ASTM D6675-23

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: D6675 − 23
Standard Practice for
Salt-Accelerated Outdoor Cosmetic Corrosion Testing of
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Organic Coatings on Automotive Sheet Steel
This standard is issued under the fixed designation D6675; 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.
INTRODUCTION
Corrosion of painted sheet steel of auto bodies is classified according to the initial location and
direction of the corrosive attack. When the corrosion starts on the visible exterior surface, mostly at
nicks and scratches in the paint, it is called “cosmetic” or “outside in” corrosion. Corrosion initiated
at an interior surface or within a closed or semi-closed part is called “perforation” or “inside out”
corrosion.
1. Scope 2. Referenced Documents
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2.1 ASTM Standards:
1.1 This practice is designed to assist procedures to be
B117 Practice for Operating Salt Spray (Fog) Apparatus
followed when conducting outdoor exposures to evaluate
D609 Practice for Preparation of Cold-Rolled Steel Panels
cosmetic corrosion that might occur in steel panels covered
for Testing Paint, Varnish, Conversion Coatings, and
with an organic coating that has been damaged. The outdoor
Related Coating Products
exposures described are based on Practices G7 and G50 and
D610 Practice for Evaluating Degree of Rusting on Painted
include periodic wetting of the test specimens with a salt
Steel Surfaces
solution.
D823 Practices for Producing Films of Uniform Thickness
1.2 The methods of preparing test specimens and the par-
of Paint, Coatings and Related Products on Test Panels
ticular exposure requirements of materials are beyond the
D1014 Practice for Conducting Exterior Exposure Tests of
scope of this practice. Paints and Coatings on Metal Substrates
D1654 Test Method for Evaluation of Painted or Coated
1.3 The values stated in SI units are to be regarded as the
Specimens Subjected to Corrosive Environments
standard. The values given in parentheses are for information
D1730 Practices for Preparation of Aluminum and
only.
Aluminum-Alloy Surfaces for Painting
1.4 This standard does not purport to address all of the D2201 Practice for Preparation of Zinc-Coated and Zinc-
safety concerns, if any, associated with its use. It is the Alloy-Coated Steel Panels for Testing Paint and Related
responsibility of the user of this standard to establish appro- Coating Products
D3170 Test Method for Chipping Resistance of Coatings
priate safety, health, and environmental practices and deter-
mine the applicability of regulatory limitations prior to use. G7 Practice for Natural Weathering of Materials
G50 Practice for Conducting Atmospheric Corrosion Tests
1.5 This international standard was developed in accor-
on Metals
dance with internationally recognized principles on standard-
ization established in the Decision on Principles for the
3. Significance and Use
Development of International Standards, Guides and Recom-
3.1 Tests of the type described in this practice are used to
mendations issued by the World Trade Organization Technical
evaluate the corrosion resistance of organic coatings on metal
Barriers to Trade (TBT) Committee.
products exposed to highly salty environments, such as areas
subjected to deicing salts or coastal areas. Exposure conditions
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This practice is under the jurisdiction of ASTM Committee D01 on Paint and
Related Coatings, Materials, and Applications and is the direct responsibility of
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Subcommittee D01.27 on Accelerated Testing. For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Current edition approved Feb. 1, 2023. Published February 2023. Originally contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
approved in 2001. Last previous edition approved in 2015 as D6675 – 01 (2015). Standards volume information, refer to the standard’s Document Summary page on
DOI: 10.1520/D6675-23. the ASTM website.
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D6675 − 23
3,4,5,6
test, or any other natural exposure conducted in severe locations.
are complex and changeable. Important factors include climate,
time of year, presence of pollution, and so forth. Generally it is
7.3 The application of electrolyte solution should be per-
difficult, if not impossible, to define or measure precisely all
formed on the scheduled day regardless of the weather co
...