K465低压涡轮叶片叶冠失效分析

Failure analysis of K465 low pressure turbine blade crown

利用光学显微镜和扫描电镜对K465涡轮叶冠断口、金相组织进行了观察,通过对设计、加工工艺、装配、叶片工作过程的复查,分析和探讨了叶冠磨损的性质及原因。结果表明:装配未设定合理的初始紧度,叶片间接触面的磨损产生间隙,同时材料地面试车服役温度明显高于850℃,使得材料抗拉强度急剧下降,在振动冲击下对接触面的磨损起到促进作用,最终形成粘着磨损。

The fracture and metallographic structure of the K465 turbine blade crown have been observed with optical microscope and scanning electron microscope.The nature and causes of blade crown abrasion have been analyzed and discussed by reviewing the design,processing technology,assembly,and blade working process.The results show that the assembly does not set a reasonable initial tightness and the wear of the contact surface between the blades creates a gap,meanwhile the service temperature of the material is significantly higher than 850℃,which makes the material’s tensile strength drop sharply and the wear of contact surface worse by vibration and impact.Finally,the abrasion wear has been formed.