Cathodic behaviour of stainless steel in coastal Indian seawater: Calcareous deposits overwhelm biofilms
IR@CECRI: CSIR-Central Electrochemical Research Institute, Karaikudi
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Title |
Cathodic behaviour of stainless steel in coastal Indian seawater: Calcareous deposits overwhelm biofilms
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Creator |
Eashwar, M.
Subramanian, G. Palanichamy, S. Rajagopal, G. Madhu, S. Kamaraj, P. |
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Subject |
Corrosion Science and Engineering
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Description |
Type-316 stainless steel (SS) was investigated as the cathode in galvanic couples in full-strength seawater from the
Gulf of Mannar on the southeast coast of India. Tests were devised to examine the impact of SS cathodes on anode
materials with or without the accrual of marine biofilms. Biofilmed SS cathodes significantly enhanced the rate of
corrosion of nickel, causing noble shifts in the couple potentials. With mild steel and zinc as the anodes, calcareous
deposits developed quite rapidly on the SS cathodes and led to a significant reduction of bacterial numbers. The
calcareous deposits also caused substantial reduction of galvanic corrosion rates for mild steel, whereas there was no
difference for zinc. The deposits were identified by XRD as essentially carbonates, oxides and hydroxides of calcium
and magnesium. Potentiodynamic polarization performed on the actual couples after disconnection and equilibration
provided reasonable interpretations of the galvanic corrosion trends. Data from this work suggest that a potential of
about 70.70 V vs. saturated calomel electrode (SCE) should provide optimum protection of SS in warmer, fullstrength
seawater that supports the precipitation of calcareous deposits. The criterion commonly recommended for
temperate conditions of lower water temperature and estuarine waters of lower alkalinity is 71.0 V (SCE).
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Publisher |
Taylor & Francis
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Date |
2009
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Type |
Article
PeerReviewed |
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Format |
application/pdf
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Identifier |
http://cecri.csircentral.net/253/1/007-2009.pdf
Eashwar, M. and Subramanian, G. and Palanichamy, S. and Rajagopal, G. and Madhu, S. and Kamaraj, P. (2009) Cathodic behaviour of stainless steel in coastal Indian seawater: Calcareous deposits overwhelm biofilms. Biofouling, 25 (3). pp. 191-201. ISSN 0892-7014 |
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Relation |
http://cecri.csircentral.net/253/
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