发动机旋流板裂纹故障分析

Fault Analysis of Cyclone Plate Crack in a Certain Engine

发动机在返厂分解检查时发现旋流板裂纹。通过对其进行宏观观察、断口分析、组织检查及晶粒度检查等,并进行热应力和振动应力分析。结果表明:旋流板裂纹性质为高周疲劳;旋流板周向裂纹产生的主要原因与改换冲切模具冲压造成旋流板局部产生大变形而带来的损伤有关;大变形导致的损伤使旋流板压痕处的抗疲劳能力降低,在热应力和振动应力的综合作用下产生初始裂纹,裂纹沿着冲切模具产生的压痕发生周向扩展。

While an engine was returned to the factory for decomposition inspection,it was found that the swirl plate had cracks.Macroscopic observation,fracture analysis,microstructure inspection,grain size inspection,as well as thermal stress and vibration stress analysis were carried out to find out the failure cause.The results show that the cracking of the swirl plate is high-cycle fatigue cracking.The circumferential cracks of the swirl plate are mainly related to the damage caused by large local deformation during stamping by improved punching die.The damage caused by large deformation reduced the anti-fatigue performance of the indentation of the swirl plate.Under the co-effect of thermal stress and vibration stress,cracks formed,and then propagated circumferentially along the indentation caused by the punching die.