钢管无损检测中的磁致伸缩导波技术试验研究

为了研究磁致伸缩导波技术对输气和输液钢管缺陷的无损检测能力,基于磁致伸缩导波检测技术,设计了磁致伸缩导波检测装置。在同一频率下分别对4根充气和充液管道不同位置的已知缺陷进行导波无损检测试验,其方法是主机产生特定大功率信号,输入到激励传感器,磁致伸缩效应在管道中产生导波,对采集信号进行数据处理,判断管道已知的焊缝及法兰有无及位置。试验结果验证了磁致伸缩导波技术对输气和输液管道无损检测的可行性,证明了该技术能够较好地检测到充气直管焊缝、法兰及支撑结构等管道突变缺陷及位置,但较难应用于弯管的检测,充液管道能够被检出缺陷,但较输气管道的衰减大,检测距离将大幅衰减。

Research of magnetostrictive ultrasonic guided wave technique in nondestructive test of steel pipes

To verify the feasibility of magnetostrictive ultrasonic guided wave technique in testing nondestructively the defect of steel pipes transporting gas or liquid, based on magnetostrictive ultrasonic guided wave technique theory and advantages, a new magnetostrictive ultrasonic guided wave detect equipment is designed. Four steels pipes filled with gas and liquid which have known defects are detected under a certain frequency using magnetostrictive ultrasonic guided wave technique. Computer sends a specific high-power signal to excitation coil, and ultrasonic guided wave is generated due to magnetostrictive effect. The collected signal is data processed, and the defect positions of known weld beads and flanges can be determined. The results show that the technology can test the defect positions of known weld beads, flanges and strut points in straight steel pipes filled with gas, but it''s difficult to test curved pipes; the defects of liquid pipes can be detected, but the wave attenuation in liquid pipe is bigger than that in gas pipe, and the detection distance would be sharply attenuated.