Burden distribution in a blast furnace not only determines the distribution of gas flow but also affects the thermal efficiency and fuel consumption of the blast furnace. Therefore, it is of great significance to study the burden segregation behaviors during the charging and discharging processes in blast furnaces. Herein, a 3D model of a 1:1 bell‐less top blast furnace with serial‐type hoppers is established based on the discrete element method. The model is used to simulate the entire process of the burden falling from the belt until it leaves the weighing hopper. The results show that the particle size segregation in the upper hopper is more severe than that in the weighing hopper, which also seriously affects the size segregation in the weighing hopper. Changing the charging sequence will reduce the segregation degree in two hoppers, but it cannot change the trend of particle size segregation in the final stage of the discharging process. The small particles are found to gather at the end of the discharging process, so the chute angle should be increased in the last few revolutions of the charging matrix to decrease the accumulation of small particles.
{"title":"Particle Size Segregation during Charging and Discharging Processes in Bell‐Less Blast Furnace with Serial‐Type Hoppers","authors":"Wang Zeng, Desheng Zou, Guangliang Wang, Wen Zheng, Yichi Zhang, Tianxiang Zhang, Heng Zhou, Shengli Wu, Mingyin Kou","doi":"10.1002/srin.202400306","DOIUrl":"https://doi.org/10.1002/srin.202400306","url":null,"abstract":"Burden distribution in a blast furnace not only determines the distribution of gas flow but also affects the thermal efficiency and fuel consumption of the blast furnace. Therefore, it is of great significance to study the burden segregation behaviors during the charging and discharging processes in blast furnaces. Herein, a 3D model of a 1:1 bell‐less top blast furnace with serial‐type hoppers is established based on the discrete element method. The model is used to simulate the entire process of the burden falling from the belt until it leaves the weighing hopper. The results show that the particle size segregation in the upper hopper is more severe than that in the weighing hopper, which also seriously affects the size segregation in the weighing hopper. Changing the charging sequence will reduce the segregation degree in two hoppers, but it cannot change the trend of particle size segregation in the final stage of the discharging process. The small particles are found to gather at the end of the discharging process, so the chute angle should be increased in the last few revolutions of the charging matrix to decrease the accumulation of small particles.","PeriodicalId":21929,"journal":{"name":"steel research international","volume":null,"pages":null},"PeriodicalIF":2.2,"publicationDate":"2024-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142219439","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}
Piotr Ledwig, Hubert Pasiowiec, Bartłomiej Truczka, Jan Falkus
This study investigates the effect of changing the chemical composition during ultrasonic atomization (UA) and laser powder bed fusion (LPBF) of low‐alloy steel. UA is used to produce a spherical powder with d50 equal to 49 μm. During UA, the chemical composition of the material changes, which is associated with selective evaporation of Mn from 1.42% to 0.35% and B from 0.0012% to <0.0001%. Thermodynamic calculations confirm that during atomization, mostly Mn and Fe evaporate. To achieve a high density of 3D printed parts, in situ remelting in LPBF is applied. A microstructure consisting of fine grains of tempered martensite and bainite in crystallized meltpools is observed. The selected high‐quality LPBF samples are austenitized in the temperature range of 900–1200 °C for 20 min and quenched in oil. The samples are characterized by light and scanning electron microscopy, as well as Vickers hardness. Changes in chemical composition result in a decrease in the hardenability of the material, and quenching only at 1200 °C produces a martensitic microstructure. LPBF samples show a hardness higher than that of the postheat‐treated sample, but still significantly lower than that of the as‐delivery condition, which is related to the change in chemical composition.
本研究探讨了在低合金钢超声雾化（UA）和激光粉末床熔融（LPBF）过程中改变化学成分的影响。超声雾化用于生产 d50 等于 49 μm 的球形粉末。在 UA 过程中，材料的化学成分发生了变化，锰从 1.42% 蒸发到 0.35%，硼从 0.0012% 蒸发到 0.0001%。热力学计算证实，在雾化过程中，大部分锰和铁会蒸发。为了实现 3D 打印部件的高密度，在 LPBF 中采用了原位重熔技术。在结晶熔池中观察到由细小的回火马氏体和贝氏体晶粒组成的微观结构。选定的高质量 LPBF 样品在 900-1200 °C 的温度范围内奥氏体化 20 分钟，然后在油中淬火。样品通过光镜和扫描电子显微镜以及维氏硬度进行表征。化学成分的变化导致材料的淬透性降低，仅在 1200 °C 下淬火会产生马氏体微观结构。LPBF 样品的硬度高于热处理后样品的硬度，但仍明显低于交货时的硬度，这与化学成分的变化有关。
{"title":"Impact of Chemical Composition Changes during Ultrasound Atomization and Laser Powder Bed Fusion of Low Alloy Steel","authors":"Piotr Ledwig, Hubert Pasiowiec, Bartłomiej Truczka, Jan Falkus","doi":"10.1002/srin.202400257","DOIUrl":"https://doi.org/10.1002/srin.202400257","url":null,"abstract":"This study investigates the effect of changing the chemical composition during ultrasonic atomization (UA) and laser powder bed fusion (LPBF) of low‐alloy steel. UA is used to produce a spherical powder with d50 equal to 49 μm. During UA, the chemical composition of the material changes, which is associated with selective evaporation of Mn from 1.42% to 0.35% and B from 0.0012% to <0.0001%. Thermodynamic calculations confirm that during atomization, mostly Mn and Fe evaporate. To achieve a high density of 3D printed parts, in situ remelting in LPBF is applied. A microstructure consisting of fine grains of tempered martensite and bainite in crystallized meltpools is observed. The selected high‐quality LPBF samples are austenitized in the temperature range of 900–1200 °C for 20 min and quenched in oil. The samples are characterized by light and scanning electron microscopy, as well as Vickers hardness. Changes in chemical composition result in a decrease in the hardenability of the material, and quenching only at 1200 °C produces a martensitic microstructure. LPBF samples show a hardness higher than that of the postheat‐treated sample, but still significantly lower than that of the as‐delivery condition, which is related to the change in chemical composition.","PeriodicalId":21929,"journal":{"name":"steel research international","volume":null,"pages":null},"PeriodicalIF":2.2,"publicationDate":"2024-08-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142227403","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 encourage the use of ultrasound in the calcium treatment of molten steel, this study utilizes the volume‐of‐fluid (VOF) method combined with a mixture model to analyze the distribution of the flow field in molten steel when ultrasound is applied. The effects of low‐frequency, high‐power ultrasound on the pressure field, volume fraction of cavitation bubbles, velocity distribution, and turbulence intensity are investigated. The results reveal a pattern of alternating positive and negative pressure in the pressure field during each cycle, with the lowest pressure measuring −9.63 × 104 Pa at 96 kW. The cavitation bubbles are concentrated in the intense cavitation area beneath the ultrasonic probe, exhibiting a maximum volume fraction of 2.50 × 10−2. The axial velocity peaks at the central axis, whereas the radial velocity is negligible. The maximum axial velocity increases from 0.36 m/s at 48 kW to 0.82 m/s at 120 kW. This velocity trend mirrors the turbulence intensity distribution, with the highest turbulence intensity of 276 at 96 kW. These findings provide a theoretical basis for low‐frequency, high‐power ultrasound to improve the calcium treatment of molten steel. The outcomes of the numerical simulation closely align with the experimental results, substantiating their reliability through a comparison with published studies.
{"title":"Numerical Simulation of Molten Steel Flow Field in a Ladle Induced by Low‐Frequency High‐Power Ultrasound","authors":"Qing Guo, Min Chen, Lei Xu, Weihao Cheng","doi":"10.1002/srin.202400312","DOIUrl":"https://doi.org/10.1002/srin.202400312","url":null,"abstract":"To encourage the use of ultrasound in the calcium treatment of molten steel, this study utilizes the volume‐of‐fluid (VOF) method combined with a mixture model to analyze the distribution of the flow field in molten steel when ultrasound is applied. The effects of low‐frequency, high‐power ultrasound on the pressure field, volume fraction of cavitation bubbles, velocity distribution, and turbulence intensity are investigated. The results reveal a pattern of alternating positive and negative pressure in the pressure field during each cycle, with the lowest pressure measuring −9.63 × 104 Pa at 96 kW. The cavitation bubbles are concentrated in the intense cavitation area beneath the ultrasonic probe, exhibiting a maximum volume fraction of 2.50 × 10<jats:sup>−2</jats:sup>. The axial velocity peaks at the central axis, whereas the radial velocity is negligible. The maximum axial velocity increases from 0.36 m/s at 48 kW to 0.82 m/s at 120 kW. This velocity trend mirrors the turbulence intensity distribution, with the highest turbulence intensity of 276 at 96 kW. These findings provide a theoretical basis for low‐frequency, high‐power ultrasound to improve the calcium treatment of molten steel. The outcomes of the numerical simulation closely align with the experimental results, substantiating their reliability through a comparison with published studies.","PeriodicalId":21929,"journal":{"name":"steel research international","volume":null,"pages":null},"PeriodicalIF":2.2,"publicationDate":"2024-08-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142219497","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":"Contents: steel research int. 9/2024","authors":"","doi":"10.1002/srin.202470093","DOIUrl":"https://doi.org/10.1002/srin.202470093","url":null,"abstract":"","PeriodicalId":21929,"journal":{"name":"steel research international","volume":null,"pages":null},"PeriodicalIF":1.9,"publicationDate":"2024-08-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/srin.202470093","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142100014","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}
The effect of sulfur content on sulfide inclusion and dendrite MnS in continuous casted 20CrMnTi gear steel is investigated. There are two main types of sulfides in 20CrMnTi steel: pure MnS and TiN–MnS composite inclusions. The number of TiN–MnS is higher than MnS, especially in the edge of the billet. TiN–MnS is smaller both in area and size than pure MnS. The statistical results of dendrite MnS show that the increase of S content decreases the average size of sulfides, whereas raises the number and the maximum size of sulfides. With the S content increasing, the proportion of large‐sized dendrite MnS in steel decreases, but the amount of large‐sized dendrite MnS increases, which results in the increase of number of large‐sized dendrite MnS. The average area of dendrite MnS inclusions first increased and then decreased from the edge to the center of billet, and the maximum area appeared at about 1/2 radius of the billet. Comparison with the microstructure of the two billets, the proportion of ferrite increased with the increase of S content.
{"title":"Effect of Sulfur Content on Precipitation Behavior of Dendrite Sulfide Inclusion in Continuous Casted 20CrMnTi Gear Steel","authors":"Qiu‐wei Zheng, Xiao‐yong Gao, Li‐feng Zhang","doi":"10.1002/srin.202400587","DOIUrl":"https://doi.org/10.1002/srin.202400587","url":null,"abstract":"The effect of sulfur content on sulfide inclusion and dendrite MnS in continuous casted 20CrMnTi gear steel is investigated. There are two main types of sulfides in 20CrMnTi steel: pure MnS and TiN–MnS composite inclusions. The number of TiN–MnS is higher than MnS, especially in the edge of the billet. TiN–MnS is smaller both in area and size than pure MnS. The statistical results of dendrite MnS show that the increase of S content decreases the average size of sulfides, whereas raises the number and the maximum size of sulfides. With the S content increasing, the proportion of large‐sized dendrite MnS in steel decreases, but the amount of large‐sized dendrite MnS increases, which results in the increase of number of large‐sized dendrite MnS. The average area of dendrite MnS inclusions first increased and then decreased from the edge to the center of billet, and the maximum area appeared at about 1/2 radius of the billet. Comparison with the microstructure of the two billets, the proportion of ferrite increased with the increase of S content.","PeriodicalId":21929,"journal":{"name":"steel research international","volume":null,"pages":null},"PeriodicalIF":2.2,"publicationDate":"2024-08-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142219496","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 effect of Cr content on the microstructure and mechanical properties of CSS‐42L steel is investigated by X‐ray diffractometer, scanning electron microscopy, and transmission electron microscopy. The results show that increasing Cr from 8% to 13.5% significantly improves toughness and ductility while moderately decreasing the strength. The tensile strength, fracture toughness (KIC), and impact absorbing energy of 13.5% Cr steel are 1.8 GPa, 88.6 MPa√m, and 58.5 J, respectively. 13.5%Cr steel possesses larger grain size and fewer undissolved M6C carbides than 8%Cr and10%Cr steels, which is attributed to that Cr addition increases Cr content in the (Mo,Cr)6C, reducing the dissolution temperature and ability to inhibit grain growth. Cr significantly decreases the Martensite start (Ms) temperature from 263 to 53.1 °C and increases the retained austenite from 0.3 to 13.19 vol%. Cr increases the number density and diameter of nanoscale M2C, which is attributed to Cr promoting the dissolution of Mo and increasing the nucleation rate. Meanwhile, the higher Cr content also increases the growth rate of the carbides along the diameter direction. Cr addition reduces the contribution from coherency strengthening caused by decreased lattice misfit and increased the contribution of Orowan dislocation looping resulted from higher volume fraction and size of M2C.
{"title":"Effect of Cr on the Microstructure and Strength‐Toughness of High‐Strength and Heat‐Resistant Stainless Steel","authors":"Hongxiao Chi, Liping Pian, Jinbo Gu, Yong Sun, Xuedong Pang, Zhenfei Xin, Dangshen Ma","doi":"10.1002/srin.202400412","DOIUrl":"https://doi.org/10.1002/srin.202400412","url":null,"abstract":"The effect of Cr content on the microstructure and mechanical properties of CSS‐42L steel is investigated by X‐ray diffractometer, scanning electron microscopy, and transmission electron microscopy. The results show that increasing Cr from 8% to 13.5% significantly improves toughness and ductility while moderately decreasing the strength. The tensile strength, fracture toughness (K<jats:sub>IC</jats:sub>), and impact absorbing energy of 13.5% Cr steel are 1.8 GPa, 88.6 MPa√m, and 58.5 J, respectively. 13.5%Cr steel possesses larger grain size and fewer undissolved M<jats:sub>6</jats:sub>C carbides than 8%Cr and10%Cr steels, which is attributed to that Cr addition increases Cr content in the (Mo,Cr)<jats:sub>6</jats:sub>C, reducing the dissolution temperature and ability to inhibit grain growth. Cr significantly decreases the Martensite start (Ms) temperature from 263 to 53.1 °C and increases the retained austenite from 0.3 to 13.19 vol%. Cr increases the number density and diameter of nanoscale M<jats:sub>2</jats:sub>C, which is attributed to Cr promoting the dissolution of Mo and increasing the nucleation rate. Meanwhile, the higher Cr content also increases the growth rate of the carbides along the diameter direction. Cr addition reduces the contribution from coherency strengthening caused by decreased lattice misfit and increased the contribution of Orowan dislocation looping resulted from higher volume fraction and size of M<jats:sub>2</jats:sub>C.","PeriodicalId":21929,"journal":{"name":"steel research international","volume":null,"pages":null},"PeriodicalIF":2.2,"publicationDate":"2024-08-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142219502","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 control of MnS inclusions is crucial in developing high‐quality nonquenched and tempered steel. Single‐pass compression experiments are conducted on F40MnVS steel using a Gleeble‐3800 thermomechanical simulation testing machine, and the hot deformation behaviors of MnS inclusions at temperatures of 950–1150 °C and strain rates of 0.01 s−1 are investigated. Based on the experimental results of hot deformation, the steel is isothermally homogenized after forging to study the effect of holding time on the morphology and characteristics of MnS. Results indicate that at a lower deformation temperature of 950 °C and increased deformation, the relative plasticity of MnS diminishes, reducing the aspect ratio from 3.38 to 1.44 and primarily causing MnS fragmentation. At 1150 °C, as deformation increases, the relative plasticity of MnS also increases, with the aspect ratio rising from 1.46 to 2.01, leading to the growth of MnS. Under either low temperature and high deformation conditions or high temperature and low deformation, MnS fragmentation is more pronounced, resulting in more spherical MnS. With extended homogenization time, elongated MnS fractures, progressively transforming into spheroidal or ellipsoidal shapes before enlarging. The diffusion of S primarily controls the fracture and growth of MnS during isothermal heating.
{"title":"Morphological Evolution of MnS During Hot Deformation and Isothermal Homogenization in Nonquenched and Tempered F40MnVS Grade Steel","authors":"Guoxing Qiu, Hongzhao Zhang, Feng Lu, Dejun Miao, Yongkun Yang, Xiaoming Li","doi":"10.1002/srin.202400574","DOIUrl":"https://doi.org/10.1002/srin.202400574","url":null,"abstract":"The control of MnS inclusions is crucial in developing high‐quality nonquenched and tempered steel. Single‐pass compression experiments are conducted on F40MnVS steel using a Gleeble‐3800 thermomechanical simulation testing machine, and the hot deformation behaviors of MnS inclusions at temperatures of 950–1150 °C and strain rates of 0.01 s<jats:sup>−1</jats:sup> are investigated. Based on the experimental results of hot deformation, the steel is isothermally homogenized after forging to study the effect of holding time on the morphology and characteristics of MnS. Results indicate that at a lower deformation temperature of 950 °C and increased deformation, the relative plasticity of MnS diminishes, reducing the aspect ratio from 3.38 to 1.44 and primarily causing MnS fragmentation. At 1150 °C, as deformation increases, the relative plasticity of MnS also increases, with the aspect ratio rising from 1.46 to 2.01, leading to the growth of MnS. Under either low temperature and high deformation conditions or high temperature and low deformation, MnS fragmentation is more pronounced, resulting in more spherical MnS. With extended homogenization time, elongated MnS fractures, progressively transforming into spheroidal or ellipsoidal shapes before enlarging. The diffusion of S primarily controls the fracture and growth of MnS during isothermal heating.","PeriodicalId":21929,"journal":{"name":"steel research international","volume":null,"pages":null},"PeriodicalIF":2.2,"publicationDate":"2024-08-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142219498","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}
Daohua Bao, Guoguang Cheng, Jinwen Zhang, Zhixiang Wang, Wei Li, Yao Li, Tao Zhang
The characteristics, formation mechanism, and removal of large‐sized CaO–Al2O3–SiO2 inclusions in D2 high‐speed railway wheel steel are investigated. Large‐sized CaO–Al2O3–SiO2 inclusions are present in the continuous casting billet, with SiO2 and CaO content ranging from 5 to 15 and 30 to 65 wt%, respectively. The size mainly exceeds 10 μm. These inclusions originate from the calcium‐treatment stage of the refining process, during which liquid CaO–Al2O3–SiO2 inclusions are formed in the liquid steel. The contact angle between these inclusions and the liquid steel is below 40°, which results in excellent wettability. Consequently, the inclusions are difficult to remove from the liquid steel and are thus inherited into the billet. By reducing the SiO2 content and controlling CaO content between 8 and 30 wt%, small‐sized inclusions are formed. This requires reasonable control of the Al and Ca content in the liquid steel. When the Al and Ca content in liquid steel is maintained at 0.012 wt% and 8 ppm, respectively, the inclusions in the billet are mainly CaO·6Al2O3 (CA6) and CaO·2Al2O3 (CA2), both under 5 μm in size. These inclusions represent the suitable inclusions in steel.
{"title":"Characteristics, Formation Mechanism, and Removal of Large‐Sized CaO–Al2O3–SiO2 Inclusions in D2 High‐Speed Railway Wheel Steel","authors":"Daohua Bao, Guoguang Cheng, Jinwen Zhang, Zhixiang Wang, Wei Li, Yao Li, Tao Zhang","doi":"10.1002/srin.202400497","DOIUrl":"https://doi.org/10.1002/srin.202400497","url":null,"abstract":"The characteristics, formation mechanism, and removal of large‐sized CaO–Al<jats:sub>2</jats:sub>O<jats:sub>3</jats:sub>–SiO<jats:sub>2</jats:sub> inclusions in D2 high‐speed railway wheel steel are investigated. Large‐sized CaO–Al<jats:sub>2</jats:sub>O<jats:sub>3</jats:sub>–SiO<jats:sub>2</jats:sub> inclusions are present in the continuous casting billet, with SiO<jats:sub>2</jats:sub> and CaO content ranging from 5 to 15 and 30 to 65 wt%, respectively. The size mainly exceeds 10 μm. These inclusions originate from the calcium‐treatment stage of the refining process, during which liquid CaO–Al<jats:sub>2</jats:sub>O<jats:sub>3</jats:sub>–SiO<jats:sub>2</jats:sub> inclusions are formed in the liquid steel. The contact angle between these inclusions and the liquid steel is below 40°, which results in excellent wettability. Consequently, the inclusions are difficult to remove from the liquid steel and are thus inherited into the billet. By reducing the SiO<jats:sub>2</jats:sub> content and controlling CaO content between 8 and 30 wt%, small‐sized inclusions are formed. This requires reasonable control of the Al and Ca content in the liquid steel. When the Al and Ca content in liquid steel is maintained at 0.012 wt% and 8 ppm, respectively, the inclusions in the billet are mainly CaO·6Al<jats:sub>2</jats:sub>O<jats:sub>3</jats:sub> (CA<jats:sub>6</jats:sub>) and CaO·2Al<jats:sub>2</jats:sub>O<jats:sub>3</jats:sub> (CA<jats:sub>2</jats:sub>), both under 5 μm in size. These inclusions represent the suitable inclusions in steel.","PeriodicalId":21929,"journal":{"name":"steel research international","volume":null,"pages":null},"PeriodicalIF":2.2,"publicationDate":"2024-08-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142227404","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}
Yuanyou Xiao, Lei Cao, Guocheng Wang, Daxian Zhang, Jianzhong He
Seven types of inclusions are observed in the Al‐deoxidized steel followed by Ti‐deoxidized steel, while ten types of inclusions are found in Al–Ti simultaneous deoxidized steel. Three special inclusions are only found in Al‐deoxidized steel followed by Ti‐deoxidized steel as Al2TiO5–TixOy, Al2TiO5–Al2O3–TiS, and Al2TiO5–Al2O3–TixOy–TiS. The precipitation order of inclusions in Al–Ti‐deoxidized steel is very dependent on the value of [%Ti]/[%Al] or [%S]/[%O]. The critical value of [%Ti]/[%Al] for the precipitation of inclusions from large to small is TixOy > Al2TiO5 > Al2O3, and the critical value of [%S]/[%O] for the precipitation of inclusions from large to small is TiS > TixOy. The critical value of [%Ti]/[%Al] for the precipitation of TixOy prior to Al2TiO5, and the precipitation of Al2TiO5 prior to Al2O3 has a close relationship with the content of [%Al]. In addition, the critical value of [%S]/[%O] for the precipitation of TiS prior to TixOy inclusions increases with an increasing content of [%O] and increased with the decreasing of temperature. The precipitation order of inclusions in the two types of steel is Al2TiO5 or Al2O3 → Ti3O5 → TiO2 → Ti2O3 → TiS.
{"title":"Evolution Pathway of Competitive Precipitation of Inclusions in Al–Ti‐Deoxidized Steel","authors":"Yuanyou Xiao, Lei Cao, Guocheng Wang, Daxian Zhang, Jianzhong He","doi":"10.1002/srin.202400500","DOIUrl":"https://doi.org/10.1002/srin.202400500","url":null,"abstract":"Seven types of inclusions are observed in the Al‐deoxidized steel followed by Ti‐deoxidized steel, while ten types of inclusions are found in Al–Ti simultaneous deoxidized steel. Three special inclusions are only found in Al‐deoxidized steel followed by Ti‐deoxidized steel as Al<jats:sub>2</jats:sub>TiO<jats:sub>5</jats:sub>–Ti<jats:sub><jats:italic>x</jats:italic></jats:sub>O<jats:sub><jats:italic>y</jats:italic></jats:sub>, Al<jats:sub>2</jats:sub>TiO<jats:sub>5</jats:sub>–Al<jats:sub>2</jats:sub>O<jats:sub>3</jats:sub>–TiS, and Al<jats:sub>2</jats:sub>TiO<jats:sub>5</jats:sub>–Al<jats:sub>2</jats:sub>O<jats:sub>3</jats:sub>–Ti<jats:sub><jats:italic>x</jats:italic></jats:sub>O<jats:sub><jats:italic>y</jats:italic></jats:sub>–TiS. The precipitation order of inclusions in Al–Ti‐deoxidized steel is very dependent on the value of [%Ti]/[%Al] or [%S]/[%O]. The critical value of [%Ti]/[%Al] for the precipitation of inclusions from large to small is Ti<jats:sub><jats:italic>x</jats:italic></jats:sub>O<jats:sub><jats:italic>y</jats:italic></jats:sub> > Al<jats:sub>2</jats:sub>TiO<jats:sub>5</jats:sub> > Al<jats:sub>2</jats:sub>O<jats:sub>3</jats:sub>, and the critical value of [%S]/[%O] for the precipitation of inclusions from large to small is TiS > Ti<jats:sub><jats:italic>x</jats:italic></jats:sub>O<jats:sub><jats:italic>y</jats:italic></jats:sub>. The critical value of [%Ti]/[%Al] for the precipitation of Ti<jats:sub><jats:italic>x</jats:italic></jats:sub>O<jats:sub><jats:italic>y</jats:italic></jats:sub> prior to Al<jats:sub>2</jats:sub>TiO<jats:sub>5</jats:sub>, and the precipitation of Al<jats:sub>2</jats:sub>TiO<jats:sub>5</jats:sub> prior to Al<jats:sub>2</jats:sub>O<jats:sub>3</jats:sub> has a close relationship with the content of [%Al]. In addition, the critical value of [%S]/[%O] for the precipitation of TiS prior to Ti<jats:sub><jats:italic>x</jats:italic></jats:sub>O<jats:sub><jats:italic>y</jats:italic></jats:sub> inclusions increases with an increasing content of [%O] and increased with the decreasing of temperature. The precipitation order of inclusions in the two types of steel is Al<jats:sub>2</jats:sub>TiO<jats:sub>5</jats:sub> or Al<jats:sub>2</jats:sub>O<jats:sub>3</jats:sub> → Ti<jats:sub>3</jats:sub>O<jats:sub>5</jats:sub> → TiO<jats:sub>2</jats:sub> → Ti<jats:sub>2</jats:sub>O<jats:sub>3</jats:sub> → TiS.","PeriodicalId":21929,"journal":{"name":"steel research international","volume":null,"pages":null},"PeriodicalIF":2.2,"publicationDate":"2024-08-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142219499","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}
Siva Sai Krishna Dasari, Henry Adekola Haffner, K. Chandrashekhara, Mario F. Buchley, Simon N. Lekakh, Ronald J. O’Malley
Hot rolling processes have been extensively used to produce round bars by reducing the cross‐sectional area of continuously cast steel. The current trend toward increasing productivity often requires a more aggressive reduction per pass. Establishing safe and optimized hot rolling parameters must be determined to avoid damage while deforming the specific steel composition. Understanding the damage mechanism during the metal forming process is vital for product quality. Herein, a combined experimental and simulation approach is developed to track the evolution potential damage during hot bar rolling. Hot tension tests are conducted on as‐cast vanadium microalloyed 15V38 steel at different hot rolling temperatures and strain rate conditions to develop Johnson–Cook‐type material model. A thermomechanical finite element model is developed to simulate potential damage trends in a 12‐pass square‐to‐round and 8‐pass round‐to‐round standard industrial hot rolling process, employing damage criteria. Results are illustrated by creating a damage map at each rolling pass to determine the critical hot rolling conditions for damage initiation. Several parametric studies are also performed to illustrate the application of the suggested methodology for hot rolling process optimization. Results show that the probability of the damage initiation is higher at higher pass reductions and lower temperatures.
{"title":"Damage Initiation of 15V38 Steel Bar during Square‐to‐Round Hot Rolling Process","authors":"Siva Sai Krishna Dasari, Henry Adekola Haffner, K. Chandrashekhara, Mario F. Buchley, Simon N. Lekakh, Ronald J. O’Malley","doi":"10.1002/srin.202400344","DOIUrl":"https://doi.org/10.1002/srin.202400344","url":null,"abstract":"Hot rolling processes have been extensively used to produce round bars by reducing the cross‐sectional area of continuously cast steel. The current trend toward increasing productivity often requires a more aggressive reduction per pass. Establishing safe and optimized hot rolling parameters must be determined to avoid damage while deforming the specific steel composition. Understanding the damage mechanism during the metal forming process is vital for product quality. Herein, a combined experimental and simulation approach is developed to track the evolution potential damage during hot bar rolling. Hot tension tests are conducted on as‐cast vanadium microalloyed 15V38 steel at different hot rolling temperatures and strain rate conditions to develop Johnson–Cook‐type material model. A thermomechanical finite element model is developed to simulate potential damage trends in a 12‐pass square‐to‐round and 8‐pass round‐to‐round standard industrial hot rolling process, employing damage criteria. Results are illustrated by creating a damage map at each rolling pass to determine the critical hot rolling conditions for damage initiation. Several parametric studies are also performed to illustrate the application of the suggested methodology for hot rolling process optimization. Results show that the probability of the damage initiation is higher at higher pass reductions and lower temperatures.","PeriodicalId":21929,"journal":{"name":"steel research international","volume":null,"pages":null},"PeriodicalIF":2.2,"publicationDate":"2024-08-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142219500","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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