中文摘要：

采用ANSYS软件对电子束熔炼提纯钨过程中的温度场进行数值模拟,探讨了不同工艺参数（熔炼功率（P）及扫描半径（R））对熔体温度及熔池形状的影响。采用已模拟的工艺参数,在250 kW电子束设备上进行了提纯钨的实验验证,并用电感耦合等离子体光谱法（ICP-MS）对熔炼钨锭的成分进行分析。结果表明,熔炼功率和扫描半径对熔体温度和熔池形状都有一定的影响。随着熔炼功率的增加,熔体温度线性增加;随着扫描半径增大,熔体最高温度随之增加,但增加速率逐渐减小,最后趋于平衡;熔炼功率和扫描半径的细微变化皆能引起熔池形状和大小的显著变化,当熔炼功率和扫描半径过小（P=110 kW,R=10 mm）时,由于施加温度过低,铸锭熔解困难,无法形成熔池,随着熔炼功率及扫描半径的增大,熔池宽度和深度均有所增加。对模拟结果进行分析得到熔炼提纯钨的最佳条件为P=130 kW,R=15 mm,在此条件下杂质Cd,As,K,Mg,P的脱除率分别为95.0%,90.0%,75.0%,71.4%和71.4%。实验验证表明所建数学模型对电子束熔炼提纯钨具有较好的适应性。

英文摘要：

The numerical simulations of temperature field during electron beam melting tungsten were carried by ANSYS software, and the effects of various melting powers （P） and scanning radii （R） on the temperature and the shape of molten pool were investigated. The stimulated parameters were proposed and verified by experiments using 250 kW electron beam device, and the compositions of the molten tungsten ingot were measured and analyzed by inductively coupled plasma atomic emission spectrometry （ICP-MS）. The results showed that the melting power and scanning radius had certain effect on the temperature and the shape of molten pool. With the increase of mehing power, the melt temperature increased linearly. With the scanning radius increasing, the max melt temperature increased, but the increasing rate reduced gradually, and kept invariable after reaching equilibrium. The subtle variation of melting power or scanning radius could significantly change the shape and size of molten pool, when the melting power and scanning radius were too small, for example P = 110 kW, R = 10 mm, it was difficult to melt the ingot to get the molten pool because of the low input tempera- ture. But the width and depth of molten pool tended to be larger when melting power and scanning radius increased. The optimized pa- rameters of refining tungsten were 130 kW of melting power and 15 mm of scanning radius, and the removal rates of main impurities, such as Cd, As, K, Mg, P, were 95.0%, 90.0%, 75.0%, 71.4% and 71.4% respectively under this process conditions. Meanwhile, that the mathematic model being applicable to the electron beam melting tungsten was proved by the actual experimental data.