1、Designation: D2485 18Standard 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 last revision. A
2、number in parentheses indicates the year of last reapproval. Asuperscript 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 sur-faces exposed to el
3、evated 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 This standard doe
4、s 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, health, and environmental practices and deter-mine the applicability of regulatory limitations prior to use.Specific hazar
5、d statements are given in Section 5.1.4 This international standard was developed in accor-dance with internationally recognized principles on standard-ization established in the Decision on Principles for theDevelopment of International Standards, Guides and Recom-mendations issued by the World Tra
6、de Organization TechnicalBarriers to Trade (TBT) Committee.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
7、Steel, Low- and Intermediate-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 ProductsD
8、823 Practices for Producing 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Test Methods for Nondestructive Measurement ofDry Film Thickness of Nonmagnetic Coatings Applied toa Ferrous Base (Withdrawn 2006)3D2200 Practice for Use of Pictorial Surface Preparation
9、Standards and Guides for 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.
10、1 Test Method A, Interior 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 CoatingsCoatedpa
11、nels are subjected to 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,
12、loss of adhesion, dulling, 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 coatingsdesign
13、ed for interior service, and of coatings designed forexterior (weather-exposed) service is included.1These test methods are under the jurisdiction of ASTM Committee D01 onPaint and Related Coatings, Materials, and Applications and are the directresponsibility of Subcommittee D01.27 on Accelerated Te
14、sting.Current edition approved March 1, 2018. Published March 2018. Originallyapproved in 1966. Last previous edition approved in 2013 as D2485 91 (2013).DOI: 10.1520/D2485-18.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. Fo
15、r 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.*A Summary of Changes section appears at the end of this standardCopyright ASTM International, 100 Ba
16、rr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United StatesThis international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for theDevelopment of International Standards, Guides and Recom
17、mendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.15. 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 o
18、f maintaining the 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.5.3 Salt spray apparatus as described in Practice B117.6. Panel Preparation6.1 TypePanel dimensions shall be established by priorag
19、reement between the purchaser and the seller. Use panels of6.4 mm (14 in.) hot-rolled steel conforming 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
20、 in Test Method A, the panels must be thin andsoft enough to be bent as described in Test Methods D522.6.2 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 fo
21、r Method B to “white” metal(removing all mill scale and rust) so that the panels complywith grade A SP-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
22、thick to bend.6.3 Coatings ApplicationsApply the coatings by auto-matic spray, Method A of Practices D823, 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 f
23、ilmthickness, and drying time before exposure shall be establishedby prior agreement between the purchaser and the seller.Determine dry film thickness in accordance with Test MethodsD1186. Allow coatings that air dry at ambient temperature todry for 168 h at a temperature of 24 6 2.5C (75 6 5F) prio
24、rto exposing to test conditions. Bake coatings that require heatconversion in accordance with the recommendation 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 und
25、er 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 furnacemaintained at the test temperature mutually agreed uponbetween the purchaser and the seller, and allow to remain for24 h. At the end of this ti
26、me plunge one of the panelsimmediately into water maintained at 21 6 2.5C (70 6 5F).After removing from the 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
27、 5F) for 1 h, then rapidlybend at 180 degrees over a 12.7-mm (12-in.) diameter steelmandrel with coated side uppermost in accordance with TestMethods D522, Method B. Examine this panel in the bent areafor evidence of film degradation such as cracking and loss ofadhesion.7.3 Test Method B:7.3.1 Expos
28、e duplicate coated panels finished with thematerials under test to the elevated temperature test schedulemutually agreed upon between 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 at a setpoint of 205C
29、 (400F) for 8 h, then increase the temperatureto 260C (500F) for 16 h. Increase the temperature in 55C(100F) increments, alternating the time periods indicated, tothe final temperature maximum previously agreed to betweenthe purchaser and the seller. Thus the schedule would be:205 6 3.5C (400 6 6F)
30、for 8 h260 6 5.0C (500 6 9F) for 16 h315 6 6.5C (600 6 12F) for 8 h370 6 8.0C (700 6 14F) for 16 h425 6 9.5C (800 6 17F) for 8 hNOTE 1Many high temperature paints depend upon service conditionsto provide the extreme heat required to cure or sinter their films. If thesepaints are never exposed to the
31、 extreme heat, they may be found to beunsuitable. Consequently, it is good practice to make observations also attemperatures less than the expected service temperatures.NOTE 2The set point is the value programmed into the muffle furnacetemperature controller by the user. The 6 values above indicate
32、themaximum allowable operational fluctuation of the temperature displayedon the controller during equilibrium conditions in the furnace. Thisoperational fluctuation is not an indication of uniformity in the furnace.7.3.3 Remove the test panels and make a visual inspectionfollowing exposure at each t
33、emperature 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 panels.7.3.4 At the end of the complete exposure, remove thepan
34、els 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 testsatisfactorily, use them, respectively, for sal
35、t 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,examine each panel for rusting or any other evidence ofcorrosive
36、 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 conduct the test and thea
37、ngle of the exposure rack should be agreed upon between theD2485 182purchaser 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.8.1.2 Air dryi
38、ng 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 langleys during e
39、xposure 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 of a qualita
40、tive nature, no mathematical state-ment of reproducibility was established.10. Keywords10.1 heating tests; paints; resistance; heat; temperature tests;elevatedSUMMARY OF CHANGESCommittee D01 has identified the location of selected changes to this standard since the last issue(D2485-91(2013) that may
41、 impact the use of this standard. (Approved March 1, 2018.)(1) Section 7.2.1 reversed callout of temperature so that SIunits are default values. Also clarified the meaning of “double”bend to mean 180 degrees and evaluations to be performed inthe bent area of the specimen.(2) Section 7.3.2 added “ope
42、rational fluctuation” values foroperation of the muffle furnace along with operational fluctua-tion definition in Note 2.ASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this standard are expres
43、sly 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 committee and must be reviewed every five years andif not revised,
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