Acetate and Chloride Effects on Hydrogen Production across Crevices

Abstract:

Crevice corrosion experiments on pure iron were carried out in a 0.5 M acetate buffer with varied chloride concentrations. Changes in resultant currents and morphology due to crevice attack were explained by IR potential drop mechanisms. The specimens experienced potential drop inside the crevice, which resulted in the formation of passive, active, and hydrogen evolution regions. The passive region did not exist in the electrolyte containing 0.05 M and 0.5 M chloride. Hydrogen evolution, which occurred inside the crevice was measured on rear side of the specimen using hydrogen permeation test. The results suggest that the hydrogen produced inside the crevice is measurable using a permeation test. The entry of diffusible hydrogen showed a significant increase with the addition of chloride into the acetate buffer.

• Periodical: Materials Science Forum (Volume 512)
• Pages: 97-102
• DOI: https://doi.org/10.4028/www.scientific.net/MSF.512.97
• Online since: April 2006
• Authors: T. Sundararajan, Eiji Akiyama, Kaneaki Tsuzaki
• Keywords: Acetate Buffer, Chloride, Crevice Corrosion, Hydrogen Permeation, IR Drop Mechanism, Iron

References

[1] NaOH compartment; 2. Acetate buffer compartment; 3. Pt wire; 4. Reference electrode.

[5] Separating plate; 6. Slit for specimen to expose into NaOH(opposite to the crevice side).

[7] Specimen; 8. Crevice plate; 9. Bolt; 10. Electrical connection from specimen to potentiostat.

[11] Crevice mouth; 12. Silicone paste at crevice bottom (also at sides).