ASTM G112-92(2015)

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 other standard exfoliation test methods, (see Terminology G15 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 given in parentheses are for information only.  
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 and health practices and determine the applicability of regulatory limitations prior to use.

General Information

• Status: Historical
• Publication Date: 31-Oct-2015
• ICS: 77.120.10 - Aluminium and aluminium alloys
• Technical Committee: G01 - Corrosion of Metals
• Drafting Committee: G01.05 - Laboratory Corrosion Tests

Standards Content (Sample)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
Designation: G112 − 92 (Reapproved 2015)
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 G85Practice for Modified Salt Spray (Fog) Testing
G92Practice for Characterization ofAtmospheric Test Sites
1.1 ThisguidediffersfromtheusualASTMstandardinthat
2.2 ASTM Adjuncts:
it does not address a specific test. Rather, it is an introductory
Illustrations of Appearance Classifications (6 glossy pho-
guide for new users of other standard exfoliation test methods,
4
tos)
(see Terminology G15 for definition of exfoliation).
1.2 This guide covers aspects of specimen preparation, 3. Terminology
exposure,inspection,andevaluationforconductingexfoliation
3.1 Definitions of Terms Specific to This Standard:
tests on aluminum alloys in both laboratory accelerated envi-
3.1.1 panel—a flat, rectangular specimen normally taken
ronments and in natural, outdoor atmospheres. The intent is to
with the test surface parallel to the longitudinal and long-
clarify any gaps in existent test methods.
transversedimensionsoffabricatedproduct.Forthinsheetand
1.3 The values stated in SI units are to be regarded as the extrusions, the thickness may be the full thickness of the part.
standard. The inch-pound units given in parentheses are for
3.1.2 sample—a portion of a large piece, or an entire piece
information only.
out of a group of many pieces, that is submitted for evaluation
1.4 This standard does not purport to address all of the andconsideredrepresentativeofthelargerpieceorpopulation.
safety concerns, if any, associated with its use. It is the For castings and forgings, this may be an extra portion or
responsibility of the user of this standard to establish appro- prolongation,orinthecaseofsmallparts,anentireextrapiece
priate safety and health practices and determine the applica- taken from a specific lot.
bility of regulatory limitations prior to use.
3.1.3 specimen—the actual test piece to be corrosion tested.
Frequently this has a specific shape with prescribed dimen-
2. Referenced Documents
sional tolerances and finishes.
2
2.1 ASTM Standards:
3.1.4 test plane—the plane in the thickness of the sample
G1Practice for Preparing, Cleaning, and Evaluating Corro-
that is being tested. Generally this is the fabricated surface or
sion Test Specimens
somespecifiedinteriorplane.Interiorplanestypicallyusedare:
G15TerminologyRelatingtoCorrosionandCorrosionTest-
(a) T/10=10% of the thickness removed, (this is representa-
3
ing (Withdrawn 2010)
tive of a minimal machining cut to obtain a flat surface), (b)
G34TestMethodforExfoliationCorrosionSusceptibilityin
T/4=quarter plane, 25% of the thickness removed, and (c)
2XXX and 7XXX SeriesAluminumAlloys (EXCO Test)
T/2=midplane, 50% of the thickness removed.
G50Practice for Conducting Atmospheric Corrosion Tests
on Metals
4. Significance and Use
G66Test Method for Visual Assessment of Exfoliation
4.1 Although there are ASTM test methods for exfoliation
Corrosion Susceptibility of 5XXX Series Aluminum Al-
testing, they concentrate on specific procedures for test meth-
loys (ASSET Test)
odology itself. Existent test methods do not discuss material
variables that can affect performance. Likewise they do not
1
This guide is under the jurisdiction ofASTM Committee G01 on Corrosion of
address the need to establish the suitability of an accelerated
Metals and is the direct responsibility of Subcommittee G01.05 on Laboratory
test for alloys never previously tested nor the need to correlate
Corrosion Tests.
results of accelerated tests with tests in outdoor atmospheres
Current edition approved Nov. 1, 2015. Published December 2015. Originally
approved in 1992. Last previous edition approved in 2009 as G112–92(2009). DOI:
and with end use performance.
10.1520/G0112-92R15.
2 4.2 This guide is a compilation of the experience of inves-
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
tigators skilled in the art of conducting exfoliation tests and
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website.
3
4
The last approved version of this historical standard is referenced on Available from ASTM International Headquarters. Order Adjunct No.
www.astm.org. ADJG003402. Original adjunct produced in 1980.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
1

---------------------- Pa
...

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 2009) G112 − 92 (Reapproved 2015)
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 other standard exfoliation test methods, (see Terminology G15 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 given in parentheses are for
information only.
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 and health practices and determine the applicability of regulatory
limitations prior to use.
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
2.2 ASTM Adjuncts:
4
Illustrations of Appearance Classifications (6 glossy photos)
3. Terminology
3.1 Definitions of Terms Specific to This Standard:
3.1.1 panel—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—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—the actual test piece to be corrosion tested. Frequently this has a specific shape with prescribed dimensional
tolerances and finishes.
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 May 1, 2009Nov. 1, 2015. Published May 2009December 2015. Originally approved in 1992. Last previous edition approved in 20032009 as
G112–92(2003).G112–92(2009). DOI: 10.1520/G0112-92R09.10.1520/G0112-92R15.
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’s Document Summary page on the ASTM website.
3
The last approved version of this historical standard is referenced on www.astm.org.
4
Available from ASTM International Headquarters. Order Adjunct No. ADJG003402. Original adjunct produced in 1980.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
1

---------------------- Page: 1 ----------------------
G112 − 92 (2015)
3.1.4 test plane—the plane in the thickness of the sample that is being tested. Generally this is the fabricated surface or some
specified interior plane. Interior planes typically used are: (a) T/10 = 10 % of the thickness removed, (this is representative of a
minimal machining cut to obtain a flat surface), (b) T/4 = quarter plane, 25 % of the thickness removed, and (c) T/2 = midplane,
50 % of the thickness removed.
4. Significance and Use
4.1 Although there are ASTM test methods for exfoliation testing, they concentrate on specific procedures for tes
...