轮盘榫齿高低周复合疲劳寿命试验研究

某二级涡轮盘榫齿在外场使用中断裂失效严重,连续发生数起二级涡轮盘甩出及叶片脱榫飞出事故.断口分析表明属疲劳和腐蚀交互作用所致,为确保发动机在外场使用的安全,对这种轮盘榫齿在高温状态下,分轻、重腐蚀2种类型进行了高、低周复合疲劳寿命对比试验研究.试验较成功地模拟了实际使用中造成榫齿损坏的主要因素,试验断口表现出明显的疲劳破坏特征,实现了盘齿故障再现,其试验成果为该发动机安全飞行提供了科学依据. 

Experiment Study on Combined Fatigue of Turbine Disc Fir-tree Slots at Elevated Temperature

Based on a practical problem of the teeth crack breakdown of a turbine disc at elevated temperature, an experiment and theoretical study on L HCCF (Low and High Cycle Combined Fatigue) of fir tree slot is carried out.The major cause of the fracture is the interreaction of high and low cycle fatigue. Further studies including contrast experiments of light and serious corrosion disc slot are also conducted. Major service factors are successfully simulated and the experiment results show obvious fatigue failure feature which is identical with that in service. A new designed test system, achieving low and high cycle noninterfering loading, high frequency induction local heating ,and the control of high cycle vibration frequency and amplitude,and the crack propagation real time detection,is established for all above purpose. This investigation is very helpful in establishing the failure standards of turbine disc's slot with corrosion.