【作者】 王秋君；

【导师】 李强；

【作者基本信息】 河北科技大学 ， 材料加工工程， 2011， 硕士

【摘要】 随着薄板坯连铸技术的发展和进步,连铸机的产量和铸坯质量已成为人们关注的热点问题。连铸的二次冷却对连铸机的产量和质量都有重要的影响。为了获得良好的铸坯质量和较高的产量,有必要对板坯的二冷制度进行深入研究,通过制定连铸机合理的二次冷却制度,使铸坯快速均匀的冷却,在保证铸坯质量的同时,进一步挖掘连铸机的生产潜力。本文建立了薄板坯凝固的二维传热数学模型,基于邯钢薄板坯连铸的实际生产情况,应用ANSYS有限元分析软件对铸坯的凝固过程进行数值模拟。通过与现场数据相比较,验证了数学模型的可靠性。从模拟得到的铸坯凝固过程的温度分布可以看出,在X.0和X.1的过渡区处由于冷却水量分布不合理导致横向温差过大,这样极易产生裂纹。依据优化设计基本理论,并结合二次冷却制度应遵循的冶金原则,建立了二冷优化数学模型。以CSP薄板坯连铸机3.8m/min拉速的工况为例,采用两种优化方法进行优化运算,并分析和对比了两种优化算法。在优化运算中,通过调整各冷却段的水量,使铸坯均匀冷却,温度场分布均匀。文本还研究了不同拉速下二冷区各冷却段的最佳水量,采用最小二乘算法分别对二冷各段总水量和各环路水量进行一次线性和二次曲线回归,参照实际生产的配水经验,得到相应的二冷区各段最佳水量分布与拉速的关系,给出二冷的最佳配水工艺。本文根据铸坯凝固过程中过渡区易产生裂纹的问题,通过大量的数值模拟计算,找出了薄板坯二次冷却制度改善的方法,为指导实际生产提供了重要的参考依据。更多还原

【Abstract】 With the development and application of the technological characteristics in the thin slab casting, the output of the caster and the quality of the slab have became the focus question that people pay close attention to gradually. Secondary cooling is of central importance for the output and the quality in continuous casting process. In order to gain a good quality, the further study on secondary cooling is necessary, and if the secondary cooling system is suitable, it will dig up more productive potentialities.According to the actual situation of Iron and Steel Company in HANDAN, a two-dimensional heat-transfer mathematical model of thin slab in continuous casting has been established in this paper. At the same time, the FEM software ANSYS is successfully applied to simulate the solidification process. In comparison with Spot Date, the reliability of the models is proved. The changing temperature of the slab in the process of solidification can be seen. With the secondary cooling water distributed unreasonably, the temperature difference between X.0 and X.1 is high, cracking of slab happens frequently.The optimization mathematical model is established with the theory of optimization and the metallurgical principle in the secondary cooling process. Combined with the parameters of the continuous casting slab CSP in drawing speed 3.8 m/min, two kinds of optimization methods for optimizing operation are used to analyze and compare water amount. On the premise of meeting the optimization requirements, it needs adjusting the water amount in each cooling part to make sure the slab cooling uniformity effectively and the temperature field is well distributed. In this paper, the optimum cooling water amount in each secondary cooling is studied and the relationship between casting speed and cooling water amount is given by using Least squares algorithm, where the optimization secondary cooling water can be seen.In this paper, the problem of the dump cracking on the transition region in the solidification process of slab has been solved, the reasonable method of secondary cooling system improved is established after vast computation, which provides vital reference foundation and instruction on technology and parameters.更多还原