Standard Historical Last Updated: Dec 31, 2010 Track Document
ASTM G69-97(2003)

Standard Test Method for Measurement of Corrosion Potentials of Aluminum Alloys

Standard Test Method for Measurement of Corrosion Potentials of Aluminum Alloys G0069-97R03 ASTM|G0069-97R03|en-US Standard Test Method for Measurement of Corrosion Potentials of Aluminum Alloys Standard new BOS Vol. 03.02 Committee G01
$ 66.00 In stock

Significance and Use

The corrosion potential of an aluminum alloy depends upon the amounts of certain alloying elements that the alloy contains in solid solution. Copper and zinc, which are two of the major alloying elements for aluminum, have the greatest effect with copper shifting the potential in the noble or positive direction, and zinc in the active or negative direction. For example, commercially unalloyed aluminum (1100 alloy)3 has a potential of 750 mV when measured in accordance with this practice, 2024T3 alloy with nearly all of its nominal 4.3 % copper in solid solution, a potential of 600 to 620 mV (Note 2), and 7072 alloy with nearly all of its nominal 1.0 % zinc in solid solution, a potential of 885 mV (SCE) (1-3).4

Note 2—The potential depends upon the rate of quenching.

Because it reflects the amount of certain alloying elements in solid solution, the corrosion potential is a useful tool for characterizing the metallurgical condition of aluminum alloys, especially those of the 2XXX and 7XXX types, which contain copper and zinc as major alloying elements. Its uses include the determination of the effectiveness of solution heat treatment and annealing (1), of the extent of precipitation during artificial aging (4) and welding (5), and of the extent of diffusion of alloying elements from the core into the cladding of alclad products (2).

Scope

1.1 This test method is a procedure for measurement of the corrosion potential (see Note 1) of an aluminum alloy in an aqueous solution of sodium chloride with enough hydrogen peroxide added to provide an ample supply of cathodic reactant.

Note 1—The corrosion potential is sometimes referred to as the open-circuit solution or rest potential.

1.2 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

Price:
Contact Sales
Related
Reprints and Permissions
Reprints and copyright permissions can be requested through the
Copyright Clearance Center
Details
Book of Standards Volume: 03.02
Developed by Subcommittee: G01.11
Pages: 4
DOI: 10.1520/G0069-97R03
ICS Code: 77.120.10