کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
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5366072 | 1388343 | 2006 | 16 صفحه PDF | دانلود رایگان |
The effects of Clâ, NO3â and SO42â aggressive anions on the corrosion and passivation behavior of carbon steel electrode in deaerated 0.50Â M NaHCO3 solutions were studied using potentiodynamic anodic polarization and SEM techniques. It was found that the presence of Clâ, NO3â and SO42â anions stimulates the anodic dissolution rate in both the active and the pre-passive potential regions. Moreover, significantly great effects were observed in both the passive and the trans-passive potential regions. Pitting corrosion was observed only in the presence of Clâ anions, while the presence of NO3â and SO42â anions facilitate only passivation by oxygen of water without themselves participating in the cathodic process. Also, it was observed that the effect of NO3â anion, which is a strong oxidizing agent acting “primarily” as stimulator of the cathodic process and then its reaction product acts “indirectly” retarding the anodic process. On the other hand, the effect of SO42â anion, which is a non-oxidizing agent, exerts an “indirect” effect on the cathodic reaction increasing its rate and then “directly” influence on the anodic reaction, retarding it.
Journal: Applied Surface Science - Volume 252, Issue 18, 15 July 2006, Pages 6179-6194