Validation of the impedance spectroscopy method (MSID2/3) for NDT and SHM research in the power industry

Abstract

The article presents a method for diagnosing steel blades of a high pressure steam turbine by analyzing the frequency of the electrical and magnetic parameters of the material during its operation. The methodology is historically derived from the analysis of normalized impedance components for defect detection and material selection. It was developed by and his research team. The extended possibilities of diagnostic tests of Multipoint Impedance Spectroscopy (SID2/3) are described, including material degradation processes and not only con tinuity defects. The test results were compared with structural studies, scanning electron microscopy (SEM) and energy dispersive X ray spectrometry (EDS) and wavelength dispersive (WDS). Impedance spectroscopy takes a significant place in diagnostic tests (NDT and SHM) in domestic literature and, thanks to the author, also in foreign literature. The topic was also presented at the World NDT Congress in Munich in 2018 [23]. Articles on this topic can be found on the NDT.net website [24]. Impedance spectroscopy is the subjec t of two doctoral theses and the promotion of Doctors of Technical Sciences [27, 28]. The thematic area covered by this article is mainly aimed at comparing the results with several selected methods.