Repozytorium publikacji - Politechnika Gdańska

This study investigates the corrosion behavior of dissimilar gas tungsten arc (GTA) welded joints between super duplex stainless steel (sDSS 2507) and pipeline steel (X-70) using electrochemical and immersion corrosion tests. The GTA welds were fabricated using ER2594 and ER309L fller metals. The study examined the electrochemical characteristics and continuous corrosion behavior of samples extracted from various zones of the weldments in a 3.5 wt.% NaCl solution, employing electrochemical impedance spectroscopy, potentiodynamic polarization methods, and an immersion corrosion test. EIS and immersion investigations revealed pitting corrosion in the X-70 base metal/X-70 heat-afected zone, indicating inferior overall corrosion resistance due to galvanic coupling. The corrosion byproducts identifed in complete immersion comprised α-FeOOH, γ-FeOOH, Fe3O4, and Fe2O3, whereas γ-FeOOH and Fe3O4 were predominant in dry/wet cyclic conditions. Corrosion escalated with dry/wet cycle conditions while maintaining a lower level in complete immersion. The corrosion mechanism involves three wet surface stages in dry/wet cycles and typical oxygen absorption during complete immersion. Proposed corrosion models highlight the infuence of Cl−, O2, and rust layers.

Autorzy

• Anup Kumar Maurya,
• Shailesh M. Pandey,
• Rahul Chhibber,
• dr hab. inż. Dariusz Fydrych link otwiera się w nowej karcie ,
• Chandan Pandey