ASTM G71-81(2019)
(Guide)Standard Guide for Conducting and Evaluating Galvanic Corrosion Tests in Electrolytes
Standard Guide for Conducting and Evaluating Galvanic Corrosion Tests in Electrolytes
SIGNIFICANCE AND USE
3.1 Use of this guide is intended to provide information on the galvanic corrosion of metals in electrical contact in an electrolyte that does not have a flow velocity sufficient to cause erosion-corrosion or cavitation.
3.2 This standard is presented as a guide for conducting galvanic corrosion tests in liquid electrolyte solutions, both in the laboratory and in service environments. Adherence to this guide will aid in avoiding some of the inherent difficulties in such testing.
SCOPE
1.1 This guide covers conducting and evaluating galvanic corrosion tests to characterize the behavior of two dissimilar metals in electrical contact in an electrolyte under low-flow conditions. It can be adapted to wrought or cast metals and alloys.
1.2 This guide covers the selection of materials, specimen preparation, test environment, method of exposure, and method for evaluating the results to characterize the behavior of galvanic couples in an electrolyte.
Note 1: Additional information on galvanic corrosion testing and examples of the conduct and evaluation of galvanic corrosion tests in electrolytes are given in Refs (1)2 through (2).
1.3 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
1.4 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, health, and environmental practices and determine the applicability of regulatory limitations prior to use.
1.5 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
General Information
Relations
Standards Content (Sample)
This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Designation: G71 − 81 (Reapproved 2019)
Standard Guide for
Conducting and Evaluating Galvanic Corrosion Tests in
1
Electrolytes
ThisstandardisissuedunderthefixeddesignationG71;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginal
adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.Asuperscript
epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope G1 Practice for Preparing, Cleaning, and Evaluating Corro-
sion Test Specimens
1.1 This guide covers conducting and evaluating galvanic
G3 Practice for Conventions Applicable to Electrochemical
corrosion tests to characterize the behavior of two dissimilar
Measurements in Corrosion Testing
metals in electrical contact in an electrolyte under low-flow
G4 Guide for Conducting Corrosion Tests in Field Applica-
conditions. It can be adapted to wrought or cast metals and
tions
alloys.
G16 Guide for Applying Statistics to Analysis of Corrosion
1.2 This guide covers the selection of materials, specimen
Data
preparation,testenvironment,methodofexposure,andmethod
G31 Guide for Laboratory Immersion Corrosion Testing of
for evaluating the results to characterize the behavior of
Metals
galvanic couples in an electrolyte.
G46 Guide for Examination and Evaluation of Pitting Cor-
rosion
NOTE 1—Additional information on galvanic corrosion testing and
examples of the conduct and evaluation of galvanic corrosion tests in
2
3. Significance and Use
electrolytes are given in Refs (1) through (2).
1.3 The values stated in SI units are to be regarded as
3.1 Use of this guide is intended to provide information on
standard. No other units of measurement are included in this the galvanic corrosion of metals in electrical contact in an
standard.
electrolytethatdoesnothaveaflowvelocitysufficienttocause
erosion-corrosion or cavitation.
1.4 This standard does not purport to address all of the
safety concerns, if any, associated with its use. It is the
3.2 This standard is presented as a guide for conducting
responsibility of the user of this standard to establish appro-
galvanic corrosion tests in liquid electrolyte solutions, both in
priate safety, health, and environmental practices and deter-
the laboratory and in service environments. Adherence to this
mine the applicability of regulatory limitations prior to use.
guide will aid in avoiding some of the inherent difficulties in
1.5 This international standard was developed in accor-
such testing.
dance with internationally recognized principles on standard-
4. Test Specimens
ization established in the Decision on Principles for the
Development of International Standards, Guides and Recom-
4.1 Material—Test specimens should be manufactured from
mendations issued by the World Trade Organization Technical
thesamematerialasthoseusedintheserviceapplicationbeing
Barriers to Trade (TBT) Committee.
modeled. Minor compositional or processing differences be-
tween materials or between different heats can greatly affect
2. Referenced Documents
the results in some cases.
3
2.1 ASTM Standards:
4.2 Size and Shape:
4.2.1 Thesizeandshapeofthetestspecimensaredependent
on restrictions imposed by the test location. When determining
1
This guide is under the jurisdiction ofASTM Committee G01 on Corrosion of
material behavior in the laboratory, it is advisable to use the
Metals and is the direct responsibility of Subcommittee G01.11 on Electrochemical
Measurements in Corrosion Testing.
largest specimens permissible within the constraints of the test
Current edition approved May 1, 2019. Published June 2019. Originally
equipment.Ingeneral,theratioofsurfaceareatometalvolume
approved in 1981. Last previous edition approved in 2014 as G71 – 81 (2014). DOI:
should be large in order to favor maximum corrosion loss per
10.1520/G0071-81R19.
2
weight. Sufficient thickness should be employed, however, to
The boldface numbers in parentheses refer to a list of references at the end of
this standard.
minimize the possibility of perforation of the specimens during
3
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
the test exposure. When modeling large components, the size
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
of the specimens should be as large as practical. When
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. modeling smaller components, specimen size should be as
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
1
---------------------- Page: 1 ---------------------
...
Questions, Comments and Discussion
Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.