GH4037合金Ⅰ级涡轮叶片断裂失效分析

Rupture Failure Analysis of GH4037 StageⅠ Turbo Blade

某发动机在服役过程中,有7片Ⅰ级涡轮叶片连续发生断裂或开裂。本文对断裂的叶片进行了断口宏微观观察、化学成分分析、金相组织检查、性能试验以及叶片排气边R检查。结果表明,叶片的断裂性质为高周疲劳断裂。断裂叶片的化学成分和力学性能符合技术条件的要求;叶片的疲劳源区未发现夹杂等冶金缺陷。7片叶片的断裂位置均在距离榫头底部62mm～67mm处,该位置是四阶振动的最大应力点,叶片的断裂与四阶振动有关。

Seven stage I turbo blades fractured during working time of an engine. Appearance test, fracture characteristics observations, chemical composition analysis, microstructure observation, mechanical test and the exhaust edge radius checking have been performed for the fracture blades. The results show that the fracture mode of the blades is high cycle fatigue. The chemical composion and machenical properties of the fracture blades all meet with technical requirements. The metallurgy defects such as inclution were not found in the source rigion of the fracture blades. The fracture position of seven blades is about 62 to 67 milli- metre from the bottom of the rabbet, and this location is the maximum stress point of the fourth order vibration. So the fracture of seven blades is related to the fourth order vibration.