摘要
本文以高转速-高温耦合环境下服役337.72 h、408.12 h和661.38 h的DZ125涡轮空心叶片为研究对象,利用微观组织分析手段,研究了枝晶形貌、γ’强化相、碳化物和γ/γ’共晶组织的演化规律。结果表明:与恒温单轴应力不同,在高转速-高温耦合作用下,DZ125服役叶片枝晶干和枝晶间微观组织的不均匀性并未随时间的延长而减弱,反而更加明显。其中温度最高的前缘位置,γ’相大量溶解和粗化,导致服役叶片的微观组织演化表现出明显的几何结构相关性和区域的不均匀性。因此,仅用枝晶干γ’相的尺寸和体积分数很难全面描述叶片服役过程中的组织演变规律,有必要建立基于叶片几何结构的宏观形貌(如枝晶形貌)和微观形貌(如γ’相)相耦合的组织演变分析方法。
This study investigated the DZ125 turbine hollow blades exposed to a high-speed rotating and high temperature coupling environment for durations of 337.72 h,408.12 h,and 661.38 h.Microstructure analysis was employed to examine the evolution of dendritic morphology,γʹstrengthening phase,carbide distribution,andγ/γʹeutectic structure.The results reveal that unlike constant temperature uniaxial stress conditions,the inhomogeneity in both dendrite stem and interdendrite microstructures of DZ125 blades does not decrease with time,but rather becomes more pronounced under the combined influence of high-speed rotating and high temperature.At the leading edge where temperatures are highest,a significant dissolution and coarsening ofγʹphases occurs,resulting in distinct geometric structure correlations and regional heterogeneity during microstructural evolution within the blade material.Consequently,it is challenging to fully characterize this evolution solely based on size and volume fraction measurements pertaining toγʹphases in dendrite stem;instead,it may be necessary to establish an analytical approach that considers both macroscopic morphology(e.g.,dendrite morphology)as well as microscopic features(e.g.,γʹphases)based blade geometry.
作者
刘柯蔓
谢亚丹
赵建江
韦华
LIU Ke-man;XIE Ya-dan;ZHAO Jian-jiang;WEI Hua(School of Materials Science and Engineering,Zhejiang University,Hangzhou 310027,China;Center for Hypergravity Experimental and Interdisciplinary Research,Zhejiang University,Hangzhou 310058,China;College of Civil Engineering and Architecture,Zhejiang University,Hangzhou 310058,China)
出处
《中国有色金属学报》
EI
CAS
CSCD
北大核心
2023年第8期2563-2576,共14页
The Chinese Journal of Nonferrous Metals
基金
国家自然科学基金资助项目(51988101)。
关键词
DZ125叶片
高转速-高温耦合作用
微观组织演化
几何结构相关性
涡轮叶片
DZ125 blades
coupling high-speed rotating and high temperature conditions
microstructure evolution
geometric structure correlation
turbine blade
