Detection of corrosion degradation using electrochemical noise (EN): review of signal processing methods for identifying corrosion forms

Electrochemical noise (EN), as one of the most promising in situ electrochemical methods in corrosion and electrochemical science, has been developing rapidly in recent years with the advancements in instrumentation and signal processing methods. One advantage of EN is its application in long-term or early stage corrosion process monitoring because it instantly detects corrosion rate and corrosion forms. Investigators have applied various mathematical methods to extract characteristic parameters from EN. In this paper, identifying corrosion forms using parameters obtained from time domain, frequency domain and time–frequency domain is reviewed, and the correlation between parameters and corrosion forms is discussed. Finally, other in situ techniques are recommended to be employed synchronously with EN measurement in order to obtain reliable analyses.