双辊铸轧工艺温度场和流场耦合的数值模拟

 双辊铸轧过程中熔池内金属的流动状态及温度分布直接影响着铸轧过程的稳定性与铸带产品的质量。针对实验室双辊铸轧试验的特点,采用三维有限元法模拟了双辊铸轧过程的热流耦合问题,利用热平衡计算、铸轧实验和模拟相结合的反向方法分段建立了凝固过程中凝壳与铸辊之间热传导系数与铸轧速度、熔池位置之间的关系模型,并分析不同工艺条件下熔池内凝固变化的情况。     

侧封对双辊铸轧薄带钢工艺稳定性及铸带质量的影响

阐述了国内外采用的固体侧封技术的原理，分析了固体侧封对辊铸轧薄带钢工艺稳定性和铸带质量的影响。主要研究了侧封的压紧装置，侧封板的材质以及铸轧过程中侧封板的温度对铸轧过程稳定性和铸带质量的影响，同时通过实验得到侧封板最佳预热温度。研究结果证明：采用熔融石英侧封板基本能满足铸轧的需要。     

Influence of Feeding Mode on Flow and Temperature Field for Twin Roll Strip Casting Process

Thetwinrollstripcastingprocess ,whichcancastmoltensteelinto 1- 5mmstripdirectly ,isat tractingtheattentionofthesteelproducersallovertheworld .Ithasmanyadvantagesoverconventionalstripproducingtechnology ,suchasreducedenergyconsumption ,lowerinvestmentandhigherflexibili ty .Comparedwiththinslabcasting process ,thistechnologycansave 70 %ofproductionandinvest mentcosts[1] ,and producestripswith poorform ability ,suchastoolsteelandsiliconsteelstrips .　　Thoughtwinrollstripcastinghasbeendevelop ing…     

Water Modeling of Twin-Roll Strip Casting

Twin-roll strip casting is regarded as a prospective technology of near net shape continuous casting. The fluid flow field and level fluctuation in the pool have a strong influence not only on composition and temperature homogeneity of pool, but also on the strip quality. A 1 ： 1 water model of a twin-roll strip caster was set up based on the criteria of Froude number and Reynold number similarity. The level fluctuation was measured. The influence of pool depth, casting speed and feeding system configuration on level fluctuation in the pool was studied. The experimental results provided a basis for the optimization of feeding system and process parameters.     

双辊薄带连铸结晶辊辊形优化

 利用弹塑性热力耦合有限元法,对薄带连铸过程中,结晶辊温度场及其热变形进行了仿真研究,并利用试验数据对仿真结果进行验证,表明仿真结果具有较高精度。同时,根据仿真结果设定初始辊形,并利用有限元方法对辊形进行优化,使结晶辊在稳定浇注时保持良好辊形,使铸带厚度横向分布均匀。     

双辊薄带连铸生产取向硅钢的技术分析

 双辊薄带连铸工艺具有流程短、单位投资低、能耗低、劳动生产率高等特点,而取向硅钢被认为是双辊法连铸工艺中最具有发展前途的钢种之一。针对此介绍了双辊薄带连铸技术的工作原理及其研究现状,总结了目前国外双辊薄带连铸生产取向硅钢相关方面的专利,并分析了双辊薄带连铸生产取向硅钢与传统工艺在组织、织构以及抑制剂控制方面的差异性,指出该流程在生产取向硅钢方面具有独特的优势,其工业化应用将会对取向硅钢的生产和发展起到革命性的推动作用。     

单辊法薄带连铸铸口包中钢液流动的数学模拟

建立了单辊法薄带连铸铸口包内钢液流动的数学模型 ,通过模拟计算 ,分析了不同结构的铸口包内钢液流动状态的变化     

双辊薄带铸轧机过程控制系统平台开发

针对双辊薄带铸轧机的过程控制要求,设计并开发了一个多进程形式的过程控制系统平台。该平台包含 多个进程,每个进程实现不同的功能,进程之间相对独立。这样的架构设计使平台具有良好的可伸缩性和稳定性。 在平台开发过程中,使用自适配通信环境ACE实现进程及线程间的通信,大大降低了开发难度,缩短了开发周期。 经过长时间测试,表明该系统平台运行稳定,能够满足在线控制要求。     

双辊薄带连铸电磁侧封静态模拟实验

在自行设计的双辊薄带电磁侧封实验装置上,测定了磁感应强度的分布。研究了感应圈安匝数及辊端进入磁轭的深度对侧封液态金属高度的影响规律。结果表明：侧封液态金属的高度随感应圈安匝数的增加而升高,基本呈线性关系;辊端进入磁轭的深度加大时,侧封高度显著增加。利用此规律可节省电能,减少设备发热。实验中还观察和分析了实验热效应和钢液表面波动现象。     

铸轧辊热辊型的研究

建立了双辊薄带铸轧过程中的铸轧辊传热及热变形三维有限元模型.通过动态模拟计算,得到了铸轧辊在稳定工作条件下的铸轧辊辊套的热辊型分布,发现铸轧辊在转动过程中,辊套内、外表面径向热变形分布呈近似椭圆形,即在一个转动周期中,有两个热变形峰值,而且铸轧辊中间对称部位的径向热变形椭圆长轴与边部径向热变形椭圆长轴不在同一个方向上.     

Heat Transfer Characteristic of Molten Pool for Twin-Roll Strip Casting

Body-fitted coordinate transformation equation was deduced and used to generate the body-fitted grids of molten pool for twin-roll strip casting. The orthogonality of the grids on the boundary was modified by adjusting source item. The energy equation and the boundary conditions were transformed from physical space to computational space. The velocity field model proposed by Hirohiko Takuda was used to calculate the temperature field of molten steel, and the influence of technical factors was also discussed.     

双辊铸轧薄带钢铸轧力计算公式及控制模型

在经典轧制理论和现代连铸理论相结合的基础上,推导出了铸轧力计算公式,并建立了一个非线性状态空间模型,描述双辊结晶器内的金属凝固和塑性变形.此模型可以作为双辊铸轧薄带钢过程铸轧力的实时在线控制模型.     

Numerical Simulation of Filling Process During Twin-Roll Strip Casting

The modeling and controlling of flow and solidification of melt metal in the filling process is important for obtaining the optimal pool level and the formation of the solidified metal layer on the surface of twin-rolls during the twin-roll strip casting. The proper delivery system and processing parameters plays a key role to control flow characteristics in the initial filling stage of the twin-roll strip casting process. In this paper, a commercial CFD software was employed to simulate the transient fluid flow, heat transfer, and solidifications behaviors during the pouring stage of twin-roll strip casting process using different delivery systems. A 3D model was set up to solve the coupled set of governing differential equations for mass, momentum, and energy balance. The transient free-surface problem was treated with the volume of fluid approach, a k–? turbulence model was employed to handle the turbulence effect and an enthalpy method was used to predict phase change during solidification. The predicted results showed that a wedge-shaped delivery system might have a beneficial impact on the distribution of molten steel and solidification. The predicted surface profile agreed well with the measured values in water model.     

薄带连铸布流器数学物理模拟研究

按照相似理论的原则,采用宝钢自主开发的布流器系统,建立了薄带连铸1：1的水模型。应用中科院DJ800系统测定了在不同的水口插入深度情况下的熔池内液面波动情况;与此同时,应用连续性方程、N-S方程及湍流k-ε方程对该模型进行了流体数值计算,得出了水模型内部的流场分布,对比数值计算的结果与水模型试验结果,两者吻合较好。     

Electromagnetic Dam in Twin-Roll Strip Caster

The electromagnetic dam （EMD） in twin-roll strip caster was simulated with FEM. The results show that the direction and magnitude of Lorentz force distributing in the EMD changed in a period. The neg ative part is about 30% of the positive part, and the acting time of the negative force is about 40% of a period. In order to prevent the liquid steel from leaking efficiently, the distance between two poles should be the same from the top to the bottom of the EMD, otherwise the magnetic induction will be very small at the top and large at the bottom.     

Physical and Numerical Simulation of Fluid Flow and Solidification at the Twin‐Roll Strip Casting Process

The fluid flow in a twin‐roll strip caster is investigated by physical and numerical simulation on a 1:1‐scale water model. A laser‐optical measurement technique (Laser Doppler Anemometry ‐ LDA) is used to validate the numerical results for the water flow. The numerical simulations are then transferred to the melt flow in the strip caster. The investigations are focused on different SEN concepts (submerged entry nozzle), a single‐nozzle system with two outlet ports and a double‐nozzle system with one outlet port each. The Influence of these concepts on the velocity, turbulence, and temperature distribution inside the liquid pool between the casting rolls and on the solidification and growth of the strip shells are investigated by numerical simulations (Computational Fluid Dynamics ‐ CFD). The non‐isothermal melt flow is calculated considering the solidification enthalpy as well as the behaviour of the solidifying melt. In addition to the numerical simulations of the melt flow inside the pool the temperature distribution in the cast strip is simulated. The SEN concept directly correlates with the temperature distribution Inside the strip. Furthermore, the surface temperature of the strip below the outlet of the roll gap is measured using a line‐scanner and is compared with the CFD simulation. In order to simulate the shape of the free surface in the liquid pool, CFD simulations of the water flow in the physical model are carried out using a Volume of Fluid model (VoF). This two‐phase model is able to reproduce free surface waves.     

Application of Fuzzy Logic Controller to Level Control of Twin-Roll Strip Casting

SymbolList　　D———Stripthickness ;　　E———Levelerror ;　　ΔE———Changeoflevelerror ;　　H———Moltensteellevel;　　L———Widthofcastingroll;　　Q———Volumeofmoltensteel;　　R———Radiusofcastingroll;　　S———Lateralareaofmoltensteelpool;　　u ,u1 ,u2 ———Outputofintelligentfuzzylogiccontrol ler,fuzzylogiccontrollerandPIDcon troller ;　　v———Castingspeed ;　　α———Proportionfactor ;　　τ———Time .　　Thetwin rollstripcastingprocessisanewstripproductionmethod …     

Modelling of Melt Flow and Solidification in the Twin‐Roll Strip Casting Process

A three‐dimensional mathematical model has been developed to simulate turbulent fluid flow, heat transfer and solidification in the pool of a twin‐roll strip caster. A Darcy‐porosity approach was used to study the fluid flow within the mushy solidification zone in the pool. The effect of the heat transfer coefficient and permeability constant on the flow and solidification was also predicted. It was shown that an even flow and temperature distribution of the pool can be obtained by using a suitable feeding system. The heat transfer between the rolls and the solidifying metal has a big influence on the location of the solidification end point. The permeability of the mushy zone is a key factor which affects the flow and solidification in the twin‐roll strip casting process.     

单辊法薄带连铸中钢液流动的数值模拟

建立了单辊法薄带连铸（厚度＜２ｍｍ）铸口包内钢液流动的数学模型。通过模拟计算，分析了尺寸等因素对钢液流动状态的影响。研究结果表明，隔墙高度是影响钢液流场分布及成带质量的关键因素。     

Numerical Simulation of Coupled Molten Steel Flow and Temperature Fields in Compact Strip Production Casting

  Based on the casting manufacture practice of steel slabs by CSP technology, the flow and the temperature fields of the funnel mould and the secondary cooling segment were simulated using the commercial code, CFX4. Compared with other physical investigations, the correlative data of the present simulation results are in good agreement with them. Therefore, a more comprehensive survey for metallurgy characteristic of the flow and the temperature fields in CSP continuous casting process can be achieved.