汽轮机叶片叶身及围带的涡流检测

Eddy current testing of steam turbine blade body and its shroud

针对汽轮机叶片检测的特殊性(如形状不规则、检测空间限制、检测比例低、检测方法少等特点),采用笔式单探头和指套式单探头进行涡流检测试验。模拟裂纹对比试样试验表明,2种探头均可有效检出缺陷,便于操作的指套式单探头灵敏度相量幅度比笔式单探头低50%左右,边缘或拉筋孔的检测需开发专用探头或工装来保障探头移动平稳。现场应用表明,涡流检测叶身及围带有一定优势,是常规检测方法的有效补充。

For the particularity of turbine blade test,such as the shape irregularity,test space limitation,low test ratio and few test methods,etc.,this paper carried out the eddy current testing experiments using pen-based single probe and fingertip single probe. The simulating crack comparison tests showed that both of the two kinds of probes could effectively detect defects,the phasor amplitude sensitivity of easy-operating fingertip single probe is about 50% lower than the pen-based single probe,and the detection of edge or lacing hole need to develop a special probe or tooling in order to ensure the smooth moving of probe.Field application indicated that the eddy current testing have certain advantages for the steam turbine blade body and its shroud,which is an effective supplement to conventional detection methods.