Corrosion of Aluminum Alloys in High Velocity Seawater
Abstract
A study was undertaken to examine the corrosion behavior of selected aluminum alloys in high velocity seawater. The work is pertinent to the development of high speed ships by the U.S. Navy. The selected aluminum alloys included 1100-H14 and 5456-H117. Plate specimens of each alloy were exposed in a flow channel at test velocities ranging from 3 to 30 m/s. The affect of cathodic polarization on the velocity-related corrosion behavior of the 5456 alloy was also investigated. Under the flow conditions established in the study, the results show that: (1) both the rate and mode of corrosion are velocity- dependent for aluminum alloys (2) velocity-related shifts in corrosion potential can occur (3) polarization resistance measurements are inadequate for predicting corrosion rates of aluminum alloys in high velocity flow (4) cathodic protection cannot retard velocity-induced corrosion of aluminum alloys (5) cathodic polarization will tend to accelerate corrosion of aluminum alloys at all velocities tested (6) at higher velocities, the predominant reduction reaction associated with the corrosion of aluminum alloys is H2O plus le give OH- 1/2 H2.
Document Details
- Document Type
- Technical Report
- Publication Date
- Nov 01, 1979
- Accession Number
- ADA078435
Entities
People
- G. A. Gehring Jr.