【作者】 李岩；

【导师】 任廷志；

【作者基本信息】 燕山大学 ， 机械设计及理论， 2015， 硕士

【摘要】 连铸坯凝固末端位置是连铸生产中一个非常重要的参数,它直接反应铸坯的凝固进程和工艺参数选取的合理程度,凝固末端位置的确定是实施轻压下、凝固末端电磁搅拌等手段改善铸坯中心疏松与偏析的前提和关键。因此,对铸坯凝固进程与凝固末端位置进行研究具有重要的理论和现实意义。建立板坯连铸二维凝固传热模型,对连铸凝固传热过程进行模拟,得到铸坯凝固过程中的温度场分布和坯壳厚度增长情况,通过铸坯表面温度实测对结果进行验证,并分析拉速、过热度和比水量等因素对铸坯表面温度、坯壳厚度、液芯长度和压下区间的影响规律。建立压下过程热弹塑性有限元模型,对板坯连铸压下过程进行数值模拟。分析不同压下量、液芯厚度对压下效率的影响规律,通过对数据的处理,拟合出了压下效率与液芯厚度的计算关系式,为新方法的建立提供了理论依据。提出基于结晶器液面检测的板坯连铸凝固末端位置的判定方法。根据压下效率与液芯厚度的计算关系式,推导出对铸坯施加可控振动时,结晶器液面波动幅值与施加位置处液芯厚度的理论关系式。利用有限元仿真软件,结合钢厂实际生产情况,对该方法进行模拟研究验证,通过与第二章所得结果进行对比,证实该创新方法真实可靠。通过本文的研究,建立了新的检测凝固末端位置的判定方法,对提高铸坯质量具有一定的理论指导意义和工程实用价值,并对现有连铸生产提供参考。更多还原

【Abstract】 It is a very important parameter to determine the solidification process and technological parameters of continuous casting production. The determination of the end position is the premise and key to improve the center porosity and segregation of casting slab. Therefore, it has important theoretical and practical significance to study the solidification process and the position of the solidification end.A two dimensional solidification heat transfer model of slab continuous casting is established. The temperature field distribution and the thickness of the billet are simulated. The influence of the surface temperature, the temperature and the ratio of the casting billet on the surface temperature, the thickness of the shell, the liquid core length and the pressure are verified.A thermal elastic-plastic finite element model is established for the process of continuous casting of slab. The influence of different pressure and liquid core thickness on the efficiency of the press is analyzed. The relationship between the efficiency and the thickness of the liquid core is fitted by the processing of the data.A method for determining the position of a slab continuous casting at the end of the mold is presented. According to the relationship between the pressure and the thickness of the liquid core, the theoretical relationship between the amplitude and the thickness of the liquid core in the liquid core is derived. Using the finite element simulation software and the actual production situation of steel mill, the method is verified by simulation study. The results are compared with the results obtained by the two methods, and the innovation method is proved to real and reliable.Through the research of this paper, the solidification process of slab is defined, and a new method to detect the position of the solidified end is established. It has a certain theoretical significance and practical value for improving the quality of slab.更多还原