Duplex Stainless Steel Laser‐Surface Textured: Stability in Brine Solution

The stability of duplex stainless steel (DSS) laser‐surface textured (LST) in brine solutions is of significant interest for industrial applications. The present study reports evidences that passive films on smooth DSS2205 surfaces (Blank) deteriorate early (<96 h) if compared to oxidized and textured surfaces of LST samples (>96 h). This lower performance is detected in anodic polarization and in accelerated cyclic polarization tests with increasing exposition time and in harsh conditions. Although both surfaces maintain their chemical resistance against corrosion in noncyclic potentiodynamic experiments, the LST microstructure shows a broader passivation area with a larger potential range than the control samples. Moreover, the DSS2205 microstructure patterned surface is preserved. On the contrary, localized corrosion with macroscopic pits and microcracks is extended on the whole Blank surface. The α / γ crystalline phase ratio was reduced in corroded flat surface, while it remains stable in the corroded LST specimens, thanks to a significant formation of FeCr ₂ O ₄ as a protective oxide film, as proved by Raman. Thus, LST treatments promise some advantages over nontreated interfaces, particularly for metallic pieces that will be in contact or installed close to salt environments.