大方坯连铸结晶器内钢水流场的数值模拟

 采用数值模拟的方法对大方坯结晶器内钢水流动过程进行了理论计算和分析,评估了浸入式水口结构对结晶器综合冶金效果的影响,并讨论了有关工艺参数与浸入式水口结构参数的关系。结果表明,浸入式水口结构及其工艺参数对结晶器内钢水流场分布及湍流粘度分布影响显著。     

中薄板坯连铸结晶器内钢水流场的数值模拟

 以鞍钢中薄板坯连铸机为对象，在商业软件CFX44的平台上对结晶器内钢水流动和液面波动过程进行了数值模拟，重点研究了其所独有的3孔浸入式水口的冶金功能。针对3孔浸入式水口不同侧孔倾角和浸入深度，数值模拟对结晶器内钢水流动做出了较为详细的预报，研究工作就此分别考察了水口中心孔流量变化和钢水液面波动幅度。     

板坯连铸结晶器内钢水流场和传热凝固数值模拟

 以鞍山钢铁集团公司中薄板坯连铸机为研究对象,利用商业软件CFX44对结晶器内钢水流场和传热凝固进行了数值模拟,主要研究了三孔浸入式水口的冶金特征及其对结晶器内钢水流场和温度场的影响。结果表明,采用三孔浸入式水口可以优化结晶器内钢水流场和温度场,稳定坯壳发育和成形,防止拉漏。     

大方坯结晶器内流场及自由液面的数值模拟

对大方坯结晶器内钢水流动过程进行理论计算和分析,评估浸入式水口结构对结晶器内流场、自由液面波动的影响,并讨论有关工艺参数与浸入式水口结构参数之间的关系。     

高速浇注板坯时浇注条件对连铸结晶器内钢水流动的影响

高速浇注时，容易发生因结晶器内保护渣的卷入而导致板坯表面下的缺陷。用水模拟试验和实机浇注试验研究了板坯连铸结晶器内钢水流动的行为。获得结果如下：（１）结晶器内钢水的液面波动，产生各种频率的波，这和钢水的表面流速有关；（２）水模拟试验揭示出，钢水液水液面的波动可通过使浸入式水口结构和其他浇注参数的最佳化来控制；（３）已表明了一个能表示结晶器窄边附近的钢水液面波动情况的参数（Ｆ值），它是在不同浇注条件     

连铸坯凝固过程中传输现象基础知识系列讲座

连铸结晶器中钢液的流动方式对去除钢水中的夹杂物，防止卷渣和铸流冲刷凝固层十分重要，介绍了板坯连铸结晶器中的钢液流动和水口出口倾角，水口浸入深度及浇铸速度等参数对流动行为的影响，同时概括了小方坯弧形结晶器中钢液流动特点。     

连铸弯月面附近的钢水流速对板坯表面质量的影响

Influence of Velocity of Molten Steel Flow near the Meniscusin a Continuous Casting Mold on Surface Quality of SlabsYu Haiying and Li Jingtao( Wuyang Iron and Steel Co.Ltd)1　前言近几年来 ,高产优质对连铸工艺的重要性不言而喻 ,而且 ,高速连铸的稳定性与防止板坯在结晶器内产生的表面缺陷密切相关。电磁制动装置或电磁搅拌装置已经在结晶器上得以应用。并选择了合适形状和浸入深度的浸入式水口来控制钢水流场。另一方面 ,已通过水模型实验或计算来模拟结晶器内钢水的流场 ,以找出合适的流场。然而 ,由于钢水的流速…     

厚板坯连铸结晶器流场数值模拟

针对鞍钢新轧钢第一炼钢厂厚板坯连铸结晶器建立了三维湍流数学模型和三维实体模型.应用有限元软件对厚板坯连铸结晶器内的流场进行了模拟,计算了铸机拉速、浸入式水口出口倾角和水口浸入深度等工艺参数对结晶器内钢液流动的影响.对比表明,数值模拟结果与水模实验结果相符.     

连铸坯凝固过程中传输现象基础知识系列讲座 第十四讲 连铸结晶器中的钢液流动

连铸结晶器中钢液的流动方式对去除钢水中的夹杂物、防止卷渣和铸流冲刷凝固层十分重要。介绍了板坯连铸结晶器中的钢液流动和水口出口倾角、水口浸入深度及浇铸速度等参数对流动行为的影响，同时概括了小方坯弧形结晶器中钢液流动特点。     

X形浸入式水口对结晶器内钢水流动影响的数值模拟

应用粘性流体力学的基本原理,釆用专业流体力学软件FLUENT对160mmx160mm方坯连铸X 形浸入式水口对结晶器内钢水流动的影响进行数值模拟,验证了 X形浸入式水口浇注时,通过两块半椭圆形 导流板上、下平面与倒锥形圆筒内腔围成的螺旋形导流通道的导向作用,使钢水以涡流形式进入到结晶器,能 有效减轻钢水的冲击深度,有利于夹杂物、气泡聚集升浮和提高连铸效率。     

板坯连铸结晶器钢液流场的数值模拟和优化

用CFD三维计算软件,采用k、ε双方程模型在给定的数值计算条件下,对900 mm高的板坯连铸结晶器内钢液流场进行了数值模拟,研究结晶器工艺参数对结晶器液面湍动能和窄边冲击压力的影响。结果表明:对于断面尺寸为220 mm×900 mm的板坯结晶器,水口插入深度为180 mm,水口倾角为向下15°,拉坯速度为1.6～1.8 m/min时,结晶器内钢液具有较好的流动方式。     

Numerical Study on Mould Powder Entrapment Caused by Vortexing in a Continuous Casting Process

Unsteady three‐dimensional turbulent flow phenomena are seen to have a major impact on steel quality in the continuous casting process. Usually steel mould powder is placed on top of the mould in order to use it as a lubricant between the solidifying steel and the mould and to prevent heat losses from the molten steel. It is well known that mould powder entrapment into the molten steel lowers the quality of the final steel products significantly. This can be caused by a vortexing flow at the interface between mould powder and molten steel near the submerged entry nozzle (SEN). The paper describes a study which was performed to analyse if commercial Computational Fluid Dynamics (CFD) software is capable of predicting the transient build‐up of vertical structures in the casting mould. Two‐phase‐flow phenomena have been modelled by using the Volume Of Fluid (VOF) method. The influence of different turbulence models, mesh densities and initial as well as boundary conditions on the resulting flow field was investigated. Due to the size and complexity of the problems the simulations partially had to be performed in parallel mode on a Linux‐cluster computing environment.     

Three-dimensional analysis of molten steel flow in slab continuous casting mould with rotated ports in submerged entry nozzle

Abstract

The purpose of this study is to develop a three-dimensional (3D) analysis system capable of analysing the flow field of molten steel in the slab continuous casting mould with rotated ports in the submerged entry nozzle. The ultimate goal is to obtain the optimal design for the entry ports of the submerged nozzle, which can introduce favourable flow patterns to remove non-metallic inclusions and avoid entrapment of molten slag and casting powder to produce steel slab of high cleanliness. In this study, a computational fluid dynamics technique, Sola-Surf, is employed to conduct the 3D fluid flow analysis. The technique has the capability of treating fluid flow problems with a free surface that slightly vibrates. The slightly vibrating free surface presents fairly accurately the behaviour of the molten slag–casting powder layer in the continuous casting mould. The developed simulation system is then tested on a slab continuous casting mould to analyse the fluid flow behaviour of molten steel under various nozzle designs. The design conditions include submerged depth of the nozzle, tilted angle of the nozzle port, and rotated angle of the nozzle port. The results of the simulations show that of the various design factors rotation of the nozzle entry ports has the greatest effect on the flow pattern. It can prolong the residence time of the molten steel and stabilise the molten slag–casting powder layer, which is very favourable for obtaining continuous casting slag of high cleanliness.     

板坯连铸结晶器内流体流动的反应工程学

 以太钢第三炼钢厂的板坯连铸为原型,使用CFX软件建立结晶器内流场流动的虚拟模型对其进行数值模拟。通过改变结晶器的几何参数和物理参数,进行板坯连铸结晶器内流体流动的反应工程学研究,得出拉坯速度、水口浸入深度和倾角对结晶器内流股冲击深度、自由液面最大湍动能、窄面最大剪切力的定量影响。     

高速连铸结晶器内卷渣机理及其控制研究

利用物理模型研究了高拉速条件下结晶器内的卷渣机理,考察了保护渣粘度、操作参数对结晶器内弯月面波动和卷渣行为的影响。研究结果表明：在高拉速条件下,表面回流卷混是引起卷渣的主要方式,表面速度可以作为判断卷渣发生的特征参数。此外,本研究还给出卷渣发生时的临界表面速度,提出了避免卷渣的改进措施     

降低超低碳钢结晶器液位波动及降级坯实践

针对鞍钢股份有限公司鲅鱼圈钢铁分公司生产超低碳钢时出现的结晶器液位波动和铸坯降级原因进行了分析,通过采取钢水顶渣改质、拉速调整、优化保护浇铸氩气流量、合理选择更换浸入式水口的时机及增加中间包钢水装入量等措施后,结晶器液位波动由14.38%降低到了7.44%,O5板比例由45.68%提高到58.23%。     

Fluid flow and heat transfer with nail dipping method in mould during continuous casting process

ABSTRACT

The character and cause of sliver defect on IF steel sheet surface are studied by means of SEM, unstable flow in mould could induce surface velocity and level fluctuations, leading to surface defects during continuous casting of steel. The nozzle clogging is a serious problem during the continuous casting of steel, due to its influence on the casting operations and products quality. In this study, the nail dipping method for measuring surface velocity and flow direction in molten steel were employed. The fluid flow in mould of whole casting sequence was investigated, especially during the nozzle clogging conditions. The results showed that when nozzle clogging occurred in the 7th heat, the flow velocities on R and L side of nozzle were 0.280 and 0.402?m/s, respectively. The surface defect ratio of hot-rolled and cold-rolled plates increases with the increase of heat flux deviation on both sides of the mould copper. The different clogging per cent on both sides of the nozzle will lead to asymmetry flow, the surface velocity is higher with the small clogging per cent side compared to that of relatively large per cent clogging side.     

双履带活块循环式薄板连铸过程的计算模拟

本文对双履带活块循环式薄板连铸过程进行了计算机模拟。由实验室热态试验结果表明凝固模型是可靠的。通过计算可知:双履带活块循环式薄板连铸过程中,结晶器内液态钢象固态钢一样随模壁运动,钢液流速和自由表面形状的主要影响因素是中间包水口的钢液出口速度。     

钙处理对钢水浇铸性能的影响

为了改善浇铸性能，应向钢中加入适量的钙，形成液态的铝酸钙。分析钙处理对钢水浇铸性能的影响，钙处理不当时不仅影响钢水的浇铸性能，而且还会影响钢水在结晶器内的凝固行为。     

钙处理对连铸钢浇铸性能的影响

分析讨论了钙处理对连铸钢浇铸性能的影响，为了改善浇铸性能，应向钢中加入合适的钙，形成液态的铝酸钙。钙处理不当时不仅影响钢水的浇铸性能，而且还会影响钢水在连铸结晶器内的凝固行为。