In-situ electrochemical corrosion measurements were performed for high-strength low-alloy steels in 5 %wt. NaCl solutions of pH 7.5, 10.6, and 12.3 at 85 °C. It was observed that the corrosion typically reached a steady state by 60 hours. The corrosion rate at steady state was slower at higher pH, regardless of H2S concentration. The addition of H2S accelerated the corrosion rates of UD-165 at pH 7.5 and 12.3, but decreased the corrosion rate at pH 10.6. This could have been related to the autocatalytic effect of H2S and the nature of the corrosion product film on the surface. Both the Pourbaix diagrams and the surface analyses suggested that the corrosion products shifted from iron sulfides to iron oxides as the solution pH was increased.
|Original language||English (US)|
|Number of pages||18|
|State||Published - 2014|
|Event||Symposium on Corrosion General Session - 225th ECS Meeting - Orlando, United States|
Duration: May 11 2014 → May 15 2014
All Science Journal Classification (ASJC) codes