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With the considerations of the behaviors of shell deformation, mold flux film and air gap dynamic distribution in shell/mold gap, a two dimensional slice-travel transient thermo-mechanical coupled model of simulation shell solidification in wide and thick slab continuous casting mold was developed by using the commercial program ANSYS. The evolutions of strand-mold system thermal behaviors, including the air gap formation and the mold flux film dynamical distribution in shell/mold gap and shell temperature field, and the evolutions of shell deformation and stress distribution of peritectic steel solidified in a 2120 mm wide and 266 mm thick slab continuous casting mold were analyzed. The results show that the air gap formation and the thick mold flux film distribution mainly concentrate in the regions 0–21 mm and 0–7 mm, 0–120 mm and 0–100 mm off the shell wide and narrow faces corners, and thus the hot spots are given rise to form in the regions 15–55 mm and 15–50 mm off the shell wide and narrow face corners. The shell server deformation occurs in the off-corners in the middle and lower parts of the mold. The stress evolution in shell surface is tensile stress, while that in shell solidification front is compressive stress. 相似文献
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Klaus Schwerdtfeger 《国际钢铁研究》2006,77(12):911-920
Two principal methods are used to investigate the heat transfer in the continuous casting mold. The direct way is to measure cooling water temperatures, mold wall temperatures, strand temperatures and shell thickness in actual operation, and then deduce from these data the correlations for heat flux densities. The other way is to investigate the “unit operations” of heat transfer theoretically or experimentally in the laboratory, viz. heat transfer through a layer of casting flux or of gas, and heat transfer in a copper wall cooled on one side by water. The results obtained in this approach can then be used to explain the data determined with the direct method and to optimize the heat transfer behaviour of the mold in the machine. In the first part of this paper some unit operations are discussed and engineering formulae are given for computation of the heat resistances of the gap and the copper/water system. In the second part of the paper the available operational data on heat flux density are analysed. Algorithms are presented for computation of local and average heat flux density as functions of casting speed, carbon content of the steel and composition of the casting flux. Finally, values of shell thickness are computed with the correlation for heat flux density and are compared with the measured data. 相似文献
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Heat transfer and deformation of initial solidification shell in soft contact continuous casting mold under high frequency electromagnetic field were analyzed using numerical simulation method; the relative electromagnetic parameters were obtained from the previous studies. Owing to the induction heating of a high frequency electromagnetic field (20 kHz), the thickness of initial solidification shell decreases, and the temperature of strand surface and slit copper mold increases when compared with the case without the electromagnetic filed. The viscosity of flux decreases because of the induction heating of the high frequency electromagnetic field, and the dimension of the flux channel increases with electromagnetic pressure; thus, the deformation behavior of initial solidification shell was different before and after the action of high frequency electromagnetic field. Furthermore, the abatement mechanism of oscillation marks under high frequency electromagnetic field was explained. 相似文献
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宝钢1930mm板坯连铸凝固传热模型的研究与开发 总被引:1,自引:0,他引:1
以二维非稳态传热数学模型为理论基础,结合铸坯在连铸二冷区的实际热量散失规律,将二冷区相邻夹辊之间传热分为夹辊接触传热、水聚集蒸发传热、水冲击传热和辐射传热四个过程,并根据宝钢一炼钢板坯连铸机具体条件,建立了宝钢1930mm板坯连铸凝固传热模型.利用面向对象的VB6.0高级语言对模型进行编程,开发出相应的连铸二冷仿真软件.利用红外线测温仪采集铸坯温度,对模型结果进行验证,现场铸坯测温和仿真结果比较得出偏差范围为0.9%~2.8%,说明仿真模型和仿真结果真实可靠.利用该仿真软件可以对宝钢1930mm连铸机的二冷工艺制度进行研究和优化,指导连铸生产. 相似文献
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Herein, a 3D mathematical model is established to elucidate the meniscus solidification and heat transfer in the chamfered mold. The fluid flow, heat transfer, the solidification of steel, the oscillation of the mold, and the steel–slag interfacial tension are considered, and the meniscus behavior on different longitudinal sections and cross sections is discussed. Under the influence of the upper roll flow, the height of the steel level increases from submerged entry nozzle to narrow face, which affects the distribution of the oscillation mark on the surface of the shell. With the mold chamfer and two new corners, the thickness of the slag film at the corner 1 with angle of 123.7° is the largest, and the shell thickness is the smallest, which is related to the 3D profile of the meniscus near the corner. The largest heat flux is located at 10–14 mm below the initial level of liquid steel and is below 3.0 MW m−2. The heat flux at the corner 1 with small obtuse angle is the smallest on the same cross section, indicating that small obtuse angle near the corner resulted in the low heat transfer. 相似文献
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热送热装工艺中板坯连铸过程传热的数学模型 总被引:2,自引:0,他引:2
建立了板坯连铸过程传热数学模型,并用实测数据对计算结果进行了验证,证明该模型可用于预报不同操作条件下板坯凝固过程中温度的变化和凝固状态。应用该模型分析了影响板坯出连铸机温度的主要因素:板坯尺寸、拉速、二冷水量及冷却方式等。适当提高拉速、改善二冷制度能提高铸坯出连铸机温度。 相似文献
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ZHU Miao-yong WANG Jun ZHANG Ying 《钢铁研究学报(英文版)》2005,12(6):14-19
SymbolList Ab,An———Surfaceareaofbroadfaceandnarrowfaceof moldrespectively,m2;Cp———Effectiveheatcapacity,J·kg-1·K-1;Cp,s———Heatcapacityofsolidphase,J·kg-1·K-1;Cp,l———Heatcapacityofliquidphase,J·kg-1·K-1;Cw———Waterheatcapacity,J·kg-1· 相似文献
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以鞍钢厚板坯连铸机为目标机型,按照传热学理论建立连铸二冷凝固传热数学模型.应用此模型对X65管线钢和船板钢的连铸过程进行仿真模拟,模拟结果同实测值基本吻合,验证了模型的可靠性. 相似文献
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Multiphase Flow and Thermo-Mechanical Behaviors of Solidifying Shell in Continuous Casting Mold 总被引:1,自引:0,他引:1
The metallurgical phenomena occurring in the continuous casting mold have a significant influence on the performance and the quality of steel product. The multiphase flow phenomena of molten steel, steel/slag interface and gas bubbles in the slab continuous casting mold were described by numerical simulation, and the effect of electromagnetic brake (EMBR) and argon gas blowing on the process were investigated. The relationship between wavy fluctuation height near meniscus and the level fluctuation index F, which reflects the situation of mold flux entrapment, was clarified. Moreover, based on a microsegregation model of solute elements in mushy zone with δ/γ transformation and a thermo-mechanical coupling finite element model of shell solidification, the thermal and mechanical behaviors of solidifying shell including the dynamic distribution laws of air gap and mold flux, temperature and stress of shell in slab continuous casting mold were described. 相似文献
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基于构形理论,以板坯热损失率、表面温度梯度、矫直点表面温度、表面极限温度和液芯长度组成的惩罚函数为优化目标,在二冷总供水流量一定的条件下对板坯连铸凝固传热过程进行优化,得到二冷区各区段最佳水量分配比,分析水量分配比、二冷总供水流量和拉坯速度对复合函数(板坯热损失率和表面温度梯度的线性加权函数)、热损失率目标、表面温度梯度目标和板坯表面温度的影响。结果表明:与初始水量分配比结果相比,水量分配比优化后的复合函数、热损失率目标和表面温度梯度目标分别降低35.04%,2.14%和59.48%;优化后的二冷区出口温度和空冷区末端温度分别提高6.79%和1.59%。最佳水量分配比方案在提高板坯蓄能的同时也提高了板坯的质量。 相似文献
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连铸机辊子与铸坯传热的研究 总被引:1,自引:0,他引:1
根据连铸机辊子的实际工作情况,将其内外表面分成传导传热区,对流换热区和辐射-对流综合换热区。利用距辊子表面3mm处所测得的温度变化曲线,通过辊子换热的平衡方程,推导出每一区域的综合传热系数及其表面温度的表达式,为正确计算辊子的温度场,供应力提供了较为可靠的依据。 相似文献
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连续铸钢过程中结晶器的传热研究 总被引:1,自引:0,他引:1
为了研究结晶器内壁温度的分布,设计了模拟结晶器工作过程的实验装置,并进行了实验。实验结果表明,结晶器内壁温度趋近于冷却水温度。基于实验,推导了结晶器边界等效导热系数。该系数用于解决金属和冷却水之间的传热,即反映结晶器的传热能力。用等效导热系数处理结晶器的边界传热,对包括结晶器在内的连铸凝固进程温度场进行数值模拟既简单又方便,并且计算结果与实验结果符合。还讨论了拉坯速度和冷却水流量对结晶器温度场的影响。 相似文献