对Incoloy-800合金进行了均匀化处理，再使用Thermorestor-W型热模拟试验机进行了高温拉伸试验，研究了试验温度和均匀化处理对该合金拉伸时裂纹敏感性的影响。结果表明：该合金产生裂纹最敏感的试验温度区间为1 000~1 150℃；经均匀化处理后，产生裂纹最敏感的温度区间不变，但临界应变增大；均匀化处理后合金的显微组织发生明显变化，晶界碳化物的形貌由连续层片状变为不连续颗粒状，因此在高温拉伸过程中该合金的拉伸载荷和流变应力均减小；在高温拉伸过程中，流变应力是合金产生裂纹的主要因素，当流变应力超过晶界结合强度时，出现沿晶界开裂的倾向增大，裂纹敏感性增加。

In order to study the effect of homogenization treatment and test temperature on cracking susceptibility of Incoloy-800 alloys during tension, the alloy was treated by homogenization treatment, and then the high temperature tensile tests were carried out on Thermorestor-W thermal simulation test machine. The results show that the most sensitive test temperature range of the alloy cracking was 1 000℃ to 1 150℃. After homogenization treatment, the most sensitive temperature range was constant, but the threshold strain increased. After homogenization treatment the microstructure of the alloy changed obviously and the structure of grain boundary carbides changed from continuous lamellar to discontinuous granular, so that the tensile load and flow stress were decreased in the process of high temperature tension. Flow stress was the main factor to produce cracks during high temperature tension, the tendency of intergranular cracking and the crack sensitivity were enhanced when the flow stress exceeded intergranular binding force.