Ahmed Abdelrahim, Mikko Iljana, Matti Aula, Timo Fabritius
{"title":"Impact of Radial Position on Iron Ore Sinter Reduction and Microstructure at 700–1100 °C","authors":"Ahmed Abdelrahim, Mikko Iljana, Matti Aula, Timo Fabritius","doi":"10.1002/srin.202400339","DOIUrl":"https://doi.org/10.1002/srin.202400339","url":null,"abstract":"In this research, the reduction of iron ore sinter in a blast furnace (BF) simulator in CO–CO<jats:sub>2</jats:sub>–N<jats:sub>2</jats:sub>‐reducing gas, simulating conditions at the BF center and wall, is investigated. Measurements from an operating BF guide the study, ensuring realistic reduction parameters. Reduction rate and extent, along with physical properties, are assessed under a temperature range of 700–1100 °C. In isothermal reduction experiments, the BF center exhibits superior conditions, particularly at 900 °C, achieving an 83.78% reduction degree compared to 27.17% at the wall for the same temperature. In this study, it is highlighted that basic iron ore sinter demonstrates higher reduction efficiency compared to acid iron ore pellets under identical BF center reducing conditions. Specific surface area and porosity measurements unveil a contrasting trend in specific surface area and porosity evolution between the BF wall and center. Surface morphology analysis reveals that the reduction in specific surface area and porosity of sinter samples at the BF center conditions at 1000–1100 °C is attributed to the sintering of the formed metallic iron. Carbon analysis confirms no carbon deposition took place during reduction. Mineralogical and physical property analyses provide detailed insights into the evolving phase composition during sinter reduction.","PeriodicalId":21929,"journal":{"name":"steel research international","volume":null,"pages":null},"PeriodicalIF":2.2,"publicationDate":"2024-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142219548","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}
{"title":"Microstructural Evolution, Mechanical and Electrochemical Performance of Duplex Stainless Steel Fabricated by Wire Arc Additive Manufacturing with ER2209 Filler Wire","authors":"Sanjeevi Prakash Karunanithi, Rajesh Kannan Arasappan, Siva Shanmugam Nallathambi","doi":"10.1002/srin.202400425","DOIUrl":"https://doi.org/10.1002/srin.202400425","url":null,"abstract":"This study examines the dependent relationship between microstructure, mechanical properties, and corrosion performance on the wire arc additive manufactured (WAAM) ER2209 duplex stainless steel (DSS). DSS is renowned for its corrosion resistance and mechanical strength, making it favorable for various applications. This study uses the gas metal arc welding (GMAW)‐ based WAAM technique to fabricate the wall structure using ER2209 DSS filler wire. Fine, equiaxed dendrites are formed along the build direction, with the austenite phase exceeding 70% due to the repeated heating and slow cooling inherent to WAAM process. X‐ray diffraction (XRD) confirms no brittle intermetallic phases. The results shows that varying austenite‐ferrite fractions significantly influences the anisotropy in mechanical properties between build and deposit directions. Along the build direction, the varying phase fraction causes difference in hardness of 19.59 HV<jats:sub>0.3</jats:sub> and tensile strength of 20 MPa. The maximum tensile strength (787.08 MPa) is observed in the deposit direction, with a 52 MPa difference between the build and deposit directions. Tafel and EIS measurements indicated that WAAM samples corrosion resistance was almost close to wrought 2205 DSS. This study highlights WAAM's potential for defect‐free DSS parts and suggests post‐heat treatment to optimize microstructure and mechanical properties.","PeriodicalId":21929,"journal":{"name":"steel research international","volume":null,"pages":null},"PeriodicalIF":2.2,"publicationDate":"2024-08-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142219584","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}
Manendra Singh Parihar, Sri Harsha Nistala, Rajan Kumar, Sristy Raj, Adity Ganguly, Venkataramana Runkana
{"title":"Optimization of Blast Furnace Ironmaking Using Machine Learning and Genetic Algorithms","authors":"Manendra Singh Parihar, Sri Harsha Nistala, Rajan Kumar, Sristy Raj, Adity Ganguly, Venkataramana Runkana","doi":"10.1002/srin.202300788","DOIUrl":"https://doi.org/10.1002/srin.202300788","url":null,"abstract":"Blast furnace is a multiphase counter‐current packed bed reactor that converts iron‐bearing materials such as lumps, sinter, and pellets into hot metal using metallurgical coke and pulverized coal. The quality of input materials has a significant impact on furnace performance, hot metal quality and steel plant economics. It is difficult for operators to identify the optimal settings required for efficient and safe operation based on their experience alone, given the large number of furnace parameters. A multiobjective optimization problem for maximizing furnace productivity (PROD) and minimizing fuel rate (FR) with constraints on hot metal silicon (HMSi) and temperature (HMT) is formulated and solved using a genetic algorithm. Machine learning (ML) models are developed for PROD, FR, HMSi, and HMT and tested with data from an industrial blast furnace. Pareto‐optimal solutions along with optimal settings for key manipulated variables are obtained. It is demonstrated that PROD and FR can be improved by ≈3–5% at steady state. The overall ML model‐based optimization framework can be used as part of a blast furnace digital twin system to operate the furnace efficiently in real‐time for the given quality of raw materials.","PeriodicalId":21929,"journal":{"name":"steel research international","volume":null,"pages":null},"PeriodicalIF":2.2,"publicationDate":"2024-08-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142219550","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}
Zhiwei Zhu, Yonghuan Guo, Xinran Zhang, Xiangning Lu, Xiwen Wang
{"title":"Effects of Pre‐Placed Nano‐TiC Powder on the Performance of Steel/Aluminum Laser Welded Joints","authors":"Zhiwei Zhu, Yonghuan Guo, Xinran Zhang, Xiangning Lu, Xiwen Wang","doi":"10.1002/srin.202400470","DOIUrl":"https://doi.org/10.1002/srin.202400470","url":null,"abstract":"The steel/aluminum dissimilar metal welding plays a significant role in lightweighting automotive structures. However, the formation of hard and brittle intermetallic compounds (IMCs) in steel/aluminum welded joints severely compromises their mechanical performance. Nano ceramic particles such as TiC possess characteristics that inhibit the diffusion of Fe and Al, thereby exhibiting a significant advantage in suppressing IMCs formation in steel/aluminum welded joints. In this study, an optimized laser‐welding process is employed to investigate the mechanical properties of steel/aluminum dissimilar metal joints with different concentrations of TiC nanoparticles. It is aimed to determine the optimal TiC addition concentration by comparing the mechanical performance. Additionally, the inhibitory effect of TiC particles on the formation and growth of brittle Fe–Al IMCs is explored through an analysis of IMCs growth kinetics. In the research results, it is shown that the optimal TiC addition concentration is 1%. At this concentration, the tensile strength of the steel/aluminum welded joint reaches 98.29 MPa, showing a remarkable improvement of 32.65% compared to the sample without TiC addition. The addition of TiC particles suppresses the mutual diffusion between Fe and Al, reduces the generation of brittle IMCs, and enhances the mechanical performance of the steel/aluminum joint.","PeriodicalId":21929,"journal":{"name":"steel research international","volume":null,"pages":null},"PeriodicalIF":2.2,"publicationDate":"2024-08-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142219551","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}
Shuai He, Zhi‐Feng Li, Xin Liu, Xu‐Ming Liu, Jun‐Sheng Wang
{"title":"Isothermal Reduction Behavior of Oxide Scale on the Surface of Hot‐Rolled Strip Steel Under Different Hydrogen Concentrations","authors":"Shuai He, Zhi‐Feng Li, Xin Liu, Xu‐Ming Liu, Jun‐Sheng Wang","doi":"10.1002/srin.202400375","DOIUrl":"https://doi.org/10.1002/srin.202400375","url":null,"abstract":"The oxide scale on the surface of hot‐rolled low‐carbon steel strips is subjected to isothermal reduction in 10 vol%H<jats:sub>2</jats:sub>–Ar and 20 vol%H<jats:sub>2</jats:sub>–Ar environments to simulate the reduction process that occurs in a continuous annealing furnace. The influence of hydrogen concentration on the reduction kinetics and the microstructural evolution of the oxide scale after reduction at temperatures ranging from 450 to 850 °C for a duration of 20 min are investigated in detail. The mass changes of the oxide scale in the two gases are quantified using a thermogravimetric analyzer. This data is then employed to calculate the reduction rate constant and the apparent activation energy. To examine the microstructure and element distribution, electron probe microanalysis and energy‐dispersive spectrometry are employed. An novel approach is also undertaken to assess the reduction degree of the oxide scale by measuring surface microhardness. In the findings, it is indicated that an increase in hydrogen concentration served primarily to accelerate the reduction reaction within the temperature ranges of 450–550 and 800–850 °C. Meanwhile, the mechanism of physical transformation of oxide scale, the microstructure of reduction layer, and hydrogen concentration on reduction efficiency under different reaction stages are proposed.","PeriodicalId":21929,"journal":{"name":"steel research international","volume":null,"pages":null},"PeriodicalIF":2.2,"publicationDate":"2024-08-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142219554","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}
{"title":"Implementing Single‐Roller Hard Reduction Technology for High‐Speed Production of High‐Carbon Hard Wire Steel Billets","authors":"Wen‐Xing Gao, Chang‐Chuan Xie, Jianke Li, Richeng Liang, Jiaming Liu, Liang Qian","doi":"10.1002/srin.202400250","DOIUrl":"https://doi.org/10.1002/srin.202400250","url":null,"abstract":"The production of high‐carbon hard wire steel at high speeds necessitates the use of appropriate technical support to ensure cost‐efficiency and optimal performance of the special steel casting machine. This study investigates the industrial application of single‐roller hard reduction technology in a domestic steel plant for the production of high‐carbon hard wire steel billets, specifically of section 165 × 165 mm. The produced billets meet all customer specifications and demonstrate the benefits of this approach, including lower comprehensive costs, suitability for modification, and advanced technical concepts. These features make this method compatible with a wide range of billet casting machines, from standard to specialized. In this research, discussion is done on the reduction process, the layout of withdrawal and straightening units (WSUs), and the optimal casting speed. It is concluded that bow‐type billet casting machines using rigid dummy bars can achieve single‐roller hard reduction by only three WSUs, offering lower comprehensive costs and suitability for modification. This approach is particularly beneficial for small billet casting machines undergoing an upgrade from general to high‐quality and ultimately to special steel. During the process of increasing the central density of the billet and improving central defects using single‐roller hard reduction technology, it is observed that defects in the central region gravitated toward the center. For billet casting machines with a bow radius of 10 m, considering process tolerance, the maximum casting speeds achievable with single‐roller hard reduction are 2.95–3.40 m min<jats:sup>−1</jats:sup> for a section of 150 × 150 mm, 2.60–3.0 m min<jats:sup>−1</jats:sup> for a section of 160 × 160 mm, and 2.45–2.80 m min<jats:sup>−1</jats:sup> for a section of 165 × 165 mm. To achieve higher casting speeds for high‐carbon hard wire steel, it is necessary to modify the machine configuration to flexible dummy bars.","PeriodicalId":21929,"journal":{"name":"steel research international","volume":null,"pages":null},"PeriodicalIF":2.2,"publicationDate":"2024-08-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142219561","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}
{"title":"Machine Learning-Based Prediction of the Martensite Start Temperature","authors":"Marcel Wentzien, Marcel Koch, Thomas Friedrich, Jerome Ingber, Henning Kempka, Dirk Schmalzried, Maik Kunert","doi":"10.1002/srin.202400210","DOIUrl":"10.1002/srin.202400210","url":null,"abstract":"<p>The prediction of the martensite start temperature (<span></span><math>\u0000 <mrow>\u0000 <msub>\u0000 <mi>M</mi>\u0000 <mi>s</mi>\u0000 </msub>\u0000 </mrow></math>) for steels based on their chemical compositions is a complex problem. Previous work has developed empirical, thermodynamic, and machine learning models to estimate <span></span><math>\u0000 <mrow>\u0000 <msub>\u0000 <mi>M</mi>\u0000 <mi>s</mi>\u0000 </msub>\u0000 </mrow></math>. However, the empirical models are limited to specific steel grades, the thermodynamic models rely on different model assumptions, and the machine learning models are based on a small number of data, are limited to specific steel grades, as well or are not available for easy use to the public. Herein, a new machine learning model for the prediction of <span></span><math>\u0000 <mrow>\u0000 <msub>\u0000 <mi>M</mi>\u0000 <mi>s</mi>\u0000 </msub>\u0000 </mrow></math> is developed on the basis of two publicly available datasets consisting of 1800 steels from different steel grades. Extensive hyperparameter tuning is performed to find the best artificial neural network for the dataset. The best model improves prediction accuracy compared to previous state of the art. Despite a very good prediction accuracy of the model, unexpected behavior is observed in specific unseen data. This opens up the discussion for the requirements of new metrics. The dataset and the model are freely available at https://github.com/EAH-Materials. An easy-to-use web tool to estimate <span></span><math>\u0000 <mrow>\u0000 <msub>\u0000 <mi>M</mi>\u0000 <mi>s</mi>\u0000 </msub>\u0000 </mrow></math> without the need of programming based on the chemical composition can be found at https://eah-jena-ms-predictor.streamlit.app/.</p>","PeriodicalId":21929,"journal":{"name":"steel research international","volume":null,"pages":null},"PeriodicalIF":1.9,"publicationDate":"2024-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/srin.202400210","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142219552","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"The Steelmaking Transformation Process and Its Consequences for Slag Utilization","authors":"Andreas Ehrenberg","doi":"10.1002/srin.202400234","DOIUrl":"https://doi.org/10.1002/srin.202400234","url":null,"abstract":"The main challenge of the European steel industry for the next decade is the steel production transformation process. Many steel producers aim to avoid their CO<jats:sub>2</jats:sub> emissions by substituting the CO<jats:sub>2</jats:sub>‐intensive blast furnace/basic oxygen furnace route by a gas‐based direct reduced iron (DRI) process combined with an electric smelting process. Thus, the well‐known latent hydraulic granulated blast furnace slag (GBS) will vanish step by step. For more than 140 years, this slag has been used as a supplementary cementitious material due to its clinker reduction potential and from there its CO<jats:sub>2</jats:sub> reduction potential for the cement and concrete production. Moreover, slag cements offer some special technical advantages. Whereas the solid‐state DRI process itself does not generate any slag, the different electric smelting processes will produce liquid steel or “electric” pig iron, respectively, together with very different types of slags. However, specific slag/metal ratios, resulting slag volumes, chemical and mineralogical composition, and physical properties of the new slags are yet unknown. Therefore, their cementitious and environmental properties are also still unknown. Different current and scheduled projects aim mainly to enable the different types of new slags to substitute GBS to continue the successful cross‐industrial cooperation between steel and cement industry.","PeriodicalId":21929,"journal":{"name":"steel research international","volume":null,"pages":null},"PeriodicalIF":2.2,"publicationDate":"2024-08-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142219559","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}
{"title":"Microstructural Evolution and Hot Deformation Behavior of Cu-Containing Twinning-Induced Plasticity Steel","authors":"Yang Feng, Xiaoyun Yuan, Yang Zhao, Liqing Chen","doi":"10.1002/srin.202400335","DOIUrl":"10.1002/srin.202400335","url":null,"abstract":"<p>\u0000High manganese twinning-induced plasticity (TWIP) steels with excellent strength and plasticity have promising applications in automotive manufacturing, but limited corrosion resistance affects their further development. Alloying with Cu is a viable solution to improve corrosion resistance. However, there remains a paucity of research concerning the effect of Cu on the hot deformation behavior of TWIP steels. So, the investigation of the recrystallization behavior and microstructural evolution in Fe-23Mn-6Cr-3Al-0.2C-<i>x</i>Cu (<i>x</i> = 0, 2.5) TWIP steels has been conducted using uniaxial hot compression test. The results reveal that Cu alloying exerts minimal influence on the high-temperatur flow behavior, with dynamic recrystallization emerging as the predominant softening mechanism in Cu-containing TWIP steels. However, owing to the drag effect of solute atoms, Cu alloying increases the activation energy for hot deformation and marginally reduces hot workability. Fine recrystallized grains in Cu-containing TWIP steels can be achieved by hot deformation at lower temperatures and strain rate regions. The recrystallization behavior of Cu-containing TWIP steels hot deformed at low temperatures and high strain rates is obviously inhibited by the increase of the activation energy and stacking fault energy, coupled with the hindering effect of Cu solute atoms clustered at grain boundaries on grain boundary migration.</p>","PeriodicalId":21929,"journal":{"name":"steel research international","volume":null,"pages":null},"PeriodicalIF":1.9,"publicationDate":"2024-08-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142219555","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}
{"title":"Modeling of Arcing, Scrap Melting, and Temperature Evolution in the Refractory of a Lab‐Scale Direct Current‐Electric Arc Furnace","authors":"Dinesh Nath, Sumanta Maji, Amarendra K. Singh","doi":"10.1002/srin.202300696","DOIUrl":"https://doi.org/10.1002/srin.202300696","url":null,"abstract":"Refractory linings of electric arc furnaces are subjected to intense thermal loads, leading to occasional failure of the insulating bricks. A numerical model that simulates the phenomena of arcing, scrap melting, and the transient thermal evolution in the refractory lining of a laboratory‐scale direct current‐electric arc furnace (DC‐EAF) is developed. The rise in the temperature of the refractory lining depends on many factors, including the duration of the melting operation, the intensity and duration of arcing, the design of the furnace, thermophysical properties, and the thickness of the lining. Continuum formulation‐based equations for the transport of momentum, energy, and species, auxiliary models of phase changes associated with scrap melting and evaporation of metal under the arc and Maxwell's equations are solved in a conjugate domain to model the progress of the melting of the scarp and temperature evolution in the refractory lining. Combining experimental data from lab‐scale DC‐EAF, the model is enhanced to represent the laboratory experiment. Scrap with high porosity needs more time for melting, and thermal damage of refractory lining is linked to prolonged arcing coupled with the poor quality of refractory materials.","PeriodicalId":21929,"journal":{"name":"steel research international","volume":null,"pages":null},"PeriodicalIF":2.2,"publicationDate":"2024-08-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142219553","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}