Pub Date : 2023-05-09DOI: 10.1080/03019233.2023.2192113
Bojian Chen, Tao Jiang, Jing Wen, Lin Li, Peng Hu
ABSTRACT It is imperative to reduce the pollution and energy consumption in the blast furnace ironmaking process. High pellets operation is a developing direction in the future. The function of blast furnace slag system cannot be ignored. In order to balance the MgO content in blast furnace slag and improve the metallurgical properties of pellets in the high pellets ratio operation, the research on MgO-bearing pellets is necessary. In this paper, the metallurgical properties of MgO-bearing pellets and the properties of blast furnace slag effect by MgO in different raw material conditions, especially for Vanadium Titanomagnetite, were analysed and summarized. This review provided a reference for the development of MgO-bearing pellets and the performance of blast furnace slag effect by MgO. It is hoped to reduce pollution and promote the technical progress of blast furnace ironmaking.
{"title":"Review of pellets and blast furnace slag research progress: the effects of MgO on metallurgical properties","authors":"Bojian Chen, Tao Jiang, Jing Wen, Lin Li, Peng Hu","doi":"10.1080/03019233.2023.2192113","DOIUrl":"https://doi.org/10.1080/03019233.2023.2192113","url":null,"abstract":"ABSTRACT It is imperative to reduce the pollution and energy consumption in the blast furnace ironmaking process. High pellets operation is a developing direction in the future. The function of blast furnace slag system cannot be ignored. In order to balance the MgO content in blast furnace slag and improve the metallurgical properties of pellets in the high pellets ratio operation, the research on MgO-bearing pellets is necessary. In this paper, the metallurgical properties of MgO-bearing pellets and the properties of blast furnace slag effect by MgO in different raw material conditions, especially for Vanadium Titanomagnetite, were analysed and summarized. This review provided a reference for the development of MgO-bearing pellets and the performance of blast furnace slag effect by MgO. It is hoped to reduce pollution and promote the technical progress of blast furnace ironmaking.","PeriodicalId":14753,"journal":{"name":"Ironmaking & Steelmaking","volume":null,"pages":null},"PeriodicalIF":2.1,"publicationDate":"2023-05-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45540084","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-05-01DOI: 10.1080/03019233.2023.2203009
Z. Yan, He-Nan Bu, Hao Li, Lei Hong
ABSTRACT It is very complicated to study the three-dimensional deformation of metal during rolling. The conventional finite element numerical analysis method generally adopts a fixed algorithm to calculate the whole rolling process. This method consumes huge computing power and sacrifices some computing accuracy. In this paper, according to the characteristics of different rolling stages, on the basis of considering the degree of metal deformation, a particle swarm hybrid algorithm with adaptive weight-learning factor is proposed.The Zoutendijk algorithm, Rosen algorithm, Wolfe algorithm and particle swarm hybrid algorithm are used to numerically simulate the rolling transverse thickness distribution. The accuracy of the rolling model and the particle swarm hybrid algorithm are verified. The influence of work roll edge contact and asymmetric roll bending on the deformation of rolling metal is analysed based on particle swarm mixing algorithm.
{"title":"Numerical simulation analysis of the rolling process based on the particle swarm hybrid algorithm","authors":"Z. Yan, He-Nan Bu, Hao Li, Lei Hong","doi":"10.1080/03019233.2023.2203009","DOIUrl":"https://doi.org/10.1080/03019233.2023.2203009","url":null,"abstract":"ABSTRACT It is very complicated to study the three-dimensional deformation of metal during rolling. The conventional finite element numerical analysis method generally adopts a fixed algorithm to calculate the whole rolling process. This method consumes huge computing power and sacrifices some computing accuracy. In this paper, according to the characteristics of different rolling stages, on the basis of considering the degree of metal deformation, a particle swarm hybrid algorithm with adaptive weight-learning factor is proposed.The Zoutendijk algorithm, Rosen algorithm, Wolfe algorithm and particle swarm hybrid algorithm are used to numerically simulate the rolling transverse thickness distribution. The accuracy of the rolling model and the particle swarm hybrid algorithm are verified. The influence of work roll edge contact and asymmetric roll bending on the deformation of rolling metal is analysed based on particle swarm mixing algorithm.","PeriodicalId":14753,"journal":{"name":"Ironmaking & Steelmaking","volume":null,"pages":null},"PeriodicalIF":2.1,"publicationDate":"2023-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43744421","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-05-01DOI: 10.1080/03019233.2023.2200596
R. Das, M. K. Mondal, S. Pramanik
ABSTRACT Utilisation of by-products of an integrated steel plant improves productivity with diverse mix of raw materials used for iron making. The strength of a briquette made with Blast furnace flue dust and iron oxide with fly ash as a binder depends upon the briquetting pressure, particle size of fly ash, fly ash quantity, and curing temperature. In this study, the effect of process variables on the strength was investigated with ANOVA. The correlation between the process parameters and the strength was examined experimentally and RSM-based optimisation was performed during the preparation of briquettes. The RSM provided optimisation with a confidence level of 95% using the CCD design. This paper demonstrates the correlation between applied pressure, particle size, fly ash quantity, and curing temperature. The developed mathematical model would help in predicting the variation in the compressive strength with the change in the level of different parameters. This model can be useful for setting the optimum value of the parameters for achieving the target compressive strength.
{"title":"Enhancement of strength of blast furnace flue dust – iron oxide – fly ash composite briquette using ANOVA-based mathematical model","authors":"R. Das, M. K. Mondal, S. Pramanik","doi":"10.1080/03019233.2023.2200596","DOIUrl":"https://doi.org/10.1080/03019233.2023.2200596","url":null,"abstract":"ABSTRACT Utilisation of by-products of an integrated steel plant improves productivity with diverse mix of raw materials used for iron making. The strength of a briquette made with Blast furnace flue dust and iron oxide with fly ash as a binder depends upon the briquetting pressure, particle size of fly ash, fly ash quantity, and curing temperature. In this study, the effect of process variables on the strength was investigated with ANOVA. The correlation between the process parameters and the strength was examined experimentally and RSM-based optimisation was performed during the preparation of briquettes. The RSM provided optimisation with a confidence level of 95% using the CCD design. This paper demonstrates the correlation between applied pressure, particle size, fly ash quantity, and curing temperature. The developed mathematical model would help in predicting the variation in the compressive strength with the change in the level of different parameters. This model can be useful for setting the optimum value of the parameters for achieving the target compressive strength.","PeriodicalId":14753,"journal":{"name":"Ironmaking & Steelmaking","volume":null,"pages":null},"PeriodicalIF":2.1,"publicationDate":"2023-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45234763","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-05-01DOI: 10.1080/03019233.2023.2199615
Nuri Şen, Tolgahan Ci̇vek, İrem Yalçin
ABSTRACT In this study, hat-shaped bending experiments have been conducted on MART1200 and MART1400 Ultra-High-Strength Steels (UHSS). To investigate the influence of different lubrication conditions, on the spring-back, three different lubricant types (Graphite, Teflon film and Teflon film + Graphite) have been used in the experiments. A constant 6.5 tons of bottoming force has been applied at the end of the bending stroke and the force has been held on the samples for 0, 10s and 60s to observe the effect of force holding time on the spring-back. In addition, the effect of blankholder force on the spring-back has also been investigated for MART1400 steel. It has been found that the decrease of blankholder force and the friction between the die and sheet interfaces has considerably reduced the spring-back in the sidewalls and flange regions and also lowered the side wall curl. It has been revealed through finite element analysis that the sheet bottom has suffered a larger deformation in lower friction conditions and blankholder forces and caused in the reduction of spring-back.
{"title":"Investigation of the effects of lubrication type, blankholder force and force holding time on the spring-back behaviour for hat-shaped MART steels","authors":"Nuri Şen, Tolgahan Ci̇vek, İrem Yalçin","doi":"10.1080/03019233.2023.2199615","DOIUrl":"https://doi.org/10.1080/03019233.2023.2199615","url":null,"abstract":"ABSTRACT In this study, hat-shaped bending experiments have been conducted on MART1200 and MART1400 Ultra-High-Strength Steels (UHSS). To investigate the influence of different lubrication conditions, on the spring-back, three different lubricant types (Graphite, Teflon film and Teflon film + Graphite) have been used in the experiments. A constant 6.5 tons of bottoming force has been applied at the end of the bending stroke and the force has been held on the samples for 0, 10s and 60s to observe the effect of force holding time on the spring-back. In addition, the effect of blankholder force on the spring-back has also been investigated for MART1400 steel. It has been found that the decrease of blankholder force and the friction between the die and sheet interfaces has considerably reduced the spring-back in the sidewalls and flange regions and also lowered the side wall curl. It has been revealed through finite element analysis that the sheet bottom has suffered a larger deformation in lower friction conditions and blankholder forces and caused in the reduction of spring-back.","PeriodicalId":14753,"journal":{"name":"Ironmaking & Steelmaking","volume":null,"pages":null},"PeriodicalIF":2.1,"publicationDate":"2023-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48735368","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-05-01DOI: 10.1080/03019233.2023.2204268
Burak Nalcaci, Meltem Baysun, A. Bahador, J. Umeda, S. Münstermann, A. Kaya, M. Erdoğan
ABSTRACT This study was undertaken to understand the effects of two-step austempering treatment on an AISI 9254 high silicon steel towards tailoring the properties as desired while simultaneously employing the benefits of high and low austempering temperatures. The samples were initially austenitized at 850°C for 20 min, followed by austempering in a salt bath at the temperatures of 250–270–290°C for 20 min during the first stage. Subsequently, a second stage austempering was carried out by raising the temperature of the salt bath to 300°C at an average heating rate of 0.5°C/min, and the samples were kept in the salt bath for achieving a total austempering time of 120 min including the heating time. A conventional single-stage austempering was also conducted for comparison purposes, in which the austenitization temperature, the austempering temperatures and total time (stage I and stage II, i.e. 120 min) were kept the same for the benchmark samples. In the characterization studies, tensile test, hardness test, XRD analysis, optical microscope and field emission-scanning electron microscope (FE-SEM) equipped with EBSD detector were utilized. The findings of this study indicated that lowering the austempering temperature resulted in refining the structure with a decrease in the amount of austenite. According to the carbon content analysis through XRD patterns, the two-step austempering processes appeared to have considerably increased the carbon content of the austenite irrespective of austempering temperature. The best ultimate tensile strength (U.T.S) of 2194 MPa was achieved in the conventionally austempered sample at the lowest temperature of 250°C, while the best yield strength (Y.S.) of 1753 MPa was reached in the stepped austempered sample initially at 250°C followed by 300°C. In general, two-step austempering process led to a higher yield strength while affecting the ultimate tensile strength and total elongation depending on the austempering temperature.
{"title":"Influence of two-step austempering at different temperatures on mechanical and microstructural properties of AISI 9254 high silicon steel","authors":"Burak Nalcaci, Meltem Baysun, A. Bahador, J. Umeda, S. Münstermann, A. Kaya, M. Erdoğan","doi":"10.1080/03019233.2023.2204268","DOIUrl":"https://doi.org/10.1080/03019233.2023.2204268","url":null,"abstract":"ABSTRACT This study was undertaken to understand the effects of two-step austempering treatment on an AISI 9254 high silicon steel towards tailoring the properties as desired while simultaneously employing the benefits of high and low austempering temperatures. The samples were initially austenitized at 850°C for 20 min, followed by austempering in a salt bath at the temperatures of 250–270–290°C for 20 min during the first stage. Subsequently, a second stage austempering was carried out by raising the temperature of the salt bath to 300°C at an average heating rate of 0.5°C/min, and the samples were kept in the salt bath for achieving a total austempering time of 120 min including the heating time. A conventional single-stage austempering was also conducted for comparison purposes, in which the austenitization temperature, the austempering temperatures and total time (stage I and stage II, i.e. 120 min) were kept the same for the benchmark samples. In the characterization studies, tensile test, hardness test, XRD analysis, optical microscope and field emission-scanning electron microscope (FE-SEM) equipped with EBSD detector were utilized. The findings of this study indicated that lowering the austempering temperature resulted in refining the structure with a decrease in the amount of austenite. According to the carbon content analysis through XRD patterns, the two-step austempering processes appeared to have considerably increased the carbon content of the austenite irrespective of austempering temperature. The best ultimate tensile strength (U.T.S) of 2194 MPa was achieved in the conventionally austempered sample at the lowest temperature of 250°C, while the best yield strength (Y.S.) of 1753 MPa was reached in the stepped austempered sample initially at 250°C followed by 300°C. In general, two-step austempering process led to a higher yield strength while affecting the ultimate tensile strength and total elongation depending on the austempering temperature.","PeriodicalId":14753,"journal":{"name":"Ironmaking & Steelmaking","volume":null,"pages":null},"PeriodicalIF":2.1,"publicationDate":"2023-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42712178","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-04-25DOI: 10.1080/03019233.2023.2200621
Ruijun Yan, Zhenggen Liu, M. Chu, Peijun Liu
ABSTRACT The use of high reactivity coke in blast furnaces is an important direction for low-carbon development. In this study, we investigated the effect of coke reactivity on the softening-melting behaviors of the sinter. The results show that the gasification temperature of coke decreased with increasing coke reactivity. With increasing coke reactivity from 24.75% to 45.11%, the initial melting temperature rose from 1294°C to 1312°C, the dripping temperature dropped from 1522°C to 1507°C and the melting region decreased from 228°C to 195°C, respectively. The cohesive zone shifted downward and the thickness narrowed. The permeability index and highest differential pressure dropped from 1219.67 KPa·°C to 607.61 KPa·°C and from 7.0962 KPa to 4.8523 KPa, respectively. Coke with high reactivity can improve the gas permeability of burden. The gas utilization ratio in the softening-melting and dripping processes of the sinter raised by about 2% with increasing coke reactivity.
{"title":"Effect of coke reactivity on softening-melting and dripping behaviors of sinter","authors":"Ruijun Yan, Zhenggen Liu, M. Chu, Peijun Liu","doi":"10.1080/03019233.2023.2200621","DOIUrl":"https://doi.org/10.1080/03019233.2023.2200621","url":null,"abstract":"ABSTRACT The use of high reactivity coke in blast furnaces is an important direction for low-carbon development. In this study, we investigated the effect of coke reactivity on the softening-melting behaviors of the sinter. The results show that the gasification temperature of coke decreased with increasing coke reactivity. With increasing coke reactivity from 24.75% to 45.11%, the initial melting temperature rose from 1294°C to 1312°C, the dripping temperature dropped from 1522°C to 1507°C and the melting region decreased from 228°C to 195°C, respectively. The cohesive zone shifted downward and the thickness narrowed. The permeability index and highest differential pressure dropped from 1219.67 KPa·°C to 607.61 KPa·°C and from 7.0962 KPa to 4.8523 KPa, respectively. Coke with high reactivity can improve the gas permeability of burden. The gas utilization ratio in the softening-melting and dripping processes of the sinter raised by about 2% with increasing coke reactivity.","PeriodicalId":14753,"journal":{"name":"Ironmaking & Steelmaking","volume":null,"pages":null},"PeriodicalIF":2.1,"publicationDate":"2023-04-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44765855","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-04-16DOI: 10.1080/03019233.2023.2197526
N. Liu, Qianren Tian, Zifei Wang, Xiangyu Xu, Jianxun Fu
ABSTRACT Under the industrial process conditions, trace tellurium (13 ppm and 22 ppm) was added to medium-carbon low-sulfur steel to optimize the morphology of MnS inclusion and thereby enhance the machinability of the steel. Voller-Beckermann microsegregation model was used to calculate the precipitation thermodynamics and growth kinetics of MnS inclusion. The morphology of observed MnS inclusion is mainly polygonal (type III), the observed microstructures of the steel are bulk-, acicular-ferrite, and pearlite, the inclusions are mainly present in the bulk-ferrite. The calculation results of inclusion relative plasticity show that 13 ppm Te reduces the relative plasticity of inclusions, while at a Te content of 22 ppm, the relative plasticity of inclusions increases by approximately 70%. Compared with the steel without Te, when containing 22 ppm Te, the material has the best machinability, the average cutting force and average surface roughness of steel are reduced by 3.47% and 38.75%, respectively.
{"title":"Modification of MnS inclusion with trace tellurium to improve the machinability of medium-carbon low-sulfur steel","authors":"N. Liu, Qianren Tian, Zifei Wang, Xiangyu Xu, Jianxun Fu","doi":"10.1080/03019233.2023.2197526","DOIUrl":"https://doi.org/10.1080/03019233.2023.2197526","url":null,"abstract":"ABSTRACT Under the industrial process conditions, trace tellurium (13 ppm and 22 ppm) was added to medium-carbon low-sulfur steel to optimize the morphology of MnS inclusion and thereby enhance the machinability of the steel. Voller-Beckermann microsegregation model was used to calculate the precipitation thermodynamics and growth kinetics of MnS inclusion. The morphology of observed MnS inclusion is mainly polygonal (type III), the observed microstructures of the steel are bulk-, acicular-ferrite, and pearlite, the inclusions are mainly present in the bulk-ferrite. The calculation results of inclusion relative plasticity show that 13 ppm Te reduces the relative plasticity of inclusions, while at a Te content of 22 ppm, the relative plasticity of inclusions increases by approximately 70%. Compared with the steel without Te, when containing 22 ppm Te, the material has the best machinability, the average cutting force and average surface roughness of steel are reduced by 3.47% and 38.75%, respectively.","PeriodicalId":14753,"journal":{"name":"Ironmaking & Steelmaking","volume":null,"pages":null},"PeriodicalIF":2.1,"publicationDate":"2023-04-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48384351","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-04-16DOI: 10.1080/03019233.2023.2196745
C. Shi, Shiyu Guo, Baoshuai Wang, Zhicai Ma, C. Wu, Peng Sun
ABSTRACT Precise control of the end-point phosphorus and sulfur content in converter steelmaking is critical to ensuring steel quality. An end-point prediction model based on LWOA-TSVR is established to better control the BOF end-point content of phosphorus and sulfur. The prediction impact is compared to the models BP, SVM, and TSVR. The results indicate that the LWOA-TSVR model outperforms the other three models in terms of accuracy. And the prediction model is applied to a steel mill. The results showed that the hit rates of phosphorus content and sulfur content were: 96.3%, 81.7%, and 94.8%, 76.9% in the range of ±0.005% and ±0.003%, respectively. The double hit rate was: 87.63% in the range of ±0.005%. Thus, it is demonstrated that the LWOA-TSVR prediction model performs effective prediction of end-point phosphorus and sulfur content with prediction accuracy that exceeds that required by the real steelmaking process in a steel mill.
{"title":"Prediction model of BOF end-point phosphorus content and sulfur content based on LWOA-TSVR","authors":"C. Shi, Shiyu Guo, Baoshuai Wang, Zhicai Ma, C. Wu, Peng Sun","doi":"10.1080/03019233.2023.2196745","DOIUrl":"https://doi.org/10.1080/03019233.2023.2196745","url":null,"abstract":"ABSTRACT Precise control of the end-point phosphorus and sulfur content in converter steelmaking is critical to ensuring steel quality. An end-point prediction model based on LWOA-TSVR is established to better control the BOF end-point content of phosphorus and sulfur. The prediction impact is compared to the models BP, SVM, and TSVR. The results indicate that the LWOA-TSVR model outperforms the other three models in terms of accuracy. And the prediction model is applied to a steel mill. The results showed that the hit rates of phosphorus content and sulfur content were: 96.3%, 81.7%, and 94.8%, 76.9% in the range of ±0.005% and ±0.003%, respectively. The double hit rate was: 87.63% in the range of ±0.005%. Thus, it is demonstrated that the LWOA-TSVR prediction model performs effective prediction of end-point phosphorus and sulfur content with prediction accuracy that exceeds that required by the real steelmaking process in a steel mill.","PeriodicalId":14753,"journal":{"name":"Ironmaking & Steelmaking","volume":null,"pages":null},"PeriodicalIF":2.1,"publicationDate":"2023-04-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48459932","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-04-16DOI: 10.1080/03019233.2023.2194736
Zhenqiang Deng, Yaqiang Li, Pengcheng Sheng, Lu-kuo Hong, Nan Zhang, Mengfan Li
ABSTRACT The solidification structure of peritectic steels (15CrMo and 20CrMo) was studied using directional solidification experiments. An island dendrite structure was observed in the hypoperitectic steel (15CrMo) at growth velocities of 15, 50, and 80 μm·s−1. While a traditional peritectic dendritic structure was observed in the hyperperitectic steel (20CrMo) at growth velocities of 15 and 50 μm·s−1, an island dendrite structure was observed at a growth velocity of 80 μm·s−1. An analysis of the solute distributions near the liquid-solid interface during solidification revealed the role of the steel grade and cooling velocity on the formation of island dendrite structures. Higher cooling velocities caused higher carbon concentration gradients in the liquid phase near the liquid-solid interface, leading to a stronger driving force for the peritectic reaction and, consequently, a more favourable formation of island dendrite structures. Hypoperitectic steel is more prone to the formation of island dendrite structures than hyperperitectic steel.
{"title":"Directionally solidified structure of peritectic steel","authors":"Zhenqiang Deng, Yaqiang Li, Pengcheng Sheng, Lu-kuo Hong, Nan Zhang, Mengfan Li","doi":"10.1080/03019233.2023.2194736","DOIUrl":"https://doi.org/10.1080/03019233.2023.2194736","url":null,"abstract":"ABSTRACT The solidification structure of peritectic steels (15CrMo and 20CrMo) was studied using directional solidification experiments. An island dendrite structure was observed in the hypoperitectic steel (15CrMo) at growth velocities of 15, 50, and 80 μm·s−1. While a traditional peritectic dendritic structure was observed in the hyperperitectic steel (20CrMo) at growth velocities of 15 and 50 μm·s−1, an island dendrite structure was observed at a growth velocity of 80 μm·s−1. An analysis of the solute distributions near the liquid-solid interface during solidification revealed the role of the steel grade and cooling velocity on the formation of island dendrite structures. Higher cooling velocities caused higher carbon concentration gradients in the liquid phase near the liquid-solid interface, leading to a stronger driving force for the peritectic reaction and, consequently, a more favourable formation of island dendrite structures. Hypoperitectic steel is more prone to the formation of island dendrite structures than hyperperitectic steel.","PeriodicalId":14753,"journal":{"name":"Ironmaking & Steelmaking","volume":null,"pages":null},"PeriodicalIF":2.1,"publicationDate":"2023-04-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48546024","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-04-16DOI: 10.1080/03019233.2023.2184988
Mohammad Kuwaiti, A. Alaei, Mehdi Mansouri Hasan Abadi, Reza Ebrahimi Kahrizsangi, H. Ghayour
ABSTRACT In the present research, the inclined plane test (IPT) and an author-developed advanced mathematical model were used to determine the viscosity of ladle-refining + CaF2 powder containing 3–10% CaF2 (LRC powder). The ladle slag powder is composed of such compounds as CaO, Al2O3, SiO2 containing percentages of CaF2 to make special changes to the chemical and physical properties of the compound. The procedure for determination of the viscosity obtained by IPT method was supported using a high-temperature viscometer. The results showed that the ribbon lengths of LRC powder obtained by using the IPT method were related to an Arrhenius relationship of viscosity. Furthermore, from the advanced mathematical relationships, it was found that there is a very close relationship between the oxygen-to-silicon molar ratio (O/Si), basic/acidic oxide molar ratio (B/A), the number of non-bridging oxygen per tetrahedrally-coordinated atoms (NBO/T), and the chemical compositions of LRC powder. Hence, the advanced mathematical relationships from the software output, and Statistical Package for the Social Sciences (SPSS), were used to determine the prediction model of the viscosity of LRC powder based on its chemical composition. This model had a very good correlation with the actual values obtained.
{"title":"Prediction of the ribbon length to determine the viscosity of ladle-refining powder containing CaF2 using inclined plane test and advanced mathematical model","authors":"Mohammad Kuwaiti, A. Alaei, Mehdi Mansouri Hasan Abadi, Reza Ebrahimi Kahrizsangi, H. Ghayour","doi":"10.1080/03019233.2023.2184988","DOIUrl":"https://doi.org/10.1080/03019233.2023.2184988","url":null,"abstract":"ABSTRACT In the present research, the inclined plane test (IPT) and an author-developed advanced mathematical model were used to determine the viscosity of ladle-refining + CaF2 powder containing 3–10% CaF2 (LRC powder). The ladle slag powder is composed of such compounds as CaO, Al2O3, SiO2 containing percentages of CaF2 to make special changes to the chemical and physical properties of the compound. The procedure for determination of the viscosity obtained by IPT method was supported using a high-temperature viscometer. The results showed that the ribbon lengths of LRC powder obtained by using the IPT method were related to an Arrhenius relationship of viscosity. Furthermore, from the advanced mathematical relationships, it was found that there is a very close relationship between the oxygen-to-silicon molar ratio (O/Si), basic/acidic oxide molar ratio (B/A), the number of non-bridging oxygen per tetrahedrally-coordinated atoms (NBO/T), and the chemical compositions of LRC powder. Hence, the advanced mathematical relationships from the software output, and Statistical Package for the Social Sciences (SPSS), were used to determine the prediction model of the viscosity of LRC powder based on its chemical composition. This model had a very good correlation with the actual values obtained.","PeriodicalId":14753,"journal":{"name":"Ironmaking & Steelmaking","volume":null,"pages":null},"PeriodicalIF":2.1,"publicationDate":"2023-04-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44705101","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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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