PERFORMANCE TESTING OF INDIUM-ACTIVATED ALUMINIUM ANODES IN SEAWATER

Indium-activated aluminium anodes have been selected as potential candidates to replace current military specification (MIL-A-18001J) zinc anodes for the cathodic protection of Navy ships. One concern regarding the use of indium-activated anodes is the anode performance in cold (40 degrees F) seawater. The subject paper presents the results of a small-scale laboratory screening test investigating this possibility. Four indium-activated anodes were immersed in individual seawater-filled bare steel tanks for a period of 180 days. The seawater in three of the tanks was maintained nominally at 40 degrees F. The fourth tank served as a warm water control . The control and two of the three test anodes were evaluated at a nominal anode current density of 500 mA/ft2, The third test anode was evaluated at 10 mA/ft2. Anode current output, anode potential, and tank potential were monitored throughout the test period. Seawater chemistry and temperature were also monitored. Over the test period, no signs of gross passivation were observed for any of the anodes. At time each of the anodes exposed in the cold seawater anodes exposed in the cold seawater exhibited variations in current output as compared to the warm water control. However, these changes in current output were temporary and did not appear to indicate the onset of any passivation. The anodes exhibited efficiencies in the range of 67 to 79%. Whilst this is lower than the values typically quoted by the manufacturers', the results agree quite well with other tests conducted.

• Supplemental Notes:
  • OTC 91, 23rd Annual Offshore Technology Conf; 6-9 May 1991; Houston, Tx, USA. Procs. Vol 2, Ppr OTC 6587, p 235 [7 p, 5 ref, 4 tab, 2 fig]
• Authors:
  • Ellor, J A
  • Brinckerhoff, B
• Publication Date: 1991

Language

• English

Subject/Index Terms

• TRT Terms: Aluminum; Anodic protection; Cathodic protection; Corrosion; Seawater
• Candidate Terms: Seawater corrosion
• Subject Areas: Construction; Marine Transportation; Materials;

Filing Info

• Accession Number: 00701343
• Record Type: Publication
• Source Agency: British Maritime Technology
• Files: TRIS
• Created Date: Aug 14 1995 12:00AM