Under Deposit Corrosion (UDC)
At the Curtin Corrosion Engineering Industry Centre, the UDC investigations involve mechanistic studies in the presence of various types of deposit. In general, the presence of deposits at a steel surface is likely to result in localized corrosion. The chemical and physical properties of a deposit will affect the mechanism of corrosion taking place at the steel surface and thus the extent of the localized attack. For example, our research has demonstrated that deposits such as calcium carbonate, silica sand and alumina will affect the size of pits at carbon steel in CO2-saturated brine. Similarly, the presence of bacteria in an oilfield deposit at carbon steel was shown to accelerate localized corrosion.
Chemical mitigation of UDC requires selection of corrosion inhibitors that have low affinity to deposit particles, thus penetrate the deposit layer and protect the underlying steel surface. We have identified a group of corrosion inhibitors that show high efficiency for mitigating CO2-corrosion at carbon steels and continue investigating the mechanisms that drive the corrosion and corrosion-inhibition at deposited steels.
Besides an effective corrosion inhibition, industry operations also require an early detection of a localized attack to avoid any equipment failure. Electrochemical noise signal processed with recurrent quantification analysis has been investigated at deposited carbon steels with the objective to identify localized corrosion events underneath various deposits.
Our UDC research currently involves two PhD projects along with industry-sponsored research.
- Corrosion inhibition of deposited steels in the presence of bacteria. (PhD candidate: Erika Suarez-Rodriguez)
- Interpretation of electrochemical noise in corrosion systems by use of phase space methods. (PhD candidate: Yang Hou). Project in collaboration with WASM, Curtin University (Professor C. Aldrich).
- Hou, C. Aldrich, K. Lepková, L. L. Machuca, B. Kinsella, Monitoring of carbon steel corrosion by use of electrochemical noise and recurrence quantification analysis, Corrosion Science, 112 (2016) 63-72.
- Pandarinathan, K. Lepková, W. van Bronswijk, Chukanovite (Fe2(OH)2CO3) identified as corrosion product at sand-deposited carbon steel in CO2-saturated brine, Corrosion Science, 85 (2014) 26-32.
- Pandarinathan, K. Lepková, S.I. Bailey, R. Gubner, Evaluation of corrosion inhibition at sand-deposited carbon steel in CO2-saturated brine, Corrosion Science, 72 (2013) 108-117.
- Pandarinathan, K. Lepková, S.I. Bailey, R. Gubner, Inhibition of under-deposit corrosion of carbon steel by Thiobenzamide, Journal of The Electrochemical Society, 160 (2013) C432-C440.
- V. Pandarinathan, K. Lepková, S.I. Bailey, R. Gubner, Impact of mineral deposits on CO2 corrosion of carbon steel, Corrosion 13, NACE International, paper no. 2579 (2013).