| In this work the study of the passivity of UNS S32003 was carried out utilizing different electrochemical, microscopy and surface characterization techniques. Optical profilometry, SEM and direct current electrochemical tests were used to support the materials characterization. A high resolution quantitative analysis from x-ray photoelectron spectroscopy (XPS) data was performed to quantify the interfacial properties of the metallic substrate; the experimental results were used to develop a theoretical approach by assuming a point defect model (PDM). This model was adapted and optimized based on electrochemical impedance spectroscopy (EIS) test results. The purpose of this work is to develop detail evaluation of the performance of this alloy in chloride-bearing environments at the interface level. The experimental results based on EIS influence the model concept, the PDM model considered a set of boundary heterogeneous reactions and transport of point defects across a passive crystalline oxide layer, the deterministic model helped to characterize the electronic properties, spatial composition distribution and the mobility properties within the layer. EIS results were used to fit the PDM and were used to determine the values of meaningful properties that can guide the path for performance of UNS S32003 in corrosive environment. |
