Electrochemical Noise (ECN) Measurements as a Corrosion Monitoring Tool: A Review

The present article reviews the feasibility of electrochemical noise (ECN) measurements as a corrosion probe for monitoring corrosion changes on stainless steel 304L (UNS 30403). Controlled tests for ECN and weight lossmeasurements were conducted in 10% NaCI solution for stainless steel 304L (UNS 30403). Corrosion behavior was established by comparing and analyzing ECN signals, from both time and frequency domains, to weight loss and visual observations. Conventional data treatment of the ECN parameters in both time and frequency domains yielded the same results, which related to physical weight loss and pitting observations. According to the findings of this study, electrode biasing occurred in all tested conditions. The source of biasing is unclear at the moment. However, it is believed that minor differences between the two nominally identical electrodes (e.g. surface finish, size, microstructure, temperature variations, solution composition) may be responsible for its occurrence. No definite explanation is available to justify the persistency of biasing through out a test