1、Designation: D 2485 91 (Reapproved 2007)Standard Test Methods forEvaluating Coatings For High Temperature Service1This standard is issued under the fixed designation D 2485; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year
2、of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) 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
3、-faces 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
4、.3 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
5、hazardstatements are given in Section 5.2. Referenced Documents2.1 ASTM Standards:A 36/A 36M Specification for Carbon Structural SteelA 283/A 283M Specification for Low and IntermediateTensile Strength Carbon Steel PlatesA 285/A 285M Specification for Pressure Vessel Plates,Carbon Steel, Low- and In
6、termediate-Tensile StrengthB117 Practice for Operating Salt Spray (Fog) ApparatusD 522 Test Methods for Mandrel Bend Test of AttachedOrganic CoatingsD 609 Practice for Preparation of Cold-Rolled Steel Panelsfor Testing Paint, Varnish, Conversion Coatings, andRelated Coating ProductsD 823 Practices f
7、or Producing Films of Uniform Thicknessof Paint, Varnish, and Related Products on Test PanelsD 1186 Test Methods for Nondestructive Measurement ofDry Film Thickness of Nonmagnetic Coatings Applied toa Ferrous Base2D 2200 Standard Pictorial Surface Preparation Standardsfor Painting Steel SurfacesG7 P
8、ractice for Atmospheric Environmental ExposureTesting 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, Interior Service CoatingsCoatedpanels
9、 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 temperatures that increase in st
10、eps 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, blister-ing, loss of adhesion, dulling, and chalking.4. Significa
11、nce 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 service, and of coatings designed fo
12、rexterior (weather-exposed) service is included.5. Apparatus5.1 Automatic spray equipment as described in PracticesD 823 (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 temperaturesdescribed in 7.2
13、 and 7.3.5.2.1 Warning: Due to the high temperatures involved inoperating the muffle furnace, extreme caution should be used.5.3 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
14、. Use panels of6.4 mm (14 in.) hot-rolled steel conforming to SpecificationA 36/A 36M or Specification A 283/A 283M, or when appro-priate, Specification A 285/A 285M for the water quench test1These test methods are under the jurisdiction of ASTM Committee D01 onPaint and Related Coatings, Materials,
15、 and Applications and are the directresponsibility of Subcommittee D01.27 on Accelerated Testing.Current edition approved June 1, 2007. Published June 2007. Originallyapproved in 1966. Last previous edition approved in 2000 as D 2485 91 (2000).2Withdrawn.1Copyright ASTM International, 100 Barr Harbo
16、r Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.in Test Method A, and for all tests under Test Method B. Forthe bend test in Test MethodA, the panels must be thin and softenough to be bent as described in Test Methods D 522.6.2 CleaningClean the panels for both test methods ina
17、ccordance with Practice D 609, 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-5 of Standard D 2200. Other blast media andblast meth
18、ods 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 D 823, or by any othersuitable method that will assure
19、 the required uniformity of filmthickness. The number of coats, technique, and cycle for dryingbetween coats of multicoat systems, limits of dry film thick-ness, and drying time before exposure shall be established byprior agreement between the purchaser and the seller. Deter-mine dry film thickness
20、 in accordance with Test MethodsD 1186. 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 recommendation of thesupplier.7. Procedure7.1 Samplin
21、gWhen 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 coated with each paint under test in a muffle f
22、urnacemaintained 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 the water, examine the coating film forevidence
23、 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 uppermost in accordance with Test MethodsD 522, Me
24、thod 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 between the purchaser and the seller. Inthe abse
25、nce 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 periods indicated, to the finaltemperature maxi
26、mum 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 condi-tions to provide the extreme heat required to cure
27、or sinter their films. Ifthese paints are never exposed to the extreme heat, they may be found tobe unsuitable. Consequently, it is good practice to make observations alsoat temperatures less than the expected service temperatures.7.3.3 Remove the test panels and make a visual inspectionfollowing ex
28、posure at each temperature level for evidence offailure, including peeling, cracking, blistering, abnormal dis-coloration, or loss of adhesion, using ASTM standards wherepossible. Disregard such failures up to 6.4 mm (14 in.) in fromthe edges of the test panels.7.3.4 At the end of the complete expos
29、ure, 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 the heat test satisfac-torily, use them, r
30、espectively, for salt spray (fog) testing andexterior exposure testing.7.3.5.1 Place one panel of each pair in a salt spray cabinetoperated in accordance with the requirements of PracticeB117, for a period of 24 h. At the conclusion of the exposureperiod, examine each panel for rusting or any other
31、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 aftertermination of the exposure. The site to condu
32、ct 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 preparation, andapplication conditions used.8.1
33、.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 of kilojoule per square metreor langle
34、ys during exposure period, and8.1.4 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 of their heat-resisting qualities. Sincerankings were
35、of a qualitative nature, no mathematical state-ment of reproducibility was established.D 2485 91 (2007)210. Keywords10.1 heating tests; paints; resistance; heat; temperature tests;elevatedASTM International takes no position respecting the validity of any patent rights asserted in connection with an
36、y 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 any time by the responsible technical
37、 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 comments will receive careful consideration a
38、t 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 by ASTM International, 100 Barr Harbor
39、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).D 2485 91 (2007)3
