Accession Number:

ADA433965

Title:

An Evaluation of Carbon Steel Corrosion Under Stagnant Seawater Conditions

Descriptive Note:

Journal article

Corporate Author:

NAVAL RESEARCH LAB STENNIS SPACE CENTER MS OCEANOGRAPHY DIV

Report Date:

2004-10-01

Pagination or Media Count:

14.0

Abstract:

Corrosion of 1020 carbon steel coupons in natural seawater over a 1-year period was more aggressive under strictly anaerobic stagnant conditions than under aerobic stagnant conditions as measured by weight loss and instantaneous corrosion rate polarization resistance. Under oxygenated conditions, a two-tiered oxide layer of lepidocrocite goethite formed. The inner layer was extremely tenacious and resistant to acid cleaning. Under anaerobic conditions, the corrosion product was initially a non-tenacious sulphur-rich corrosion product, mackinawite, with enmeshed bacteria. As more sulphide was produced the mackinawite was transformed to pyrrhotite. In both aerobic and anaerobic exposures, corrosion was more aggressive on horizontally oriented coupons compared to vertically oriented samples.

Subject Categories:

  • Physical and Dynamic Oceanography
  • Properties of Metals and Alloys

Distribution Statement:

APPROVED FOR PUBLIC RELEASE