New Theories for Erosion-Corrosion: ASSERT Supplement.
Abstract
The erosion-corrosion of copper and copper-nickel alloys in synthetic seawater was investigated using an impinging jet. Video microscopy, corrosion potential monitoring, and impedance spectroscopy were used to investigate the state of the system and the reactivity of the electrode surface. Shear-induced removal of salt films was observed and found to be associated with significant increases in surface reactivity. Direct shear-induced removal of oxide films, however, was not observed. Nevertheless, the protective oxide layer showed sensitivity in passively aerated seawater to large fluid velocities and to small perturbations in potential. The films were stable under all conditions tested in continuously aerated seawater. The present work supports the argument that localized corrosion of copper alloys is caused by galvanic coupling between different regions of a metal coupon. The potential difference driving the galvanic couple could originate from localized shear-induced removal of salt films as well as from non-uniformly distributed oxygen transport rates.
Document Details
- Document Type
- Technical Report
- Publication Date
- May 28, 1998
- Accession Number
- ADA345877
Entities
People
- Mark E. Orazem
Organizations
- University of Florida