Raja A. Anand, Manish M. Pande, Deepoo Kumar, Nurni N. Viswanathan
Thermal decomposition of hematite plays an important role during pelletization and the iron fine‐based smelting processes such as HIsarna and flash shaft smelter. The temperature at which pure hematite decomposition occurs depends on the partial pressure of oxygen in the gaseous atmosphere. In the air, that is, at = 0.21, the hematite decomposes at 1386 °C. In the present work, for an ore of a given composition, the effect of gangue on the thermal decomposition of hematite is experimentally determined using thermogravimetric analysis (TGA). A decomposition temperature of 1320 °C is found in the platinum crucible after analyzing the TGA curve. Thermodynamic calculations have been carried out using FactSage8.1 to investigate the effect of gangue on the stability of hematite. Thermodynamics calculations confirm that the hematite present in the ore decomposes at a lower temperature with the increase in the gangue content. Additionally, if gangue content can affect the temperature at which dissociation of hematite occurs, it is expected that the crucible material can also affect the dissociation. Interestingly most of the reported TGA experiments are performed either in alumina crucibles or it was not reported in the literature. Therefore, the effect of crucible materials, namely alumina and platinum, is also investigated.
{"title":"Thermal Decomposition of Hematite Ore Fines in Air","authors":"Raja A. Anand, Manish M. Pande, Deepoo Kumar, Nurni N. Viswanathan","doi":"10.1002/srin.202400200","DOIUrl":"https://doi.org/10.1002/srin.202400200","url":null,"abstract":"Thermal decomposition of hematite plays an important role during pelletization and the iron fine‐based smelting processes such as HIsarna and flash shaft smelter. The temperature at which pure hematite decomposition occurs depends on the partial pressure of oxygen in the gaseous atmosphere. In the air, that is, at = 0.21, the hematite decomposes at 1386 °C. In the present work, for an ore of a given composition, the effect of gangue on the thermal decomposition of hematite is experimentally determined using thermogravimetric analysis (TGA). A decomposition temperature of 1320 °C is found in the platinum crucible after analyzing the TGA curve. Thermodynamic calculations have been carried out using FactSage8.1 to investigate the effect of gangue on the stability of hematite. Thermodynamics calculations confirm that the hematite present in the ore decomposes at a lower temperature with the increase in the gangue content. Additionally, if gangue content can affect the temperature at which dissociation of hematite occurs, it is expected that the crucible material can also affect the dissociation. Interestingly most of the reported TGA experiments are performed either in alumina crucibles or it was not reported in the literature. Therefore, the effect of crucible materials, namely alumina and platinum, is also investigated.","PeriodicalId":21929,"journal":{"name":"steel research international","volume":null,"pages":null},"PeriodicalIF":2.2,"publicationDate":"2024-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142251828","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}
The microstructural and textural evolution, as well as the recrystallization kinetics under different cold‐rolling methods and their influencing mechanism on the properties of the thin‐gauge 3.5%Si nonoriented silicon steel, are investigated by electron backscattering diffraction, X‐ray diffractometer, tensile, and magnetic properties test. The results indicate that compared with the primary cold‐rolling process, the reduction rate of secondary cold‐rolling process is lower (58.3%), and many shear bands are formed in the coarse cold‐rolled sheet, which leads to the formation of strong Goss and cube texture after recrystallization annealing. Owing to the high annealing temperature, the average grain size of finished annealed sheet is little different under different cold‐rolling processes, so the mechanical properties and high‐frequency iron loss are basically the same. The iron loss of the secondary cold‐rolled products decreases with an increase in frequency, and the improvement in the iron loss of the high field (1.5 T) becomes larger than that of the low field (1.0 T). Given the high anisotropy index of the Goss texture, the iron loss anisotropy of the secondary cold‐rolled sheet is higher. Considering the magnetic and mechanical properties, the optimum process is the secondary cold rolling with the intermediate annealing temperature of 900 °C.
{"title":"Ultra‐Thin 3.5%Si Steel with Both Magnetic Properties and Mechanical Properties Produced by Different Process Routes of Large‐Scale Production","authors":"Yuan Lin, Xiao‐Ge Pei, Hui Wei, Hong‐Xia Wang, Hui‐Hu Lu, Jian‐Xiang Zhao, Xiang Chen, Xiang‐Yu Gu, Shi‐Jia Wang, Li‐Qiang Xue, Wen‐Kang Zhang, Yi‐De Wang","doi":"10.1002/srin.202400431","DOIUrl":"https://doi.org/10.1002/srin.202400431","url":null,"abstract":"The microstructural and textural evolution, as well as the recrystallization kinetics under different cold‐rolling methods and their influencing mechanism on the properties of the thin‐gauge 3.5%Si nonoriented silicon steel, are investigated by electron backscattering diffraction, X‐ray diffractometer, tensile, and magnetic properties test. The results indicate that compared with the primary cold‐rolling process, the reduction rate of secondary cold‐rolling process is lower (58.3%), and many shear bands are formed in the coarse cold‐rolled sheet, which leads to the formation of strong Goss and cube texture after recrystallization annealing. Owing to the high annealing temperature, the average grain size of finished annealed sheet is little different under different cold‐rolling processes, so the mechanical properties and high‐frequency iron loss are basically the same. The iron loss of the secondary cold‐rolled products decreases with an increase in frequency, and the improvement in the iron loss of the high field (1.5 T) becomes larger than that of the low field (1.0 T). Given the high anisotropy index of the Goss texture, the iron loss anisotropy of the secondary cold‐rolled sheet is higher. Considering the magnetic and mechanical properties, the optimum process is the secondary cold rolling with the intermediate annealing temperature of 900 °C.","PeriodicalId":21929,"journal":{"name":"steel research international","volume":null,"pages":null},"PeriodicalIF":2.2,"publicationDate":"2024-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142251829","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}
To realize the overall optimization of electric arc furnace (EAF) steelmaking system, a multi‐objective optimization model including smelting cost, energy consumption per ton of steel, and carbon emission per ton of steel is established. The model is optimized by multi‐objective genetic algorithm to improve the charging structure. At the same time, the data in the optimal solution set are used to analyze the influence of the change of scrap ratio on smelting cost, carbon emission per ton of steel, and smelting cycle. According to the actual working conditions and the demand of steel plant, the optimized results are selected. Compared with the actual production data, the proportion of scrap steel increases to 50.9%, the ratio of molten iron decreases to 38.8%, the smelting cost per ton of steel decreases by 12 Yuan, the energy consumption per ton of steel decreases by 4%, the carbon emission per ton of steel significantly decreases by 13%, and the smelting cycle is shortened by 2 min, but at the cost of increasing the power consumption per ton of steel. The optimized results and the analysis of the change of scrap ratio provide reference for the optimization of EAF steelmaking system.
{"title":"Enhancing Efficiency in Electric Arc Furnace Steelmaking: A Multi‐Objective Optimization Approach Using the Non‐Dominated Sorting Genetic Algorithm II","authors":"Xiaoyu Yi, Qiang Yue, Zhihe Dou, Qingcai Bu","doi":"10.1002/srin.202400370","DOIUrl":"https://doi.org/10.1002/srin.202400370","url":null,"abstract":"To realize the overall optimization of electric arc furnace (EAF) steelmaking system, a multi‐objective optimization model including smelting cost, energy consumption per ton of steel, and carbon emission per ton of steel is established. The model is optimized by multi‐objective genetic algorithm to improve the charging structure. At the same time, the data in the optimal solution set are used to analyze the influence of the change of scrap ratio on smelting cost, carbon emission per ton of steel, and smelting cycle. According to the actual working conditions and the demand of steel plant, the optimized results are selected. Compared with the actual production data, the proportion of scrap steel increases to 50.9%, the ratio of molten iron decreases to 38.8%, the smelting cost per ton of steel decreases by 12 Yuan, the energy consumption per ton of steel decreases by 4%, the carbon emission per ton of steel significantly decreases by 13%, and the smelting cycle is shortened by 2 min, but at the cost of increasing the power consumption per ton of steel. The optimized results and the analysis of the change of scrap ratio provide reference for the optimization of EAF steelmaking system.","PeriodicalId":21929,"journal":{"name":"steel research international","volume":null,"pages":null},"PeriodicalIF":2.2,"publicationDate":"2024-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142251831","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}
Additive manufacturing (AM) is a cutting‐edge technique for constructing intricate components with unique microstructural features and strength comparable to wrought alloys. Due to their exceptional corrosion resistance and mechanical properties, duplex stainless steels (DSS) are used in a wide range of critical applications. Over the past several years, a substantial body of research has been conducted on the AM of DSS. In‐depth knowledge is required to understand the complete benefits of the AM process. This review overviews the AM‐processed DSS parts based on process‐specific microstructural changes, mechanical behavior, electrochemical performance, and postheat treatment processes based on the classifications of directed energy deposition and powder bed fusion AM techniques along with future perspectives. Major challenges in AM of DSS are optimizing the austenite–ferrite fractions and controlling the formations of deleterious phases. This review will be extensively useful to researchers and industries working in the AM of DSS.
快速成型制造（AM）是一种尖端技术，用于制造具有独特微观结构特征和媲美锻造合金强度的复杂部件。由于双相不锈钢（DSS）具有优异的耐腐蚀性和机械性能，因此被广泛应用于各种关键领域。在过去几年中，对双相不锈钢的 AM 进行了大量研究。要了解 AM 工艺的全部优点，就必须深入了解 AM 工艺。本综述根据定向能沉积和粉末床熔融 AM 技术的分类，概述了基于特定工艺的微观结构变化、机械性能、电化学性能和后热处理工艺的 DSS 零件 AM 加工以及未来展望。定向能沉积和粉末床熔融 AM 技术的主要挑战是优化奥氏体-铁素体分数和控制有害相的形成。这篇综述将对从事 DSS AM 的研究人员和行业大有裨益。
{"title":"An Overview on Additive Manufacturing of Duplex Stainless Steels: Microstructure, Mechanical Properties, Corrosion Resistance, Postheat Treatment, and Future Perspectives","authors":"Sanjeevi Prakash Karunanithi, Rajesh Kannan Arasappan, Siva Shanmugam Nallathambi","doi":"10.1002/srin.202400463","DOIUrl":"https://doi.org/10.1002/srin.202400463","url":null,"abstract":"Additive manufacturing (AM) is a cutting‐edge technique for constructing intricate components with unique microstructural features and strength comparable to wrought alloys. Due to their exceptional corrosion resistance and mechanical properties, duplex stainless steels (DSS) are used in a wide range of critical applications. Over the past several years, a substantial body of research has been conducted on the AM of DSS. In‐depth knowledge is required to understand the complete benefits of the AM process. This review overviews the AM‐processed DSS parts based on process‐specific microstructural changes, mechanical behavior, electrochemical performance, and postheat treatment processes based on the classifications of directed energy deposition and powder bed fusion AM techniques along with future perspectives. Major challenges in AM of DSS are optimizing the austenite–ferrite fractions and controlling the formations of deleterious phases. This review will be extensively useful to researchers and industries working in the AM of DSS.","PeriodicalId":21929,"journal":{"name":"steel research international","volume":null,"pages":null},"PeriodicalIF":2.2,"publicationDate":"2024-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142251827","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}
Gao Yang, Xiangning Meng, Rui Yang, Ruiqi Zeng, Wei Li
Herein, the influence of P2O5 on the break temperature and phase composition of slag from the double slag converter steelmaking process is investigated comprehensively. The composition and micromorphology of crystallized phase are analyzed by X‐Ray diffractometer and scanning electron microscope equipped with energy dispersive spectrometer. The results reveal that the break temperature of slag increases owing to an increase of P2O5 content. When the P2O5 content is 2%, the break temperature is 1198 °C, and it increases to 1209 °C for the slag with 4% P2O5. With the increase of P2O5 content from 2% to 8%, the activation energy for viscous flow shows an upward trend. The crystallized phase at the same temperature with different P2O5 contents remains nearly unchanged, but the diffraction peak intensity is different. When the P2O5 content remains constant, a decrease in temperature results in significant changes in the micromorphology of crystallized phases. The present results improve the knowledge about the P‐rich slag, and are also significant in optimizing the double slag converter steelmaking process.
{"title":"Investigation of P2O5 on the Break Temperature and Phase Composition of Slag from the Double Slag Converter Steelmaking Process","authors":"Gao Yang, Xiangning Meng, Rui Yang, Ruiqi Zeng, Wei Li","doi":"10.1002/srin.202400507","DOIUrl":"https://doi.org/10.1002/srin.202400507","url":null,"abstract":"Herein, the influence of P<jats:sub>2</jats:sub>O<jats:sub>5</jats:sub> on the break temperature and phase composition of slag from the double slag converter steelmaking process is investigated comprehensively. The composition and micromorphology of crystallized phase are analyzed by X‐Ray diffractometer and scanning electron microscope equipped with energy dispersive spectrometer. The results reveal that the break temperature of slag increases owing to an increase of P<jats:sub>2</jats:sub>O<jats:sub>5</jats:sub> content. When the P<jats:sub>2</jats:sub>O<jats:sub>5</jats:sub> content is 2%, the break temperature is 1198 °C, and it increases to 1209 °C for the slag with 4% P<jats:sub>2</jats:sub>O<jats:sub>5</jats:sub>. With the increase of P<jats:sub>2</jats:sub>O<jats:sub>5</jats:sub> content from 2% to 8%, the activation energy for viscous flow shows an upward trend. The crystallized phase at the same temperature with different P<jats:sub>2</jats:sub>O<jats:sub>5</jats:sub> contents remains nearly unchanged, but the diffraction peak intensity is different. When the P<jats:sub>2</jats:sub>O<jats:sub>5</jats:sub> content remains constant, a decrease in temperature results in significant changes in the micromorphology of crystallized phases. The present results improve the knowledge about the P‐rich slag, and are also significant in optimizing the double slag converter steelmaking process.","PeriodicalId":21929,"journal":{"name":"steel research international","volume":null,"pages":null},"PeriodicalIF":2.2,"publicationDate":"2024-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142251830","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}
Guangming Cao, Wentao Song, Hengxiang Yu, Yongcheng Bi, Zhenyu Liu
The microstructure and composition of the scales formed are examined after being exposed to atmosphere containing 2.0% SO2 + 5.0% O2 for 60 min in the temperature range of 900–1200 °C. The composition of the scale post‐oxidation primarily varies with temperature rather than silicon content. FeS exhibits a melting temperature of 950 °C, whereas FeSi2O4 melts at 1150 °C. Two mechanisms for FeS formation are proposed. Eutectoid transformation of molten FeS occurs during subsequent cooling, resulting in lamellar FeS + Fe–S–O compounds. Above 1150 °C, the melt of Fe2SiO4 further increases the Fe diffusion rate. This dual‐liquefaction mechanism involving FeS and Fe2SiO4 accounts for the anomalous oxidative mass gain observed in Fe–Si alloys exposed to a sulfur‐containing atmosphere.
{"title":"High‐Temperature Oxidation of Fe–Si Alloys in Atmospheres Containing 2.0% SO2 + 5.0% O2","authors":"Guangming Cao, Wentao Song, Hengxiang Yu, Yongcheng Bi, Zhenyu Liu","doi":"10.1002/srin.202400547","DOIUrl":"https://doi.org/10.1002/srin.202400547","url":null,"abstract":"The microstructure and composition of the scales formed are examined after being exposed to atmosphere containing 2.0% SO<jats:sub>2</jats:sub> + 5.0% O<jats:sub>2</jats:sub> for 60 min in the temperature range of 900–1200 °C. The composition of the scale post‐oxidation primarily varies with temperature rather than silicon content. FeS exhibits a melting temperature of 950 °C, whereas FeSi<jats:sub>2</jats:sub>O<jats:sub>4</jats:sub> melts at 1150 °C. Two mechanisms for FeS formation are proposed. Eutectoid transformation of molten FeS occurs during subsequent cooling, resulting in lamellar FeS + Fe–S–O compounds. Above 1150 °C, the melt of Fe<jats:sub>2</jats:sub>SiO<jats:sub>4</jats:sub> further increases the Fe diffusion rate. This dual‐liquefaction mechanism involving FeS and Fe<jats:sub>2</jats:sub>SiO<jats:sub>4</jats:sub> accounts for the anomalous oxidative mass gain observed in Fe–Si alloys exposed to a sulfur‐containing atmosphere.","PeriodicalId":21929,"journal":{"name":"steel research international","volume":null,"pages":null},"PeriodicalIF":2.2,"publicationDate":"2024-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142251832","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}
Christopher DiGiovanni, Delin Li, Ka Wing Ng, Xianai Huang
The electric arc furnace (EAF) is a promising approach to decarbonize the iron and steel industry. In EAF steelmaking, injecting carbon into the molten slag remains crucial for creating a foamy slag, which enhances the energy efficiency of the process and protects the furnace. Biochar (BC) has emerged as a potential alternative to traditional fossil carbon for slag foaming. However, fully replacing fossil carbon with BC poses technical challenges. In this study, the partial replacement of fossil carbon with BC is considered, in the form of a petroleum coke (petcoke) and BC blend. Interestingly, a blend of petcoke and BC matches or possibly outperforms either carbon type individually, due to a synergistic effect. Using an induction furnace to simulate EAF conditions, a synthetic slag is melted, and injection carbon is added into the slag layer. The slag foaming effectiveness of petcoke, BC, and three blend cases are studied. Thermogravimetric analysis reveals that the BC is more reactive with slag compared to petcoke, which leads to an initial high intensity of CO generation. However, the CO generation was not continuous or consistent. All experimental results are combined to propose a mechanistic description of the slag foaming behavior of BC blends.
电弧炉（EAF）是实现钢铁工业脱碳的一种前景广阔的方法。在电弧炉炼钢过程中，向熔渣中注入碳对于形成泡沫状熔渣仍然至关重要，因为泡沫状熔渣可以提高工艺的能效并保护熔炉。生物炭（BC）已成为传统化石碳在熔渣发泡方面的潜在替代品。然而，用 BC 完全替代化石碳在技术上存在挑战。在本研究中，考虑了用 BC 部分替代化石碳，即石油焦（petcoke）和 BC 混合物的形式。有趣的是，由于协同效应，石油焦和萃取碳的混合物与单独使用其中一种碳的效果相当，甚至可能优于单独使用其中一种碳的效果。使用感应炉模拟 EAF 条件，熔化合成炉渣，并在炉渣层中加入喷射碳。研究了石油焦、BC 和三种混合物的炉渣发泡效果。热重分析表明，与石油焦相比，BC 与炉渣的反应性更强，从而导致最初高强度的 CO 生成。然而，CO 的生成并不连续或一致。综合所有实验结果，提出了 BC 混合物渣发泡行为的机理描述。
{"title":"Evaluation of Biochar and Coke Blends for Slag Foaming Applications in Electric Arc Furnace Steelmaking","authors":"Christopher DiGiovanni, Delin Li, Ka Wing Ng, Xianai Huang","doi":"10.1002/srin.202400518","DOIUrl":"https://doi.org/10.1002/srin.202400518","url":null,"abstract":"The electric arc furnace (EAF) is a promising approach to decarbonize the iron and steel industry. In EAF steelmaking, injecting carbon into the molten slag remains crucial for creating a foamy slag, which enhances the energy efficiency of the process and protects the furnace. Biochar (BC) has emerged as a potential alternative to traditional fossil carbon for slag foaming. However, fully replacing fossil carbon with BC poses technical challenges. In this study, the partial replacement of fossil carbon with BC is considered, in the form of a petroleum coke (petcoke) and BC blend. Interestingly, a blend of petcoke and BC matches or possibly outperforms either carbon type individually, due to a synergistic effect. Using an induction furnace to simulate EAF conditions, a synthetic slag is melted, and injection carbon is added into the slag layer. The slag foaming effectiveness of petcoke, BC, and three blend cases are studied. Thermogravimetric analysis reveals that the BC is more reactive with slag compared to petcoke, which leads to an initial high intensity of CO generation. However, the CO generation was not continuous or consistent. All experimental results are combined to propose a mechanistic description of the slag foaming behavior of BC blends.","PeriodicalId":21929,"journal":{"name":"steel research international","volume":null,"pages":null},"PeriodicalIF":2.2,"publicationDate":"2024-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142251892","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}
This work presents the development and validation of a static thermochemical model for predicting process parameters in the MIDREX shaft furnace, a method used for producing direct reduced iron from lump ore and pellets. Industrial plant data is used to validate the model. Furthermore, the model is utilized to analyze the process based on different parameters. Genetic algorithm (GA) is used to estimate the critical parameters of the process (like reaction factors and extent of reactions) and validate the model with industrial data. Further investigations are conducted to assess the possibility of replacing the reformer gas (bustle gas) with hydrogen and coke oven gas (COG) to make the process greener and almost free from carbon emissions, using a systematic approach of overall heat balance, using already developed coupled thermodynamics and kinetics-based model, and further using those data to estimate the reaction factors and extent of reactions using GA to be used in the static model. The results demonstrate the feasibility of replacing hydrogen and COG without much adverse effect on the process outcomes; however, this results in better metallization and reduced carbon footprint of the process effectively.
这项工作介绍了用于预测 MIDREX竖炉工艺参数的静态热化学模型的开发和验证，MIDREX竖炉是一种利用块矿和球团矿生产直接还原铁的方法。工业设备数据用于验证模型。此外，该模型还可用于根据不同参数分析工艺。遗传算法（GA）用于估算工艺的关键参数（如反应因子和反应程度），并利用工业数据对模型进行验证。利用已开发的基于热力学和动力学的耦合模型，采用整体热平衡的系统方法，并进一步利用这些数据，使用 GA 估算反应因子和反应程度，将其用于静态模型中。结果表明，替代氢气和 COG 是可行的，不会对工艺结果产生太大的不利影响；不过，这将有效改善金属化效果并减少工艺的碳足迹。
{"title":"Static Thermochemical Model of MIDREX: Genetic Algorithm Validation and Green Ironmaking with Hydrogen and Coke Oven Gas Injection","authors":"Sunil Yadav, C. Srishilan, Ajay Kumar Shukla","doi":"10.1002/srin.202400082","DOIUrl":"10.1002/srin.202400082","url":null,"abstract":"<p>This work presents the development and validation of a static thermochemical model for predicting process parameters in the MIDREX shaft furnace, a method used for producing direct reduced iron from lump ore and pellets. Industrial plant data is used to validate the model. Furthermore, the model is utilized to analyze the process based on different parameters. Genetic algorithm (GA) is used to estimate the critical parameters of the process (like reaction factors and extent of reactions) and validate the model with industrial data. Further investigations are conducted to assess the possibility of replacing the reformer gas (bustle gas) with hydrogen and coke oven gas (COG) to make the process greener and almost free from carbon emissions, using a systematic approach of overall heat balance, using already developed coupled thermodynamics and kinetics-based model, and further using those data to estimate the reaction factors and extent of reactions using GA to be used in the static model. The results demonstrate the feasibility of replacing hydrogen and COG without much adverse effect on the process outcomes; however, this results in better metallization and reduced carbon footprint of the process effectively.</p>","PeriodicalId":21929,"journal":{"name":"steel research international","volume":null,"pages":null},"PeriodicalIF":1.9,"publicationDate":"2024-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142251854","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}
Water‐based nanolubricants are playing increasingly important roles in hot steel rolling over the past decade regarding environmental protection, energy saving, and product quality improvement. The contact friction between the work roll and the workpiece under water‐based nanolubrication, however, has been scarcely investigated. In this study, water‐based lubricants containing 0–4.0 wt% TiO2 nanoparticles are employed in hot rolling of a mild steel under different rolling conditions. The Taguchi method is used for the orthogonal design of the hot‐rolling tests to sequence the key factors that affect the rolling force in terms of importance. The as‐synthesized water‐based nanolubricants indicate excellent dispersion stability after standing for 24 h, which can be readily restored to the original state via manual shaking. The coefficient of friction (COF) during the steady‐state hot steel rolling is inversely calculated using a flow stress model developed from hot compression testing. A novel COF model for hot rolling of the steel is thus proposed through multiple linear regression. It is found that the result of linear regression agreed well with that of inverse calculation, indicating that the proposed COF model is applicable. Finally, the lubrication mechanism is examined through a boundary lubrication regime determined from a modified lubricant film thickness model.
{"title":"Analysis of Rolling Force and Friction in Hot Steel Rolling with Water‐Based Nanolubrication","authors":"Hui Wu, Shengnan Yuan, Fei Lin, Mengyuan Ren, Jingru Yan, Muyuan Zhou, Zhao Xing, Sihai Jiao, Zhengyi Jiang","doi":"10.1002/srin.202400229","DOIUrl":"https://doi.org/10.1002/srin.202400229","url":null,"abstract":"Water‐based nanolubricants are playing increasingly important roles in hot steel rolling over the past decade regarding environmental protection, energy saving, and product quality improvement. The contact friction between the work roll and the workpiece under water‐based nanolubrication, however, has been scarcely investigated. In this study, water‐based lubricants containing 0–4.0 wt% TiO<jats:sub>2</jats:sub> nanoparticles are employed in hot rolling of a mild steel under different rolling conditions. The Taguchi method is used for the orthogonal design of the hot‐rolling tests to sequence the key factors that affect the rolling force in terms of importance. The as‐synthesized water‐based nanolubricants indicate excellent dispersion stability after standing for 24 h, which can be readily restored to the original state via manual shaking. The coefficient of friction (COF) during the steady‐state hot steel rolling is inversely calculated using a flow stress model developed from hot compression testing. A novel COF model for hot rolling of the steel is thus proposed through multiple linear regression. It is found that the result of linear regression agreed well with that of inverse calculation, indicating that the proposed COF model is applicable. Finally, the lubrication mechanism is examined through a boundary lubrication regime determined from a modified lubricant film thickness model.","PeriodicalId":21929,"journal":{"name":"steel research international","volume":null,"pages":null},"PeriodicalIF":2.2,"publicationDate":"2024-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142219418","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}
Pengzhao Zhang, Ze Meng, Guangqiang Li, Chang Liu, Xijie Wang, Yu Liu
The effects of rare‐earth treatment on cleanliness, corrosion resistance, microstructure, and mechanical properties of 75Cr1 steel are investigated by industrial trial. In the results, it is shown that the appropriate La–Ce addition can effectively remove oxygen and sulfur elements in steel, and total oxygen (T.O) and S contents decrease by 45% and 33%, respectively. After La–Ce treatment, the typical inclusions in steel are transformed from (Mg–Al–O)–CaS composite inclusions to RExSy–CaS inclusion with a small amount of Al2O3. The number and average size of inclusions in steel are significantly reduced, and the morphology of inclusions changes from irregular shape to spherical shape, which contributes to the improvement of the corrosion resistance of 75Cr1 steel. Furthermore, the pearlite spacing and the grain size are refined, the tensile and yield strengths are significantly enhanced in the test of La–Ce‐treated steel. The 75Cr1 steels are fabricated in small batches, which avoids the nozzle clogging resulted by rare‐earth treatment during continuous casting. It implies that rare‐earth treatment to improve the quality of 75Cr1 steel shows the strong industrial applicability.
{"title":"Industrial Trials on the Cleanliness Improvement, Microstructure Refinement and Performance Enhancement of Rare‐Earth‐Treated 75Cr1 Steel","authors":"Pengzhao Zhang, Ze Meng, Guangqiang Li, Chang Liu, Xijie Wang, Yu Liu","doi":"10.1002/srin.202400576","DOIUrl":"https://doi.org/10.1002/srin.202400576","url":null,"abstract":"The effects of rare‐earth treatment on cleanliness, corrosion resistance, microstructure, and mechanical properties of 75Cr1 steel are investigated by industrial trial. In the results, it is shown that the appropriate La–Ce addition can effectively remove oxygen and sulfur elements in steel, and total oxygen (T.O) and S contents decrease by 45% and 33%, respectively. After La–Ce treatment, the typical inclusions in steel are transformed from (Mg–Al–O)–CaS composite inclusions to RE<jats:sub>x</jats:sub>S<jats:sub>y</jats:sub>–CaS inclusion with a small amount of Al<jats:sub>2</jats:sub>O<jats:sub>3</jats:sub>. The number and average size of inclusions in steel are significantly reduced, and the morphology of inclusions changes from irregular shape to spherical shape, which contributes to the improvement of the corrosion resistance of 75Cr1 steel. Furthermore, the pearlite spacing and the grain size are refined, the tensile and yield strengths are significantly enhanced in the test of La–Ce‐treated steel. The 75Cr1 steels are fabricated in small batches, which avoids the nozzle clogging resulted by rare‐earth treatment during continuous casting. It implies that rare‐earth treatment to improve the quality of 75Cr1 steel shows the strong industrial applicability.","PeriodicalId":21929,"journal":{"name":"steel research international","volume":null,"pages":null},"PeriodicalIF":2.2,"publicationDate":"2024-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142219415","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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