基于磁致伸缩超声导波的管道周向扫查技术

The Circumferential Scan Technology for Pipes Based on Magnetostrictive Ultrasonic Guided Waves

超声导波因其单点激励、传播距离远、全截面检测等突出优势,已被大量应用于油气管道的检测中。然而,现有的轴对称超声导波检测方法只可以通过A扫信号对缺陷在管道轴向的位置进行定位,且在大直径管道以及焊接支架、不等径三通等特定部位的检测效果不佳。通过建模和仿真对比了基于局部加载下的周向扫查技术和现有导波检测技术在管道上的应用特点,得出周向扫查技术更适用于大直径管道的中距离检测的结论。最后开展了验证试验,验证了周向扫查技术可通过B扫成像图对管道上的缺陷进行轴向和周向定位,缺陷回波幅值是现有T(0,1)模态导波检测的3倍以上。

Ultrasonic guided waves have been widely used in oil and gas pipelines nondestructive evaluation due to its various corresponding advantages, such as single-point excitation. long detection range and 100% cross- sectional detectability. However . the existing ultrasonic guided waves detect technology only can locate the defects in the axis position along the pipe by A-scan signal, and the application effectiveness is not good in large diameter pipes and some specific parts, such as pipe bracket and unequal-diameter three-way piece. This article compares the application characteristic of circumferential scan technology with existing detect technology by modeling and simulation, and has found that the circumferential scan technology is more suitable for middle range of large diameter pipe. Then numerical evaluations and experiments indicate that the defects both in axial and circumferential direction can be located by B-scan imaging by using circumferential scan technology, and the backscattering amplitude of defects is three times larger than that by existing T(0,1) mode detected.