ASTM D7093-13

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
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Designation: D7093 − 13
Standard Test Method for
Formability of Thin Film Organic Coatings on Steel Over a
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Biaxially Stretched Dome
This standard is issued under the fixed designation D7093; 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 3.1.1 dome height, n—the height of the dome formed in the
test.
1.1 Thistestmethodcoverstheevaluationoftheformability
3.1.2 indenting ball diameter, n—the diameter of the
and adhesion of factory applied thin film organic coatings on
spherical-ended penetrator (ball) used to deform the specimen.
steel with thicknesses of 2.5 to 10 microns (0.10 to 0.40 mils)
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3.1.2.1 Discussion—The 41 mm (1 ⁄8 in.) diameter ball was
typical of those used in the coil coating industry.
selected because it minimizes the variability in the localized
1.2 The degree of oil removal prior to forming, the tech-
peak strain. This size ball is commercially available and is as
niques of taping, and differences in adhesive strength of the
large as most testing machines can accommodate.
tape can affect the adhesion rating.
3.1.3 percent strain, n—the percent elongation of scribed
1.3 The values stated in SI units are to be regarded as the
gage lengths after forming.
standard. The values given in parentheses are for information
3.1.3.1 Discussion—For the draw height of 13 mm (0.512
only.
in.), using a 41 mm diameter ball, the localized peak strain is
1.4 This standard does not purport to address all of the
about 19 % (see Fig. 1).
safety concerns, if any, associated with its use. It is the
4. Summary of Test Method
responsibility of the user of this standard to establish appro-
priate safety and health practices and determine the applica-
4.1 A coated specimen is biaxially stretched a given dis-
bility of regulatory limitations prior to use. For a specific
tance in an appropriate machine, adhesive tape is applied to the
hazard statement, see Section 7.
deformed area (dome) and then pulled off, and the amount of
coating removed is compared with a photographic standard to
2. Referenced Documents
determine the coating adhesion rating.
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2.1 ASTM Standards:
5. Significance and Use
D3330/D3330M Test Method for PeelAdhesion of Pressure-
5.1 The results of the combined deformation and tape test
Sensitive Tape
are related to the ability of the coated metal to withstand
2.2 Other Document:
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stamping in factory applications.
Pictorial Standards of Coating Defects
5.2 This test can be used to control the manufacturing
3. Terminology
process or in development work to improve the product.
3.1 Definitions of Terms Specific to This Standard:
5.3 It should be recognized that variability in the results
persist due to the test conditions and forming machine varia-
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tions.
This test method is under the jurisdiction of ASTM Committee D01 on Paint
and Related Coatings, Materials, andApplications and is the direct responsibility of
6. Apparatus and Materials (see Fig. 2)
Subcommittee D01.53 on Coil Coated Metal.
CurrenteditionapprovedJune1,2013.PublishedJuly2013.Originallyapproved
6.1 Forming Machine, equipped with a spherical-ended
in 2004. Last previous edition approved in 2004 as D7093 – 04 which was
penetrator to deform the specimen with appropriate dies, until
withdrawn January 2013 and reinstated in June 2013. DOI: 10.1520/D7093-13.
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For referenced ASTM standards, visit the ASTM website, www.astm.org, or
the required height is obtained, and clamping arrangement to
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
hold the specimen with a minimum pressure of 8.9 kN (2000
Standards volume information, refer to the standard’s Document Summary page on
lb).
the ASTM website.
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6.1.1 The speed of forming shall be between 4.8 and 25
Copies of the pictorial photographic reference standard are contained in the
publication Pictorial Standards of Coatings Defects and may be obtained from the
mm/min (0.2 and 1.0 in./min). The speed is usually slowed to
Federation of Societies for CoatingsTechnology, 492 Norristown Rd., Blue Bell, PA
measure more accurately the final height as shown on the dial
19422. The silver halide gelatin photographs are intended to be the only primary
indicator, but the final punch speed shall be controlled at 6 mm
reference standards for this test method. The reproductions of them in this test
method are for the purpose of illustration only. (0.24 in.) per min maximum.
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D7093 − 13
6.4 Upper and Lo
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