中文摘要：

根据有限元方法，建立了考虑磁导率非线性条件下的脉冲涡流检测系统瞬态数学模型；在磁导率非线性条件下，对不同激励电流下的油套管脉冲涡流检测过程进行了仿真。通过对每一时刻的磁导率进行迭代计算，得到更为精确的求解结果。利用该模型，获得了不同激励电流下4mm腐蚀深度时所产生的脉冲涡流信号检测结果。根据仿真计算检测结果，发现由于材料磁导率非线性特点的存在，加大激励电流并不一定能提高检测灵敏度。

英文摘要：

According to the principle of 2D electromagnetic finite element analysis, a transient mathematic model of pulsed eddy current（PEC） testing system considering permeability nonlinear was established and simulation research for oil casing PEC testing process of different drive current was conducted in permeability nonlinear. Through the iterative calculation to permeability by every moment, more accurate results were obtained. Using this model, we achieved the PEC signals detection results corresponding to the different excitation current in 4 mm corrosion depth. According to the test results, we found that due to the material permeability nonlinear, increasing excitation current does not necessarily improve the detection sensitivity.