MONITORING OF CORROSION UNDER CATHODIC PROTECTION CONDITIONS UTILIZING COUPLED MULTIELECTRODE SENSORS
Real-time corrosion monitoring for carbon steel materials in simulated seawater under cathodic protection conditions was conducted, utilizing coupled multielectrode sensors. It was demonstrated that the coupled multielectrode sensor is an effective real-time tool for monitoring the effectiveness of cathodic protection and for measurement of the threshold value of the protection potential for specific equipment.
ONLINE MONITORING OF UNDERCOATING CORROSIONS UTILIZING COUPLED MULTIELECTRODE SENSORS
Online monitoring of carbon steel corrosion under different commercial coatings was conducted, utilizing coupled multielectrode sensors. The experimental results showed that the coupled multielectrode corrosion sensor is an effective tool for detecting initial defects and real-time degradation of the coatings. Because of their high sensitivity, the coupled multielectrode sensors may also be used as a quick and convenient tool for optimizing the selection of proper coatings for different applications.
Microbially influenced corrosion of stainless steels in nuclear power plants
This paper reviews the components, causative agents, corrosion sites, and potential failure modes of stainless steel components susceptible to microbially influenced corrosion (MIC). The stainless steel components susceptible to MIC are located in the reactor coolant, emergency, and reactor auxiliary systems, and in many plants, in the feedwater train and condenser. The authors assessed the areas of most high occurrence of corrosion and found the sites most susceptible to MIC to the heat-affected zones in the weldments of sensitized stainless steel. Pitting is the predominant MIC corrosion mechanisms, caused by sulfur reducing bacteria (SRB). Also discussed is the current status of the diagnostic, preventive, and mitigation techniques, including use of improved water chemistry, alternate materials, and improved thermomechanical treatments. 37 refs., 3 figs.