奥氏体不锈钢管道导波信号分析技术研究

Research on Guided Wave Signal Analysis Technology of Austenitic Stainless Steel Pipeline

奥氏体不锈钢管道超声导波检测具有长距离、全范围覆盖等优点,由于奥氏体不锈钢材料具有高衰减和各向异性,其导波信号信噪比较低,较低幅值的缺陷信号被噪声信号湮没,使有效检测距离下降甚至漏检。通过加工含多种缺陷的奥氏体不锈钢样管,获取导波检测信号,基于匹配追踪算法,采用时频信号分析的方法对信号进行处理。结果表明:该方法能有效分离检测信号中的噪声,使信噪比提高6 dB以上,去噪后,能够有效识别信号中的样管缺陷。

Ultrasonic guided wave testing of austenitic stainless steel pipeline had the advantages of long distance and full coverage. Due to the high attenuation and anisotropy of the austenitic stainless steel material, the signal-to-noise ratio of the guided wave signal was low, and the low-amplitude defect signal was annihilated by the noise signal, which reduced the effective detection distance or even misses the detection. By processing the austenitic stainless steel sample tube with multiple defects, the guided wave detection signal was obtained. Based on the matching pursuit algorithm, the signal was processed by the method of time-frequency signal analysis. The results showed that this method could effectively separate the noise in the detection signal and increase the signalto-noise ratio by more than 6 dB. After denoising, it could effectively identify sample tube defects in the signal.