Behaviour of CuNi10Fe1Mn-clad ship plates in seawater

✍ Scribed by Dr. P. Drodten; Dr. H. Pircher

• Publisher: John Wiley and Sons
• Year: 1990
• Tongue: German
• Weight: 765 KB
• Volume: 41
• Category: Article
• ISSN: 0947-5117
• DOI: 10.1002/maco.19900410203

✦ Synopsis

Abstract

CuNi10Fe1Mn‐clad shipbuilding plates were subjected to long‐term exposure tests in natural seawater. This involved mounting the test pieces in the immersion zone of the test rig on Helgoland and on the outer wall of the hull of a sea‐going tug. A part of the test pieces were given defects of differing shape and size extending through the cladding to the base material. The corrosion of the shipbuilding steel, which is more intensive at these defects, is dependent upon the cathode and anode area ratio S~C~/S~A~ and attains a limit value at S~C~/S~A~ > 140. This limit value is governed by the oxygen content of the seawater and is much lower in the summer than it is in the winter. The highest corrosion rate, at 1 mm/month, was measured only on very small defects during the winter months. The resistance of the CuNi10 material to marine fouling maintained itself over the entire period, and the loss of cladding material as a result of corrosion or abrasion was negligible, even on those test pieces exposed to high mechanical stress on the tug.