Eddy Current Effect in Pulsed Magnetic Flux Leakage Testing

In order to comprehend the characteristic of eddy current effect in pulsed magnetic flux leakage testing, this paper lays the foundation to further analyze pulsed magnetic flux leakage testing signal, builds simulating model of finite element in pulsed magnetic flux leakage testing, observes the distribution of transient magnetic field and induced eddy current in the test and analyzes and studies the features of characteristic quantity of induced eddy current and influential factors. The result shows that transient magnetic field and induced eddy current overall correspond with skin effect and affect each other in pulsed magnetic flux leakage testing. Induced eddy current has the feature of shallow penetrating depth and strong induction. Peak time of eddy current density has relative stronger resolution on depth direction. Electrical conductivity and magnetic conductivity affect the penetrating depth of induced eddy current and resolution of peak time of density on depth direction; pulsed stimulating ascendant time constant only affects the penetrating depth of induced eddy current, not relevant to resolution of peak time of density on depth direction.