2A50锻造铝合金风机叶片断裂失效分析

Fracture Failure Analysis of 2A50 Forged Aluminum Alloy Fan Blade

青海某火电厂送风机叶片在运行中发生断裂。通过力学性能测试、微观形貌及能谱分析、金相观察等方法,结合叶片工况对其断裂原因进行了分析。结果表明:叶片断裂形式为应力腐蚀开裂。叶片表面腐蚀严重,出现了腐蚀坑。叶片高速运转过程中受到风力和离心力作用,在腐蚀坑处产生应力集中,引起了裂纹的萌生与扩展,最终造成叶片失稳断裂。

The blade of forced draft fan of a thermal power plant in Qinghai province fractured during operation.The fracture reason of the blade was analyzed by means of mechanical property test,micro morphology,energy spectrum analysis,metallographic observation and combined with the blade working condition.The results show that the fracture mode of the blade is stress corrosion cracking.The blade surface corrosion is serious,and the corrosion pit appears.During high-speed operation,the blade receives wind and centrifugal force,and it produces stress concentration at corrosion pit,causes initiation and expansion of cracks,and eventually causes the instability and fracture of the blade.