VISUALIZING DYNAMIC CORROSION AND COATING DISBONDMENT PROCESSES ON SIMULATED PIPELINE CONDITIONS

摘要

This paper presents an overview of several new methods we developed to overcome major difficulties in monitoring and evaluating buried pipeline corrosion and coating failure under complex environmental conditions.We take advantage of the high temporal and spatial resolution of an electrochemically integrated multi-electrode array for probing localised electrode processes evolving and propagating dynamically on pipeline steel surfaces under the effect of cathodic shielding,anodic transients and coating disbondment.We present cases to illustrate:(i)monitoring localised corrosion under dynamically changing electrochemical environments beneath a simulated pipeline coating,(ii)visualising passivity and its breakdown,and localised pipeline corrosion under the effect of dynamic anodic transients,and(iii)visualising coating disbondment under excessive cathodic protection conditions.