THE CONDITIONS OF CATHODIC PROTECTION FOR AL-MG ALLOY

Ship hulls made of Al-Mg alloy tend to have pitting corrosion in anchorage. Cathodic protection systems using galvanic anodes have been applied to prevent such pitting corrosion. To clarify problematic points on application of cathodic protection, such as optimum protection potential, over-protection potential ranges and the most suitable galvanic anode, some experiments were conducted for bare and welded metal of A1-Mg alloy (JIS A-5083) in artificial sea water. The following results were obtained. A galvanic anode of A1-Zn-Mg- In-Si alloy was the most suitable from the view point of cost performance and protection efficiency. Optimum protection potentials were in the range of -950 ~ -1000 mV refer to a saturated calomel electrode for the welded metal and -1000 mV for the base metal. Re-passivation potential of the base metal measured in de-aerated artificial sea water of pH 10 at 25 oC showed good coincidence with the optimum protection potential.

• Supplemental Notes:
  • J Kansai Soc Naval Arch, n 225, March 1996, p 195 [6 p, 5 ref, 3 tab, 8 fig]
• Authors:
  • Uchibori, T
  • Tamura, Y
• Publication Date: 1996

Language

• Japanese

Subject/Index Terms

• TRT Terms: Aluminum alloys; Anodic protection; Cathodic protection; Pitting
• Subject Areas: Construction; Marine Transportation;

Filing Info

• Accession Number: 00733328
• Record Type: Publication
• Source Agency: British Maritime Technology
• Files: TRIS
• Created Date: Mar 27 1997 12:00AM