High-Frequency Resonance Eddy Current Multiparameter Fusion Sensing Method for 12CrMoV Steel Thermal Aging Characterization

The minimal lattice changes caused by thermal aging present a significant challenge for nondestructive testing. This study proposes the use of a high-frequency resonance eddy current (R-ECT) sensor and a multiphysical field fusion method to address this issue. Initially, high-frequency resonance technology is employed, whereby not only is an eddy current secondary magnetic field generated but also an electric field in the gap between the planar coil and the metal. Therefore, the excitation of a multiphysical field in eddy current sensors has been achieved. Second, a probe multiparameter separation algorithm is proposed. Consequently, the separation of the magnetic and electric fields can be achieved. The results of experiments conducted on 12CrMoV steel demonstrate that the parameter capacitance relating to electric fields is more accurate and linear than the parameters resistance and inductance relating to eddy current secondary magnetic fields. Finally, the multiparameter and multiphysical field fusion method is discussed in order to enhance the accuracy of thermal aging characterization. The results of the experiments demonstrate that the fusion characterization method, which combines resistance and capacitance, leads to a significant reduction in error, by as much as 80%, when applied to the characterization of eddy current magnetic fields and gap electric fields.