电子束冷床熔炼TC4钛合金连铸凝固过程数值模拟

Numerical simulation of continuous casting solidification process of TC4 titanium alloy during EBCHM

利用PROCAST有限元软件对电子束冷床熔炼TC4钛合金连铸凝固过程进行数值模拟,研究不同工况条件下的温度场分布规律、熔池形状以及组织分布特征。结果表明:在相同的浇注温度条件下,随着铸造速度的增加,熔池加深,糊状区域变浅,初生枝晶半径和二次枝晶臂间距逐渐增加,凝固组织变得粗大。而在铸造速度相同的条件下,随着浇注温度的提高,过热度增大,熔池加深,糊状区域变浅,合金的晶粒尺寸增大。在本实验条件下,选择铸造速度10 mm/min以及浇注温度1760℃作为最佳工艺参数,这有利于在保证较高生产效率的同时,获得组织细小、冶金质量优良的钛合金铸锭。

The continuous casting solidification process of TC4 alloy during electro beam cold hearth melting （EBCHM） was simulated by using PROCAST finite element software. The temperature field distribution, the molten pool shape and the distribution characteristics of the microstructure under different conditions were studied. The results show that the deepening of molten pool, shallowing of pasty region, as well as the increasing of primary dendrite radius and secondary dendrite arm spacing under the same pouring temperature were caused by increasing casting speed. While under the same casting speed, the deepening of molten pool, shallowing of pasty region, and the increasing of grain size were caused by increasing pouring temperature. In this experimental condition, the casting speed of 10 mm/min and the pouring temperaatre of 1 760 ℃ were chosen as the best technique parameters, which are of benefit to ensuring high productive efficiency and obtaining titanium alloy ingot with good metallurgical quality and fine microstructure at the same time.