1、Designation: D2485 91 (Reapproved 2013)Standard Test Methods forEvaluating Coatings For High Temperature Service1This standard is issued under the fixed designation D2485; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of
2、 last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 These test methods cover the evaluation of the heat-resistant properties of coatings designed to protect steel sur-fa
3、ces exposed to elevated temperatures during their servicelife. Two test methods are described as follows:Method AInterior Service CoatingsMethod BExterior Service Coatings1.2 The values stated in SI units are to be regarded as thestandard. The values given in parentheses are for informationonly.1.3
4、This standard does not purport to address the safetyconcerns, if any, associated with its use. It is the responsibilityof whoever uses this standard to consult and establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use. Specific haz
5、ardstatements are given in Section 5.2. Referenced Documents2.1 ASTM Standards:2A36/A36M Specification for Carbon Structural SteelA283/A283M Specification for Low and Intermediate Ten-sile Strength Carbon Steel PlatesA285/A285M Specification for Pressure Vessel Plates, Car-bon Steel, Low- and Interm
6、ediate-Tensile StrengthB117 Practice for Operating Salt Spray (Fog) ApparatusD522 Test Methods for Mandrel Bend Test of AttachedOrganic CoatingsD609 Practice for Preparation of Cold-Rolled Steel Panelsfor Testing Paint, Varnish, Conversion Coatings, andRelated Coating ProductsD823 Practices for Prod
7、ucing Films of Uniform Thicknessof Paint, Varnish, and Related Products on Test PanelsD1186 Test Methods for Nondestructive Measurement ofDry Film Thickness of Nonmagnetic Coatings Applied toa Ferrous Base (Withdrawn 2006)3D2200 Practice for Use of Pictorial Surface PreparationStandards and Guides f
8、or Painting Steel SurfacesG7 Practice for Atmospheric Environmental Exposure Test-ing of Nonmetallic Materials3. Summary of Test Methods3.1 Panels suitably coated with the material under test areevaluated under one or both of two test methods depending onthe intended usage.3.1.1 Test Method A, Inter
9、ior Service CoatingsCoatedpanels are heated for 24 h in a muffle furnace at a temperatureagreed upon between the purchaser and the seller. One panel isplunged into water and the other cooled and then subjected toa bend test.3.1.2 Test Method B, Exterior Service CoatingsCoatedpanels are subjected to
10、temperatures that increase in steps from205 to 425C (400 to 800F). One panel is subjected to saltspray for 24 h, and one is exposed outdoors for 12 months.3.2 When tests are completed, the panels are examined forevidence of film degradation including rust formation,blistering, loss of adhesion, dull
11、ing, and chalking.4. Significance and Use4.1 Some coating systems are developed for use over steelthat is exposed to high temperatures during service life. Thismethod provides an accelerated means of determining theperformance of these coating systems. Testing of coatingsdesigned for interior servic
12、e, and of coatings designed forexterior (weather-exposed) service is included.5. Apparatus5.1 Automatic spray equipment as described in PracticesD823 (Method A) or any other suitable method that will givethe required uniformity of film and film thickness.5.2 Muffle furnace capable of maintaining the
13、 temperaturesdescribed in 7.2 and 7.3.5.2.1 WarningDue to the high temperatures involved inoperating the muffle furnace, extreme caution should be used.1These test methods are under the jurisdiction of ASTM Committee D01 onPaint and Related Coatings, Materials, and Applications and are the directres
14、ponsibility of Subcommittee D01.27 on Accelerated Testing.Current edition approved June 1, 2013. Published June 2013. Originallyapproved in 1966. Last previous edition approved in 2007 as D2485 91 (2007).DOI: 10.1520/D2485-91R13.2For referenced ASTM standards, visit the ASTM website, www.astm.org, o
15、rcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.3The last approved version of this historical standard is referenced onwww.astm.org.Copyright ASTM International, 100 Barr Harbor Dr
16、ive, PO Box C700, West Conshohocken, PA 19428-2959. United States15.3 Salt spray apparatus as described in Practice B117.6. Panel Preparation6.1 TypePanel dimensions shall be established by prioragreement between the purchaser and the seller. Use panels of6.4 mm (14 in.) hot-rolled steel conforming
17、to SpecificationA36/A36M or Specification A283/A283M, or whenappropriate, Specification A285/A285M for the water quenchtest 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 andsoft enough to be bent as described in Test Methods D522.
18、6.2 CleaningClean the panels for both test methods inaccordance with Practice D609, Methods B or D. Then, usinga fine silica sand (graded to pass through a No. 40 (425-m)sieve), blast the panels for Method B to “white” metal(removing all mill scale and rust) so that the panels complywith grade A SP-
19、5 of Standard D2200. Other blast media andblast methods are acceptable if agreed upon between the buyerand the seller. Blast-cleaned panels cannot be subjected to thebend test because they are too thick to bend.6.3 Coatings ApplicationsApply the coatings by auto-matic spray, Method A of Practices D8
20、23, or by any othersuitable method that will assure the required uniformity of filmthickness. The number of coats, technique, and cycle for dryingbetween coats of multicoat systems, limits of dry filmthickness, and drying time before exposure shall be establishedby prior agreement between the purcha
21、ser and the seller.Determine dry film thickness in accordance with Test MethodsD1186. Allow coatings that air dry at ambient temperature todry a 168 h at a temperature of 24 6 2.5C (75 6 5F) priorto exposing to test conditions. Bake coatings that require heatconversion in accordance with the recomme
22、ndation of thesupplier.7. Procedure7.1 SamplingWhen panels have been coated at anotherlocation, select at random from different packages two speci-mens for each method of each type of coating under investi-gation.7.2 Test Method A:7.2.1 Place one panel each of the two types described in 6.1and 6.2 c
23、oated with each paint under test in a muffle furnacemaintained at the test temperature mutually agreed uponbetween the purchaser and the seller, and allow to remain for24 h. At the end of this time plunge one of the panelsimmediately into water maintained at 70 6 5F (21 6 2.5C).After removing from t
24、he water, examine the coating film forevidence of film failure including dulling, blistering, cracking,and loss of adhesion. Allow the second panel to cool at a roomtemperature of 24 6 2.5C (75 6 5F) for 1 h, then rapidlybend double over a 12.7-mm (12-in.) diameter steel mandrelwith coated side uppe
25、rmost in accordance with Test MethodsD522, Method B. Examine this panel for evidence of filmdegradation such as cracking and loss of adhesion.7.3 Test Method B:7.3.1 Expose duplicate coated panels finished with thematerials under test to the elevated temperature test schedulemutually agreed upon bet
26、ween the purchaser and the seller. Inthe absence of such a specified schedule use the following:7.3.2 Place the panels in a muffle furnace maintained at205C (400F) for 8 h, then increase the temperature to 260C(500F) for 16 h. Increase the temperature in 55C (100F)increments, alternating the time pe
27、riods indicated, to the finaltemperature maximum previously agreed to between the pur-chaser and the seller. Thus the schedule would be:205C (400F) for 8 h260C (500F) for 16 h315C (600F) for 8 h370C (700F) for 16 h425C (800F) for 8 hNOTE 1Many high temperature paints depend upon service conditionsto
28、 provide the extreme heat required to cure or sinter their films. If thesepaints are never exposed to the extreme heat, they may be found to beunsuitable. Consequently, it is good practice to make observations also attemperatures less than the expected service temperatures.7.3.3 Remove the test pane
29、ls and make a visual inspectionfollowing exposure at each temperature level for evidence offailure, including peeling, cracking, blistering, abnormaldiscoloration, or loss of adhesion, using ASTM standardswhere possible. Disregard such failures up to 6.4 mm (14 in.)in from the edges of the test pane
30、ls.7.3.4 At the end of the complete exposure, remove thepanels from the oven or muffle furnace and allow to air cool atambient temperature for a minimum period of 1 h. As de-scribed in 7.3.3, inspect for evidence of failure due to the hightemperature exposure.7.3.5 If both panels of each pair pass t
31、he heat testsatisfactorily, use them, respectively, for salt spray (fog) testingand exterior exposure testing.7.3.5.1 Place one panel of each pair in a salt spray cabinetoperated in accordance with the requirements of Practice B117,for a period of 24 h. At the conclusion of the exposure period,exami
32、ne each panel for rusting or any other evidence ofcorrosive attack.7.3.5.2 Expose the second panel of each pair on aninsulated-type rack, as described in Practice G7, or as agreedupon between the purchaser and seller, for a period of 12months. Make a visual inspection after 6 months and aftertermina
33、tion of the exposure. The site to conduct the test and theangle of the exposure rack should be agreed upon between thepurchaser and the seller, and should relate to the end-useapplication of the coating.8. Report8.1 Report the following information:8.1.1 Description of substrates, substrate preparat
34、ion, andapplication conditions used.8.1.2 Air drying and the baking schedule used.8.1.3 Details of outdoor exposure when applicable, includ-ing:8.1.3.1 Exposure site, type (insulated rack, black box, openrack, etc.) and angle of exposure,8.1.3.2 Date of exposure start,8.1.3.3 Radiation data in terms
35、 of kilojoule per square metreor langleys during exposure period, andD2485 91 (2013)28.1.4 Any defects or changes as described under Section 7.9. Precision9.1 Four operators in four laboratories tested six materialscovering a range of heat-resistant properties, and were able torank products in order
36、 of their heat-resisting qualities. Sincerankings were of a qualitative nature, no mathematical state-ment of reproducibility was established.10. Keywords10.1 heating tests; paints; resistance; heat; temperature tests;elevatedASTM International takes no position respecting the validity of any patent
37、 rights asserted in connection with any item mentionedin this standard. Users of this standard are expressly advised that determination of the validity of any such patent rights, and the riskof infringement of such rights, are entirely their own responsibility.This standard is subject to revision at
38、 any time by the responsible technical committee and must be reviewed every five years andif not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standardsand should be addressed to ASTM International Headquarters. Your comment
39、s will receive careful consideration at a meeting of theresponsible technical committee, which you may attend. If you feel that your comments have not received a fair hearing you shouldmake your views known to the ASTM Committee on Standards, at the address shown below.This standard is copyrighted b
40、y ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,United States. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the aboveaddress or at 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.org). Permission rights to photocopy the standard may also be secured from the ASTM website (www.astm.org/COPYRIGHT/).D2485 91 (2013)3
