Application of Electrochemical Noise Technology to the Study of Pitting Behavior of 2205 Steel

The pitting corrosion behavior of 2205 steel in 0.05 mol·L^-1 HCl+6% FeCl₃·6H₂O solution was characterized by electrochemical noise (EN) analysis technique. The corrosion processes for the steel were studied in detail by analyzing time-domain and frequency-domain characteristics of electrochemical noise together with the observation of corrosion morphology. The whole process can be divided into four steps, which can be differentiated clearly according to the characteristic EN transient peaks. It was found that the current standard deviation S_I, noise resistance R_n and the slope of the current power spectrum density K_I can reflect the corrosion intensity.