Eddy Current Testing Frequency Optimization of Steel Tube Based on ANSYS Simulation

In traditional eddy current testing,the optimal excitation frequency is difficult to determine and deviations are usually encountered during practical examination. To solve this problem,an inner coil and through-type eddy current testing model for a 1Cr18Ni9 Ti stainless steel tube with 19 mm diameter and 2 mm thickness was established using the common finite element software ANSYS. According to the characteristic of differential probe,the real and imaginary part of the electric current,IREALand IIMAG,and the impedance difference Z of the coil with different distance from defect were calculated and then the simulation signal of the artificial defect were obtained. After a careful comparison between the amplitude and phase of the signal of different frequencies,the optimal testing frequency of through-type eddy current was determined as 50 kHz.