Electrochemical Noise Analysis on the General Corrosion of Mild steel in Hydrochloric Acid Solution

  • Seo, Do-Soo (Korea Heat Surface Treatment Reseach Association) ;
  • Lee, Kwang-Hak (Korea Heat Surface Treatment Reseach Association) ;
  • Kim, Heung-Sik (School of Materials Science and Engineering, University of Ulsan)
  • Published : 2008.12.01


The polarization resistance of mild steel in 0.5M hydrochloric acid has been evaluated by using impedance (Z) and linear polarization (LPR) techniques and compared to the noise resistance obtained from electrochemical noise data. The degree of localization of this general corrosion has also been discussed by evaluating localization index and power spectral density. Polarization resistance obtained by LPR technique ($28\Omega$) was higher than that obtained by impedance technique ($15\Omega$). Noise resistance ($11\Omega$) was much lower than polarization resistance measured by both of above techniques. Higher polarization resistance obtained by LPR technique is generally caused by passivation effect in the presence of scales or deposits which can introduce an increased resistance as can low conductivity electrolytes. The reason why noise resistance is lower than polarization resistance is the effect of background noise detected by using three platinum electrodes cell in 0.5M hydrochloric acid. Slope($-\beta$) of power spectral density (PSD) obtained from analysis of noise data ($-\beta$ = 3.3) was much higher than 2 which indicates mild steel corroded uniformly. Localization index (LI) calculated from statistical analysis (LI=0.08) is much lower than 1 which indicates that mild steel did not corroded locally. However, LI value is still higher than $1x10^{-3}$ and this indicates that mild steel corroded locally in microscopic point of view.


  1. W. P. Iverson, J. Electrochem. Soc., 115, 617 (1968) https://doi.org/10.1149/1.2411362
  2. G. Blanc, C. Gabrielli, and M. Keddam, Electrochimica Acta, 20, 687 (1975) https://doi.org/10.1016/0013-4686(75)90069-9
  3. G. Blanc, C. Gabrielli, and R. Wiart, Electrochimica Acta, 23, 337 (1978) https://doi.org/10.1016/0013-4686(78)80071-1
  4. K. Hladky, European Patent 084404A3, USA Patent 455709, Canadian Patent 418938, (1981)
  5. D. A. Eden, J. L. Dawson, and D. G. John, UK Patent App. 861158, (May 1986), US Patent 5139627
  6. T. Hagyard and J. R. Williams, Transactions of the Faraday Society, 57, 2288 (1961) https://doi.org/10.1039/tf9615702288
  7. W. P. Iverson, Electrochemical Society, 115, 617 (1968) https://doi.org/10.1149/1.2411362
  8. M. Seralathan and S. K. Rangarajan, Journal of Electroanalytical Chemistry, 208, 13 (1986) https://doi.org/10.1016/0022-0728(86)90292-5
  9. M. Seralathan and S. K. Rangarajan, Journal of Electroanalytical Chemistry, 208, 29 (1986) https://doi.org/10.1016/0022-0728(86)90293-7
  10. D. A. Eden, A. N. Rothwell, and J. L. Dawson, Corrosion/91, Paper 444, National Association of Corrosion Engineers, Houston (1991)
  11. G. T. Burnstein, P. C. Pistorius, and S. P. Mattin, Corrosion Science, 35, 57 (1993) https://doi.org/10.1016/0010-938X(93)90133-2
  12. P. C. Searson, Ph. D. thesis, University of Manchester, 1982
  13. M. A. Winsters, P. S. N. Stokers, P. O. Zuniga, and D. J. Schlottenmeier, Corrosion Science (1993)
  14. M. Moon and B. S. Skerry, Polymer Preprints, 35, 303 (1994) https://doi.org/10.1002/pi.1994.210350401
  15. F. Mansfeld and Z. Sun, Corrosion, Vol. 55, (1999)