大体积K4169高温合金深过冷及其组织均匀性的研究（英文）

Homogeneous Microstructure of Bulk K4169 Superalloy Obtained by Stable Undercooling

在传统深过冷工艺的基础上,通过对传统工艺中B2O3玻璃净化法和循环过热方法的改进,可使较大体积K4169高温合金稳定地获得200 K以上过冷度,其中100 g合金熔体的最大过冷度达271 K。采用ANSYS软件模拟了100 g K4169高温合金冷却过程中熔体温度场的分布,熔体形核前最大温差仅为14 K。在此基础上观察合金不同部位的凝固组织,发现组织随着形核温度的升高而增大。总体来看组织只有微小差别,其平均晶粒尺寸为12±2μm,与模拟结果相吻合。

By improving the method of B2O3 glass purification combined with cycle superheating based on traditional undercooling method, a stable undercooling above 200 K of 100 g bulk K4169 superalloy was obtained, and the largest undercooling went to 271 K. The effects of purification and superheating temperature on undercooling have been discussed. Moreover, the three-dimensional numerical analysis of temperature field inside the undercooled melt has been presented, and the maximum temperature deviation in different parts is only 14 K before nucleation. In contrast with the as-solidified microstructure, the grain size will increase with the increment of nucleating temperature. Generally, the difference of microstructure in 100 g undercooled K4169 superalloy is tiny and the average grain size of the superalloy with 271 K undercooling is 12±2 μm.