Effect of electrodissolution time on surface modification and corrosion resistance of AISI 304 SS

Abstract

Electrodissolution is an electrochemical process where anodic dissolution selectively removes less noble elements, like iron, while preserving noble elements, such as chromium, to improve the corrosion resistance of stainless steel (SS). This study examines the effect of electrodissolution time on the chemical composition of AISI 304 SS using eco-friendly electrolytes. The techniques X-ray photoelectron spectroscopy (XPS), electrochemical impedance spectroscopy (EIS), and cyclic potentiodynamic polarisation (CPDP) were applied to analyse the surface and corrosion properties. Electrodissolution was performed at 2 mA cm−2 for 10, 20, and 30 min in ethaline. XPS revealed an increase in the Cr/Fe ratio from 0.64 in untreated samples to 0.81 after 30 min of electrodissolution. EIS showed a general corrosion rate of 0.008 mm per year, and CPDP measured pitting resistance at 0.437 V. These results highlight the potential of electrodissolution to enhance corrosion resistance for biomedical and seawater applications.