摘要
发动机在进行试车时发现Ⅰ级涡轮叶片在进气边出现裂纹。涡轮叶片材质为K465铸造高温合金,截至裂纹发现时,发动机累计工作时间为145 h。通过外观观察、断口观察、金相检查和温度热模拟试验等手段,分析了叶片裂纹的性质和原因。结果表明:Ⅰ级涡轮叶片裂纹性质为疲劳裂纹;叶片出现裂纹的原因是榫头型芯未脱除干净,榫头冷却通道堵塞,叶片超温造成组织和性能弱化,导致叶片在高温区萌生裂纹,提前失效;根据热模拟试验结果可以判断,叶片裂纹处承受温度在1 260℃以上。
A first-stage turbine blade in aero-engine cracked at the leading edge during 200 h accelerating trial. The turbine blade was made of K465 superalloy. The engine had worked for 145 h when the crack was found. To find out the failure mode and cause of the blade, appearance observation, fracture observation, metallographic examination and thermal simulation experiment were carried out. The results show the failure mode of the blade is fatigue crack. The crack was caused by over heat because the tenon core had not been completely cleaned and the tenon cooling channel was blocked. Over heat weakened microstructure and property of the blade. As a result, the blade cracked at high temperature region and early failure happened. According to the result of thermal simulation experiment, it is estimated that the temperature of the blade near the crack was over 1 260 ℃.
出处
《失效分析与预防》
2015年第1期15-20,共6页
Failure Analysis and Prevention
关键词
K465
疲劳裂纹
超温
初熔
K465
fatigue crack
over heat
incipient melting
