ASTM D2485-22

This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Because
it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
Designation: D2485 − 18 D2485 − 22
Standard Test Methods for
Evaluating Coatings For High Temperature Service
This standard is issued under the fixed designation D2485; 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*
1.1 These test methods cover the evaluation of the heat-resistant properties of coatings designed to protect steel surfaces exposed
to elevated temperatures during their service life. Two test methods are described as follows:
Method A—Interior Service Coatings
Method B—Exterior Service Coatings
1.2 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.
1.3 This standard does not purport to address the safety concerns, if any, associated with its use. It is the responsibility of
whoever uses this standard to consult and establish appropriate safety, health, and environmental practices and determine the
applicability of regulatory limitations prior to use. Specific hazard statements are given in Section 5.
1.4 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.
2. Referenced Documents
2.1 ASTM Standards:
A36/A36M Specification for Carbon Structural Steel
A283/A283M Specification for Low and Intermediate Tensile Strength Carbon Steel Plates
A285/A285M Specification for Pressure Vessel Plates, Carbon Steel, Low- and Intermediate-Tensile Strength
B117 Practice for Operating Salt Spray (Fog) Apparatus
D522 Test Methods for Mandrel Bend Test of Attached Organic Coatings
D609 Practice for Preparation of Cold-Rolled Steel Panels for Testing Paint, Varnish, Conversion Coatings, and Related Coating
Products
D823 Practices for Producing Films of Uniform Thickness of Paint, Coatings and Related Products on Test Panels
D1186 Test Methods for Nondestructive Measurement of Dry Film Thickness of Nonmagnetic Coatings Applied to a Ferrous
Base (Withdrawn 2006)
D2200 Practice for Use of Pictorial Surface Preparation Standards and Guides for Painting Steel Surfaces
G7 Practice for Natural Weathering of Materials
These test methods are under the jurisdiction of ASTM Committee D01 on Paint and Related Coatings, Materials, and Applications and are the direct responsibility of
Subcommittee D01.27 on Accelerated Testing.
Current edition approved March 1, 2018Dec. 1, 2022. Published March 2018December 2022. Originally approved in 1966. Last previous edition approved in 20132018
as D2485 – 91 (2013).D2485 – 18. DOI: 10.1520/D2485-18.10.1520/D2485-22.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
The last approved version of this historical standard is referenced on www.astm.org.
*A Summary of Changes section appears at the end of this standard
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D2485 − 22
3. Summary of Test Methods
3.1 Panels suitably coated with the material under test are evaluated under one or both of two test methods depending on the
intended usage.
3.1.1 Test Method A, Interior Service Coatings—Coated panels are heated for 24 h in a muffle furnace at a temperature agreed upon
between the purchaser and the seller. One panel is plunged into water and the other cooled and then subjected to a bend test.
3.1.2 Test Method B, Exterior Service Coatings—Coated panels are subjected to temperatures that increase in steps from
205205 °C to 425°C (400425 °C (400 °F to 800°F).800 °F). One panel is subjected to salt spray for 24 h, and one is exposed
outdoors for 12 months.
3.2 When tests are completed, the panels are examined for evidence of film degradation including rust formation, blistering, loss
of adhesion, dulling, and chalking.
4. Significance and Use
4.1 Some coating systems are developed for use over steel that is exposed to high temperatures during service life. This method
provides an accelerated means of determining the performance of these coating systems. Testing of coatings designed for interior
service, and of coatings designed for exterior (weather-exposed) service is included.
5. Apparatus
5.1 Automatic spray equipment as described in Practices D823 (Method A) or any other suitable method that will give the required
uniformity of film and film thickness.
5.2 Muffle furnace capable of maintaining the temperatures described in 7.2 and 7.3.
5.2.1 Warning—Due to the high temperatures involved in operating the muffle furnace, extreme caution shouldshall be used.
5.3 Salt spray apparatus as described in Practice B117.
6. Panel Preparation
6.1 Type—Panel dimensions shall be established by prior agreement between the purchaser and the seller. Use panels of 6.4 mm
( ⁄4 in.) hot-rolled steel conforming to Specification A36/A36M or Specification A283/A283M, or when appropriate, Specification
A285/A285M for the water quench test in Test Method A, and for all tests under Test Method B. For the bend test in Test Method
A, the panels must be thin and soft enough to be bent as described in Test Methods D522.
6.2 Cleaning—Clean the panels for both test methods in accordance with Practice D609, Methods B or D. Then, using a fine silica
sand (graded to pass through a No. 40 (425-μm) sieve), blast the panels for Method B to “white” metal (removing all mill scale
and rust) so that the panels comply with grade A SP-5 of Standard D2200. Other blast media and blast methods are acceptable if
agreed upon between the buyer and the seller. Blast-cleaned panels cannot be subjected to the bend test because they are too thick
to bend.
6.3 Coatings Applications—Apply the coatings by automatic spray, Method A of Practices D823, or by any other suitable method
that will assure the required uniformity of film thickness. The number of coats, technique, and cycle for drying between coats of
multicoat systems, limits of dry film thickness, and drying time before exposure shall be established by prior agreement between
the purchaser and the seller. Determine dry film thickness in accordance with Test Methods D1186. Allow coatings that air dry at
ambient temperature to dry for 168 h at a temperature of 2424 °C 6 2.5°C (752.5 °C (75 °F 6 5°F)5 °F) prior to exposing to test
conditions. Bake coatings that require heat conversion in accordance with the recommendation of the supplier.
7. Procedure
7.1 Sampling—When panels have been coated at another location, select at random from d
...