Quantitative Understanding of the Current Responses under Elastic Cyclic Loading for 304 Stainless Steel

Abstract

The electrochemical current responses induced by cyclic stress can provide valuable information on the surface damage; therefore quantitative understanding of the current responses cannot be over emphasized. A theoretical model has been proposed to explain the current responses under elastic cyclic loading for 304 stainless steel in 1 M NaCl (pH 2) solution. The model predicts that the current amplitude increases linearly with increasing frequency, stress amplitude and applied potential. Additionally, the phase angle is a function of frequency, double layer capacitance and solution resistance. The deviation of linear law at high frequency is due to the solution resistance. The model successfully explains the observed results and those reported in the literature, which demonstrates that the non-faradaic current dominates during elastic cyclic loading. The proposed model is helpful in the study of more complicated corrosion behavior during cyclic loading, since the non-faradaic current can be reasonably removed mathematically.