Do Wettability Measurements Define Corrosion Inhibition of Etched Surfaces? A Study on Acid-Etched 316L Stainless Steel

Abstract

Special wetting surfaces have attracted attention owing to their potential applications in the automotive, engineering, environmental, and biomedical industries. Specifically, nature-inspired superhydrophobic surfaces are more effective in blocking moisture, thus limiting corrosion. Hence, surface wettability analysis remains the primary method for demonstrating the corrosion mitigation characteristics of rough-engineered surfaces. Herein, the influence of wettability measurements on the corrosion inhibition of 316L stainless steel surfaces etched in HCl: HNO₃ acid is systematically investigated. Interestingly, etched hydrophobic surfaces with a contact angle of ≈125° significantly improve the corrosion resistance by 50%, resulting in suppressed corrosion rates. Furthermore, the surface chemical states of the etched 316L steel are analyzed and discussed in detail.