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Improvement of tundish shape and optimization of flow control devices for sequence casting heavy steel ingots 被引量:10
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作者 Guang-hua Wen Yong-feng Huang +1 位作者 Ping Tang Ming-mei Zhu 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 2012年第1期15-20,共6页
The metallurgical effect of a round tundish used to cast heavy steel ingots in machine works at present was evaluated through water modeling experiments. The flow control devices of the improved oval tundish, which wa... The metallurgical effect of a round tundish used to cast heavy steel ingots in machine works at present was evaluated through water modeling experiments. The flow control devices of the improved oval tundish, which was used instead of the round tundish, had been optimized. The results show that the residence time of the round tundish is short, its inclusion removal efficiency is too low, and it has more dead zones and an unreasonable flow field. Compared with the round tundish, the improved oval tundish with the optimized weir and dam has a better effect: its minimum residence time is prolonged by 38.1 s, the average residence time is prolonged by 233.4 s, its dead volume fraction decreases from 26% to 15%, and the ratio of plug volume fraction to dead volume fraction increases from 0.54 to 1.27. The inclusion removal efficiency also increases by 17.5%. 展开更多
关键词 TUNDISH steel ingots water modeling flow control devices INCLUSIONS
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Numerical simulation of macrosegregation in steel ingots using a two-phase model 被引量:9
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作者 Wen-sheng Li Hou-fa Shen Bai-cheng Liu 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 2012年第9期787-794,共8页
A two-phase model for the prediction of macrosegregation formed during solidification is presented. This model incorporates the descriptions of heat transfer, melt convection, solute transport, and solid movement on t... A two-phase model for the prediction of macrosegregation formed during solidification is presented. This model incorporates the descriptions of heat transfer, melt convection, solute transport, and solid movement on the system scale with microscopic relations for grain nucleation and growth. Then the model is used to simulate the solidification of a benchmark industrial 3.3-t steel ingot. Simulations are per- formed to investigate the effects of grain motion and pipe shrinkage formation on the final macrosegregation pattern. The model predictions are compared with experimental data and numerical results from literatures. It is demonstrated that the model is able to express the overall macrosegregation patterns in the ingot. Furthermore, the results show that it is essential to consider the motion of equiaxed grains and the formation of pipe shrinkage in modelling. Several issues for future model improvements are identified. 展开更多
关键词 steel ingots SOLIDIFICATION SEGREGATION SHRINKAGE modelling
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Effects of hot top pulsed magneto-oscillation on solidification structure of steel ingot 被引量:12
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作者 Hui-cheng Li Yu-xiang Liu +2 位作者 Yun-hu Zhang Zhen Liu Qi-jie Zhai 《China Foundry》 SCIE 2018年第2期110-116,共7页
Achieving a uniform structure with few defects in heavy steel ingot is of high commercial importance. In this present work, in order to verify the potential of pulsed magneto-oscillation(PMO) applied in the production... Achieving a uniform structure with few defects in heavy steel ingot is of high commercial importance. In this present work, in order to verify the potential of pulsed magneto-oscillation(PMO) applied in the production of heavy ingot, an induction coil was located at the hot top of the steel ingot to develop a novel technique, named hot top pulsed magneto oscillation(HPMO). The influences of HPMO on the solidification structure, macro segregation and compactness of a cylindrical medium carbon steel ingot with the weight of 160 kg were systematically investigated by optical microscope(OM) and laser induced breakdown spectroscopy original position metal analyzer(LIBSOPA-100). The results show that HPMO not only causes significant grain refinement and promotes the occurrence of columnar to equiaxed transition(CET) but also can homogenize the carbon distribution and enhance the compactness of the steel ingot. Therefore, HPMO technique has the potential to be applied in the production of heavy steel ingots on an industrial scale. 展开更多
关键词 hot-top pulsed magneto oscillation(HPMO) solidified structures defects of steel ingot
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Simulation of macrosegregation in a 36-t steel ingot using a multiphase model 被引量:4
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作者 Zhuo Chen Hou-fa Shen 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 2020年第2期200-209,共10页
Macrosegregation is the major defect in large steel ingots caused by solute partitioning and melt convection during casting.In this study,a three-phase(liquid,columnar dendrites,and equiaxed grains)model is proposed t... Macrosegregation is the major defect in large steel ingots caused by solute partitioning and melt convection during casting.In this study,a three-phase(liquid,columnar dendrites,and equiaxed grains)model is proposed to simulate macrosegregation in a 36-t steel ingot.A supplementary set of conservation equations are employed in the model such that two types of equiaxed grains,either settling or adhering to the solid shell,are well simulated.The predicted concentration agrees quantitatively with the experimental value.A negative segregation cone was located at the bottom owing to the grain settlement and solute-enriched melt leaving from the mushy zone.The interdendritic liquid flow was carefully analyzed,and the formation of A-type segregations in the mid-height of the ingot is discussed.Negative segregation was observed near the riser neck due to the specific relationship between flow direction and temperature gradient.Additionally,the as-cast macrostructure of the ingot is presented,including the grain size distribution and columnar–equiaxed transition. 展开更多
关键词 MACROSEGREGATION multiphase model TRANSPORTATION SOLIDIFICATION steel ingot
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Numerical simulation of central shrinkage crack formation in a 234-t steel ingot 被引量:5
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作者 Jing-an Yang Yue-qiao Wang +1 位作者 Hou-fa Shen Bai-cheng Liu 《China Foundry》 SCIE 2017年第5期365-372,共8页
Central shrinkage crack is a common defect encountered in steel ingot casting. It is necessary to limit the degree of crack in case of further propagation in forging. A 234-t steel ingot was dissected to check the int... Central shrinkage crack is a common defect encountered in steel ingot casting. It is necessary to limit the degree of crack in case of further propagation in forging. A 234-t steel ingot was dissected to check the internal quality, and a central shrinkage crack band of 1,400 mm in height and 120 mm in width, was found at a distance of 450 mm under the riser bottom line. Then, thermo-mechanical simulation using an elasto-viscoplastic finite-element model was conducted to analyze the stress-strain evolution during ingot solidification. A new criterion considering mush mechanical property in the brittle temperature range as well as shrinkage porosity was used to identify the shrinkage crack potential, where the degree of shrinkage porosity is regarded as a probability factor using a modified sigmoid function. Different casting processes, such as pouring speed, mould preheating and riser insulation, were optimized with the simulation model. The results show that fast pouring, proper mould preheating and good riser insulation can alleviate shrinkage crack potential in the ingot center. 展开更多
关键词 shrinkage crack FINITE-ELEMENT crack potential thermo-mechanical simulation steel ingot
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Numerical simulation on multiple pouring process for a 292 t steel ingot 被引量:5
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作者 Tu Wutao Zhang Xiong +1 位作者 Shen Houfa Liu Baicheng 《China Foundry》 SCIE CAS 2014年第1期52-58,共7页
A ladle-tundish-mould transportation model considering the entire multiple pouring(MP) process is proposed. Numerical simulation is carried out to study the carbon distribution and variation in both the tundish and th... A ladle-tundish-mould transportation model considering the entire multiple pouring(MP) process is proposed. Numerical simulation is carried out to study the carbon distribution and variation in both the tundish and the mould for making a 292 t steel ingot. Firstly, the fluid flow as well as the heat and mass transfer of the molten steel in the tundish is simulated based on the multiphase transient turbulence model. Then, the carbon mixing in the mould is calculated by using the species concentration at the tundish outlet as the inlet condition during the teeming process. The results show a high concentration of carbon at the bottom and a low concentration of carbon at the top of the mould after a MP process with carbon content high in the first ladle and low in the last ladle. Such carbon concentration distribution would help reduce the negative segregation at the bottom and the positive segregation at the top of the solidified ingot. 展开更多
关键词 multiple pouring TRANSPORTATION numerical simulation large steel ingot
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Teeming stream protection using an argon shroud during casting of steel ingots 被引量:3
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作者 Chao-jie Zhang Yan-ping Bao +1 位作者 Min Wang Le-chen Zhang 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 2017年第1期47-54,共8页
Two kinds of argon shroud protection devices with two different basic structures were designed and investigated. Industrial experiments and numerical simulations were used to examine the protection effect, and the mec... Two kinds of argon shroud protection devices with two different basic structures were designed and investigated. Industrial experiments and numerical simulations were used to examine the protection effect, and the mechanism of air entrapment during the casting of steel ingots was analyzed. The influence of the structure of the argon shroud protection device on the protection effect was investigated. An argon shroud protection device mounted to the nozzle holder on the bottom of the ladle does not provide a good protection effect because air can easily flow into the teeming system and cause reoxidation of molten steel during teeming. By contrast, an argon shroud protection device seated on the top of the central trumpet provides an excellent protection effect, where air has little chance of flowing into the teeming system during casting. The feasibilities of the argon shroud protection devices are discussed. 展开更多
关键词 steel ingots ingot casting teeming protection devices REOXIDATION
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NUMERICAL SIMULATION OF MACRO-SEGREGATION IN STEEL INGOT DURING SOLIDIFICATION 被引量:3
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作者 C.W.Ma H.F.Shen +1 位作者 T.Y.Huang B.C.Liu 《Acta Metallurgica Sinica(English Letters)》 SCIE EI CAS CSCD 2004年第3期288-294,共7页
A mathematical model coupling the momentum, energy and species conservation equa-tions was proposed to calculate the macro--segregation of Fe--C alloy ingot during solid-ification. The corresponding simulation softwar... A mathematical model coupling the momentum, energy and species conservation equa-tions was proposed to calculate the macro--segregation of Fe--C alloy ingot during solid-ification. The corresponding simulation software which concurrently solves the macro-scopic mass, momentum, energy and species conservation equations has been developedby applying the SIMPLE algorithm.The thermo--solutal convection in a NH_4 Cl--H_2O ingot is verified and the result showsgood agreement with that reported. Then macro--segregation in a steel ingot is simu-lated by using the developed program. The steel ingot is in a rectangular mold with ariser. The fluid flow is mainly induced by the temperature field and the solid fraction.The macro--segregation pattern is mainly affected by the thermo--induced convectionin the mushy zone. The negative segregation forms along the walls of the casting.The positive segregation forms at the top center of the casting into the riser. Thespecies concentration reaches the peak in the center of the ingot where solidificationends lastly. 展开更多
关键词 macro-segregation thermo-solutal convection steel ingot numerical simulation
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Electro-Pulse on Improving Steel Ingot Solidification Structure 被引量:3
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作者 Yong Tang Jianzhong Wang Daqing Cang(Metallurgy School, University of Science and Technology Beijing, Beijing 100083, China) 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 1999年第2期94-96,共3页
Pulse Electric Discharging (PED) is a novel technique that can modify solidifying structure and reduce grain size. ItS effectsapplied to the high carbon liquid steel were presented here. The macrostructure and microst... Pulse Electric Discharging (PED) is a novel technique that can modify solidifying structure and reduce grain size. ItS effectsapplied to the high carbon liquid steel were presented here. The macrostructure and microstructure of the high carbon alloy steel werealso observed. Results show that (1 ) the length of columnar crystal at the edge of ingot without PED treatment is much longer than thatwith PED, and (2) the perlite lamellae of steel billets after deposed by PED are twisted and shortened. An explanation of those experimental results is given. 展开更多
关键词 electro-pulse solidification structure steel ingot
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Internal shrinkage crack in a 10 t water-cooled steel ingot with a large height-to-diameter ratio
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作者 Jing-an Yang Hou-fa Shen 《China Foundry》 SCIE CAS 2021年第2期110-117,共8页
Steel ingot with a large height-to-diameter ratio is utilized to produce multiple products by one stock in practice.Water cooling is a usual way to enhance production efficiency.However,the combination of the two fact... Steel ingot with a large height-to-diameter ratio is utilized to produce multiple products by one stock in practice.Water cooling is a usual way to enhance production efficiency.However,the combination of the two factors will generate internal defects,such as shrinkage porosity and hot crack.The characteristic of internal shrinkage crack in a 10 t water-cooled steel ingot with a large height-to-diameter ratio was examined by an ultrasonic test.A slice was sectioned from the ingot middle part where billets containing star-like crack were further extracted.The billets were examined by X-ray high energy industrial CT,and the compactness was reconstructed in three dimensions.Microstructure near the crack was observed using scanning electron microscopy,and the solidification process and grain size were studied by high temperature confocal microscopy.Moreover,thermo-mechanical simulation and post-processing were carried out to analyze the formation of shrinkage porosity and hot crack.A new criterion considering mushy zone mechanical behavior in brittle temperature as well as grain size distribution was proposed to evaluate hot cracking potential in the ingot.The results show that a deep shrinkage porosity band easily forms in the center line of such an ingot with a large height-to-diameter ratio,and water-cooling further generates excessive tensile stress tearing the liquid films around the porosities.Then,hot cracks begin to propagate along grain boundaries.The grain size in the upper and center of the ingot is large,which leads to an inverted cone shape defects zone in the ingot center. 展开更多
关键词 steel ingot POROSITY hot crack industrial CT thermo-mechanical simulation
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Finite element modeling of macrosegregation coupled with shrinkage cavity in steel ingots using arbitrary Lagrangian-Eulerian model
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作者 Kang-xin Chen Hao Shi Hou-fa Shen 《China Foundry》 SCIE 2019年第5期291-299,共9页
Shrinkage cavity has significant influence on macrosegregation in steel ingots. An arbitrary Lagrangian-Eulerian (ALE) model based on volume averaging method is developed to predict the coupled formation progress of m... Shrinkage cavity has significant influence on macrosegregation in steel ingots. An arbitrary Lagrangian-Eulerian (ALE) model based on volume averaging method is developed to predict the coupled formation progress of macrosegregation and shrinkage cavity during solidification of steel ingots. The combined effect of thermal-solutal convection and solidification shrinkage on macrosegregation is considered in the model. A specially designed mesh update algorithm is proposed to consider the formation of shrinkage cavity. The streamline-upwind/Petrov–Galerkin (SUPG) stabilized finite element algorithm is adopted to solve the conservation equations. Two solution methods for the energy conservation equation are proposed, i.e. the temperature-based solver and enthalpy-based solver. A Pb-48wt.%Sn solidification benchmark is used for validation. Then, the ALE model is applied to a Fe-3.6wt.%C industrial steel ingot. The formation progress of macrosegregation coupled with shrinkage cavity is predicted. By comparison with the predictions of the finite element model and finite volume model, the effect of shrinkage cavity formation on macrosegregation is investigated. Results show that the formation of shrinkage cavity can significantly change the segregation region and segregation degree at the hot top. It is demonstrated that the ALE model can predict the coupled formation of macrosegregation and shrinkage cavity in steel ingots. 展开更多
关键词 steel ingot MACROSEGREGATION SHRINKAGE cavity ALE model finite element modeling
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Industrial test of a 6-m long bearing steel ingot by electroslag remelting withdrawing process
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作者 Xi-min Zang Tian-yu Qiu +2 位作者 Xin Deng Zhou-hua Jiang Hua-bing Li 《China Foundry》 SCIE CAS 2015年第3期202-207,共6页
In this study, the key technologies of a 6-m long bearing steel ingot produced by electroslag remelting withdrawing(ESRW) process, including bifilar mode supply, slag system development, and design of mold, were studi... In this study, the key technologies of a 6-m long bearing steel ingot produced by electroslag remelting withdrawing(ESRW) process, including bifilar mode supply, slag system development, and design of mold, were studied based on the laboratory research achievements. The 6-m long ingot of bearing steel GGr15 with a cross-section of 300 mm × 340 mm was produced using the ESRW process with a bifilar mode and a multi-taper T-mold in a plant. The testing results show that the melting rate using the ESRW bifilar mode technology is three times faster than traditional electroslag remelting(ESR), and the power consumption is only 1,320 k Wh per ton steel. Through testing for the chemical composition, macrostructure and inclusions of remelted ingot, it can be concluded that the ESRW bifilar mode technology not only retains the characteristics of traditional ESR, but also improves the production efficiency and reduces the cost compared to traditional ESR. 展开更多
关键词 electroslag remelting withdrawing bifilar mode slag leakage and steel leakage slag physicochemical properties ingot solidification shrinkage
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Influence of Mould and Insulation Design on Soundness of Tool Steel Ingot by Numerical Simulation 被引量:9
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作者 M Heidarzadeh H Keshmiri 《Journal of Iron and Steel Research International》 SCIE EI CAS CSCD 2013年第7期78-83,共6页
The solidification of 4.4 t cold work tool steel ingot type X210Crl2 was simulated by Magma software. By the reduction of ingot height, solidification modeling and pouring of a new 3 t ingot were performed and decreas... The solidification of 4.4 t cold work tool steel ingot type X210Crl2 was simulated by Magma software. By the reduction of ingot height, solidification modeling and pouring of a new 3 t ingot were performed and decreasing the porosity formation potential in 3 t ingot in comparison with 4.4 t ingot on the basis of Niyama criterion was ob-served which was in good accordance with experimental data. In order to produce sound ingot, a new 2.8 t ingot mould was designed which includes some parameteric changes in mould such as mould slope, slenderness ratio, mould concavity radius, fillet radius of mould internal corners and feeding diameter to ingot upper diameter ratio. Furthermore, the effects of insulating between kokil and feeding ring and also insulating the outer surface of feeding ring as well as insulating the outer surface of one third of kokil upper part on eenterline porosity formation were in-vestigated in both 2.8 and 4.4 t ingots. The results show that the ingot which was produced in new designed 2.8 t mould has a better Niyama pattern and the centerline porosities were eliminated. 展开更多
关键词 numerical modeling steel ingot mould parameter POROSITY
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A Numerical Study of the Effect of Multiple Pouring on Macrosegregation in a 438-Ton Steel Ingot 被引量:3
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作者 Zhen-Hu Duan Hou-Fa Shen Bai-Cheng Liu 《Acta Metallurgica Sinica(English Letters)》 SCIE EI CAS CSCD 2015年第9期1123-1133,共11页
In present paper, a ladle-tundish-mold CFD model and a macrosegregation model were utilized to investigate the effects of the multiple pouring (MP) process on the macrosegregation in a 438-ton steel ingot. Firstly, ... In present paper, a ladle-tundish-mold CFD model and a macrosegregation model were utilized to investigate the effects of the multiple pouring (MP) process on the macrosegregation in a 438-ton steel ingot. Firstly, the model was partially proved as compared to the measured carbon distributions along the transverse sections in the riser of ingot. Then, the comparison between the single pouring (SP) and MP process has been carried out to study their influences on the macrosegregation in ingot. Besides, the predicted macrosegregation results in MP process which introduced the improved riser fixed with an insulating sleeve were compared with that in traditional MP process. The traditional MP process leads to certain favorable initial carbon distribution in the mold, which has some favorable influence on suppressing the positive segregation in ingot. The holding time of the low carbon in the riser is the main factor to suppress the positive segregation in ingot. Improved insulating sleeve can prolong the holding time of the low carbon in the riser and release the positive segregation in the riser of ingot. Improvement of the insulating effect of the riser is an efficient method to control macrosegregation in large steel ingot. 展开更多
关键词 Multiple pouring process MACROSEGREGATION Numerical simulation Large steel ingot
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A review on prediction of casting defects in steel ingots:from macrosegregation to multi-defect model 被引量:3
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作者 Jun Li Xiao-wei Xu +2 位作者 Neng Ren Ming-xu Xia Jian-guo Li 《Journal of Iron and Steel Research International》 SCIE EI CAS CSCD 2022年第12期1901-1914,共14页
Due to the nature of the solute redistribution,the reduction in the solidification rate with time in a square root relationship,and the multiphase melt flow during the solidification,casting defects such as macrosegre... Due to the nature of the solute redistribution,the reduction in the solidification rate with time in a square root relationship,and the multiphase melt flow during the solidification,casting defects such as macrosegregation,shrinkage cavity,and porosity will inevitably occur in the steel ingot and intensify with the increase in ingot size.These defects directly affect the performance of the final product and severely restrict the choice of subsequent thermal processing methods and process windows.Therefore,the solidification defects including macrosegregation,shrinkage/porosity,and inclusions encountered in the preparation of large steel ingots and their formation mechanisms were reviewed.The development progress and the latest development of the macrosegregation model for steel ingots were introduced in detail,especially the latest progress in the coupling prediction of macrosegregation and shrinkage as well as macrosegregation and inclusions.Some methods to reduce macrosegregation of ingots were discussed as well.Finally,a new casting method called layered casting was introduced in detail.This method can effectively improve the uniformity of the macrostructure and reduce the macrosegregation of the large ingots and therefore is a promising method for preparing large ingots with high homogeneity. 展开更多
关键词 steel ingot MACROSEGREGATION Numerical modeling Multiphase model Solidification defect
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Application of heat absorption method to reduce macrosegregation during solidification of bearing steel ingot 被引量:2
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作者 Sheng Yu Long-qiang Zhu +6 位作者 Jin-hu Lai Ming-xu Pan Yue-yun Liu Wei-dong Xuan Jiang Wang Chuan-jun Li Zhong-ming Ren 《Journal of Iron and Steel Research International》 SCIE EI CAS CSCD 2022年第12期1915-1926,共12页
The control of macrosegregation is still a difficult problem for the production of large steel ingots.In order to develop new techniques for producing low-macrosegregation and high-quality steel ingots,the effect of t... The control of macrosegregation is still a difficult problem for the production of large steel ingots.In order to develop new techniques for producing low-macrosegregation and high-quality steel ingots,the effect of the heat absorption method(HAM)used by the inorganic material rods to cool the liquid steel on the formation of macrosegregation during solidification of a 5-t GCr15SiMn bearing steel ingot was studied using experiment and mathematical simulation.The inorganic material was a mixture of CaF2 and CaO.The levels of macrosegregation in the longitudinal sections of two ingots with and without HAM were compared.Experimental results showed that the application of HAM reduced the positive segregation in the upper part of the ingot and the negative segregation in the lower part.The levels of carbon segregation along the longitudinal centerline and horizontal direction at different heights were all alleviated and the fluctuation of carbon segregation was significantly reduced.The simulation results confirmed that the melting and floating of the inorganic material could carry the sensible heat to the top of the liquid steel quickly.This leads to the acceleration of the cooling rate of the liquid steel,thereby alleviating the level of macrosegregation. 展开更多
关键词 Large steel ingot MACROSEGREGATION Inorganic material Heat absorption method Mathematical simulation
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Numerical Simulation of Macrosegregation During Steel Ingot Solidification Using Continuum Model 被引量:1
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作者 王励 石伟 《Journal of Shanghai Jiaotong university(Science)》 EI 2011年第2期145-148,共4页
A continuum model is adopted to study the macrosegregation phenomena during solidification of large steel ingots.Evolution of temperature,melt velocity,and compositional concentration field during a 22 t steel ingot s... A continuum model is adopted to study the macrosegregation phenomena during solidification of large steel ingots.Evolution of temperature,melt velocity,and compositional concentration field during a 22 t steel ingot solidification are illustrated by using the finite volume method.Numerical results of temperature distribution are validated by experiments.The influence of local permeability relates to the friction that the melt experienced in mushy region is investigated.It is shown that the continuum model is able to predict the temperature field,and the variation of permeability obviously affects the melt flowing behavior and the final compositional distribution. 展开更多
关键词 continuum model steel ingot MACROSEGREGATION CONVECTION PERMEABILITY
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Practice and numerical simulation of ingot solidification for high-performance homogeneous steel
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作者 ZHANG Hao JIANG Chengbin 《Baosteel Technical Research》 CAS 2022年第2期42-47,共6页
A 40 t EAF+LF+VD→mold casting 20 t ingot→hot forging and heating process is employed to produce high-performance homogeneous steel.The solidification process of the 20 t ingot for the high-performance homogeneous st... A 40 t EAF+LF+VD→mold casting 20 t ingot→hot forging and heating process is employed to produce high-performance homogeneous steel.The solidification process of the 20 t ingot for the high-performance homogeneous steel was simulated by ProCAST casting simulation software.The distribution area and degree of segregation or porosity defects in the longitudinal section of the ingot were analyzed.The reason for the defect formation in the large-scale ingot for forging material was determined, which can be used as a guide for production.The results show that controlling the superheat of die casting and adding a riser heating agent improve ingot quality for forging high-performance homogeneous steel and that flaw detection defects are effectively controlled after forging. 展开更多
关键词 homogeneous steel steel ingot SHRINKAGE porosity defect
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Melting and floating processes of inorganic materials in molten steel:Visualization physical simulation and mathematical modelling
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作者 Jin-hu Lai Sheng Yu +4 位作者 Yang-jian Xu Dan-qing Jiang San-san Shuai Jiang Wang Zhong-ming Ren 《China Foundry》 SCIE CAS CSCD 2023年第2期89-98,共10页
It has been demonstrated that heat absorption method by using the inorganic material rod to cool the molten steel can significantly reduce the macrosegregation level of the large steel ingot.However,owing to the opaci... It has been demonstrated that heat absorption method by using the inorganic material rod to cool the molten steel can significantly reduce the macrosegregation level of the large steel ingot.However,owing to the opacity of the molten steel,the physical mechanism of the heat absorption method is not clear.In this work,a transparent hydraulic physical model with water and paraffin wax was built to simulate the melting and floating processes of inorganic materials in the molten steel.A mathematical simulation was also carried out to analyze the connection between the actual ingot and the physical model.Results show that it is feasible to simulate the molten steel and inorganic materials with water and paraffin wax.With the help of the physical model,the process of the melting of paraffin wax and its floating to the surface of water were clearly observed,during which the temperature of water at some characteristic positions in the mold was recorded.The visualization findings demonstrate that the melting and floating processes of paraffin wax can help to bring the heat from the center of the mold to the top surface more quickly,which reduces the superheat and significantly accelerates the cooling rate of water.The experimental results show that for the water with a certain superheat,the use of a larger mass of paraffin wax can accelerate the cooling of the water,but there is a risk of incomplete melting of the paraffin wax.A higher superheat of water will lead to a quicker melting rate for a given mass of paraffin wax,while a lower superheat leads to the incomplete melting of paraffin wax as well. 展开更多
关键词 water and paraffin wax heat absorption method physical simulation SUPERHEAT large steel ingot
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Quenching distortion induced by ingot segregation in gear steel 被引量:1
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作者 DING Yi QIN Ming AN Jinmin 《Baosteel Technical Research》 CAS 2013年第1期44-48,共5页
The influence of ingot segregation on quenching distortion of gear steel was investigated in this paper. The results show that the shape of ingot segregation of rod steel depends on the shape of continuous casting (C... The influence of ingot segregation on quenching distortion of gear steel was investigated in this paper. The results show that the shape of ingot segregation of rod steel depends on the shape of continuous casting (CC) molds ,and that the distortion of gear steel with square ingot segregation is uniform, while that of gear steel with rectangular ingot segregation is anisotropic. After quenching,the outer circle of the ring sample with a large rectangular segregation area is distorted into an oval shape. No obvious element segregation has been found in the rod steel produced through the rectangular CC mold. Obvious difference in density has been detected at the cross section of rod steel. It suggests that center porosity may be the main reason for the strong impact of segregation on heat treatment distortion of gear steel. 展开更多
关键词 gear steel QUENCHING DISTORTION ingot segregation SHAPE
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