电子束熔炼已成为制备高温合金铸锭的关键技术，其凝固组织直接决定着铸造质量以及后续开坯锻造的 性能。 对铸锭凝固过程中组织的形成进行系统、详细分析，具有现实和重要意义。 考虑到实验成本高、难度大，本文基于 ProCAST 软件建立了高温合金制备充型与凝固过程数学模型， 以预测电子束熔炼条件下逐层充型与凝固过程中温度 场、流场及凝固结构演变，模拟了不同浇注速度下(0.5、1.0、1.5、2.0 和 4.0kg/s)铸造直径 220mm 高温合金铸锭的温度 场、流场及凝固组织，探讨了温度场、流速及凝固组织随浇注速度的变化规律。结果表明，镍基高温合金铸锭逐层浇注过 程中，铸锭顶部合金温度高，底部合金温度低，实现了从底部到顶部的顺序凝固。随着浇注速度的增大，温度梯度明显增 大，上层合金熔体对下层合金温度变化影响变小，即温度回升幅度减小。在中心区域，热量积聚更为显著，可能导致铸锭 内部产生较大的热应力和缺陷。 浇注速度的变化对合金流动的最大速度及合金液面波动的影响较大。 随着浇注速度增 加，监测点的流体速度变化呈现出更为明显的波动现象，特别是在靠近浇注入口的区域，浇注速度越大，合金液的冲击 深度越大。浇注速度显著影响了凝固过程中晶粒的生长行为与取向分布。较低的浇注速度有利于柱状晶的形成，晶粒尺 寸较大且取向较为有序；而较高的浇注速度则促使中心区域晶粒细化，晶粒取向更加杂乱。

Electron beam melting has become a key technology for the preparation of superalloy ingots, and its solidification structure directly affects the casting quality as well as the performance of subsequent billet forging. It is practical and important to carry out a systematic and detailed analysis of the structure formation during the solidification of the ingot. Considering the high cost and difficulty of experimental research, a mathematical model of the filling and solidification process of superalloy preparation was established via ProCAST software to predict the evolution of the temperature field, flow field, and solidification structure during the layer-by-layer filling and solidification process under the conditions of electron beam melting. This paper simulated the temperature field, flow field, and solidification microstructure of a casting superalloy ingot with a diameter of 220 mm under different pouring speeds (0.5, 1.0, 1.5, 2.0, and 4.0 kg/s). It then explored the change rules of the temperature field, flow velocity, and solidification structure in relation to the pouring speed. The results show that during the layer casting process of nickel-based superalloy  ingots, the temperature at the top of the ingot is high, whereas the temperature at the bottom is low, which results in sequential solidification from the bottom to the top. As the pouring speed increases, the temperature gradient increases significantly, and the influence of the upper layer alloy melt on the temperature change in the lower layer alloy decreases; that is, the temperature rise decreases. In the center region, heat accumulation is more significant, which may lead to greater thermal stresses and defects inside the ingot. Changes in the pouring speed have a greater influence on the maximum speed of melt flow and melt level fluctuations. With increasing pouring speed, the fluid velocity change at the monitoring points clearly fluctuates, especially in the area near the pouring inlet. The greater the pouring speed is, the greater the impact depth of the alloy liquid. The pouring speed significantly affects the grain growth behavior and orientation distribution during solidification. A lower pouring speed is conducive to the formation of columnar crystals with larger grain sizes and more ordered orientations, whereas a higher pouring speed promotes grain refinement of the center region and more disordered grain orientations.