(1. 南京航空航天大学 材料科学与技术学院，南京 210016；
2. 哈尔滨工业大学 现代焊接生产技术国家重点实验室，哈尔滨 150001)
摘 要: 通过构建元胞自动机与有限差分耦合的CA-FD(cellular automaton-finite difference)模型，实现Ni-Cr二元合金焊接熔池柱状枝晶生长过程的模拟，研究熔池边缘柱状晶的生长过程以及该过程中的溶质浓度分布形态。模拟结果再现了焊接熔池中二次、三次枝晶的生长，枝晶间的竞争生长以及晶界偏析等微观现象。基于模拟结果深入分析了焊接熔池中枝晶生长的特点，同时对溶质浓度场进行了定量分析。对模拟结果的分析表明，焊接熔池中枝晶间竞争生长激烈，枝晶形态复杂，枝晶偏析和晶界偏析显著。
关键字: Ni-Cr二元合金；柱状枝晶；焊接熔池；元胞自动机；数值模拟
weld pool of Ni-Cr binary alloy
（1. College of Material Science and Technology, Nanjing University of Aeronautics and Astronautics,
Nanjing 210016, China;
2. State Key Laboratory of Advanced Welding Production Technology,
Harbin Institute of Technology, Harbin 150001, China）
Abstract:A cellular automaton-finite difference (CA-FD) model was established and the dendritic grain growh processes in the weld pool of Ni-Cr binary alloy were simulated based on this model. The dendritic grain growth processes in the edge of the weld pool and the solute distribution during the growth processes were studied. The simulated results reproduce the growth of secondary and tertiary dendrite arms, the competative growth and the grain boundary segregation, etc. The characters of the dendrite growth process in the weld pool were analyzed and the solute fields were quantitatively analyzed. It is indicated that the competative growth of columnar dendrite grain in weld pool is acute, the dendrite morphologies are complicated and the macro and micro segregations are obvious.
Key words: Ni-Cr binary alloy; columnar dendrite grain; weld pool; cellular automaton; numerical simulation
