单晶连铸是一项新型金属型材制造技术． 单晶组织的演化是在引晶初期通过晶粒的竞争生长机制完成的， 晶粒的竞争生长过程依赖由传热条件决定的固液界面形状． 本文观察了工业纯铝单晶连铸引晶初期的组织演化过程， 并通过液淬观察了宏观固液界面形状与单晶演化的关系， 指出形成中心向液体中凸出的固液界面是完成单晶演化的必要条件． 在此基础上建立了测算单晶演化速度的几何模型， 讨论了铸锭尺寸、连铸速度及固液界面形状因子对单晶演化速度的影响． 研究结果表明， 铸锭尺寸越大， 完成单晶演化所需时间越长； 提高连铸牵引速度和界面形状因子， 有利于单晶组织的演化． 典型实验结果与理论分析吻合得很好 Single crystal continuous casting is a new type of metal profile manufacturing technology. The evolution of the single crystal structure is achieved through the competitive growth mechanism of the crystal grains at the initial stage of seeding. The competitive growth of the crystal grains depends on the solid-liquid interface shape determined by the heat transfer conditions. In this paper, the microstructure evolution of single-crystal continuous casting of industrial pure aluminum was observed and the relationship between the shape of the solid-liquid interface and the evolution of single crystal was observed by liquid quenching. It was pointed out that the solid-liquid interface protruding from the center to the liquid was completed Necessary conditions of single crystal evolution. On this basis, a geometric model for calculating the evolution speed of single crystal was established. The effects of ingot size, continuous casting speed and solid-liquid interface shape factor on single crystal evolution rate were discussed. The results show that the larger the ingot size, the longer it takes to complete the single crystal evolution. The improvement of continuous casting speed and interface shape factor is beneficial to the evolution of single crystal structure. The typical experimental results are in good agreement with the theoretical analysis