燃气轮机低压压气机转子叶片断裂分析

Fracture Analysis on Low-pressure Compressor Rotor Blade of Gas Turbine

某型燃气轮机运行近1 000 h后,发生2片低压压气机转子叶片脱榫断裂和同级多片榫头裂纹故障。通过对断裂和裂纹叶片外观观察、断口分析、化学成分分析、硬度检测和金相检验等手段,确认了断裂和裂纹叶片失效模式相同,均属振动疲劳断裂,盘和叶片配合不良引起微动磨损是该级叶片早期振动疲劳断裂的主要原因。盘、片配合不良主要是由于配合面间无防磨损涂层,在应用过程中产生氧化和磨损引起的;通过盘和叶片榫齿配合面涂干膜润滑,有效解决了盘片配合面微动磨损问题。

After working for nearly 1 000 h, two low-pressure compressor rotor blades fractured at the position of tenon and some others were found to have cracks at the same position. The failure mode was studied by macro observation, fracture analysis, chemical composition analysis, hardness testing and metallographic analysis. The results show that the failure mode for the fractures and cracks is vibration fatigue fracture. The poor fit between the disk and the blades resulted in fretting wear, which was the main cause of the early vibration fatigue failure of the blades. The poor fit between the disk and the blades was mainly caused by lack of antiwear lubricant, and thus can be effectively solved by using solid film lubricant.