MARINTEK A/S, Sandefjord,
Norwegian Geotechnical Institute (NGI), Tasen,
Pages: 14 Published: Jan 1989
In-situ corrosion tests and laboratory corrosion studies have been performed on superficial marine sediments from water depths down to 500 m. The corrosivity of the superficial sediments on the Norwegian continental shelf is generally low, being in the range 1 to 50 μm/year. For most sediments which have a glacial or glaciomarine origin and have a low organic content, the corrosion rate will be in the range of 1 to 20 μm/year. However, in some limited areas where the sediments contain a high amount of partly decomposed organic material, the corrosion rate can be as high as 360 μm/year. It is considered that the sulfide environment created by the reduction of the biogenous material will decide the corrosivity of these marine sediments. Based on the studies performed on the various marine sediments found on the shelf, a reasonable evaluation of the corrosivity can now be based on the soil description and the geotechnical properties. However, more detailed electrochemical studies are necessary for an accurate determination of the corrosivity rate. A methodology for the evaluation of the corrosivity of steel in marine sediments is presented.
corrosion, marine sediments, steel, polarization, sulfides, deep waters
Paper ID: STP19713S