An Eddy Current Testing Probe with Dual-Frequency Excitation to Detect Deep Cracks


The skin effect is a common phenomenon in the eddy current testing (ECT), which can make the eddy currents concentrated near the specimen surface and cannot flow into the material. In order to improve the ability of the eddy current probe to detect the deep defects, a new probe with dual-frequency excitation is proposed, which can suppress the eddy current density near the surface of the specimen. The purpose of identifying deep crack defects in stainless steel specimen is achieved with the probe. In this paper, the ANSYS software is used to determine the frequency, excitation current and coil arrangement of the probe. The ability of the new probe to detect deep cracks is verified by experiments. The results show that the detection signal of the cracks with depth of 10 and 15 mm is 4 times and 4.47 times than that of the crack with 5 mm depth. It is more sensitive to the depth change of deep cracks.

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This work was supported in part by National Natural Science Foundation of China (Grant no. 51667001), Key Scientific Research Projects of North Minzu University (Grant no. 2019KJ36) and General research projects of Key Laboratory of Chemical Engineering and Technology Foundation of State Ethnic Affairs Commission (Grant no. 2017HG06).

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The methodology and programming was performed by Dongli Zhang. Material preparation, data collection and validation were performed by Chuanglong Wang. The first draft of the manuscript was written by Chuanglong Wang. Revision and polishment of the manuscript was performed by Meixian Wu.

Funding acquisition was performed by Dongli Zhang and Meixian Wu. All authors read and approved the final manuscript.

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Correspondence to Dongli Zhang.

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Chuanglong Wang, Wu, M. & Zhang, D. An Eddy Current Testing Probe with Dual-Frequency Excitation to Detect Deep Cracks. Russ J Nondestruct Test 56, 1056–1063 (2020).

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  • ECT
  • probe
  • Deep Crack
  • dual-frequency excitation