圆坯中频电磁软接触连铸结晶器内磁场分布数值模拟

 用数值模拟方法研究了圆坯中频电磁软接触连铸结晶器内磁场分布,讨论改变结晶器结构参数、工艺参数和电参数等因素对结晶器内磁场的影响。结果表明,结晶器内磁场强度在结晶器高度方向上先增大再减小,在感应线圈中心偏下处,磁感应强度达最大;综合考虑结晶器结构和透磁性,切缝宽度选为05 mm,切缝数为8;当自由液面位于感应线圈的中心位置时能获得最大的磁感应强度;随着电流和频率的增加,结晶器内磁感应强度也随着增加。     

大方坯连铸M-EMS参数对磁场和流场分布的影响

采用数值模拟与现场实测相结合的方法,对大方坯结晶器电磁搅拌(M-EMS)过程进行了耦合数值模拟,研究了电磁搅拌参数及结晶器铜管厚度对钢液磁场和流场分布的影响。结果表明:当其他参数不变时,磁感应强度、电磁力和流速随着电流的增大而增加。磁感应强度随频率增加而减小,电磁力和流速随频率的增加而增大;且随着频率的增加,最大磁感应强度、电磁力和流速的变化值减小。对于连铸470mm×350mm大方坯,电磁搅拌电流和频率分别为550A和2Hz,结晶器铜板厚度为35mm时,能起到良好的电磁搅拌效果。     

双流低频电磁连铸过程中磁场分布的数值模拟

采用数值模拟的方法研究了双流低频电磁连铸过程中磁场分布规律.建立了单、双流低频电磁连铸中包括铸锭、结晶器、线圈和屏蔽罩的二维轴对称有限元模型.利用ANSYS软件包进行划分网格及计算,模拟出了磁场在连铸结晶器区域的分布.研究了电流频率、电流强度、电流方向和线圈距离对金属熔体内磁感应强度的影响.计算结果表明:单流时,电流频率升高,磁感应强度降低;电流强度增大,磁感应强度升高.双流时,无论电流方向是同向还是反向,同一铸锭的远端磁场强度要大于其近端磁场强度,相邻线圈电流方向为反向时,铸锭内磁场强度高于相邻线圈电流方向为同向的情况;增大线圈之间的距离时,铸锭远端和近端的磁感应强度的差值降低.     

圆坯钢电磁软接触连铸的实验研究

为确定工业实验基本参数,对电磁软接触连铸结晶器进行了优化设计计算,设计制作了φ100 mm圆坯电磁软接触连铸结晶器,利用Sn-Pb-Bi合金实验研究了结晶器内的弯月面行为,并进行了w(C)为0.22%钢坯的电磁软接触连铸实验。结果表明,电磁软接触连铸结晶器内磁场和弯月面变形具有不均匀性,切缝数为12时,磁场周向分布和弯月面变形较均匀。输入功率增加,弯月面高度增高,液面波动加剧。对于100 mm圆坯电磁软接触连铸系统,功率可控制在50~60 kW左右。实际应用中,浇注液面应控制在线圈中心偏上位置。较低的电源频率可获得较高的弯月面,频率应控制在20 kHz左右,可获得较高的周向均匀的磁场。获得了表面质量改善的电磁软接触连铸钢坯。随功率增加,铸坯表面依次会出现环状振痕、无振痕和波纹状振痕等3种振痕形态。     

380mm×280mm大方坯连铸结晶器电磁搅拌的数值模拟

利用有限元分析软件,建立了380 mm×280 mm大方坯结晶器电磁搅拌的三维数学模型,系统研究了电磁搅拌工艺参数(电流250～500 A,频率1.5～3.0 Hz,结晶器铜板厚度34～40 mm)对结晶器内电磁场的分布影响。结果表明,结晶器内磁感应强度沿铸流轴向呈"两端小、中间大"分布;电流从350 A增大到500 A,搅拌器中心的磁感应强度呈线性递增;频率由1.5Hz增大到3.0Hz,搅拌器中心磁感应强度仅减小0.001 5 T;随着结晶器铜板厚度的增大,铸坯宽面、窄面和角部的磁感应强度都减小。在实际连铸U71Mn重轨钢中,电流应该维持在400 A以上。     

软接触结晶器连铸实验与电磁场分析

软接触结晶器连铸准三维电磁场数值模拟,结合锡等低熔点金属的软接触连铸实验,分析了软接触结晶器连铸中电磁场频率及感应圈电流等与铸坯表面磁感应强度、电磁力及电磁压力的关系。     

大圆坯结晶器电磁搅拌器磁场的数值模拟

基于有限元方法,利用ANSYS软件模拟计算了大圆坯连铸结晶器电磁搅拌(M-EMS)器内三维磁场分布,分析了铜管厚度、断面和搅拌电流、频率对磁场分布的定量影响,并通过磁场的实验测定对数学模型进行了验证.研究表明,磁场模拟结果与实测结果吻合得较好;结晶器铜管对磁场具有较强的屏蔽作用,铜管越厚,屏蔽作用越强;小断面结晶器内磁感应强度大于大断面的情况;磁感应强度随着频率的增大而减小,随电流的增大而增大.     

结晶器内磁感应强度分布研究

采用CST—11A型数字特斯拉计对圆坯连铸机结晶器内磁感应强度进行了研究,研究表明:结晶器的磁感应强度随电流的增加而增大,随频率的增大而降低;结晶器内磁感应强度轴向最大位置在距结晶器上口900 mm位置,向两侧陡降;径向分布不均匀,由搅拌器内表面向中心逐渐减小;高频率经结晶器铜管后衰减更大.研究结果对合理制定及优化电磁搅拌工艺参数提供了理论依据.     

160 mm x 160 mm连铸坯结晶器电磁搅拌对钢液流场影响的数值模拟

采用数值模拟方法对比研究了160 mm×160 mm铸坯电磁搅拌参数对钢液搅动和结晶器内流场的影响。结果表明,在频率(1.0～5.0 Hz)条件下,磁感应强度随着频率的增大而减小,且变化量较大。钢液内电磁力沿圆周方向对称分布。在电流(200～500 A)条件下,磁感应强度随着电流的增大而增大。结晶器内半径方向上电磁力波动较大,存在多个波峰,波峰最大的位置都在距结晶器铜管15 mm处,与搅拌电流的大小无关,电磁力随电流的增大而增大。小方坯结晶器电磁搅拌频率应控制在3～4.5 Hz,电流大小应控制在300～500 A。     

大方坯结晶器电磁搅拌参数对磁场分布的影响

采用有限元软件,研究了连铸470mm×350mm大方坯结晶器电磁搅拌电流和频率对磁感应和电磁力分布的影响,并与实测数值进行了对比.研究表明,磁场模拟结果与现场实测数据一致.电磁力在大方坯水平截面上呈周向分布.当电流相同时,随着频率的增加,磁感应强度减小.电磁力随着频率的增加而增加,且随着频率的增加,最大电磁力增加量减小...     

Finite Element Analysis of 3-D Electromagnetic Field in Bloom Continuous Casting Mold

Three-dimensional finite element model of electromagnetic stirrer was built to predict magnetic field in a bloom continuous casting mold for steel during operation.The effects of current intensity,current frequency,and mold copper plate thickness on the magnetic field distribution in the mold were investigated.The results show that the magnetic induction intensity increases linearly with the increase in current intensity and decreases with the increase in current frequency.Increasing current intensity and frequency is available in increasing the electromagnetic force.The Joule heat decreases gradually from surface to center of bloom,and a maximum Joule heat can be found on corner of bloom.The prediction of magnetic induction intensity is in good agreement with the measured values.     

立式组合电磁制动对CSP结晶器内钢液流动及偏流控制

紧凑型带钢(CSP)薄板坯连铸结晶器在浸入式水口下方设置水平式的全幅一段电磁制动器(Ruler-EMBr),在进一步提高薄板坯连铸拉坯速度的情况下,不能有效控制CSP结晶器自由表面的钢液流速和液面的稳定性.为此提出一种新型的立式组合电磁制动(VC-EMBr)技术,并利用商业软件ANSYS FLUENT数值模拟研究了全幅...     

Numerical Simulation and Applications of F-EMS for High Carbon Steel Billet

The distribution of electromagnetic fields and electromagnetic force of F-EMS were simulated by ANSYS12.0 software. The magnetic induction intensity and electromagnetic force of billet with various stirring parameters were cal- culated, then the relationship between the magnetic induction intensity and electromagnetic force was calculated. The results showed that the electromagnetic force is not positive with the magnetic induction intensity. Depending on the com- bination of the practical production, the central segregation of high carbon steel SWRH77B is improved effectively under the best stirring parameter that the current is 360A and the frequency is 12Hz.     

Effect of Structure Parameters on Power and Magnetic Field in Electromagnetic Soft-Contact Continuous Casting System

To design a power source system and mold for electromagnetic soft-contact continuous casting process and to theoretically estimate the heat losses from the charges and the system power, the effect of structure parameters on system power and magnetic flux density distribution was calculated using finite element method. The results show that as for electromagnetic soft-contact continuous casting system with partial-segment type mold, the power consumption is much more than that with a full-segment type mold; about 62% of electric power is dissipated in the mold, and the effective acting range of magnetic field is relatively narrow. Optimizing mold structure is a crucial measure of remarkably reducing mold power consumption and saving electric energy. Increasing slit number, width, and length can remarkably increase the magnetic flux density in the mold and can reduce the electric energy consumption. Among structure parameters, slit number and slit width are relatively more effective to reduce energy consumption. For a round billet electromagnetic continuous casting system with diameter of 178 ram, the reasonable slit number, width, and length are about 24--32, 0. 5--1.0 mm, and 160 mm, respectively.     

结晶器电磁搅拌对圆坯质量影响的研究

通过数值模拟计算了马钢圆坯连铸（断面尺寸为Ф450mm）电磁搅拌参数对磁场分布的影响,并通过生产试验研究了电磁搅拌参数对铸坯质量的影响。模拟计算表明,结晶器磁场强度随着搅拌电流的增加而增大,电流不变时,频率越小,磁场强度越大。现场试验表明,采用电磁搅拌能有效改善铸坯低倍组织,搅拌电流越大,铸坯中心等轴晶比率越高;电磁搅拌还能有效改善铸坯疏松和中心偏析状况。选择合适的电磁搅拌参数可以获得良好的铸坯质量。     

GCr15钢大方坯结晶器电磁搅拌工艺参数优化研究

摘要：为明确不同电磁搅拌条件对结晶器内钢液流动、传热行为的影响规律,对现场大方坯连铸结晶器电磁搅拌工艺参数的配置提供依据,采用ANSYS Fluent及Maxwell研究了320mm×280mm断面GCr15高碳轴承钢连铸过程中结晶器电磁搅拌工艺参数对结晶器内钢液温度场、磁场特性、注流冲击深度及液面波动的影响规律。研究结果表明,在M-EMS作用下,结晶器内钢液温度的耗散明显优于无电磁场作用工况,有利于改善结晶器内温度均匀性。注流的冲击深度随电流强度的增大而降低,而频率改变对钢液冲击深度影响不明显。当电磁搅拌电流强度一定时,随着搅拌频率增加,液面波动趋于平缓;当搅拌频率一定时,随着电流强度增加,液面波动变剧烈。对于320mm×280mm断面GCr15高碳轴承钢不同工艺进行工业试验,只改变结晶器电磁搅拌参数,从300A/2Hz调整到350A/3Hz,铸坯横截面中心碳偏析指数从1.06降低到1.01,铸坯纵截面中心碳偏析指数的平均值从0.98升至0.99,适合该钢种结晶器电磁搅拌工艺参数为350A/3Hz。     

Distribution of Magnetic Flux Density in Soft-Contact EMCC Rectangular Mold

The distribution of the magnetic flux density in a soft-contact electromagnetic continuous casting （EMCC） rectangular mold was investigated. The experimental results show that with an increase in electric power, the magnetic flux density increases. The position where the maximum magnetic flux density appears will shift up when the coil moves to the top of the mold. At the same time, the maximum magnetic flux density will increase and the effective acting range of electromagnetic pressure will widen. As a result, in practice, the coil should be placed near the top part of the mold. The meniscus should be controlled near the top part of the coil, as this not only remarkably improves the billet surface quality but also saves energy. With the same electric power input, the higher the frequency, the lower the magnetic flux density.     

Effect of Electromagnetic Stirring on Molten Steel Flow and Solidification in Bloom Mold

The effect of electromagnetic stirring on molten steel flow and heat transfer in a 260 mm× 300 mm bloom mold was investigated by using a method combining both finite element method and finite volume method. The simu lation results related to magnetic fields were consistent with the onsite measured data. The magnetic flux density in creased with increasing the current intensity but decreased with increasing the current frequency. Electromagnetic stirring caused molten steel to flow with rotation on a horizontal section and two sets of recirculation regions with opposite fellow directions in a longitudinal section formed. The maximum tangential velocity increased with increasing the current intensity and frequency. Furthermore, the superheat degree of the molten steel on the outlet cross section of the mold decreased with increasing the current intensity. growth zone of solidified shell in the effective stirring zone. bearing steel, the appropriate values of current intensity and to be 300 A and 3 Hz, respectively. Electromagnetic stirring caused the emergence of a zero For the 260 mm N 300 mm bloom continuous caster of current frequency of electromagnetic stirring were found