ASTM D2485-91(2000)

Designation:D2485–91(Reapproved 2000)
Standard Test Methods for
Evaluating Coatings For High Temperature Service
This standard is issued under the fixed designation D 2485; 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 D 1186 Test Methods for Nondestructive Measurement of
Dry Film Thickness of Nonmagnetic Coatings Applied to
1.1 These test methods cover the evaluation of the heat-
a Ferrous Base
resistant properties of coatings designed to protect steel sur-
D 2200 Pictorial Surface Preparation Standards for Painting
faces exposed to elevated temperatures during their service
Steel Surfaces
life. Two test methods are described as follows:
G7 Practice for Atmospheric Environmental Exposure
Method A—Interior Service Coatings
Testing of Nonmetallic Materials
Method B—Exterior Service Coatings
1.2 The values stated in SI units are to be regarded as the
3. Summary of Test Methods
standard. The values given in parentheses are for information
3.1 Panels suitably coated with the material under test are
only.
evaluated under one or both of two test methods depending on
1.3 This standard does not purport to address the safety
the intended usage.
concerns, if any, associated with its use. It is the responsibility
3.1.1 Test Method A, Interior Service Coatings—Coated
of whoever uses this standard to consult and establish appro-
panels are heated for 24 h in a muffle furnace at a temperature
priate safety and health practices and determine the applica-
agreed upon between the purchaser and the seller. One panel is
bility of regulatory limitations prior to use. Specific hazard
plunged into water and the other cooled and then subjected to
statements are given in Section 5.
a bend test.
2. Referenced Documents 3.1.2 Test Method B, Exterior Service Coatings—Coated
panels are subjected to temperatures that increase in steps from
2.1 ASTM Standards:
205 to 425°C (400 to 800°F). One panel is subjected to salt
A 36/A36M Specification for Carbon Structural Steel
spray for 24 h, and one is exposed outdoors for 12 months.
A 283/A283M Specification for Low and Intermediate Ten-
2 3.2 When tests are completed, the panels are examined for
sile Strength Carbon Steel Plates
evidence of film degradation including rust formation, blister-
A 285/A285M SpecificationforPressureVesselPlates,Car-
2 ing, loss of adhesion, dulling, and chalking.
bon Steel, Low- and Intermediate-Tensile Strength
B117 Practice for Operating Salt Spray (Fog) Apparatus
4. Significance and Use
D 522 Test Methods for Mandrel Bend Test of Attached
4 4.1 Some coating systems are developed for use over steel
Organic Coatings
that is exposed to high temperatures during service life. This
D 609 Practice for Preparation of Cold-Rolled Steel Panels
method provides an accelerated means of determining the
for Testing Paint, Varnish, Conversion Coatings, and
4 performance of these coating systems. Testing of coatings
Related Coating Products
designed for interior service, and of coatings designed for
D 823 Practices for Producing Films of Uniform Thickness
4 exterior (weather-exposed) service is included.
of Paint, Varnish, and Related Products on Test Panels
5. Apparatus
ThesetestmethodsareunderthejurisdictionofASTMCommitteeD-1onPaint 5.1 Automatic spray equipment as described in Practices
and Related Coatings, Materials, and Applications and are the direct responsibility
D 823 (Method A) or any other suitable method that will give
of Subcommittee D01.27 on Accelerated Testing.
the required uniformity of film and film thickness.
Current edition approved May 15, 1991. Published July 1991. Originally
published as D 2485 – 66 T. Last previous edition D 2485 – 84.
Annual Book of ASTM Standards, Vol 01.04.
3 5
Annual Book of ASTM Standards, Vol 03.02. Annual Book of ASTM Standards, Vol 06.02.
4 6
Annual Book of ASTM Standards, Vol 06.01. Annual Book of ASTM Standards, Vol 14.02.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
D2485–91 (2000)
5.2 Muffle furnace capable of maintaining the temperatures 7.3.1 Expose duplicate coated panels finished with the
described in 7.2 and 7.3. materials under test to the elevated temperature test schedule
5.2.1 Warning: Due to the high temperatures involved in mutually agreed upon between the purchaser and the seller. In
operating the muffle furnace, extreme caution should be used. the absence of such a specified schedule use the following:
5.3 Salt spray apparatus as described in PracticeB117. 7.3.2 Place the panels in a muffle furnace maintained at
205°C (400°F) for 8 h, then increase the temperature to 260°C
6. Panel Preparation
(500°F) for 16 h. Increase the temperature in 55°C (100°F)
6.1 Type—Panel dimensions shall be established by prior
increments, alternating the time periods indicated, to the final
agreement between the purchaser and the seller. Use panels of
temperature maximum previously agreed to between the pur-
6.4 mm ( ⁄4 in.) hot-rolled steel conforming to Specification
chaser and the seller. Thus the schedule would be:
A 36/A 36M or Specification A 283/A 283M, or when appro-
205°C (400°F) for 8 h
priate, Specification A 285/A 285M for the water quench test
260°C (500°F) for 16 h
in Test Method A, and for all tests under Test Method B. For
315°C (600°F) for 8 h
the bend test inTest MethodA, the panels must be thin and soft
370°C (700°F) for 16 h
enough to be bent as described in Test Methods D 522.
425°C (800°F) for 8 h
6.2 Cleaning—Clean the panels for both test methods in
NOTE 1—Many high temperature paints depend upon service condi-
accordance with Practice D 609, Methods B or D. Then, using
tions to provide the extreme heat required to cure or sinter their films. If
a fine silica sand (graded to pass through a No. 40 (425-µm)
these paints are never expos
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