Electrochemical evaluation of the effect of heat treatment and stress on the corrosion characteristics of 7050 aluminum in 3. 5% NaCl solution

Technical Report · Fri Nov 01 00:00:00 EST 1985

OSTI ID:6350872

Glass, R S; Estill, J C

Potentiodynamic polarization curves have been used to evaluate (in a survey mode) the effect of heat treatment and stress on the corrosion behavior of 7050-XX aluminum in deaerated 3.5% NaCl solutions. Specimens, which were machined from extruded ring material, were examined in the as-received condition and following heat treatment at 580/sup 0/F for 0.5 min. The stress levels used in this study ranged from 40 to 90% of the 0.2% offset yield strength. Results indicate that within this stress range, using the given experimental method, medium, and timescales, that there is no significant trend for the effect of stress on the electrochemical-corrosion behavior for the materials examined. The heat-treated specimens have lower uniform corrosion rates than the as-received forms, but are more susceptible to pitting. However, pitting is not spontaneous for either material in this environment. In addition to investigating the variables of stress and heat treatment, we have also compared the behavior of specimens machined from three different orientations within extruded ring material. Generally, the longitudinal and circumferentially oriented specimens were more similar electrochemically than specimens obtained from the radial orientation. The radial specimens generally showed lower uniform corrosion rates and appeared to be less susceptible to pitting.

• Research Organization: Lawrence Livermore National Lab., CA (USA)
• DOE Contract Number: W-7405-ENG-48
• OSTI ID: 6350872
• Report Number(s): UCID-20597; ON: DE86004181
• Resource Relation: Other Information: Portions of this document are illegible in microfiche products. Original copy available until stock is exhausted
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ALUMINIUM
ELECTROCHEMICAL CORROSION
PITTING CORROSION
STRESS CORROSION
AQUEOUS SOLUTIONS
HEAT TREATMENTS
PASSIVATION
SODIUM CHLORIDES
STRESSES
ALKALI METAL COMPOUNDS
CHEMICAL REACTIONS
CHLORIDES
CHLORINE COMPOUNDS
CORROSION
DISPERSIONS
ELEMENTS
HALIDES
HALOGEN COMPOUNDS
METALS
MIXTURES
SODIUM COMPOUNDS
SOLUTIONS
360105* - Metals & Alloys- Corrosion & Erosion