服役后的René N5镍基单晶高温合金燃机涡轮叶片定量表征与评估

Quantitative characterization and assessment of a served René N5 Ni-based single crystal industrial gas turbine blade

摘要:

对一个服役近26000小时的René N5单晶高温合金燃机高压一级涡轮叶片进行解剖分析，研究了叶片不同部位的组织演化和损伤程度。分析了γ′相的形貌和体积分数，拓扑反转程度，碳化物的形貌和成分。研究结果表明，γ′相的体积分数和拓扑反转程度可以作为服役叶片显微组织损伤的定量表征参数，γ′相的形貌和TCP相的析出可以作为半定量的表征参数。根据以上参数，服役后的燃机涡轮叶片的组织损伤程度可以分为3个等级：轻度损伤，中度损伤和重度损伤。本研究结果为燃机用单晶涡轮叶片的组织损伤评价奠定了基础，并对叶片服役安全具有重要意义。

Abstract:

A high-pressure 1st stage IGT blade made of René N5 served for nearly 26000 hours was studied to figure out the evolution of microstructure and the degradation degree in different locations of the blade. The morphology and volume fraction of γ′ precipitates, the topological inverse degree, and the morphology and composition of carbides were analyzed. It has been confirmed that the volume fraction of γ′ precipitates and topological inverse degree are applicable to be quantitative microstructural characteristic parameters to characterize the microstructural degradation in the served blade. And the morphology of the γ′ precipitates and the precipitation of TCP can be employed as the qualitative microstructural characteristic parameters. In terms of these parameters, the microstructural degradation of the served IGT blade could be classified into 3 degrees: slightly, moderately and seriously degraded. These results are expected to established as solid foundation for the assessment of the degree of the microstructural degradation of single crystal IGT blades and also have practical significance in service safety.