Analysis methods applied to electrochemical noise transient signals

In this paper an analysis technique comparison is reported. Techniques are applied to EN signals acquired during a stress corrosion cracking test. Tests are conducted following the ASTM G36 rule, using a martensitic 17-4PH iron steel, with a mechanical stress applied equal to the 90% of the yield strength. The electrochemical noise signal acquisition covered the full period of the test, using a three electrodes set-up with a ZRA configuration. The sampling frequency was 1 Hz. Acquired signals are analysed using both timedomain and frequency-domain (PSD, CWT, HHT) techniques. Results highlight that the Hilbert Huang Transform (HHT) seems to be an optimal solution for the corrosion phenomena analysis.