ASTM D6208-07

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
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Designation: D6208 − 07
StandardTest Method for
Repassivation Potential of Aluminum and Its Alloys by
1
Galvanostatic Measurement
This standard is issued under the fixed designation D6208; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope G107Guide for Formats for Collection and Compilation of
Corrosion Data for Metals for Computerized Database
1.1 A procedure to determine the repassivation potential of
2 Input
aluminumalloy3003-H14(UNSA93003) (1) asameasureof
relative susceptibility to pitting corrosion by conducting a
3. Terminology
galvanostaticpolarizationisdescribed.Aprocedurethatcanbe
3.1 Definitions:Termsusedinthistestmethodcanbefound
used to check experimental technique and instrumentation is
in Practice G3 and Terminology G15.
described, as well.
3.2 Symbols:
1.2 The test method serves as a guide for similar measure-
3.2.1 E —break potential, potential at which the passive
ment on other aluminum alloys and metals (2-5).
B
aluminum oxide layer breaks down.
1.3 The values stated in SI units are to be regarded as the
3.2.2 E —protection potential as measured in this galvano-
G
standard.Values given in parentheses are for information only.
static method, potential at which oxide layer repassivates.
1.4 This standard does not purport to address all of the
2
3.2.3 J—current density, in A/m
safety concerns, if any, associated with its use. It is the
responsibility of the user of this standard to establish appro-
4. Summary of Test Method
priate safety and health practices and determine the applica-
bility of regulatory limitations prior to use. 4.1 The test method described is an adaptation of the
method described in FORD Motor Company standards (6).
2. Referenced Documents
4.2 An aluminum alloy specimen is polarized at fixed
3
2.1 ASTM Standards:
current density for 20 min. in a solution of coolant and
D1193Specification for Reagent Water
corrosivewatercontainingchloride.Thepotentialasafunction
D3585Specification forASTM Reference Fluid for Coolant
of time is recorded.
Tests
4.3 The maximum potential, E reached upon polarization
B
G3Practice for Conventions Applicable to Electrochemical
is determined, as is the minimum potential following the
Measurements in Corrosion Testing
maximum potential, E .
G
G15TerminologyRelatingtoCorrosionandCorrosionTest-
4
4.4 Visual examination of the specimen may be made using
ing (Withdrawn 2010)
Guide G46 as a guide after disassembly and rinsing.
G46Guide for Examination and Evaluation of Pitting Cor-
rosion
5. Significance and Use
5.1 This test method is designed to measure the relative
1 effectiveness of inhibitors to mitigate pitting corrosion of
This test method is under the jurisdiction ofASTM CommitteeD15 on Engine
CoolantsandRelatedFluidsandisthedirectresponsibilityofSubcommitteeD15.06
aluminum and its alloys, in particular AA3003-H14, rapidly
on Glassware Performance Tests.
and reproducibly. The measurements are not intended to
Current edition approved April 1, 2007. Published April 2007. Originally
correlate quantitatively with other test method values or with
approved in 1997. Last previous edition approved in 2002 as D6208-97(2002).
susceptibility to localized corrosion of aluminum observed in
DOI: 10.1520/D6208-07.
2
Theboldfacenumbersinparenthesesrefertothelistofreferencesattheendof
service. Qualitative correlation of the measurements and sus-
this standard.
ceptibility in service has been established (1).
3
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
5.2 The maximum potential reached upon initial
Standards volume information, refer to the standard’s Document Summary page on
polarization,E isameasureoftheresistancetobreakdownof
B,
the ASTM website.
4
the aluminum oxide film. Lower susceptibility to initiation of
The last approved version of this historical standard is referenced on
www.astm.org. pitting corrosion is indicated by a more noble potential (See
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D6208 − 07
Practice G3 and Terminology G15.) This potential, as mea- current supply and mV strip chart recorder, and Fig. X2.1
sured in this test method, is not very sensitive to the inhibitors shows a schematic for using a computer and potentiostat/
present. galvanostat.
5.3 The minimum potential, E following the maximum 6.4 Electrodes:
G,
potential is a measure of the protection against continued
6.4.1 Working Electrode (WE
...