(中国工程物理研究院，绵阳 621900)
摘 要: 利用ProCast和CalcoSoft-3D软件中的CA-FE模块， 采用元胞自动机-有限元方法(Cellular automaton-finite element)， 对U-Nb合金以50℃/min的铸造冷却速度铸造的d107mm/d77mm×80mm管形铸件作为算例， 对该铸件的微观组织和晶粒度进行模拟计算。结果表明：U-Nb合金的凝固微观组织的晶粒度变化规律为，在铸件的同一高度上， 内层晶粒半径＜外层晶粒半径＜中间层晶粒半径； 按从上到下的顺序晶粒半径逐渐减小。 用金相方法实测了U-Nb合金铸件在各个高度位置之中间层的凝固微观组织晶粒半径，实测值小于模拟计算值近1倍，但是二者晶粒度的变化趋势是一致的， 模拟结果达到了定性或半定量的水平。
关键字: 铀铌合金; 铸造; 晶粒度; 计算机模拟
（China Academy of Engineering and Physics,
Mianyang 621900, China）
Abstract:Using cellular automaton-finite element method, the casting grain size of d107mm/d77mm×80mm tube-like part for Uranium-2%(mass fraction) Niobium alloy in the cooling rate of about 50℃/min was simulated by professional software ProCast and CalcoSoft-3D. The simulated results show that the casting grain size varied from the inner to the outer in the same height of section of the casting part as following: the inner grain size＜the middle grain size＜the outer grain size. The grain size gradually reduces from top to the bottom of the part. The casting grain size was verified by optical metallurgical method. The grain size of the experimental results were smaller than that of simulated results, but the changing trends was in the same way.
Key words: uranium-niobium alloy; cast; grain size; computer simulation
