The moderate supersonic carbon added to the mold flux for ultra - low carbon steel is used to stay the melting speed as skeleton . then the mold flux coils have the good adiabatic , insulation and even flow property . at the same time it cause the carbon increase in the steel slabs and the operation of the ultra - low carbon is affected at last 超低碳钢连铸结晶器用保护渣中,外加中超碳黑作为骨架降低熔化速度,使保护渣具有良好的绝热保温性、均匀流动的润滑性,但同时却会引起钢铸坯的碳增量,最终影响超低碳钢的成功操作。
In order to overcome the difficulty mentioned above , this paper provides an improved heat transfer equation and a mended bem for the problems . first of all , the enthalpy and the " virtual temperature " are introduced into the paper to eliminate several mutative thermophysical properties in the heat transfer equation . secondly , the movement of the boundary between the solid and liquid phases in the billet is educed by virtue of the laplace transform 这些改进包括:引入热焓和“虚拟温度”的概念,对非常数的热物性参数进行整合:充分考虑铸坯凝固潜热释放带来的影响,利用“温度回升法”来加以处理;利用拉氏变换和反拉氏变换的原理来对凝固过程中铸坯内部固液相界面的移动方程进行了推导和求解,在凝固过程中充分考虑铸坯内部的固液两相的影响等等。
Thermal and structure character of straight reheating furnace were analyzed in csp technological process . coupling with heat conduction differential equations of the thin slab and the furnace lining , the mathemat ical model of heat transfer is established in the long one dimension furnace by using zone method for making the model of radiant heat transfer . the effect of the moving velocity and kinds of the slab on temperature distribution in the furnace is discussed based upon the solutions to the mathematical model 通过分析csp工艺中直通式辊底加热炉的热工及结构特性,采用区域法建立炉内辐射换热数学模型,与加热炉内连铸坯及炉衬的一维导热方程相耦合,建立长一维直通式辊底加热炉炉内传热数学模型.通过对数学模型的求解,研究分析了不同的薄板坯移动速度及钢种对加热炉炉内温度分布的影响
Steel casting : 20 tons arc - furnace steelmaking , 40tlf refiner furnace ; the max elevating capacity 125t ; the max casting products 80t , dimension of casting products length , width , high 8 . 54 . 53m , spun casting min outer diameter , min wall thickness , max length 1000154000mm ; various specification steel strands 铸钢: 20t电弧炼钢炉40tlf精炼炉最大起重能力125t最大铸钢件80t铸钢件最大尺寸长宽高8 . 54 . 53m离心浇注最大外径最小壁厚最大长度1000154000mm各种规格连铸坯。
Abstract : according to the site condition of the bisc , a mathematical model of two - dimensional unsteady solidification and heat transfer was established for the bloom caster in the mold . the mathematical model was solved with a finite difference method to characterize the temperature profiles and thickness of the solidified shell in the mold , the effects of casting speed on thickness of the solidified shell are also studied 文摘:根据包钢的现场条件,建立了大方坯连铸机结晶器内二维非稳态凝固传热数学模型,采用有限差分法对数学模型求解,得出结晶器中铸坯的温度分布规律和凝固坯壳生成规律,同时研究了拉坯速度对坯壳生成厚度的影响
Abstract : the method to determine the shape of solidification shell in the process of continuous casting of steel is studied . by establishing the model of stable temperature field , with the observation of first and second boundary value on the exterior of the ingot , the algorithm method to identify the shape of solidification shell is given with boundary variation in existing observation condition . numerical test shows that the method is valid 文摘:讨论了钢铁工业连铸过程中结晶器内连铸坯凝壳形状的确定方法.通过建立稳定温度场模型,在现有观测条件下,用边界变分方法给出了确定铸坯凝壳形状的辨识算法.实验数据显示此方法是有效的
On the basis of analysis and synthesis of the two type of different thermal boundary conditions , a method was developed , which can convert the thermal boundary conditions written by the beat transfer coefficient style into the thermal boundary conditions written by the heat transfer density style 摘要在对结晶器传热数学模型中广泛使用的给定铸坯与结晶器界面间热流密度以及给定铸坯与结晶器界面间传热系数两种不同形式的传热边界条件进行分析与综合的基础上,提出把传热系数形式的传热边界条件式转换为热流密度形式的传热边界条件式的方法。
This segregation behavior of sn accords with the mechanism of non - equilibrium segregation . it can be obtained through the theoretical calculations that the critical time of sn non - equilibrium segregation is 124 seconds at 750 and the critical cooling rate is 8 / s when cooling from 1320 . it is suggested that controlling the cooling rate during continuous casting to avoid the critical cooling rate ( 8 / s ) and avoiding high stress near the trough temperature ( 750 ) may control the form 通过研究残留元素sn的偏聚机制及其对o . 15wt . % c钢热塑性的影响,对试验钢进行脆性预测:建议在该钢的连铸过程中弯道矫直温度尽量避开塑性谷底温度750 ,二冷区的冷速尽量避开临界冷却速率8 / s ,从而可以减少该低碳钢连铸坯表面裂纹和横向裂纹,提高其成材率。
Abstract : thermal and structure character of straight reheating furnace were analyzed in csp technological process . coupling with heat conduction differential equations of the thin slab and the furnace lining , the mathemat ical model of heat transfer is established in the long one dimension furnace by using zone method for making the model of radiant heat transfer . the effect of the moving velocity and kinds of the slab on temperature distribution in the furnace is discussed based upon the solutions to the mathematical model 文摘:通过分析csp工艺中直通式辊底加热炉的热工及结构特性,采用区域法建立炉内辐射换热数学模型,与加热炉内连铸坯及炉衬的一维导热方程相耦合,建立长一维直通式辊底加热炉炉内传热数学模型.通过对数学模型的求解,研究分析了不同的薄板坯移动速度及钢种对加热炉炉内温度分布的影响
Testing results are analyzed , then the boundary condition ( the heat transfer coefficient of and the water density ) for computer simulation is acquired . through simulation in computer using the all - purpose computer simulation software secondary cooling in slab continuous casting and test results , the influence of the factor such as casting speed , casting temperature , shell thickness and secondary cooling system are analyzed . the secondary cooling system is evaluated , the reasons of crack are analyzed 应用仿真软件和实验数据对宝钢1930铸机进行了仿真计算,分析了拉速、配水制度、过热度对铸坯温度场和坯壳厚度的影响;对宝钢1930铸机的二冷制度进行了评估,分析了产生裂纹的原因;并对二冷制度进行优化,提出了改进建议。