ScienceAsia 32 (2006): 007-012 |doi: 10.2306/scienceasia1513-1874.2006.32.007

Monitoring Pitting Corrosion of Carbon Steel Using the Combined WBE-Noise Signatures Method

Naing Naing Aung^* and Nurot Panich

 
ABSTRACT: An electrochemically integrated multi-electrode array namely the wire beam electrode (WBE) in combination with noise signatures analysis has been applied to study localized corrosion, especially pitting. The classic pitting corrosion of carbon steel in Evans solution was carried out by the correlation of electrochemical potential noise signatures and WBE current distribution maps. During carbon steel pitting corrosion process, the characteristic ‘peak’ of rapid potential transient, towards less negative direction, followed by recovery was found to correlate with the disappearance of unstable anodes leading to formation and propagation of stable anodes in WBE current distribution maps. Localized corrosion was the result of the anodic dissolution of the remaining anodic sites after disappearance of unstable anodes. This result suggests that the combined WBE-noise signatures method could be applied as a means of early detection and prediction of localized corrosion.

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School of Materials Science and Engineering, Nanyang Technological University, Singapore 639798.

* Corresponding author, E-mail: p115573@ntu.edu.sg

Received 14 Jan 2005, Accepted 15 Aug 2005