ASTM C703-72(2006)
(Test Method)Standard Test Methods for Spalling Resistance of Porcelain Enameled Aluminum
Standard Test Methods for Spalling Resistance of Porcelain Enameled Aluminum
SIGNIFICANCE AND USE
It is difficult to overemphasize the importance of the spall test. Porcelain enameled aluminum that fails this test will probably spall in service if subjected to moisture or weathering.
SCOPE
1.1 These test methods cover accelerated determination of the resistance of porcelain enamel coatings on aluminum alloys to spalling from exposure to moisture or weathering. Test Method A, using a 5 % solution of ammonium chloride, requires 96-h immersion while Test Method B, using a 1 % solution of antimony trichloride, is completed after 20 h of immersion. The spalling tendency is evaluated by the same criteria in both methods. While either method is suitable for magnesium silicon alloys, such as 6061, Test Method B is preferred for simple alloys or commercially pure aluminum, such as 1100.
1.2 The test methods appear in the following order: SectionsTest Method A-Ammonium ChlorideTest Method B-Antimony Trichloride
General Information
Relations
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NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.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:C703–72(Reapproved2006)
Standard Test Methods for
Spalling Resistance of Porcelain Enameled Aluminum
This standard is issued under the fixed designation C703; 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 TEST METHOD A—AMMONIUM CHLORIDE
1.1 These test methods cover accelerated determination of
4. Apparatus
theresistanceofporcelainenamelcoatingsonaluminumalloys
4.1 Container, glass or plastic, large enough to immerse the
to spalling from exposure to moisture or weathering. Test
2 test area of the specimen completely and hold a minimum of 3
Method A, using a 5 % solution of ammonium chloride,
3 mL of solution per square centimetre of the immersed surface.
requires 96-h immersion while Test Method B, using a 1 %
No metal other than the base metal of the specimen may be
solution of antimony trichloride, is completed after 20 h of
exposed to the test solution.
immersion. The spalling tendency is evaluated by the same
criteria in both methods. While either method is suitable for
5. Reagent
magnesium silicon alloys, such as 6061, Test Method B is
5.1 Ammonium Chloride Solution (5 %)—The test solution,
preferred for simple alloys or commercially pure aluminum,
freshly prepared, shall consist of 5 parts, by mass, of ammo-
such as 1100.
nium chloride (NH Cl) (technical grade is adequate) dissolved
1.2 The test methods appear in the following order:
in 95 parts, by mass, of water. Deionized or distilled water is
Sections
preferred, but in the case of very large production pieces, tap
Test MethodA—Ammonium Chloride 4-9
Test Method B—Antimony Trichloride 10-15
water may be used. Sufficient solution shall be prepared to
permit complete immersion of the specimens.
2. Terminology
2.1 Definitions: 6. Test Specimens
2.1.1 spalling—a defect characterized by separation of the
6.1 Full-size production pieces should be tested. When this
porcelain enamel from the aluminum base metal without
is not practical, specimens approximately 4 by 6 in. (102 by
apparent external cause. Spalling can result from the use of
152 mm), cut from production parts should be tested. At least
improper alloys or enamel formulations, incorrect pretreatment
one representative specimen from each “job” or each 1000 ft
of the base metal, or faulty application and firing procedures.
(93 m ) of production, whichever is applicable, should be spall
tested. Spall-tested pieces should not be shipped.
3. Significance and Use
6.2 Test production parts in as-produced condition.
3.1 It is difficult to overemphasize the importance of the
spall test. Porcelain enameled aluminum that fails this test will 7. Procedure
probably spall in service if subjected to moisture or weather-
7.1 Immerse the test specimens completely in the NH Cl
ing.
solution at room temperature. Large production pieces may be
immersed in a container made by lining a packing box with
1 polyethylene plastic sheeting.
These test methods are under the jurisdiction of ASTM Committee B08 on
7.2 Make a visual inspection after 96 h of immersion.
Metallic and Inorganic Coatings and are the direct responsibility of Subcommittee
B08.12 on Materials for Porcelain Enamel and Ceramic-Metal Systems.
NOTE 1—Variations of this test may be used for studies of processing
Current edition approved April 1, 2006. Published April 2006. Originally
variables.These include scored or deformed samples, 24 h inspection, and
approved in 1972. Last previous edition approved in 1999 as C703 – 72 (1999).
DOI: 10.1520/C0703-72R06. multiple cycles of 96 h each.
Method A is based on Bulletin AL-1a, Recommended Test Methods for
Evaluation and Control of Quality of Porcelain Enamel on Aluminum ,ofthe
8. Evaluation
Porcelain Enamel Institute.
3 8.1 Any of the following types of spall that develop within
Method B is based on Bulletin T-51, Antimony Trichloride Spall Test of
Porcelain Enameled Aluminum, of the Porcelain Enamel Institute. 96 h shall constitute failure:
Copyright ©ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA19428-2959, United States.
C703–72 (2006)
8.1.1 Any spall area (revealing bare metal) extending ⁄8 in. 13. Procedure
(3 mm), or more, in from an edge and more than 1 in. (25 mm)
13.1 Immerse as much of the test specimen as practical in
in length,
the SbCl solution at room temperature. If a sample has been
8.1.2 Any spall area on the interior surface (not touching an
bent over a mandrel, the bent portion must be immersed in the
edge) that is more than ⁄8 in. (3 mm) to its maximum
solution.
dimension, or
13.2 After 20 h of immersion, rinse the sample in water and
2 2
8.1.3 Morethansixvisiblespallspotsper1ft (929cm )on
scrub with a sponge to remove loose glass flakes (particularly
the interior surface.
on the bent areas).
9. Report
14. Evaluation
9.1 The report shall include the following:
9.1.1 Evaluation of the specimen as passing or failing th
...
Questions, Comments and Discussion
Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.