国内外涡流检测标准通常规定通孔缺陷的信号相位为40°左右。但是在实际换热器管检测中发现, 泄漏缺陷信号的相位大到105°左右, 小至25°附近, 若使用常规的相位-缺陷深度曲线进行评定, 将导致缺陷深度的误差很大。分析了相关文献以及实际检测中通孔信号的涡流检测相位规律, 发现通孔类缺陷的检测相位与孔径和壁厚等体积因素有关。若通孔的金属流失量大, 则相位超前; 若金属流失量小, 则相位滞后。在使用涡流方法检测管道时, 应该结合缺陷信号的幅值和相位信息, 才能准确综合评定缺陷深度。

Eddy current testing standards at home and abroad are usually provided for through-hole defects in the signal phase for about 40 °. However, the actual detection of heat exchanger tube was found that the phase signal of leakage defects was as large as about 105 °, and as small as near 25 °. If the conventional phase-depth curve was used to evaluate the defect depth, the error would be very serious. The laws of signal phase of through-hole in relevant literature and the actual testing were analyzed, and it was found that through-hole defect signal phase was related to aperture size and wall thickness and such as volume factors. The more amount metal loss, the smaller the phase; and on the contrary, the less amount the metal loss, the larger the phase. So when testing the pipe defect with eddy current method, signal amplitude and phase should be combined to evaluate the defect size.