针对油气管道在外加磁场条件下磁化至非饱和状态时，管道缺陷不能被漏磁方法检测的问题，利用铁磁性材料高磁导率特性，研制了钢板漏磁检测装置，介绍了漏磁检测原理及各部分结构。利用该装置进行了大量试验并构建了试验装置的ANSYS三维仿真模型。对比分析了检测信号幅值与不同厚度钢板之间的电磁对应关系。试验结果表明，此装置能够在合适磁化条件下检测出小于20 mm厚钢板的10%深的上下表面缺陷，20 mm也为临界的磁化饱和状态点。

On the question of unsaturated magnetic field of the oil and gas pipeline being liable to resultin undetected defects, high magnetic permeability of the ferromagnetic material was used to develop the MFL test instrument. This article introduced the principle of the detection and the various parts of the device comprehensively. The ANSYS 3D model was constructed and the critical value of the non-saturation magnetic field was found. Through massive physical experiments, the electromagnetic correspondence relationship between the detection signals and the steel sheet was analyzed. The test results showed that the apparatus could detect the defects of 10% of the upper and lower surfaces of the steel plate with less than 20mm thickness, under the appropriate magnetization condition.