摘要
为了观察分析烟气轮机动叶片GH864合金在热加工过程中组织演化规律,并进一步进行组织的优化控制,对取自棒材和成品叶片的热加工态及随后经热处理的样品进行系统的显微组织对比分析。结果表明:原始棒料晶粒度较均匀,叶片局部位置存在项链状组织;叶片晶粒度的不均匀性主要是由于锻造的过程中各部位的应变量不同,因而产生不同的动态再结晶行为;经过标准热处理后叶片发生了静态再结晶和晶粒长大现象,晶粒度较为均匀。在叶片的锻造过程中,M23C6和部分次生MC发生了回溶,在合金中仅有一些少量的TiC存在,它们主要分布于基体的晶界处;热处理之后大量的M23C6碳化物非连续地沿晶界呈块状析出。
The microstructural evolution of GH864 superalloy during the hot working process of gas turbine blades was systematically studied by observation of grain size, SEM micrographs and X-ray analysis of samples extracted from rolled bars and forged blades with or without standard heat treatment. The results show that the original rolled bar had uniform equiaxed grains, while necklace structure was found in some locations of blades. This kind of non-uniform grain size was caused mainly by different dynamic recrystallization behavior due to unequal strain in different locations of the blade during forging. Static recrystallization and grain growth happened during heat treatment, which led to more uniform and bigger grain structure. M23C6 and partial secondary MC dissolved after forging. Only a small amount of TiC existed in alloy, which mostly distributed in the grain boundaries, and heat treatment resulted in sufficient precipitation of block-shaped M23C6 discontinuously precipitated along the grain boundaries.
出处
《稀有金属材料与工程》
SCIE
EI
CAS
CSCD
北大核心
2009年第3期510-514,共5页
Rare Metal Materials and Engineering
基金
国家自然科学基金(50771011)