ASTM G112-22

Standard Guide for Conducting Exfoliation Corrosion Tests in Aluminum Alloys

SIGNIFICANCE AND USE
4.1 Although there are ASTM test methods for exfoliation testing, they concentrate on specific procedures for test methodology itself. Existent test methods do not discuss material variables that can affect performance. Likewise they do not address the need to establish the suitability of an accelerated test for alloys never previously tested nor the need to correlate results of accelerated tests with tests in outdoor atmospheres and with end-use performance.  
4.2 This guide is a compilation of the experience of investigators skilled in the art of conducting exfoliation tests and assessing the degree and significance of the damage encountered. The focus is on two general aspects: guides to techniques that will enhance the likelihood of obtaining reliable information, and tips and procedures to avoid pitfalls that could lead to erroneous results and conclusions.  
4.3 The following three areas of testing are considered: the test materials starting with the “as-received” sample up through final specimen preparation, the corrosion test procedures including choice of test, inspection periods, termination point, and rating procedures, and analyses of results and methods for reporting them.  
4.4 This guide is not intended as a specific corrosion test procedure by which to evaluate the resistance to exfoliation of an aluminum alloy product.  
4.5 This guide is not intended as a basis for specifications, nor as a guide for material lot acceptance.
SCOPE
1.1 This guide differs from the usual ASTM standard in that it does not address a specific test. Rather, it is an introductory guide for new users of various standard exfoliation test methods with consideration for specific aluminum alloy families (see Terminology G193 for definition of exfoliation).  
1.2 This guide covers aspects of specimen preparation, exposure, inspection, and evaluation for conducting exfoliation tests on aluminum alloys in both laboratory accelerated environments and in natural, outdoor atmospheres. The intent is to clarify any gaps in existent test methods.  
1.3 The values stated in SI units are to be regarded as standard. The values given in parentheses after SI units are provided for information only and are not considered 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

• Status: Published
• Publication Date: 30-Nov-2022
• ICS: 77.120.10 - Aluminium and aluminium alloys
• Technical Committee: G01 - Corrosion of Metals
• Drafting Committee: G01.05 - Laboratory Corrosion Tests

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: G112 − 22
Standard Guide for
1
Conducting Exfoliation Corrosion Tests in Aluminum Alloys
This standard is issued under the fixed designation G112; 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 G66Test Method for Visual Assessment of Exfoliation
Corrosion Susceptibility of 5XXX Series Aluminum Al-
1.1 ThisguidediffersfromtheusualASTMstandardinthat
loys (ASSET Test)
it does not address a specific test. Rather, it is an introductory
G85Practice for Modified Salt Spray (Fog) Testing
guide for new users of various standard exfoliation test
G92Practice for Characterization ofAtmospheric Test Sites
methods with consideration for specific aluminum alloy fami-
G193Terminology and Acronyms Relating to Corrosion
lies (see Terminology G193 for definition of exfoliation).
3
2.2 ASTM Adjunct:
1.2 This guide covers aspects of specimen preparation,
IllustrationsofAppearanceClassifications(6glossyphotos)
exposure,inspection,andevaluationforconductingexfoliation
tests on aluminum alloys in both laboratory accelerated envi-
3. Terminology
ronments and in natural, outdoor atmospheres. The intent is to
3.1 Definitions of Terms Specific to This Standard:
clarify any gaps in existent test methods.
3.1.1 panel, n—a flat, rectangular specimen normally taken
1.3 The values stated in SI units are to be regarded as
with the test surface parallel to the longitudinal and long-
standard. The values given in parentheses after SI units are
transversedimensionsoffabricatedproduct.Forthinsheetand
providedforinformationonlyandarenotconsideredstandard.
extrusions, the thickness may be the full thickness of the part.
1.4 This standard does not purport to address all of the
3.1.2 sample, n—a portion of a large piece, or an entire
safety concerns, if any, associated with its use. It is the
piece out of a group of many pieces, that is submitted for
responsibility of the user of this standard to establish appro-
evaluation and considered representative of the larger piece or
priate safety, health, and environmental practices and deter-
population. For castings and forgings, this may be an extra
mine the applicability of regulatory limitations prior to use.
portion or prolongation, or in the case of small parts, an entire
1.5 This international standard was developed in accor-
extra piece taken from a specific lot.
dance with internationally recognized principles on standard-
3.1.3 specimen, n—the actual test piece to be corrosion
ization established in the Decision on Principles for the
tested. Frequently this has a specific shape with prescribed
Development of International Standards, Guides and Recom-
dimensional tolerances and finishes.
mendations issued by the World Trade Organization Technical
Barriers to Trade (TBT) Committee. 3.1.4 test plane, n—the plane in the thickness of the sample
that is being tested. Generally this is the fabricated surface or
2. Referenced Documents
somespecifiedinteriorplane.Interiorplanestypicallyusedare:
2
2.1 ASTM Standards: (a) T/10=10% of the thickness removed, (this is representa-
G1Practice for Preparing, Cleaning, and Evaluating Corro-
tive of a minimal machining cut to obtain a flat surface), (b)
sion Test Specimens T/4=quarter plane, 25% of the thickness removed, and (c)
G34TestMethodforExfoliationCorrosionSusceptibilityin
T/2=midplane, 50% of the thickness removed.
2XXX and 7XXX SeriesAluminumAlloys (EXCO Test)
G50Practice for Conducting Atmospheric Corrosion Tests 4. Significance and Use
on Metals
4.1 Although there are ASTM test methods for exfoliation
testing, they concentrate on specific procedures for test meth-
1
This guide is under the jurisdiction ofASTM Committee G01 on Corrosion of
odology itself. Existent test methods do not discuss material
Metals and is the direct responsibility of Subcommittee G01.05 on Laboratory
variables that can affect performance. Likewise they do not
Corrosion Tests.
address the need to establish the suitability of an accelerated
Current edition approved Dec. 1, 2022. Published January 2023. Originally
approvedin1992.Lastpreviouseditionapprovedin2015asG112–92(2015).DOI:
test for alloys never previously tested nor the need to correlate
10.1520/G0112-22.
2
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
3
Standards volume information, refer to the standard’s Document Summary page on Available from ASTM In
...

This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Because
it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
Designation: G112 − 92 (Reapproved 2015) G112 − 22
Standard Guide for
1
Conducting Exfoliation Corrosion Tests in Aluminum Alloys
This standard is issued under the fixed designation G112; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope
1.1 This guide differs from the usual ASTM standard in that it does not address a specific test. Rather, it is an introductory guide
for new users of othervarious standard exfoliation test methods, methods with consideration for specific aluminum alloy families
(see Terminology G15G193 for definition of exfoliation).
1.2 This guide covers aspects of specimen preparation, exposure, inspection, and evaluation for conducting exfoliation tests on
aluminum alloys in both laboratory accelerated environments and in natural, outdoor atmospheres. The intent is to clarify any gaps
in existent test methods.
1.3 The values stated in SI units are to be regarded as the standard. The inch-pound units values given in parentheses are for
information only.after SI units are provided for information only and are not considered 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 safety, health, and healthenvironmental 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.
2. Referenced Documents
2
2.1 ASTM Standards:
G1 Practice for Preparing, Cleaning, and Evaluating Corrosion Test Specimens
3
G15 Terminology Relating to Corrosion and Corrosion Testing (Withdrawn 2010)
G34 Test Method for Exfoliation Corrosion Susceptibility in 2XXX and 7XXX Series Aluminum Alloys (EXCO Test)
G50 Practice for Conducting Atmospheric Corrosion Tests on Metals
G66 Test Method for Visual Assessment of Exfoliation Corrosion Susceptibility of 5XXX Series Aluminum Alloys (ASSET
Test)
G85 Practice for Modified Salt Spray (Fog) Testing
G92 Practice for Characterization of Atmospheric Test Sites
G193 Terminology and Acronyms Relating to Corrosion
3
2.2 ASTM Adjuncts:Adjunct:
Illustrations of Appearance Classifications (6 glossy photos)
1
This guide is under the jurisdiction of ASTM Committee G01 on Corrosion of Metals and is the direct responsibility of Subcommittee G01.05 on Laboratory Corrosion
Tests.
Current edition approved Nov. 1, 2015Dec. 1, 2022. Published December 2015January 2023. Originally approved in 1992. Last previous edition approved in 20092015
as G112–92(2009).G112–92 (2015). DOI: 10.1520/G0112-92R15.10.1520/G0112-22.
2
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM Standards
volume information, refer to the standard’sstandard’s Document Summary page on the ASTM website.
3
Available from ASTM International Headquarters. Order Adjunct No. ADJG003402ADJG003402-E-PDF. Original adjunct produced in 1980.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
1

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G112 − 22
3. Terminology
3.1 Definitions of Terms Specific to This Standard:
3.1.1 panel—panel, n—a flat, rectangular specimen normally taken with the test surface parallel to the longitudinal and
long-transverse dimensions of fabricated product. For thin sheet and extrusions, the thickness may be the full thickness of the part.
3.1.2 sample—sample, n—a portion of a large piece, or an entire piece out of a group of many pieces, that is submitted for
evaluation and considered representative of the larger piece or population. For castings and forgings, this may be an extra portion
or prolongation, or in the case of small parts, an entire extra piece taken from a specific lot.
3.1.3 specimen—specimen, n—the actual test piece to be corrosion tested. Frequently this has a specific shape with prescribed
dimensional tolerances and finishes.
3.1.4 test plane—plane, n—the pla
...