Corrosion Science and Technology

The Corrosion Science Society of Korea (한국부식방식학회)
권호 표지
DOI QR코드

DOI QR Code

An Electrochemical Method to Predict Corrosion Rates in Soils

  • Dafter, M.R (Hunter Water Australia Pty Ltd.)
  • Received : 2016.09.22
  • Accepted : 2016.10.20
  • Published : 2016.10.31
Download PDF
⟨ Previous Next ⟩

Abstract

Linear polarization resistance (LPR) testing of soils has been used extensively by a number of water utilities across Australia for many years now to determine the condition of buried ferrous water mains. The LPR test itself is a relatively simple, inexpensive test that serves as a substitute for actual exhumation and physical inspection of buried water mains to determine corrosion losses. LPR testing results (and the corresponding pit depth estimates) in combination with proprietary pipe failure algorithms can provideauseful predictive tool in determiningthe current and future conditions of an asset. Anumber of LPR tests have been developed on soil by various researchers over the years1), but few have gained widespread commercial use, partly due to the difficulty in replicating the results. This author developed an electrochemical cell that was suitable for LPR soil testing and utilized this cell to test a series of soil samples obtained through an extensive program of field exhumations. The objective of this testing was to examine the relationship between short-term electrochemical testing and long-term in-situ corrosion of buried water mains, utilizing an LPR test that could be robustly replicated. Forty-one soil samples and related corrosion data were obtained from ad hoc condition assessments of buried water mains located throughout the Hunter region of New South Wales, Australia. Each sample was subjected to the electrochemical test developed by the author, and the resulting polarization data were compared with long-term pitting data obtained from each water main. The results of this testing program enabled the author to undertake a comprehensive review of the LPR technique as it is applied to soils and to examine whether correlations can be made between LPR testing results and long-term field corrosion.

Keywords

References

  1. D. M. F. Nicholas, Review of the Linear Polarisation Resistance Technique (LPR) Methodology for the Condition Assessment of Buried Ferrous Pressure Pipelines, WSAA (2009).
  2. M. R. Dafter, Proceedings of the ACA Conference on An Electrochemical Method to Measure Corrosion in Soils, ACA, Coffs Harbour (2009).
  3. M. R. Dafter, Proceedings of the ACA Conference on Practical Considerations for Electrochemical Testing of Soils, ACA, Adelaide (2010).
  4. M. R. Dafter, Proceedings of the ACA Conference on Electrochemical Impedance Spectroscopy of Soils, ACA, Perth(2011).
  5. M. R. Dafter, D. M. F. Nicholas and R. E. Melchers, Proceedings of the ACA Conference on Prediction of Long-Term Corrosion in Soils using Electrochemical Tests, ACA, Melbourne (2012).
  6. M. R. Dafter, Proceedings of the ACA Conference on Long-Term Corrosion of Buried Watermains Compared with Short-Term Electrochemical Testing, ACA, Brisbane (2013).
  7. D. M. F Nicholas, and G. Moore, Proceedings of the ACA Corrosion Conference on Corrosion of Ferrous Watermains: Past Performance and Future Prediction: a Review, ACA, Sydney (2007).
  8. I. S. Cole and D. Marrney, Corros. Sci., 56, 5(2012). https://doi.org/10.1016/j.corsci.2011.12.001
  9. R. B. Petersen, M. R. Dafter and R. E. Melchers, Proceedings of the ACA Corrosion Conference on Modelling the Long-Term Corrosion of Cast Iron Pipes, ACA, Brisbane (2013).
  10. ASTM D6913-04, Standard Test Methods for Particle-Size Distribution (Graduation) of Soils using Sieve Analysis (2009).
  11. G. S. Campbell, Determining the -15bar (permanent wilt) Water Content of Soils with the WP4C, Application Note, http://www.decagon.com.
  12. M. R. Dafter, Ph. D. Thesis, University of Newcastle (2014).
  13. M. Heathcote and D. M. F. Nicholas, Life assessment of Large Cast Iron Watermains, UWRAA Report 146 (1998).
  14. L. Hay, Ms. Thesis, The University of Sydney (1984).
  15. D. M. F. Nicholas, Private correspondence (2014).
  16. M. Norin and T.-G.Vinka, Mater. Corros., 54, 641 (2003). https://doi.org/10.1002/maco.200303680
  17. R. E. Melchers, Proceedings of the ACA Conference on Long-Term Corrosion of Grey Cast Iron in Marine Environments, Melbourne (2012).