Localized corrosion and electrochemical current noise

The analysis of current transients resulting from metastable pitting events is a useful method for the investigation of the mechanisms of localized co rrosion. Until recently, the noise of the passive current limited the detec tion of smaller metastable and pit initiation events. The analysis of the n oise itself was not very successful, and was only a disturbing factor in th e detection of the current transients. Improvements made in electrochemical data acquisition instrumentation and the appearance of novel methods of an alysis, such as microelectrochemistry, now enables the analysis of the elec trochemical noise. The investigation of localized corrosion on stainless st eels reveals, that the current noise is influenced by numerous small pit in itiation events due to the dissolution of non-metallic inclusions. This obs ervation and the dependence on surface area of the current noise help in cl arifying the mechanistic aspects of pitting corrosion.