Study of imitative micro pit morphology evaluation

Abstract

This study examined the imitative micro pit formation of pitting corrosion on 304 stainless steel under electrochemical control in a 3.0% NaCl solution. Results demonstrated that the micro pits changed from a conical to a cap shape during growth, indicating that their evolution in shape and growth did not follow the same morphology over time. Additionally, the piecewise polynomial method was employed to compare real-time micro pit growth morphology evolution with current density, which was consistent with cross-sectional images of actual micro pits, enabling the separation of the pitting corrosion stages. Furthermore, 3D images obtained from SRXTM were similar to cross-sectional images of real micro pits, further validating the technique's usefulness in studying micro pits.