Monitoring localized and general corrosion using membrane-based electrochemical sensors

In previous years, we have explored the use of electrochemical sensors for humidity and corrosion measurements inside of natural gas pipelines. Designed to operate in systems where a conductive aqueous phase is intermittent or unavailable, these membrane-based sensors utilize electrochemical techniques such as linear polarization resistance and electrochemical impedance spectroscopy to determine the environment’s corrosivity to the pipeline material. We now aim to explore this sensor’s performance and capabilities in more complex systems, specifically in environments that promote localized corrosion. Using the aforementioned electrochemical techniques, along with electrochemical noise and cyclic voltammetry, we probe and monitor localized corrosion and general corrosion of X65 steel in the presence of inorganic pitting agents. Experiments are conducted in both aqueous and nonaqueous environments. The additional functionality increases the quantity and quality of corrosion data from these sensors, offering to internal corrosion-monitoring programs a more complete picture of real-time corrosion within their natural gas pipelines.