交流漏磁检测法趋肤深度的机理与实验研究

Abstract

随着管道、储罐的推广使用,管道、储罐腐蚀泄漏事故频发。漏磁检测方法是当前最频繁使用的管道无损检测技术。探讨了交流漏磁检测中趋肤深效应的机理。首先,对交流漏磁检测的涡流效应进行实验和分析;然后,根据麦克斯韦方程组推导出模型的三维交流漏磁场分布,分析了不同频率下钢板的磁力线分布情况,从而得出交流漏磁检测中趋肤深度的规律。最后,制造一系列人工缺陷并开展实际漏磁检测实验,以验证三维仿真结果的有效性,对进一步研究该方法的机理提供了理论和实验依据。

With the wide use of pipelines and tanks,corrosion leakage accidents happen frequently.The magnetic flux leakage( MFL) testing method is currently the most commonly used nondestructive pipeline inspection technique.In this paper,the mechanism of the skin effect in AC MFL inspection is discussed.Firstly,the eddy current effects in AC MFL detection were tested and analyzed.Then,according to the Maxwell equations,the 3-D MFL field distributions were deduced,and the distributions of the magnetic induction lines under different frequencies in steel plate were analyzed,thus the law of the skin depth in AC MFL inspection was acquired.Finally,a set of artificial defects were made and the actual MFL test experiments were performed to verify the effectiveness of the 3-D simulation results,which provides a theoretical and experiment basis for further studying the mechanism of the method.