Wavelet analysis of electrochemical noise measurements during corrosion of austenitic and superduplex stainless steels in chloride media

Abstract

A wavelet variance analysis procedure has been used for the characterisation of electrochemical noise measurements (ENM) made during corrosion of three grades of austenitic and superduplex stainless steels, with varying sulphur contents, when exposed to chloride media. The resulting electrochemical noise has been interpreted in terms of coupled current and free corrosion potential measurements. The wavelet variance exponent has been used to characterise the behaviour of the signals. It is shown that the wavelet analysis technique is able to discriminate between various corrosion processes covering a wide range of ENM.