume":"67 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130289025","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}
TiNi alloys have good biocompatibility and are widely used as biomaterials in the human body. Mo is a nontoxic element and increases biocompatibility as well as corrosion resistance. Ti-Mo-Ni-based alloys utilized in biomedical applications should have high strength. In this context, the microstructure and mechanical properties of TixMo6Ni alloys produced by the powder metallurgy method were investigated in this study. Five different Ti alloys were obtained by adding a fixed amount of (6%) Ni and different ratios (1, 3, 5, 8, 10%) Mo into the Ti powder. Alloy powders were sintered at different temperatures after pressing with a constant pressure of 520 MPa. In general, the highest density values were reached at 1250 °C. Microstructure examinations were performed by scanning electron microscopy (SEM), energy distribution spectrometry (EDS) and X-ray diffraction analysis (XRD) analyses. In the microstructure, it was observed that the grain size and pores increased as the Mo ratio increased. The hardness values increased with the increase of the Mo ratio. However, the relative density values decreased with increasing Mo ratio.
TiNi合金具有良好的生物相容性，在人体中作为生物材料得到了广泛的应用。钼是一种无毒元素，增加了生物相容性和耐腐蚀性。用于生物医学应用的ti - mo - ni基合金应具有高强度。在此背景下，对粉末冶金法制备的TixMo6Ni合金的显微组织和力学性能进行了研究。在Ti粉末中加入一定量(6%)的Ni和不同比例(1、3、5、8、10%)的Mo，得到5种不同的Ti合金。在520 MPa的恒压下，在不同温度下烧结合金粉末。通常，在1250°C时达到最高密度值。采用扫描电镜(SEM)、能谱分析(EDS)和x射线衍射分析(XRD)对样品进行微观结构分析。在显微组织中，随着Mo比的增加，晶粒尺寸和气孔逐渐增大。硬度值随Mo比的增大而增大。相对密度随Mo比的增大而减小。
{"title":"Effect of Mo ratio on the microstructure and mechanical properties of TiMoNi alloys fabricated by powder metallurgy method","authors":"Sabri Bulbul, Z. Balalan, O. Ozgun, O. Ekinci","doi":"10.1051/metal/2023055","DOIUrl":"https://doi.org/10.1051/metal/2023055","url":null,"abstract":"TiNi alloys have good biocompatibility and are widely used as biomaterials in the human body. Mo is a nontoxic element and increases biocompatibility as well as corrosion resistance. Ti-Mo-Ni-based alloys utilized in biomedical applications should have high strength. In this context, the microstructure and mechanical properties of TixMo6Ni alloys produced by the powder metallurgy method were investigated in this study. Five different Ti alloys were obtained by adding a fixed amount of (6%) Ni and different ratios (1, 3, 5, 8, 10%) Mo into the Ti powder. Alloy powders were sintered at different temperatures after pressing with a constant pressure of 520 MPa. In general, the highest density values were reached at 1250 °C. Microstructure examinations were performed by scanning electron microscopy (SEM), energy distribution spectrometry (EDS) and X-ray diffraction analysis (XRD) analyses. In the microstructure, it was observed that the grain size and pores increased as the Mo ratio increased. The hardness values increased with the increase of the Mo ratio. However, the relative density values decreased with increasing Mo ratio.","PeriodicalId":370509,"journal":{"name":"Metallurgical Research & Technology","volume":"8 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130800465","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}
The effects of intercritical annealing time on microstructure evolution and mechanical properties of a novel medium Mn steel (Fe-0.14C-5Mn-1Al-Ce) were investigated. The microstructure composed of lamellar ferrite and retained austenite (RA)/α’-martensite mixed phases after intercritical annealing. With the extension of intercritical annealing holding time, the volume fraction of RA first increases and then decreases, and RA is always formed at the high-angle grain boundaries of the ferrite. Both the product of Rm*A and the total elongation increase as the volume fraction of RA increases. The greater volume fraction of RA, the greater total elongation and Rm*A. The enrichment of carbon in RA was investigated by XRD and DICTRA. As intercritical annealing holding time increases, the carbon concentration in austenite decreases, while the change of the carbon concentration will affect the volume fraction of RA after intercritical annealing.
{"title":"Microstructural evolution and mechanical properties of Fe-0.14C-5Mn-1Al-Ce steel during intercritical annealing","authors":"Zhenjiang Li, Yujing Liu, P. Jia, Ruyi Zhang, Chao Luo, Huiping Qi","doi":"10.1051/metal/2022061","DOIUrl":"https://doi.org/10.1051/metal/2022061","url":null,"abstract":"The effects of intercritical annealing time on microstructure evolution and mechanical properties of a novel medium Mn steel (Fe-0.14C-5Mn-1Al-Ce) were investigated. The microstructure composed of lamellar ferrite and retained austenite (RA)/α’-martensite mixed phases after intercritical annealing. With the extension of intercritical annealing holding time, the volume fraction of RA first increases and then decreases, and RA is always formed at the high-angle grain boundaries of the ferrite. Both the product of Rm*A and the total elongation increase as the volume fraction of RA increases. The greater volume fraction of RA, the greater total elongation and Rm*A. The enrichment of carbon in RA was investigated by XRD and DICTRA. As intercritical annealing holding time increases, the carbon concentration in austenite decreases, while the change of the carbon concentration will affect the volume fraction of RA after intercritical annealing.","PeriodicalId":370509,"journal":{"name":"Metallurgical Research & Technology","volume":"79 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134527510","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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