Electrochemistry of stress corrosion cracking of brass

Thesis/Dissertation · Wed Jan 01 04:00:00 EST 1986

OSTI ID:7241074

Seleet, M M

Stress corrosion cracking (SCC) susceptibility of pure copper and two brass (copper-zinc alloy) compositions (80/20 and 60/39) was studied in several ammoniacal and nonammoniacal aqueous solutions at open circuit potential, applying a constant load technique. The SCC tests, using tensile stress and loop specimens, showed pure copper to be immune in all solutions tested, the ..cap alpha..BETA'-brass (60/39) alloy to be most susceptible to SCC, and the (80/20) alloy to have intermediate SCC susceptibility. The electrochemical tests (corrosion potential and Tafel plots) were utilized to prove the validity of the dissolution mechanism for the SCC propagation in solution with intermediate corrosion rates (approx.0.1 < I/sub cor/ < approx.5 mA/cm/sup 2/). The electrochemical tests were also used to predict the preferential dissolution of zinc (dezincification) in noncomplexing solutions, and the higher dissolution of copper (than that of zinc) in complexing solutions. The formation of intermediate cuprous complexes was detected using a rotating ring disc electrode (RRDE) composed of a brass (80/20) disc and platinum ring, in ammonium chloride-cupric chloride solution. At very low corrosion rates, the stress corrosion cracking (is present) is assumed to operate by the brittle mechanical fracture mechanism in solution where ammonium ions (NH/sub 4//sup +/) can be generated.

• Research Organization: Iowa State Univ. of Science and Technology, Ames (USA)
• OSTI ID: 7241074
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360103 -- Metals &amp; Alloys-- Mechanical Properties
360105* -- Metals &amp; Alloys-- Corrosion &amp; Erosion
ALLOYS
AMMONIA
AQUEOUS SOLUTIONS
BRASS
CHEMICAL REACTIONS
CHEMISTRY
COPPER
COPPER ALLOYS
COPPER BASE ALLOYS
CORROSION
CRACKS
DISPERSIONS
DISSOLUTION
ELECTROCHEMISTRY
ELEMENTS
HYDRIDES
HYDROGEN COMPOUNDS
METALS
MIXTURES
NITROGEN COMPOUNDS
NITROGEN HYDRIDES
SOLUTIONS
STRESS CORROSION
TRANSITION ELEMENTS
ZINC
ZINC ALLOYS