Abstract

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.

中文翻译：

---

带有双频激励的涡流测试探头，可检测深裂缝

摘要

趋肤效应是涡流测试（ECT）中的常见现象，它会使涡流集中在样品表面附近，并且不能流入材料中。为了提高涡流探头探测深部缺陷的能力，提出了一种新型的双频激励探头，它可以抑制试样表面附近的涡流密度。用探头实现了识别不锈钢试样中深层裂纹缺陷的目的。在本文中，ANSYS软件用于确定探头的频率，励磁电流和线圈布置。实验证明了新探针探测深层裂纹的能力。结果表明，深度为10和15 mm的裂纹的检测信号分别为深度为5 mm的裂纹的4倍和4.47倍。