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本文研究了凝固速度对一种新型定向凝固钴基高温合金（ＤＳＸ４０Ｍ）凝固组织的影响。作为该合金强化相的晶间碳化物主要有Ｍ２３Ｃ６、ＭＣ、Ｍ７Ｃ３三种。研究发现，定向凝固速度的变化并不改变碳化物的类型，但对碳化物的体积分数和平均尺寸有强烈影响。给出了该合金碳化物体积分数、平均尺寸和持久寿命随凝固速度变化的规律。采用电子探针技术分析了不同凝固速度条件下合金元素的偏析情况。研究还发现，Ｔｉ、Ｔａ、Ｚｒ、Ｃｒ呈正偏析，向枝晶间富集，而Ａｌ、Ｗ、Ｃｏ、Ｎｉ则呈负偏析，趋于晶内分布。找出了凝固速度与偏析系数之间的关系。从热力学和动力学角度讨论分析了凝固速度对该合金凝固组织的影响机制。
In this paper, the effect of solidification rate on the solidification structure of a new type of directional solidification Co-based superalloy (DSX40M) was studied. Intergranular carbides as the alloy strengthening phase are mainly M23C6, MC, M7C3 three. The study found that the rate of directional solidification does not change the type of carbide, but the volume fraction of carbide and the average size has a strong impact. The rules of volume fraction, average size and life span of the alloy with the solidification rate are given. The electron probe technique was used to analyze the segregation of alloying elements under different solidification rates. It is also found that Ti, Ta, Zr and Cr are positively segregated and enrich to dendrites, while Al, W, Co and Ni are negatively segregated and tend to intragranular distribution. The relationship between solidification rate and segregation coefficient was found out. From thermodynamic and kinetic point of view, the mechanism of solidification speed on the solidified structure of the alloy was analyzed.