A novel electrochemical method for monitoring corrosion under insulation

Purpose - The objective of this work was to develop practical experimental techniques for monitoring corrosion in "difficult-to-test" conditions such as corrosion under insulation (CUI).

Design/methodology/approach - An electrochemically integrated multi-electrode array namely the wire beam electrode (WBE) method has been used in combination with noise signature analysis for the first time to monitor the penetration of corrosive species under simulated corrosion-under-insulation conditions. Corrosion of aluminium exposed under insulation materials such as rock wool, glass wool, cotton wool and tissue paper has been successfully monitored.

Findings - A typical potential noise signature of a major potential jump from AA1100 WBE was observed which corresponded to the corrosive species reaching the WBE surface in WBE current distribution map. A good correlation between the galvanic current maps and the corroded surface was also observed.

Originality/value - The preliminary results suggest that the proposed novel electrochemical method is capable of monitoring CUI.