Study On Two Kinds Of Corrosion Detecting Technique In Field

In recent years, corrosion in field detecting techniques develops very quickly. But few about Al alloy atmospheric corrosion detecting and grounding grid corrosion detecting are reported, therefore, this paper was focused on the above two difficulties.Fiber Optical Corrosion Sensor (FOCS) based on non-electrochemical technique was studied to detect Al alloy atmospheric corrosion. The technics of fabricating pure Al corrosion sensing film with vacuum sputter were groped. Physical analysis techniques, such as Metallographic Microscope, Scanning Electron Microscope (SEM), X-ray diffraction spectrum were used to study the structure parameters of the film. And the corrosion performance of the sensing film in low-concentration NaCl solution (0.001-0.1mol/L) was evaluated with galvanostatic step and Electrochemical Impedance Spectroscopy (EIS). The results show that the pure Aluminum corrosion sensing film distributes even around the fiber core, and has good surface condition. And the crystal structure and corrosion performance were similar to that of industrial pure aluminum. The treated sensing film is expected to meet the requirement of the sensor fabrication. And the work established foundation for later optics sensing performance studying.The key of corrosion detecting technique of ground grid was to solve the problem of in field current distribution, detecting methods and the noise interfering. A detecting probe with current limited structure was designed and fabricated. Its capability of detecting voltage was steady, and the current limitation function was obvious. The corrosion of the ground grid of the Panshan power station transformer substation was detected with the detecting probe and detecting system. The data were analyzed with wavelet analysis program to wipe off the noise interfering. The results showed that the detecting probe, detecting system and methods were adaptable to in field inspection; however more work still has to be done to evaluate the corrosion of the ground grid.