Advanced Characterization and Corrosion Behavior Analysis of AISI SS 304 and SS 316 in HCI Solutions

Advanced material characterization and electrochemical corrosion behavior of AISI SS304 and SS316 were examined in hydrochloric acid HCl solutions at various concentrations. In this research, electrochemical techniques such as open-circuit potential (OCP) method, potentiodynamic polarization (PDP), Tafel curves, cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), Scanning electron microscopy (SEM), and X-ray photo-electron spectroscopy (XPS) were used to characterize the microstructure and texture of AISI SS304 and SS316. The corrosion rate of AISI SS304 and SS316 escalates with increasing temperature and shows significant susceptibility to pitting formation and growth as the concentration of hydrochloric acid rises from 0.3 to 2 M. The corrosion rates of AISI SS304 and SS316 are positively correlated with both higher acid concentrations and elevated temperatures. Cyclic voltammograms obtained at different cycle numbers and potential scanning rates revealed that AISI SS304 is less resistant to pitting corrosion than AISI SS316 at room temperature T = 294K. Electrochemical impedance spectroscopy EIS measurements indicate that the charge transfer resistance R _ct of electrons across the interface between the metal surface of both grades and the corrosive medium is higher at 0.3M HCI. The charge transfer resistance R _ct of AISI SS 316 is greater than that of SS 304 indicating that AISI SS 316 has better corrosion resistance.