ASTM B201-80(2004)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
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Endorsed by American
Designation:B201–80(Reapproved 2004) Electroplaters’ Society
Endorsed by National
Association of Metal Finishers
Standard Practice for
Testing Chromate Coatings on Zinc and Cadmium Surfaces
This standard is issued under the fixed designation B201; 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.
This standard has been approved for use by agencies of the Department of Defense.
1. Scope 3.1.1.1 Discussion—In most instances, failure is defined as
the first appearance on significant surfaces of white corrosion
1.1 This practice covers a procedure for evaluating the
products visible to the unaided eye at normal reading distance,
protective value of chemical and electrochemical conversion
except that the presence of white corrosion products at sharp
coatings produced by chromate treatments of zinc and cad-
edges (for example, on threaded fasteners) and at junctions
mium surfaces.
between dissimilar metals should not be considered failure. In
1.2 The protective value of a chromate coating is usually
some instances, it may be desirable to regard the first appear-
determined by salt-spray test and by determining whether or
ance of red rust as failure.
not the coating possesses adequate abrasion resistance.
3.1.2 significant surfaces—in general, significant surfaces
1.3 Other methods, such as exposure to a humidity environ-
are those surfaces that are visible and subject to corrosion or
ment, can be used, but are generally of too long a duration to
wear, or both, except that surfaces that are normally difficult to
be of practical value. “Steam Tests” using pressure cookers
coat by electroplating or mechanical deposition may be ex-
have also been used for testing chromate films on hot-dip
empt. The designation of significant surfaces may be indicated
galvanized surfaces.
on the drawing.
1.4 This standard does not purport to address all of the
safety concerns, if any, associated with its use. It is the
4. Significance and Use
responsibility of the user of this standard to establish appro-
4.1 This practice is applicable to chromate coatings of the
priate safety and health practices and determine the applica-
colorless (both one and two-dip), iridescent yellow or bronze,
bility of regulatory limitations prior to use.
olive drab, black, colorless anodic, yellow or black anodic
2. Referenced Documents types, and of the dyed variety, when applied to surfaces of
electrodeposited zinc, mechanically deposited zinc, hot-dipped
2.1 ASTM Standards:
zinc, rolled zinc, electrodeposited cadmium, mechanically
B117 Practice for Operating Salt Spray (Fog) Apparatus
deposited cadmium, and zinc die castings.
3. Terminology
NOTE 1—Colorless coatings are also referred to as clear-bright or
3.1 Descriptions of Terms:
blue-bright coatings.
3.1.1 time to failure—timetofailurewilldependonthetype
4.2 Because of variables inherent in the salt-spray test,
of coating tested. A list of some expected protective values
which may differ from one test cabinet to another, interpreta-
obtainable in a given salt spray test is shown in Appendix X2.
tion of test results for compliance with expected performance
should be specified by the purchaser.
4.3 Properties such as thickness, color, luster, and ability to
This practice is under the jurisdiction of ASTM Committee B08 on Metallic
provide good paint adhesion are not covered in this practice,
and Inorganic Coatings and is the direct responsibility of Subcommittee B08.07 on
nor are the chemical composition and the method of applica-
Chromate Conversion Coatings.
tion of these finishes.
Current edition approved Oct. 1, 2004. Published October 2004. Originally
approved in 1945. Last previous edition approved in 2000 as B201 – 80 (2000).
5. Conditioning
DOI: 10.1520/B0201-80R04.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
5.1 Aging—Before subjecting a chromate coating to test, it
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
must be aged at room temperature in a clean environment for
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. at least 24 h after the chromating treatment.
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B201–80 (2004)
5.2 Preparation of Specimen—The test surface must be free 6.3 Test for Colorless (Clear) Coatings—This test applies
of fingerprints and other extraneous stains and must not be only to coatings that are free of secondary supplementary
cleaned except by gentle wiping with a clean, dry, soft cloth to
coatings, such as oil, water or solvent-based polymers, or wax.
remove loose particles. Oily or greasy surfaces should not be
6.3.1 Determine the presence of a colorless (clear) coating
used for testing, and degreasing with organic solvents is not
byplacingadropofleadacetatetestingsolutiononthesurface.
recommended.
Allow the drop to remain on the surface for 5 s. Remove the
testing solution by blotting gently, taking care not to disturb
6. Procedure
anydepositthatmayhaveformed.Adarkdepositorblackstain
6.1 Salt Spray Test—Expose the clean specimen to a 5 %
is indicative of the absence of a coating.
solution salt spray and conduct the test in accordance with the
6.3.2 Prepare the test solution by diss
...