Optimization of 8-shaped Coil for Crack Detection Using Resonance Eddy Current Technology

Carbon steel materials are widely used in various pipelines in nuclear power equipment. However, due to its long-term exposure to high-temperature and high-pressure environments, its surface is prone to defects. Stress corrosion cracking (SCC) is one of the defects, which usually appears as a colony and is small in size, making it difficult to detect. To detect the SCC defects, the resonant eddy current testing (RECT) technology is used, and the probe is designed and optimized in this paper. The probe composed of two 8-shaped excitation coils and two rectangular receiver coils is designed, and the inclined edges angle and the superimposed angle of the 8-shaped excitation coils are optimized by simulation and experiment. Results show that when the inclined angle is 90 ° and the superimposed angle is 90 °, the probe has higher detection sensitivity. This work can provide a method for SCC detection in nuclear power.