某发动机Ⅲ级涡轮叶片断裂失效分析

某发动机Ⅲ级涡轮叶片连续发生三起断裂失效，对这三个叶片的设计强度、材质进行了综合分析，并对三叶片的断口源区及源区附近的断裂细节特征进行了研究，对断口裂纹扩展区进行了定量分析，计算出了叶片的疲劳扩展寿命，并据此给出了叶片的定期检查周期。断裂的主要原因是失效位置处的锉磨缺口和振动应力，提出了采用高性能材料和提高叶片根转接R处的加工质量，及每间隔500h对第一榫齿与伸根转接R处进行检查的预防措施。

Fracture Failure Analysis of the Third Class Turbine Vanes in Some Engine

The third class turbine vanes of some engine have fractured three times successively. The designing strength, material quality and fracture characteristics nearby origin zone were analyzed. In the fatigue expansion zone, quantitative analysis was performed for calculating the fatigue expansion life and the fixed examination period of the turbine vanes was suggested. The main causes of fracture were the worn gaps at mot R of vanes and the vibration stress The preventive and improving measures, such as adopting high performnce material, improving machining quality at mot R and adopting 500 h as the fixed examination period of the turbine vanes, were also presented.