ASTM B201-80(2019)

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: B201 − 80 (Reapproved 2019) Endorsed by American
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 U.S. Department of Defense.
1. Scope 2. Referenced Documents
2.1 ASTM Standards:
1.1 This practice covers a procedure for evaluating the
B117 Practice for Operating Salt Spray (Fog) Apparatus
protective value of chemical and electrochemical conversion
coatings produced by chromate treatments of zinc and cad-
3. Terminology
mium surfaces.
3.1 Definitions of Terms Specific to This Standard:
1.2 The protective value of a chromate coating is usually
3.1.1 time to failure—time to failure will depend on the type
determined by salt-spray test and by determining whether or
of coating tested. A list of some expected protective values
not the coating possesses adequate abrasion resistance.
obtainable in a given salt spray test is shown in Appendix X2.
3.1.1.1 Discussion—In most instances, failure is defined as
1.3 Other methods, such as exposure to a humidity
the first appearance on significant surfaces of white corrosion
environment, can be used, but are generally of too long a
products visible to the unaided eye at normal reading distance,
duration to be of practical value. “Steam Tests” using pressure
except that the presence of white corrosion products at sharp
cookers have also been used for testing chromate films on
edges (for example, on threaded fasteners) and at junctions
hot-dip galvanized surfaces.
between dissimilar metals should not be considered failure. In
1.4 The values stated in SI units are to be regarded as
some instances, it may be desirable to regard the first appear-
standard. No other units of measurement are included in this
ance of red rust as failure.
standard.
3.1.2 significant surfaces—in general, significant surfaces
are those surfaces that are visible and subject to corrosion or
1.5 This standard does not purport to address all of the
wear, or both, except that surfaces that are normally difficult to
safety concerns, if any, associated with its use. It is the
coat by electroplating or mechanical deposition may be ex-
responsibility of the user of this standard to establish appro-
empt. The designation of significant surfaces may be indicated
priate safety, health, and environmental practices and deter-
on the drawing.
mine the applicability of regulatory limitations prior to use.
1.6 This international standard was developed in accor-
4. Significance and Use
dance with internationally recognized principles on standard-
4.1 This practice is applicable to chromate coatings of the
ization established in the Decision on Principles for the
colorless (both one and two-dip), iridescent yellow or bronze,
Development of International Standards, Guides and Recom-
olive drab, black, colorless anodic, yellow or black anodic
mendations issued by the World Trade Organization Technical
types, and of the dyed variety, when applied to surfaces of
Barriers to Trade (TBT) Committee.
electrodeposited zinc, mechanically deposited zinc, hot-dipped
zinc, rolled zinc, electrodeposited cadmium, mechanically
deposited cadmium, and zinc die castings.
NOTE 1—Colorless coatings are also referred to as clear-bright or
blue-bright coatings.
This practice is under the jurisdiction of ASTM Committee B08 on Metallic
and Inorganic Coatings and is the direct responsibility of Subcommittee B08.07 on
Conversion Coatings. For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Current edition approved April 1, 2019. Published April 2019. Originally contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
approvedin1945.Lastpreviouseditionapprovedin2014asB201 – 80(2014).DOI: Standards volume information, refer to the standard’s Document Summary page on
10.1520/B0201-80R19. the ASTM website.
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B201 − 80 (2019)
4.2 Because of variables inherent in the salt-spray test, 6.2 Abrasion Resistance Test—To determine whether the
which may differ from one test cabinet to another, interpreta- coating is adherent, nonpowdery, and abrasion resistant, rub
tion of test results for compliance with expected performance thechromatedsurfacewithagritless,softgumeraser(art-gum)
should be specified by the purchaser. for2to3sby hand (about ten strokes) using normal pressure
(about 70 kPa (10 psi)) and a stroke approximately 50 mm
4.3 Properties such as thickness, color, luster, and ability to
long. The chromate coating should not be removed or worn
provide good paint adhesion are not covered in this practice,
through to the underlying metal as a result of this treatment.
nor are the chemical composition and the method of applica-
tion of these finishes.
6.3 Test for Colorless (Clear) Coatings—This test applies
only to coatings that are free of secondary supplementary
5. Conditioning
coatings, such as oil, water or solvent-based polymers, or wax.
5.1 Aging—Before subjecting a chromate coating to test, it
6.3.1 Determine the presence of a colorless (clear) coating
must be aged at room temperature in a clean environment for
byplacingadropofleadacetatetestingsolutiononthesurface.
at least 24 h after the chromating treatment.
Allow the drop to remain on the surface for 5 s. Remove the
testing solution
...