| The electrochemical noise analysis (ENA) technique has been studied and developed in this research, aided by the impedance measurements of various corrosion systems. An electrochemical noise measuring system was developed and used in investigations of the corrosion behaviors of several systems.;Pitting corrosion of Al alloys was studied by impedance and noise measurements. Using the pitting model, normalized pit polarization resistance R;Pure Fe was exposed to NaCl solutions with and without oxygen, and with or without inhibitor. Electrochemical noise data were collected sequentially and simultaneously for these systems. Although statistical analysis was not affected by the data collection methods, simultaneous data collection can provide frequency domain information by spectral analysis. Impedance tests were also conducted, and satisfactory results were obtained in comparing the noise resistance R;Thirteen different polymer coating systems were exposed to NaCl, artificial sea water (AS) and natural sea water (NS). Impedance and noise measurements as well as visual rating were conducted to monitor coating degradation. A remote control multi-channel measuring system was developed, which allowed impedance and noise measurements of multiple samples at a remote test location. Comparison of the impedance and noise data between AS and NS exposures were made, and statistical analyses were performed to identify the possible effects of microorganisms in NS. The damage functions of the coatings were determined for AS and NS exposures.;Equivalent circuits (EC) were used to derive the relationship between R... |
