摘要
选取两种典型铸造高温合金DD407及K480,研究其固溶及时效过程中γ'相析出行为。结果表明,经热力学平衡相图计算获知,铸造高温合金K480及DD407合金的凝固温度范围是158、30℃,室温下γ'相体积分数分别为54%,80%;合金在凝固或固溶后的冷却过程中,γ'相形核率低,长大速率高,γ'相粒子易于长大;当其尺寸超过临界尺寸就会发生分解;两合金经过固溶后,较大尺寸的一次γ'相溶解后重新析出较小的二次γ'相;在一次时效空冷热处理后,合金在立方状的二次γ'相通道周围析出弥散细小球形三次γ'相;经过二次时效后,三次γ'相回溶、扩散直至消失,同时二次γ'相进一步长大,立方度增加。
The evolution behaviors of γ＇ phase in cast superalloy K480 and DD407 were studied during solution and aging heat treatment processes. The results indicate that the temperature range of solidification and volume of γ＇ phase for K480 and DD407 superalloys are 158 ℃ , 54% and 30 ℃ , 80% , respectively. During solidification and solution, theγ＇ phase grows easily in the way of low nucleation rate and high growth rate. Decomposition of some γ＇ phases occurrs, when the size of the γ＇ phase reaches the critical size. The primary γ＇phase can be dissolved and the second γ＇ phase precipitates after solution heat treatment. There is small amount spherical third γ＇ phase precipitating out along interfaces of the second cubic γ＇ phase. And the tertiary γ＇ phase re-dissolves, diffuses and ultimately disappears, meanwhile, the second γ＇ phase further grows up and its degree of cubic increases.
出处
《材料热处理学报》
EI
CAS
CSCD
北大核心
2014年第3期51-57,共7页
Transactions of Materials and Heat Treatment
基金
中央高校基本业务基金(FRF-TP-13-010A)
教育部博士点基金(20130006120005)
