The Experts below are selected from a list of 147174 Experts worldwide ranked by ideXlab platform
Lifeng Zhang - One of the best experts on this subject based on the ideXlab platform.
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Development of Online Control Software for Precise Calcium Treatment of Steels
11th International Symposium on High-Temperature Metallurgical Processing, 2020Co-Authors: Yan Luo, Lifeng Zhang, Ying Ren, Weijian Wang, Yang Liu, Wen YangAbstract:Calcium Treatment is an important method to reduce nozzle clogging and modify inclusions in steel. However, the problems of the low yield and stability of Ca in the molten steel, and the low accuracy of the modification inclusions caused by the experiential Calcium addition are always a key issue of the Calcium Treatment for high-quality steels. The current modeling of Precise Calcium Treatment was built according to the laboratory experiment, theoretical calculation, and plant trial. Compared with the traditional method, the modeling first built a database based on the actual molten steel composition. Considering the different operating parameters in the plant, the calculation results of the suitable Calcium wire were returned in time. The software was mainly composed of four parts: input of steel composition, calculation result, operation parameter, and function selection. The current modeling can save costs, improve efficiency, and give precise guiding suggestions.
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Effect of Calcium Treatment on inclusions in Si-Mn-killed 304 stainless steels
Journal of Materials Research and Technology, 2020Co-Authors: Yi Wang, Xiaohui Sun, Lifeng Zhang, Ying RenAbstract:Abstract In the current study, two plant trials for the ladle refining process without and with the Calcium Treatment were compared to investigate the effect of the Calcium Treatment on the inclusion deformation in Si-Mn-killed 18Cr-8Ni stainless steels. The total aluminum rose from 10 ppm to 25 ppm due to the slag and steel reaction, increasing the Al2O3 in inclusions during the ladle refining process. Without the Calcium Treatment, inclusions changed from Al2O3-SiO2-MnO-CaO with about 20% MnO to Al2O3-MgO-SiO2-CaO with about 10% MnO. The Calcium Treatment obviously lowered Al2O3 and MnO in inclusions and led to the formation of CaO-rich inclusions. Inclusions changed from Al2O3-SiO2-CaO-MnO to SiO2-CaO-Al2O3 after the Calcium Treatment of Si-Mn-killed stainless steels. Calculations showed that the Calcium Treatment of 15−25 ppm lowered the melting temperature of inclusions but further additions increased the melting temperature. Calculations also showed that Calcium addition lowered Young’s modulus. Calcium Treatment was an effective method to improve the deformability of inclusions in Si-Mn-killed stainless steel during the cold rolling process.
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Effect of Calcium Treatment on magnetic properties of non-oriented electrical steels
Journal of Magnetism and Magnetic Materials, 2020Co-Authors: Qiang Ren, Wen Yang, Lin Cheng, Lifeng ZhangAbstract:Abstract The effect of Calcium Treatment on magnetic properties of non-oriented electrical steels was studied. Inclusions, precipitates, grain size and textures of final annealed sheets were analyzed and their effects on magnetic properties of the steel were discussed. Inclusions varied from Al2O3-MnS to Al2O3-CaS-(CaO) due to the reaction of Calcium and sulfur after Calcium Treatment. The number density of (Mn,Cu)S precipitates decreased with the increasing Ca/S in the steel, which also favored to the grain growth of final products. Both of the texture factors of 100 / 111 and ( 100 + 110 )/ 111 were increased from 0.22 and 0.34 to 0.37 and 0.50, respectively, due to the increase of the volume fraction of 100 from 8.34% to 15.80% with the increasing Ca/S from 0 to 1. The core loss decreased by 0.25 W/kg with Ca/S increasing from 0 to 1 in the steel, due to less (Mn,Cu)S precipitates and larger grain size. However, the increase in the number density of Al2O3-CaS-(CaO) inclusions caused by Calcium Treatment increased the volume fraction of 111 fiber textures, having a detrimental effect on the magnetic induction of the steel. Therefore, in order to improve the steel magnetic properties, inclusions of Al2O3-CaS-(CaO) formed after Calcium Treatment should be removed as much as possible.
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Effect of reoxidation on inclusions in steel during Calcium Treatment
Metallurgical Research & Technology, 2019Co-Authors: Ming Li, Lifeng ZhangAbstract:In the current study, the effect of reoxidation on inclusions during Calcium Treatment was studied via adding Fe2 O3 into a Al-killed molten steel at 1 min after the addition of Calcium. The total oxygen (T.O.) content increased from 10 to 24 ppm just after the reoxidation occurred, while it finally decreased to 14 ppm since inclusions were floated to the top of the steel and absorbed by the formed slag layer. The increased T.O. favored the decomposition of CaS, especially for the heat with high sulfur contents. The vaporization of Calcium, which leads to the decrease of Calcium content, is the driving force for the evolution of inclusions from CaO-CaS-(Al2 O3 ) to CaO-Al2 O3 -(CaS) due to the limited degree of reoxidation. The contact angle between inclusions and the molten steel increased with the increase of Al2 O3 in Calcium alumina, which favored the removal of inclusions. Increased sulfur content decreased the surface tension of molten steel, which led to remove less inclusions since the contact angle between inclusions and the molten steel was decreased. Thus, more inclusions were measured in heats with higher sulfur content.
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Transient Evolution of Nonmetallic Inclusions During Calcium Treatment of Molten Steel
Metallurgical and Materials Transactions B, 2018Co-Authors: Lifeng Zhang, Yang Liu, Wen Yang, Ying Zhang, Wei ChenAbstract:The transient evolution of nonmetallic inclusions after Calcium addition in pipeline steels was investigated with a vacuum induction furnace. Samples were taken at 1, 5, 10, 15, and 20 minutes after Calcium Treatment in both MgO and Al2O3 crucibles. It was found that the total oxygen and the number density of inclusions were increased during Calcium modification, while they were dropped to a low level in the last tapped sample. Due to the evaporation of Calcium, inclusions were transferred from CaO-CaS to Al2O3-CaO-CaS, and then to Al2O3-CaO. The decomposition of CaS was highly dependent on the decrease of the total Calcium and the increase of the total oxygen in the steel. Thermodynamic calculation was performed to predict the composition of inclusions considering the effect of the total oxygen and the total Calcium and was validated by measurement. The relationship between the content of Al2O3 in inclusions and the ratio of the total Calcium and the total oxygen in steels was measured and compared with the calculated one using thermodynamic software Factsage 7.0. The mass-transfer coefficient of the dissolved Calcium in the steel was estimated in the range of 2.35 × 10−4 to 3.53 × 10−4 m/s.
Michael A Watson - One of the best experts on this subject based on the ideXlab platform.
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effect of Calcium Treatment temperature on fresh cut cantaloupe melon during storage
Journal of Food Science, 2006Co-Authors: Olusola Lamikanra, Michael A WatsonAbstract:The effect of Calcium Treatment temperature on cut cantaloupe fruit during storage was determined. Fruit dipped in Calcium solution at 4 °C had lower respiration and moisture loss rates than treated fruit at ambient temperature. Calcium Treatment lowered lipase activity at both temperatures, but the effect was more notable in fruit treated at the lower temperature where lipase activity was undetectable in the freshly processed fruit and after storage for 24 h. The ability of Calcium to confer rigidity to the tissue components at low temperatures, possibly through improved covalent crosslinking, was indicated by viscosity measurements indicating higher values for pulverized cantaloupe melon with added Calcium at 4 °C than fruit blended under similar conditions at ambient temperature.
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Effect of Calcium Treatment Temperature on Fresh‐cut Cantaloupe Melon during Storage
Journal of Food Science, 2006Co-Authors: Olusola Lamikanra, Michael A WatsonAbstract:The effect of Calcium Treatment temperature on cut cantaloupe fruit during storage was determined. Fruit dipped in Calcium solution at 4 °C had lower respiration and moisture loss rates than treated fruit at ambient temperature. Calcium Treatment lowered lipase activity at both temperatures, but the effect was more notable in fruit treated at the lower temperature where lipase activity was undetectable in the freshly processed fruit and after storage for 24 h. The ability of Calcium to confer rigidity to the tissue components at low temperatures, possibly through improved covalent crosslinking, was indicated by viscosity measurements indicating higher values for pulverized cantaloupe melon with added Calcium at 4 °C than fruit blended under similar conditions at ambient temperature.
Zhonggao Jiao - One of the best experts on this subject based on the ideXlab platform.
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effects of Calcium Treatment and low temperature storage on cell wall polysaccharide nanostructures and quality of postharvest apricot prunus armeniaca
Food Chemistry, 2017Co-Authors: Fusheng Chen, Hongshun Yang, Zhonggao JiaoAbstract:Abstract Cell wall polysaccharides play an important role in postharvest fruit texture softening. Effects of Calcium Treatment combined with cold storage on the physical properties, polysaccharide content and nanostructure of apricots were investigated. Apricots were immersed in distilled water, 1% or 3% w/v Calcium chloride, then stored at 5 °C or 10 °C. Storage at 5 °C significantly improved apricot quality and shelf life. Significant changes in the concentration and nanostructure of cell wall pectins and hemicelluloses revealed their disassembly and degradation during apricot storage. These modifications could be retarded by 1% w/v Calcium chloride Treatment. Meanwhile, the basic width units of apricot cell wall polysaccharide chains were 11.7, 31.2 and 39.1 nm for water-soluble pectin, 11.7, 17.6 and 19.5 nm for chelate-soluble pectin, and 15.6 and 23.4 nm for hemicellulose. The results suggest that texture of apricots can be effectively maintained by 1% Calcium chloride Treatment and storage at 5 °C.
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effects of Calcium Treatment and low temperature storage on cell wall polysaccharide nanostructures and quality of postharvest apricot prunus armeniaca
Food Chemistry, 2017Co-Authors: Hui Liu, Fusheng Chen, Hongshun Yang, Shaojuan Lai, Junrui Tao, Zhonggao JiaoAbstract:Cell wall polysaccharides play an important role in postharvest fruit texture softening. Effects of Calcium Treatment combined with cold storage on the physical properties, polysaccharide content and nanostructure of apricots were investigated. Apricots were immersed in distilled water, 1% or 3% w/v Calcium chloride, then stored at 5°C or 10°C. Storage at 5°C significantly improved apricot quality and shelf life. Significant changes in the concentration and nanostructure of cell wall pectins and hemicelluloses revealed their disassembly and degradation during apricot storage. These modifications could be retarded by 1% w/v Calcium chloride Treatment. Meanwhile, the basic width units of apricot cell wall polysaccharide chains were 11.7, 31.2 and 39.1nm for water-soluble pectin, 11.7, 17.6 and 19.5nm for chelate-soluble pectin, and 15.6 and 23.4nm for hemicellulose. The results suggest that texture of apricots can be effectively maintained by 1% Calcium chloride Treatment and storage at 5°C.
Ying Ren - One of the best experts on this subject based on the ideXlab platform.
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Development of Online Control Software for Precise Calcium Treatment of Steels
11th International Symposium on High-Temperature Metallurgical Processing, 2020Co-Authors: Yan Luo, Lifeng Zhang, Ying Ren, Weijian Wang, Yang Liu, Wen YangAbstract:Calcium Treatment is an important method to reduce nozzle clogging and modify inclusions in steel. However, the problems of the low yield and stability of Ca in the molten steel, and the low accuracy of the modification inclusions caused by the experiential Calcium addition are always a key issue of the Calcium Treatment for high-quality steels. The current modeling of Precise Calcium Treatment was built according to the laboratory experiment, theoretical calculation, and plant trial. Compared with the traditional method, the modeling first built a database based on the actual molten steel composition. Considering the different operating parameters in the plant, the calculation results of the suitable Calcium wire were returned in time. The software was mainly composed of four parts: input of steel composition, calculation result, operation parameter, and function selection. The current modeling can save costs, improve efficiency, and give precise guiding suggestions.
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Effect of Calcium Treatment on inclusions in Si-Mn-killed 304 stainless steels
Journal of Materials Research and Technology, 2020Co-Authors: Yi Wang, Xiaohui Sun, Lifeng Zhang, Ying RenAbstract:Abstract In the current study, two plant trials for the ladle refining process without and with the Calcium Treatment were compared to investigate the effect of the Calcium Treatment on the inclusion deformation in Si-Mn-killed 18Cr-8Ni stainless steels. The total aluminum rose from 10 ppm to 25 ppm due to the slag and steel reaction, increasing the Al2O3 in inclusions during the ladle refining process. Without the Calcium Treatment, inclusions changed from Al2O3-SiO2-MnO-CaO with about 20% MnO to Al2O3-MgO-SiO2-CaO with about 10% MnO. The Calcium Treatment obviously lowered Al2O3 and MnO in inclusions and led to the formation of CaO-rich inclusions. Inclusions changed from Al2O3-SiO2-CaO-MnO to SiO2-CaO-Al2O3 after the Calcium Treatment of Si-Mn-killed stainless steels. Calculations showed that the Calcium Treatment of 15−25 ppm lowered the melting temperature of inclusions but further additions increased the melting temperature. Calculations also showed that Calcium addition lowered Young’s modulus. Calcium Treatment was an effective method to improve the deformability of inclusions in Si-Mn-killed stainless steel during the cold rolling process.
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Effect of Sulfur in Steel on Transient Evolution of Inclusions During Calcium Treatment
Metallurgical and Materials Transactions B, 2018Co-Authors: Yang Liu, Lifeng Zhang, Ying Ren, Ying Zhang, Haojian Duan, Wen YangAbstract:In the current study, the effect of S content in the molten steel on inclusions during Calcium Treatment was studied using an induction furnace. The Calcium in steel decreased from 48 to 2 ppm, and the sulfur in steel changed a little with time. When sulfur content in steel was as low as 25 ppm during Calcium Treatment, inclusions shifted from CaO-Al2O3-CaS to Al2O3-CaO with about 35 pct CaO. When the sulfur increased over 90 ppm, more CaS-CaO formed just after the addition of Calcium, and then the CaS content decreased from over 45 pct to lower than 15 pct and inclusions were mostly Al2O3-CaO-CaS and Al2O3-CaO with a high Al2O3 content. Thermodynamic calculation predicted the variation of the composition of inclusions, indicating good agreement with the measurement, while a certain deviation existed, especially for heats with 90 and 180 ppm sulfur. A reaction model was proposed for the formation of CaO and CaS, which considered the reaction between Calcium vapor bubbles in the zone and the dissolved oxygen and sulfur in the molten steel, as described by a Langmuir-type adsorption isotherm with a reaction occurring on the remaining vacant sites. The variation of transient CaS inclusions was discussed based on the thermodynamic calculation and the morphology evolution of typical inclusions containing CaS.
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characteristics of inclusions in low carbon al killed steel during ladle furnace refining and Calcium Treatment
Isij International, 2013Co-Authors: Wen Yang, Xinhua Wang, Lifeng Zhang, Ying Ren, Xuefeng Liu, Qinglin ShanAbstract:A plant trial of the productions of LCAK steel was performed, and characteristics of inclusions during LF refining and Calcium Treatment were investigated. Besides, thermodynamic diagram among magnesium, aluminum, and oxygen as well as Calcium, magnesium, aluminum, and oxygen in the steel melt were studied to understand the fundamentals of inclusion modification by Calcium Treatment in LCAK steel. Furthermore, the change mechanisms of oxide inclusions and the precipitation of Calcium sulfide were discussed. The experimental results showed that oxide inclusions were partly changed along with the path of Al 2 O 3 →MgO·Al 2 O 3 →(MgO·)CaO·Al 2 O 3 , which was a little different from the thermodynamic calculation results due to the limited kinetic conditions. Calcium Treatment somehow modified the inclusions, however, many large inclusions were generated, and the modification effect would be dramatically decreased by the formation of large amount of CaS inclusions, which appeared with three main distribution forms. The formation of inclusions after Calcium Treatment were discussed based on the thermodynamic analysis. In order to reach the target of modification, sulfur concertration in steel should be reduced to a small amount to decrease the formation of CaS.
Wen Yang - One of the best experts on this subject based on the ideXlab platform.
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Development of Online Control Software for Precise Calcium Treatment of Steels
11th International Symposium on High-Temperature Metallurgical Processing, 2020Co-Authors: Yan Luo, Lifeng Zhang, Ying Ren, Weijian Wang, Yang Liu, Wen YangAbstract:Calcium Treatment is an important method to reduce nozzle clogging and modify inclusions in steel. However, the problems of the low yield and stability of Ca in the molten steel, and the low accuracy of the modification inclusions caused by the experiential Calcium addition are always a key issue of the Calcium Treatment for high-quality steels. The current modeling of Precise Calcium Treatment was built according to the laboratory experiment, theoretical calculation, and plant trial. Compared with the traditional method, the modeling first built a database based on the actual molten steel composition. Considering the different operating parameters in the plant, the calculation results of the suitable Calcium wire were returned in time. The software was mainly composed of four parts: input of steel composition, calculation result, operation parameter, and function selection. The current modeling can save costs, improve efficiency, and give precise guiding suggestions.
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Effect of Calcium Treatment on magnetic properties of non-oriented electrical steels
Journal of Magnetism and Magnetic Materials, 2020Co-Authors: Qiang Ren, Wen Yang, Lin Cheng, Lifeng ZhangAbstract:Abstract The effect of Calcium Treatment on magnetic properties of non-oriented electrical steels was studied. Inclusions, precipitates, grain size and textures of final annealed sheets were analyzed and their effects on magnetic properties of the steel were discussed. Inclusions varied from Al2O3-MnS to Al2O3-CaS-(CaO) due to the reaction of Calcium and sulfur after Calcium Treatment. The number density of (Mn,Cu)S precipitates decreased with the increasing Ca/S in the steel, which also favored to the grain growth of final products. Both of the texture factors of 100 / 111 and ( 100 + 110 )/ 111 were increased from 0.22 and 0.34 to 0.37 and 0.50, respectively, due to the increase of the volume fraction of 100 from 8.34% to 15.80% with the increasing Ca/S from 0 to 1. The core loss decreased by 0.25 W/kg with Ca/S increasing from 0 to 1 in the steel, due to less (Mn,Cu)S precipitates and larger grain size. However, the increase in the number density of Al2O3-CaS-(CaO) inclusions caused by Calcium Treatment increased the volume fraction of 111 fiber textures, having a detrimental effect on the magnetic induction of the steel. Therefore, in order to improve the steel magnetic properties, inclusions of Al2O3-CaS-(CaO) formed after Calcium Treatment should be removed as much as possible.
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Transient Evolution of Nonmetallic Inclusions During Calcium Treatment of Molten Steel
Metallurgical and Materials Transactions B, 2018Co-Authors: Lifeng Zhang, Yang Liu, Wen Yang, Ying Zhang, Wei ChenAbstract:The transient evolution of nonmetallic inclusions after Calcium addition in pipeline steels was investigated with a vacuum induction furnace. Samples were taken at 1, 5, 10, 15, and 20 minutes after Calcium Treatment in both MgO and Al2O3 crucibles. It was found that the total oxygen and the number density of inclusions were increased during Calcium modification, while they were dropped to a low level in the last tapped sample. Due to the evaporation of Calcium, inclusions were transferred from CaO-CaS to Al2O3-CaO-CaS, and then to Al2O3-CaO. The decomposition of CaS was highly dependent on the decrease of the total Calcium and the increase of the total oxygen in the steel. Thermodynamic calculation was performed to predict the composition of inclusions considering the effect of the total oxygen and the total Calcium and was validated by measurement. The relationship between the content of Al2O3 in inclusions and the ratio of the total Calcium and the total oxygen in steels was measured and compared with the calculated one using thermodynamic software Factsage 7.0. The mass-transfer coefficient of the dissolved Calcium in the steel was estimated in the range of 2.35 × 10−4 to 3.53 × 10−4 m/s.
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Effect of Sulfur in Steel on Transient Evolution of Inclusions During Calcium Treatment
Metallurgical and Materials Transactions B, 2018Co-Authors: Yang Liu, Lifeng Zhang, Ying Ren, Ying Zhang, Haojian Duan, Wen YangAbstract:In the current study, the effect of S content in the molten steel on inclusions during Calcium Treatment was studied using an induction furnace. The Calcium in steel decreased from 48 to 2 ppm, and the sulfur in steel changed a little with time. When sulfur content in steel was as low as 25 ppm during Calcium Treatment, inclusions shifted from CaO-Al2O3-CaS to Al2O3-CaO with about 35 pct CaO. When the sulfur increased over 90 ppm, more CaS-CaO formed just after the addition of Calcium, and then the CaS content decreased from over 45 pct to lower than 15 pct and inclusions were mostly Al2O3-CaO-CaS and Al2O3-CaO with a high Al2O3 content. Thermodynamic calculation predicted the variation of the composition of inclusions, indicating good agreement with the measurement, while a certain deviation existed, especially for heats with 90 and 180 ppm sulfur. A reaction model was proposed for the formation of CaO and CaS, which considered the reaction between Calcium vapor bubbles in the zone and the dissolved oxygen and sulfur in the molten steel, as described by a Langmuir-type adsorption isotherm with a reaction occurring on the remaining vacant sites. The variation of transient CaS inclusions was discussed based on the thermodynamic calculation and the morphology evolution of typical inclusions containing CaS.
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characteristics of inclusions in low carbon al killed steel during ladle furnace refining and Calcium Treatment
Isij International, 2013Co-Authors: Wen Yang, Xinhua Wang, Lifeng Zhang, Ying Ren, Xuefeng Liu, Qinglin ShanAbstract:A plant trial of the productions of LCAK steel was performed, and characteristics of inclusions during LF refining and Calcium Treatment were investigated. Besides, thermodynamic diagram among magnesium, aluminum, and oxygen as well as Calcium, magnesium, aluminum, and oxygen in the steel melt were studied to understand the fundamentals of inclusion modification by Calcium Treatment in LCAK steel. Furthermore, the change mechanisms of oxide inclusions and the precipitation of Calcium sulfide were discussed. The experimental results showed that oxide inclusions were partly changed along with the path of Al 2 O 3 →MgO·Al 2 O 3 →(MgO·)CaO·Al 2 O 3 , which was a little different from the thermodynamic calculation results due to the limited kinetic conditions. Calcium Treatment somehow modified the inclusions, however, many large inclusions were generated, and the modification effect would be dramatically decreased by the formation of large amount of CaS inclusions, which appeared with three main distribution forms. The formation of inclusions after Calcium Treatment were discussed based on the thermodynamic analysis. In order to reach the target of modification, sulfur concertration in steel should be reduced to a small amount to decrease the formation of CaS.
