INVESTIGATION OF THE MECHANISM OF STRESS CORROSION OF ALUMINUM ALLOYS
Abstract
The cathodic protection of 7075 alloy in a corrosive, acid chloride solution was investigated. Subsize tensile specimens for protection were taken in the short-transverse direction from 2-inch thick plate in two tempers, one (- T6) susceptible to stress corrosion and one (-T73) not susceptible to this type of corrosion. In the solution used a susceptible specimen stressed to 75% of its yield strength failed by stress corrosion in an hour while a stresses nonsuspectible specimen failed by general corrosion within two days. At a potential 0.57 volts negative to the free corrosion potential, a stressed susceptible specimen could be protected for an indefinitely long period; one susceptible specimen stressed to 75% of its yield strength and held at this potential for 400 hours showed no evidence of stress corrosion. This potential of cathodic protection appeared to be independent of the stress applied to a specimen. Considerable evidence indicates that the potential reflected metallurgical structure rather than extraneous conditions such as the alkalinity produced by cathodic reactions.
Document Details
- Document Type
- Technical Report
- Publication Date
- Feb 06, 1965
- Accession Number
- AD0615789
Entities
People
- G. C. English
Organizations
- Alcoa