长期时效对 DD4 单晶高温合金组织稳定性的影响

Influence of Prolonged Ageing about Stability of DD4 Singel Crystal Superalloy

在８５０℃和９５０℃（ＴＣＰ相析出的敏感温度）对ＤＤ４单晶高温合金进行了１０００ｈ的长期时效，并采用定期取样的方法进行分析。结果表明：ＤＤ４单晶合金具有良好的组织稳定性，经过长期高温时效后未出现ＴＣＰ相，与理论计算的结果相符。在８５０℃下，γ相的尺寸和形态无明显变化，持久性能也未发生明显变化。在９５０℃下，γ相的尺寸和形态有一定变化，导致持久性能下降。

This paper deals with DD4 single crystal superalloy at 850℃ and 950℃ for 1000 hours of prolonged ageing The experiments and analysis have been carried out by picking out samples every 200 hours The experimental results show that there isnt TCP in DD4 after 1000 hours prolonged ageing And the microstructure is stable The morphology and size of γ change no much after 1000 hours prolonged ageing at 850℃,but they change a little after 1000 hours prolonged ageing at 950℃resulting in decreasing about 35% of the high temperature stress rupture life