Electrochemical Noise Detection During Slow-strain-rate-testing of Sensitized 304SS

The corrosion behaviors of sensitized 304 SS were studied in 0.5 mol/L Na2S2O3 solution under slow-strain-rate-testing (SSRT) condition by electrochemical noise (EN). The electrochemical voltage and current noise were measured simultaneously in the zero resistance ammeter (ZRA) mode. There were several cracks at the surface of the specimen. In order to characterize the stress corrosion cracking (SCC) processes of sensitized 304SS, time analysis of the current data along with the spectral estimation that the using (FFT) method and Wavelet analysis gave useful information of these corrosion processes. The results showed SCC processes consisted of crack initiation and crack propagation. According to the varieties of spectrums in time, frequency domain and current energy distribution by wavelets analysis, the different state can be distinguished. The present work contribute to the research of indicator for real-time detection of SCC in plant.