Application of electrochemical noise (EN) monitoring within an industrial corrosion management system involves several prerequisites. An underpinning of electrochemical characteristics must be gained with respect to relevant corrosion mechanisms, and translated into a schematic and physical measurement system with high sensitivity and resilience to false positives.
An adapted EN technique was developed using a non-symmetric electrochemical cell to confine localized corrosion to one functionalized working electrode, whilst considering the impact on interpretation. The materials studied included (i) a niobium stabilized stainless steel, used as a nuclear fuel clad material in the UK, and central to a nationally significant spent fuel management strategy and (ii) conventional stainless steels which form structural components of light water reactor (LWR) fuel assemblies. Observations were made in-situ of corrosion processes occurring through milli- to nano-meter scale to correlate degradation mechanisms to EN signals. Time-resolved measurements were made simultaneously from multiple cells and analyzed in parallel to provide mechanism distinction, uncertainties and error capture, for example, data rejection during periods of heavy interference. This research presents the ability to embed, via a proportionate action level hierarchy, unambiguous, real time “early warning” information within highly complex operational corrosion management strategies.
Key words: Electrochemical noise, Non-symmetric electrochemical cell, Localized corrosion, Early warning, In-situ monitoring, Stainless steel