ASTM D3170-2003(2007) Standard Test Method for Chipping Resistance of Coatings《覆层耐切割的标准试验方法》.pdf

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1、Designation: D 3170 03 (Reapproved 2007)Standard Test Method forChipping Resistance of Coatings1This standard is issued under the fixed designation D 3170; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision.

2、A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.This standard has been approved for use by agencies of the Department of Defense.1. Scope1.1 This test method covers the determination of the re

3、sis-tance of coatings to chipping damage by stones or other flyingobjects.NOTE 1This test method is similar to SAE J-400.1.2 The values stated in metric units are to be regarded asthe standard. The English units given in parentheses are forinformation only. All dimensions are nominal unless otherwis

4、especified.1.3 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2. R

5、eferenced Documents2.1 ASTM Standards:2D 609 Practice for Preparation of Cold-Rolled Steel Panelsfor Testing Paint, Varnish, Conversion Coatings, andRelated Coating ProductsD 823 Practices for Producing Films of Uniform Thicknessof Paint, Varnish, and Related Products on Test PanelsD 1005 Test Metho

6、d for Measurement of Dry-Film Thick-ness of Organic Coatings Using MicrometersD 1186 Test Methods for Nondestructive Measurement ofDry Film Thickness of Nonmagnetic Coatings Applied toa Ferrous Base3D 1400 Test Method for Nondestructive Measurement ofDry Film Thickness of Nonconductive CoatingsAppli

7、ed toa Nonferrous Metal Base3D 1733 Method of Preparation of Aluminum-Alloy Panelsfor Testing Paint, Varnish, Lacquer, and Related Products3D 2201 Practice for Preparation of Zinc-Coated and Zinc-Alloy-Coated Steel Panels for Testing Paint and RelatedCoating Products2.2 Other Documents:Test for Chip

8、 Resistance of Surface Coatings (J-400)43. Summary of Test Method3.1 Standardized road gravel is projected by means of acontrolled air blast at the coated specimens. All testing isconducted under controlled temperature conditions, generallyeither at ambient (room) temperature or at -29 6 3C (-20 65F

9、). After the gravel impact, tape is applied to remove anyloose coating chips and the degree of chipping is determined.4. Significance and Use4.1 Owners consider chipping of coatings, particularly onthe leading faces and edges of automobile surfaces, unaccept-able. In formulating a coating or coating

10、 system to meet servicerequirements, the resistance to chipping damage by flyingobjects such as gravel is one of the properties of importancesince it can vary considerably as other properties are adjusted.Since resistance to chipping decreases at lower temperaturespartly as the result of decreased f

11、lexibility, the test may bemore directly related to service conditions by performing it ata low temperature. This test method is designed to produce acontrolled amount of impact by the media on the coated panelin order to enhance reproducibility.5. Apparatus5.1 Gravel-Projecting Machine (Gravelomete

12、r), con-structed according to the design specifications shown in Fig.1.5,6There are two types of Gravelometers: the old cabinetstyle and the newer, modular style with an electronic feedmechanism.NOTE 2It is recommended that the operation/maintenance checklistshown in Appendix X1 should be completed

13、at least once per month for1This test method is under the jurisdiction of ASTM Committee D01 on Paintand Related Coatings, Materials, and Applications and is the direct responsibility ofSubcommittee D01.55 on Factory Applied Coatings on Preformed Products.Current edition approved June 1, 2007. Publi

14、shed July 2007. Originally approvedin 1973. Last previous edition approved in 2003 as D 3170 - 03.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Docu

15、ment Summary page onthe ASTM website.3Withdrawn.4Available from Society of Automotive Engineers (SAE), 400 CommonwealthDr., Warrendale, PA 15096-0001, http:/www.sae.org.5The sole source of a suitable apparatus meeting these specifications known tothe committee at this time is Q-Panel Co., 26200 Firs

16、t St., Westlake, OH 44135.6If you are aware of alternative suppliers, please provide this information toASTM International Headquarters. Your comments will receive careful consider-ation at a meeting of the responsible technical committee,1which you may attend.1Copyright ASTM International, 100 Barr

17、 Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.gravelometers that are operated on a weekly basis, and once every 6months for gravelometers that are operated less frequently. Note thatvalues in the checklist are specific to the standard gravel testing protocol.Different s

18、pecifications may be necessary for other media types.5.2 GravelWater-eroded alluvial road gravel7,6passingthrough a 16-mm (58-in.) space screen but retained on a9.5-mm (38-in.) space screen. Note that mesh screen is not asubstitute for a space screen. It is important to remove thesmall pieces of gra

19、vel before reusing the gravel. Other mediamay be used as agreed by contractual parties.5.3 Tape, 100 mm (4 in.) wide.8,6Other tape may be used asagreed upon by the contractual parties.5.4 Temperature-Conditioning Equipment (alternatives):5.4.1 A cold room or freezer of sufficient size in which thegr

20、avel-projecting machine and test specimens can be main-tained at the specified temperature of testing.5.4.2 A freezer or cooler in which the test panels can becooled 5C (10F) below the specified test temperature.5.4.3 AmbientRoom maintained at a temperature between20C (68F) and 30C (86F).5.5 Transpa

21、rent GridA chip counting aid constructed oftransparent plastic approximately 3.176 mm thick by 12.7 cmsquare (18 by 5 by 5 in.), on which a 10.16 cm by 10.16 cm (4by 4 in.) grid of 2.54 cm (1 in.) squares has been etched orscribed.7The sole source of supply of gravel meeting these specifications kno

22、wn to thecommittee at this time is Q-Panel Co., 26200 First St., Westlake, OH 44135.8The sole source of supply of No. 898 filament strapping tape known to thecommittee at this time is the 3M Co., St. Paul MN 55101.FIG. 1 Gravel Projecting MachineD 3170 03 (2007)25.6 Chipping Rating StandardsA photog

23、raphic transpar-ency9,6depicting size and number of chips in each category.See Fig. 2 for an example of the transparencies. Thesestandards depict various degrees of chipping severity and arearranged sequentially from best to worst according to chippingfrequency.6. Test Specimens6.1 The composition,

24、surface preparation, and size of speci-mens shall be agreed upon between the purchaser and theseller. Test panels of 102 by 305 mm (4 by 12 in.) arecommonly used.NOTE 3It is recommended that three replicates of each test specimenbe exposed in the gravelometer. More replicates will improve theaccurac

25、y.6.2 The number, type, method of application, and aging ofcoatings shall be agreed upon between the purchaser and theseller.NOTE 4Application, metal preparation, and film thickness measure-ment methods are given in the following ASTM Practices: D 609, D 823and D 2201, and Test Methods D 1005, D 118

26、6, D 1400, and D 1733.7. Procedure7.1 Condition the specimens for a minimum of1hatthespecified test temperature in the equipment specified in 5.4.Make certain the test specimens are separated and have freeaccess to the conditioning environment so that optimum heattransfer occurs.9The sole source of

27、supply of Chipping Rating Standards , Part #AE-400, knownto the committee at this time is the Society of Automotive Engineers, 400Commonwealth Dr., Warrendale, PA 15096.NOTE 1Reprinted with permission from SAE EA-400 (c) 1985, Society of Automotive Engineers, Inc.FIG. 2 Representation of Chipping Ra

28、tingsD 3170 03 (2007)37.2 Adjust the air pressure on the gravel apparatus to 480 620 kPa (70 6 3 psi) with the air valve open.NOTE 5For cabinet type gravelometers, keep the lid to the gravelchamber closed during this operation as a safety precaution. Other airpressures can be used as agreed upon by

29、the contractual parties.7.3 Cabinet Style Gravelometer:7.3.1 After adjusting the air pressure, shut off the air valve,open the lid to the gravel chamber and collect 550 mL (1 pt) ofgraded gravel (approx 250 to 3000 stones) in a suitablecontainer. Collect the gravel by scraping across the screen toal

30、low fines to fall through.7.3.2 Place one test specimen at the desired test temperaturein the panel holder with the coated side facing the front of theapparatus and close the lid to the panel chamber.7.3.3 Open the gravel feed door and pour gravel from theone pint container obtained from 7.3.1 into

31、the top of the gravelhopper. Do not allow gravel to fall into the nozzle entrance.7.3.4 Open the air valve to allow the air to project the gravelat the specimen.NOTE 6The gravel hopper must empty in 7 to 10 s. If gravel remainsin the hopper after 10 s, stop the test and investigate the cause. Theope

32、rator should not touch the gravel during the test or otherwisephysically help the gravel into the funnel.NOTE 7It is important to know that the vibrator may become frozenwhen the chamber is installed in a cold room or freezer. If the vibrator isfrozen, discontinue the test until the vibrator has tha

33、wed and is operatingcorrectly.7.3.5 Shut the air valve, open the lid to the specimenchamber and remove the specimen.7.4 Modular Style Gravelometer:7.4.1 After adjusting the air pressure, shut off the air valve,open the lid to the gravel hopper and pour 550 ml (1 pt) ofgraded gravel (approx. 250 to 3

34、000 stones) into the top of thegravel hopper.7.4.2 Pull back on the specimen mounting clamp to open thespecimen holder on the holder assembly. Place one testspecimen at the desired test temperature in the panel holderwith the coated side facing the front of the apparatus. Clamp toclose the specimen

35、holder.7.4.3 Set the test timer.NOTE 8There are two ways to operate a test on the Modular stylegravelometer. A timed test is a test that shuts off the machine after a presetamount of time has passed. A manual test requires the operator to shut offthe machine after the desired amount of time has pass

36、ed.7.4.3.1 Timed Test:7.4.3.1.1 Make sure that the control switch is set to stop.7.4.3.1.2 Set the test timer to the desired test time. A typicaltest time is 10 s.7.4.3.1.3 Turn the main power switch on.7.4.3.1.4 Turn the control switch to Timed Start.7.4.3.2 Manual Test:7.4.3.2.1 Make sure that the

37、 control switch is set to stop.7.4.3.2.2 Turn the main power switch on.7.4.3.2.3 Turn the control switch to Manual7.4.3.2.4 After the desired amount of time has passed thecontrol switch to Off.NOTE 9Manual mode requires the operator to manually stop the test.Once started, the test will not stop by i

38、tself.7.4.4 When the test has been completed, remove the testpanel from the specimen holder by pulling back on theSpecimen Mounting Clamp and removing the test specimen.7.4.5 Remove the gravel from the return receptacle andscreen before reuse.7.5 Allow the test specimens to return to room temperatur

39、eand dry with a soft cloth to remove any condensation.7.6 Use the tape referenced in 5.3 to remove all loose ordamaged paint.7.6.1 Cover the test area of the specimen with a strip(s) oftape. Apply uniform pressure to ensure that the tape is firmlyadhered to the specimen. There should not be any air

40、bubblestrapped beneath the tape.NOTE 10Uniform pressure can be applied by using a pencil eraser ortongue depressor.7.6.2 Remove the tape by pulling straight up.7.6.3 Apply new strips of tape as specified in 7.6.1.7.6.4 Remove the tape by pulling straight up in the oppositedirection to 7.6.2.7.6.5 Co

41、ntinue this procedure using new strips of tape untilall loose or damaged paint is removed.NOTE 11Other tapes or loose paint removal methods may be used asagreed upon by contractual parties.8. Chip Rating Systems8.1 There are two generally accepted methods for determin-ing the degree of chipping on t

42、he test panel. In the first method,the exact number of chips in each size range is tabulated for thetest area. The second method utilizes a visual comparison ofthe test panel to the Chipping Rating Standards.9An exampleof the chipping standards is shown in Fig. 2.NOTE 12The first method, while the m

43、ost time consuming, is themost precise and should be used where definitive accuracy is required oras the referee method in case differences arise between laboratories. Thesecond method, while more of an approximation than the first method, canbe used for many routine laboratory evaluations where the

44、 accuracy of thefirst method is not required. The second method also lends itself to fieldsurvey work where the chipped areas can be rated by direct comparisonwith the Chipping Rating Standards.NOTE 13Other rating methods may be employed as agreed upon bycontractual parties. The evaluation may also

45、be carried out using digitaloptical imaging which offers further possibilities of evaluation andreproducibility. A guide for use of digital optical imaging is beingprepared by ASTM Subcommittee D01.25.8.2 The chipped area to be evaluated on the test specimenshould be the 10.2 by 10.2 cm (4 by 4 in)

46、square that is thecenter of the chipped area.8.3 The chip rating system consists of one or more number-letter combinations in which the numbers indicate the numberof chips and the letters designate the size of the correspondingchips. A point of failure notation may also be included in therating if a

47、 more descriptive statement is desired.8.3.1 Number of ChipsA number, as shown in Table 1,from 100 that is used to indicate the number size in the 10.2by 10.2 cm (4 by 4 in) test area.8.3.2 Size of ChipsA letter, as shown in Table 2, fromAD that is used to indicate the size of the chip. Due to their

48、regular nature of chipping, the size cannot always be mea-sured exactly so it has to be approximated.D 3170 03 (2007)48.3.3 Point of Failure NotationThe coating layer, asshown in Table 3, at which the most predominate chippingfailure occurs is designated as the point of failure.NOTE 14Cohesional fai

49、lures are failures within a coating. Adhesionalfailures are failures between coatings.9. Physical Count Procedure9.1 Place the transparent grid, as described in 5.5, over thearea to be measured.9.2 The operator examines the area within a 2.54 by 2.54 cm(1 by 1 in.) square and determines the size of each chip asencountered and records it. Repeat for all 16 squares andrecord the results.9.3 Convert the number of chips encountered for each sizeinto the number-letter combinations using Tables 1 and 2. Thenumber-letter combinations are arranged with t