Affiliations: [a] State Key Laboratory for Strength and Vibration of Mechanical Structures, Shaanxi Engineering Research Center of Nondestructive Testing and Structural Integrity Evaluation, Xi’an Jiaotong University, Xi’an 710049, Shaanxi, China | [b] Innovative Energy Research Center, Institute of Fluid Science, ELyTMaX UMI3757, Tohoku University, Aoba-ku, Sendai 980-8577, Japan
Correspondence:
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Corresponding author: Zhenmao Chen, State Key Laboratory for Strength and Vibration of Mechanical Structures, Shaanxi Engineering Research Center of Nondestructive Testing and Structural Integrity Evaluation, Xi’an Jiaotong University, Xi’an 710049, Shaanxi, China. Tel./Fax: +86 29 82668736; E-mail: chenzm@mail.xjtu.edu.cn.
Abstract: One of the major safety issues in nuclear power plants is pipe wall thinning where the pipe is mainly of magnetic material. Due to the large magnetic relative permeability of piping and the skin depth effect, the conventional PECT method is difficult for detecting the opposite side wall thinning. In this study, a pulsed eddy current testing (PECT) method under magnetic saturation was proposed and validated through numerical simulations and experiments. First, the mechanism of how magnetic saturation can increase the skin depth was studied through numerical simulation with help of COMSOL Multiphysics software. Second, the detection sensitivity of magnetic field signal and voltage signal for wall thinning defect of specimens with various magnetic permeability was investigated through numerical simulation. Finally, the experiments of magnetic saturation PECT were conducted, and the feasibility and superiority of the proposed magnetic saturation PECT method were demonstrated.
Keywords: Magnetic material, magnetic saturation PECT, numerical simulation, experiment, detection sensitivity
