Abstract
Soil is a complex environment where various forms of localized corrosion could occur on buried metal structures such as pipelines. Protective coatings and cathodic protection (CP) are widely applied as principal means of protecting buried steel pipeline from soil corrosion, unfortunately coating defects and disbondment could create some complex environmental conditions for localized corrosion to initiate and propagate. Stray currents could also cause dynamic and rapid localized corrosion on buried pipelines. This paper summarizes typical results and first-hand experiences from recent work aimed at developing corrosion probes based on an electrochemically integrated multi-electrode arrays for monitoring and understanding complex forms of localized corrosion on buried pipelines. Experimental and field testing results have demonstrated the capability of the probes to be used in laboratory research and field conditions. Evidence found on localized corrosion under disbonded coatings and stray currents illustrate some of the unique advantages of the electrode array method for visualizing and understanding localized corrosion of buried steels. It also briefly discusses needs for future work to enhance the reliability of corrosion probes as a structural health monitoring tool for early detection and diagnosis of corrosion, for providing industrial system ‘health’ alarm, for forecasting maintenance requirements, and for generating data for integrated and automated corrosion management systems.
