On site underground tests at 6 widely differing sites were made of 26Cr-6.5Ni, Type 304 (18Cr-8Ni) and Type 409 (less than 11 Cr ferritic) coupled to commercially pure copper. Galvanic current tests were made over 3 to 4 years and retrieved specimens were examined in the laboratory. When exposure conditions made Cu anodic to the stainless, local corrosion was minimized. Pitting occurred on some stainless specimens at some sites. Type 409 pitted more than other alloys and copper was cathodically protected by stainless in some cases. Chloride-containing, poorly aerated soils (400-15,500 ohm cm) in a tidal marsh caused greatest attack. Cu lost 3 mils and pits formed were 1 to 5 mils deep; 409 perforated and lost 30% weight at one site and other alloys at the site pited to less than 30 mils. Data indicate no increase in attack on stainless steels coupled to Cu over that on uncoupled specimens in same environments. /Author/

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  • Supplemental Notes:
    • Presented during Corrosion/75, April 14-18, 1975, Toronto, Canada.
  • Corporate Authors:

    National Association of Corrosion Engineers

    P.O. Box 1499
    Houston, TX  United States  77001
  • Authors:
    • Escalante, E
    • Gerhold, W F
  • Publication Date: 1975-10

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Filing Info

  • Accession Number: 00127468
  • Record Type: Publication
  • Files: TRIS
  • Created Date: Nov 18 1975 12:00AM