连铸坯凝固钩形成机理与控制技术综述

Overview of formation mechanism and control technology of hooks in continuous casting slab

对凝固钩的形成机理与控制技术进行了文献综述。凝固钩的研究方法主要有金相观察法和数值模拟法,两者共同加深了对凝固钩形成机理的认识。在铸坯宽面中心、宽面和窄面边缘处凝固钩平均长度要大于其他部位,凝固钩尺寸随着振痕深度的增加而增大。凝固钩的平均长度随钢中碳含量的降低而增大,超低碳钢和低碳钢中凝固钩问题尤为突出。减小凝固钩尺寸的连铸工艺措施有:提高浇铸温度和连铸拉速,采用放热型保护渣、减小保护渣导热系数、适当增大黏度,采用高频小振幅、非正弦振动波形,采用电磁搅拌或电磁制动等。

The formation mechanism and control technology of hooks are reviewed in this paper. The research methods of hooks include metallographic observation method and numerical simulation method. Both of them deepen the understanding of formation mechanism of hooks. The average length of hooks at the center of wide surface,edges of wide and narrow surface is larger than that at the other parts of slab,and the sizes of hooks increase with the increase of oscillation mark depth. The average length of hooks increases with the decrease of carbon content in steels,which is particularly prominent in ultra-low carbon steel and low carbon steel. Measures to reduce the size of hooks in continuous casting process are as follows:increasing casting temperature and casting speed,adopting exothermic mold powder,reducing thermal conductivity of mold flux,increasing viscosity appropriately,adopting mold vibration with high frequency,small amplitude and non-sinusoidal waveform,adopting electromagnetic stirring or electromagnetic braking,etc.