Journal of Materials Engineering and Performance

, Volume 16, Issue 4, pp 494–499

Use of Electrochemical Noise (EN) Technique to Study the Effect of sulfate and Chloride Ions on Passivation and Pitting Corrosion Behavior of 316 Stainless Steel

  • M.G. Pujar
  • T. Anita
  • H. Shaikh
  • R.K. Dayal
  • H.S. Khatak
Article

DOI: 10.1007/s11665-007-9078-3

Cite this article as:
Pujar, M., Anita, T., Shaikh, H. et al. J. of Materi Eng and Perform (2007) 16: 494. doi:10.1007/s11665-007-9078-3

In the present paper, studies were conducted on AISI Type 316 stainless steel (SS) in deaerated solutions of sodium sulfate as well as sodium chloride to establish the effect of sulfate and chloride ions on the electrochemical corrosion behavior of the material. The experiments were conducted in deaerated solutions of 0.5 M sodium sulfate as well as 0.5 M sodium chloride using electrochemical noise (EN) technique at open circuit potential (OCP) to collect the correlated current and potential signals. Visual records of the current and potential, analysis of data to arrive at the statistical parameters, spectral density estimation using the maximum entropy method (MEM) showed that sulfate ions were incorporated in the passive film to strengthen the same. However, the adsorption of chloride ions resulted in pitting corrosion thereby adversely affecting noise resistance (RN). Distinct current and potential signals were observed for metastable pitting, stable pitting and passive film build-up. Distinct changes in the values of the statistical parameters like RN and the spectral noise resistance at zero frequency (R°SN) revealed adsorption and incorporation of sulfate and chloride ions on the passive film/solution interface.

Keywords

316SSadsorptionchlorideelectrochemical noisepassive filmsulfate

Copyright information

© ASM International 2007

Authors and Affiliations

  • M.G. Pujar
    • 1
  • T. Anita
    • 1
  • H. Shaikh
    • 1
  • R.K. Dayal
    • 1
  • H.S. Khatak
    • 1
  1. 1.Corrosion Science and Technology DivisionIndira Gandhi Centre for Atomic ResearchKalpakkamIndia