ASTM D6899-03

Standard Guide for Laboratory Cyclic Corrosion Testing of Automotive Painted Steel (Withdrawn 2010)

SIGNIFICANCE AND USE
When a laboratory-accelerated test simulates the changing conditions to which automotive finishes are exposed, more realistic corrosion failures are produced.
Cyclic corrosion tests are effective for evaluating a variety of corrosion mechanisms, such as general, galvanic, crevice, etc. The cyclic corrosion tests make use of many types of environments, such as salt fog (Practice B 117), humidity (Practice D 2247 or Practice D 1735) and dry conditions to accelerate metallic corrosion. In cyclic corrosion testing, specimens can be exposed to many different types of environmental conditions and cycled from one environment to another.
In all tests it is imperative to expose control specimens with an established corrosion performance together with the test specimens to make a comparison possible of the corrosion performance of the two sets.
Guidelines are included for those who evaluate the corrosion performance of painted metal parts in cyclic corrosion tests. These guidelines are intended to help ensure that the results of the tests can be used to reach conclusions concerning the variables under study, without being affected by the test procedure itself. The guidelines are also intended to assist users of this type of test in obtaining good inter-laboratory agreement of results.
This guide is not intended to be a substitute for the described cyclic corrosion test standard. In all cases, the laboratory should obtain the most recent published standard for complete details. The published standard supersedes this guide.
SCOPE
1.1 This guide is designed to assist in determining the appropriate corrosion test methods for automotive painted steel.
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 requirements prior to use.
WITHDRAWN RATIONALE
This guide is designed to assist in determining the appropriate corrosion test methods for automotive painted steel.
Formerly under the jurisdiction of Committee D01 on Paint and Related Coatings, Materials, and Applications, this guide was withdrawn in March 2010. This standard is being withdrawn without replacement because the standard has methods in it that are no longer used.

General Information

• Status: Withdrawn
• Publication Date: 09-Jul-2003
• Withdrawal Date: 28-Feb-2010
• ICS: 77.060 - Corrosion of metals
• Technical Committee: D01 - Paint and Related Coatings, Materials, and Applications
• Drafting Committee: D01.27 - Accelerated Testing

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:D6899–03
Standard Guide for
Laboratory Cyclic Corrosion Testing of Automotive Painted
Steel
This standard is issued under the fixed designation D6899; 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 sion Test Specimens
G15 Terminology Relating to Corrosion and Corrosion
1.1 This guide is designed to assist in determining the
Testing
appropriate corrosion test methods for automotive painted
G16 Guide forApplying Statistics toAnalysis of Corrosion
steel.
Data
1.2 This standard does not purport to address all of the
G113 TerminologyRelatingtoNaturalandArtificialWeath-
safety concerns, if any, associated with its use. It is the
ering Tests of Nonmetallic Materials
responsibility of the user of this standard to establish appro-
priate safety and health practices and determine the applica-
NOTE 1—Practice D6675 describes an outdoor accelerated cosmetic
bility of regulatory requirements prior to use. corrosion test that uses periodic application of an electrolyte solution to
materials exposed at 45 degrees to the horizontal and facing the equator.
2. Referenced Documents
2.2 SAE Publications:
2.1 ASTM Standards:
SAE J1563 Guidelines for Laboratory Cyclic Corrosion
B117 Practice for Operating Salt Spray (Fog) Apparatus
Test Procedures for Painted Automotive Parts
D16 Terminology for Paint, Related Coatings, Materials,
SAE J2334 Cosmetic Corrosion Lab Test
and Applications
2.3 Other Standards:
D609 Practice for Preparation of Cold-Rolled Steel Panels
GM 9540P General Motors Accelerated Corrosion Test
for Testing Paint, Varnish, Conversion Coatings, and
JASO M610 Cosmetic Corrosion Test Method forAutomo-
Related Coating Products
tive Parts
D823 Practices for Producing Films of Uniform Thickness
JIS Z 2371 Methods of Neutral Salt Spray Testing
of Paint, Varnish, and Related Products on Test Panels
D870 Practice for Testing Water Resistance of Coatings 3. Terminology
Using Water Immersion
3.1 Definitions—For definition of terms used in this stan-
D1193 Specification for Reagent Water
dard, refer to Terminologies D16, G15, and G113.
D1654 Test Method for Evaluation of Painted or Coated
4. Significance and Use
Specimens Subjected to Corrosive Environments
D1735 Practice for Testing Water Resistance of Coatings
4.1 When a laboratory-accelerated test simulates the chang-
Using Water Fog Apparatus
ing conditions to which automotive finishes are exposed, more
D2247 Practice for Testing Water Resistance of Coatings in
realistic corrosion failures are produced.
100 % Relative Humidity
4.2 Cyclic corrosion tests are effective for evaluating a
D3170 Test Method for Chipping Resistance of Coatings
variety of corrosion mechanisms, such as general, galvanic,
D6675 Practice for Salt-Accelerated Outdoor Cosmetic
crevice, etc.The cyclic corrosion tests make use of many types
Corrosion Testing of Organic Coatings on Automotive
of environments, such as salt fog (Practice B117), humidity
Sheet Steel
(Practice D2247 or Practice D1735) and dry conditions to
G1 Practice for Preparing, Cleaning, and Evaluating Corro-
acceleratemetalliccorrosion.Incycliccorrosiontesting,speci-
mens can be exposed to many different types of environmental
conditions and cycled from one environment to another.
This guide is under the jurisdiction of ASTM Committee D01 on Paint and
4.3 In all tests it is imperative to expose control specimens
Related Coatings, Materials, and Applications and is the direct responsibility of
with an established corrosion performance together with the
Subcommittee D01.27 on Accelerated Testing.
test specimens to make a comparison possible of the corrosion
Current edition approved July 10, 2003. Published August 2003. DOI: 10.1520/
performance of the two sets.
D6899-03.
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 Available from SAE International (SAE), 400 Commonwealth Dr.,Warrendale,
the ASTM website. PA 15096-0001, http://www.sae.org.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
D6899–03
4.4 Guidelines are included for those who evaluate the results, unless otherwise agreed upon between purchaser and
corrosion performance of painted metal parts in cyclic corro- seller.Atypical test parameter is one pint road gravel at 70 psi
sion tests.These guidelines are intended to help ensure that the within 5 to 10 s.
results of the tests can be used to reach conclusions concerning 7.3.2 The procedure to scribe test specimens, including the
the variables under study, without being affected by the test scribing tool, shall be agreed upon between purchaser and
procedureitself.Theguidelinesarealsointendedtoassistusers seller. Unless otherwise specified, the scribe shall be made in
ofthistypeoftestinobtaininggoodinter-laboratoryagreement accordance with Test Method D1654.
of results.
4.5 This guide is not intended to be a substitute for the
8. General Guidelines
described cyclic corrosion test standard. In all cases, the
8.1 Test Conditions:
laboratoryshouldobtainthemostrecentpublishedstandardfor
8.1.1 Chamber Conditions—Cycling between different en-
completedetails.Thepublishedstandardsupersedesthisguide.
vironments may be performed in one chamber or may require
physically moving the test specimens from one chamber to
5. Apparatus
another. Unless otherwise indicated in the test specification,
5.1 Dependinguponthetestcyclechosen,someorallofthe
test chamber conditions shall be held within the following
following may be required.
limits to achieve consistent results—temperature 62°C and
5.1.1 Salt Spray (Fog) Chamber, as described in Practices
relative humidity 65 % RH. Each set point and its tolerance
B117 and D1735.
represents an operational control point for equilibrium condi-
5.1.2 Humidity Test Chamber, as described in Practice
tions at a single location in the cabinet which may not
D2247.
necessarily represent the uniformity of conditions throughout
5.1.3 StoneChipTester,asdescribedinTestMethodD3170.
the cabinet.
5.1.4 Scribing Tool, as described in Test Method D1654.
NOTE 2—Under existing calibration methods, it may be difficult to
5.1.5 Immersion Tank, as described in Practice D870.
measure temperature tolerance within 2°C. Committees D01 and G03 are
expanding tolerances to reflect actual operating conditions and measure-
6. Test Specimens
ment uncertainty. Refer to the currently published document for clarifi-
6.1 The type of specimen and necessary surface prepara-
cation.
tions shall be specified in the applicable documents, or be
8.1.2 Chamber Uniformity—To assure consistency of re-
agreed upon in advance by the parties involved and should
sults, the uniformity of the test conditions should be estab-
simulate normal production materials and conditions. The
lished on a periodic basis by placing identical test panels at
number of test specimens selected must be sufficient to ensure
various locations in the test equipment. If unacceptable repeat-
that the test results are statistically significant at some prede-
ability of results is observed, ensure that the equipment is
termined confidence level. Any unusual observations made
operating in accordance with the relevant test methods and
during specimen preparation shall be recorded and reported as
these guidelines. Guide G16 offers accepted methods of
part of the test results.
statistical analyses which are commonly-used in the interpre-
6.2 In addition to the test specimens, control specimens
tation of corrosion test results.
(panels of known performance in the test conducted) should be
8.2 Racking—Specimens shall be mounted so that there is
tested concurrently. The controls may be used to compare the
no metal-to-metal contact. The racks used in any of the cycles
performanceofthetestmaterialswiththatofacontrolmaterial
shall be constructed of non-metallic materials that are not
having already-established corrosion performance and allow
conductive. The angle of exposure and the panel orientation
comparisons of test results from repeat exposures to the same
specified in the test must be followed for consistency and
test conditions.
repeatability of test results. Periodic inspection of the sample
7. Preparation of Test Specimens
racks may be necessary to assure that any protective coating
has not been damaged or removed, exposing a metal surface.
7.1 Coat the steel panels or product specimens with the
8.3 Sample Placement—To assist in obtaining good repeat-
material under test in accordance with the procedure agreed
ability, equipment must be loaded evenly to maintain good
upon between interested parties. If no prior agreement takes
precedence, Practices D609 and D823 may be appropriate. airflow during the test. In order to assure uniformity of
exposure conditions, samples should be rotated on a regular
7.2 Use a suitable coating that is stable under the conditions
of exposure to protect any uncoated backs, cut edges, or areas basis. For test methods which include a salt fog cycle, care
mustbetakentoassurethatsaltsolutiondoesnotdripfromone
of the specimen that contain identification marks. Protecting
the uncoated back of test panels prevents an unrealistic specimen to another.
8.4 Test Interruptions—In situations where the test cycle is
relationship of cathode to anode in corrosion cells on the test
surface. interrupted, the test specimens should be stored under the least
corrosive conditions, either a dry or freeze cycle. Preferably,
7.3 Specimensmaybesubmittedtothetestscribed,chipped
or undamaged, as agreed upon between interested parties. testinterruptionsshouldnotexceedmorethan25 %ofthetotal
test time, but all interruptions should be noted.
Usually the stone chip test or a scribing tool is used to provide
damage prior to cyclic corrosion testing. 8.5 Ramp Time—The time needed to adjust the temperature
7.3.1 Whenastonechiptestisused,theprocedureshownin and humidity to the new exposure conditions is considered
Test Method D3170 shall be followed to assure consistent ramptime.Dependinguponthetypeofequipmentusedandthe
D6899–03
chamberloading,ramptimemayvaryandshouldbemonitored 10.1.3 Exposure Duration—One cycle is 8 h. The typical
andreported,whenthechamberisequippedwithatemperature duration is 200 cycles.
and humidity recorder. 10.1.4 Ramp Time—Ramp time must be less than 30 min.
8.6 Atomization and Quantity of Fog—For tests which 10.2 Compound Corrosion Test II—Commonly known as
include a fog cycle, collect the fog in a separate, continuous CCT II. This method is described in JASO M610.
spray run of at least 16 h, performed between test runs. The 10.2.1 Salt Solution—The solution used shall be 5 % so-
regular spray periods of most cyclic corrosion tests exposures dium chloride solution as described in JIS Z 2371. The pH of
are not long enough to collect sufficient fog to make accurate the collected solution shall be 6.5 to 7.2.
determinations of deposition rate. 10.2.2 The exposure cycle is as follows:
Time Condition Test Parameters
NOTE 3—Chambers equipped with external condensation monitoring
2 h Salt mist application 35°C 6 2°C
systems may be used for ongoing monitoring of condensation volume.
4 h Dry off 60°C 6 2°C and <35 % RH
2 h Humidity 50°C 6 2°C and >95 % RH
9. Test Environments
10.2.3 Test Duration—One cycle is 8 h.
9.1 Salt Solution Application—Salt solution application can
10.2.4 Ramp Time—The following ramp times are allowed:
take place as a fog, spray or immersion in a test chamber, or
Fog to Dry within 30 min
may be performed manually in a separate tank. The salt
Dry to Wet within 15 min
Wet to Fog within 30 min
solution used shall be as specified in the appropriate specifi-
cation or as agreed upon by interested parties.
10.3 Compound Corrosion Test III—Commonly known as
9.1.1 Commonly used solutions may include one or more of
CCT III. This method uses a dip instead of a spray.
the following: sodium chloride, calcium chloride, sodium
10.3.1 The solution used shall be 5 % sodium chloride
bicarbonate, etc.
solution as described in JIS Z 2371. The pH of the collected
9.1.2 Solution Preparation—Unless otherwise indicated,
solution shall be 6.5 to 7.2.
prepare the solution by dissolving in water which meets
10.3.2 The exposure cycle is as follows:
Specification D1193, Type IV. Ensure that the solution is
Time Condition Test Parameters
7.5 min Salt Solution Dip 40°C
thoroughly mixed prior to use.
15 min Humidity 40°C and >95 % RH
9.1.3 Unless otherwise specified, replace the solution when
7.5 min Dry Off 60°C and <30 % RH
itfallsoutsidethespecifiedlimits,orweekly,whicheveroccurs
10.3.3 Test Duration—A typical exposure period is 4000
first.
cycles.
NOTE 4—If calcium chloride and sodium bicarbonate are used in the
10.4 Compound Corrosion Test IV—This test is commonly
same solution, a precipitate may occur. Filtering prior to spraying will
referred to as CCT IV and used for external panels and
avoid clogging of the spray nozzles.
topcoats. It has shown good correlation with exposure in
9.2 High Humidity—Conditions in excess of 95 % relative
Okinawa.
humidity. These conditions can be obtained through vapor,
10.4.1 The solution used shall be 5 % sodium chloride
steam or fog generation. Refer to Practices D1735 and D2247 solution as described in JIS Z 2371. The pH of the collected
for commonly used high humidity test conditions.
solution shall be 6.5 to 7.2.
9.3 Dry Off—Conditions of less than 30 % relative humid- 10.4.2 The exposure cycle is as follows:
ity. The dry off shall be maintained with sufficient air circula-
Time Condition Test Parameters
10 min Salt mist application 50 6 2°C
tion to prevent temperature stratification, and also allow
155 min Dry off 60 6 2°C and <30 % RH
complete drying of the samples.
75 min Humidity 60 6 2°C and 95 % 6 5% RH
160 min Dry off* 60 6 2°C and <30 % RH
80 min Humidity* 60 6 2°C and 95 % 6 5% RH
10. Cyclic Corrosion Test Procedures
* Repeat steps 4 and 5, five times.
10.1 Compound Corrosion Test I—Commonly known as
10.4.3 Test Duration—One cycle must not be greater than
CCT I. Common applications include vehicle body panels,
24 h and 10 min. There are no provisions for testing over the
drive train components and fasteners.
weekend.
10.1.1 Salt Solution—The solution used shall be 5 % so-
10.4.4 Ramp time must be less than 30 min, except humid-
dium chloride solution
...