1、Designation: D3170 03 (Reapproved 2007) D3170 12Standard Test Method forChipping Resistance of Coatings1This standard is issued under the fixed designation D3170; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last rev
2、ision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () 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
3、the resistance of coatings to chipping damage by stones or other flying objects.NOTE 1This test method is similar to SAE J-400.1.2 The values stated in metric units are to be regarded as the standard. The English units given in parentheses are forinformation only. All dimensions are nominal unless o
4、therwise specified.1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibilityof the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatorylimitations prior to us
5、e.2. Referenced Documents2.1 ASTM Standards:2D609 Practice for Preparation of Cold-Rolled Steel Panels for Testing Paint, Varnish, Conversion Coatings, and Related CoatingProductsD823 Practices for Producing Films of Uniform Thickness of Paint, Varnish, and Related Products on Test PanelsD1005 Test
6、Method for Measurement of Dry-Film Thickness of Organic Coatings Using MicrometersD1186 Test Methods for Nondestructive Measurement of Dry Film Thickness of Nonmagnetic Coatings Applied to a FerrousBase (Withdrawn 2006)3D1400 Test Method for Nondestructive Measurement of Dry Film Thickness of Noncon
7、ductive Coatings Applied to aNonferrous Metal Base (Withdrawn 2006)3D1733 Method for Preparation of Aluminum Alloy Panels for Testing Paint, Varnish, Lacquer, and Related Products (Withdrawn1979)3D2201 Practice for Preparation of Zinc-Coated and Zinc-Alloy-Coated Steel Panels for Testing Paint and R
8、elated CoatingProducts2.2 Other Documents:Test for Chip Resistance of Surface Coatings (J-400)43. Summary of Test Method3.1 Standardized road gravel is projected by means of a controlled air blast at the coated specimens. All testing is conductedunder controlled temperature conditions, generally eit
9、her at ambient (room) temperature or at -29 6 3C (-20 6 5F). After thegravel impact, tape is applied to remove any loose coating chips and the degree of chipping is determined.4. Significance and Use4.1 Owners consider chipping of coatings, particularly on the leading faces and edges of automobile s
10、urfaces, unacceptable. Informulating a coating or coating system to meet service requirements, the resistance to chipping damage by flying objects such1 This test method is under the jurisdiction of ASTM Committee D01 on Paint and Related Coatings, Materials, and Applications and is the direct respo
11、nsibility ofSubcommittee D01.55 on Factory Applied Coatings on Preformed Products.Current edition approved June 1, 2007July 15, 2012. Published July 2007October 2012. Originally approved in 1973. Last previous edition approved in 20032007 asD3170 - 03.D3170 DOI: 10.1520/D3170-03R07. 03 (2007). DOI:
12、10.1520/D3170-12.2 For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standardsvolume information, refer to the standards Document Summary page on the ASTM website.3 The last approved version of this histo
13、rical standard is referenced on www.astm.org.4 Available from Society of Automotive Engineers (SAE), 400 Commonwealth Dr., Warrendale, PA 15096-0001, http:/www.sae.org.This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes hav
14、e been made to the previous version. Becauseit 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 versionof the standard as published by ASTM is to be considered the official doc
15、ument.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States1as gravel is one of the properties of importance since it can vary considerably as other properties are adjusted. Since resistanceto chipping decreases at lower temperatures partly
16、 as the result of decreased flexibility, the test may be more directly related toservice conditions by performing it at a low temperature. This test method is designed to produce a controlled amount of impactby the media on the coated panel in order to enhance reproducibility.5. Apparatus5.1 Gravel-
17、Projecting Machine (Gravelometer), constructed according to the design specifications shown in Fig. 1.5,6 There aretwo types of Gravelometers: the old cabinet style and the newer, modular style with an electronic feed mechanism.NOTE 2It is recommended that the operation/maintenance checklist shown i
18、n Appendix X1 should be completed at least once per month forgravelometers that are operated on a weekly basis, and once every 6 months for gravelometers that are operated less frequently. Note that values in thechecklist are specific to the standard gravel testing protocol. Different specifications
19、 may be necessary for other media types.5.2 GravelWater-eroded alluvial road gravel7,6 passing through a 16-mm (58-in.) space screen but retained on a 9.5-mm(38-in.) space screen. Note that mesh screen is not a substitute for a space screen. It is important to remove the small pieces ofgravel before
20、 reusing the gravel. Other media may be used as agreed by contractual parties.5 The sole source of a suitable apparatus meeting these specifications known to the committee at this time is Q-Panel Co., 26200 First St., Westlake, OH 44135.6 If you are aware of alternative suppliers, please provide thi
21、s information to ASTM International Headquarters. Your comments will receive careful consideration at ameeting of the responsible technical committee,1 which you may attend.7 The sole source of supply of gravel meeting these specifications known to the committee at this time is Q-Panel Co., 26200 Fi
22、rst St., Westlake, OH 44135.FIG. 1 Gravel Projecting MachineD3170 1225.3 Tape, 100 mm (4 in.) wide.8,6 Other tape may be used as agreed upon by the contractual parties.5.4 Temperature-Conditioning Equipment (alternatives):5.4.1 A cold room or freezer of sufficient size in which the gravel-projecting
23、 machine and test specimens can be maintained atthe specified temperature of testing.5.4.2 A freezer or cooler in which the test panels can be cooled 5C (10F) below the specified test temperature.5.4.3 AmbientRoom maintained at a temperature between 20C (68F) and 30C (86F).5.5 Transparent GridA chip
24、 counting aid constructed of transparent plastic approximately 3.176 mm thick by 12.7 cm square(18 by 5 by 5 in.), on which a 10.16 cm by 10.16 cm (4 by 4 in.) grid of 2.54 cm (1 in.) squares has been etched or scribed.8 The sole source of supply of No. 898 filament strapping tape known to the commi
25、ttee at this time is the 3M Co., St. Paul MN 55101.NOTE 1Reprinted with permission from SAE EA-400 (c) 1985, Society of Automotive Engineers, Inc.FIG. 2 Representation of Chipping RatingsD3170 1235.6 Chipping Rating StandardsA photographic transparency9,6 depicting size and number of chips in each c
26、ategory. See Fig.2 for an example of the transparencies. These standards depict various degrees of chipping severity and are arranged sequentiallyfrom best to worst according to chipping frequency.6. Test Specimens6.1 The composition, surface preparation, and size of specimens shall be agreed upon b
27、etween the purchaser and the seller. Testpanels of 102 by 305 mm (4 by 12 in.) are commonly used.NOTE 3It is recommended that three replicates of each test specimen be exposed in the gravelometer. More replicates will improve the accuracy.6.2 The number, type, method of application, and aging of coa
28、tings shall be agreed upon between the purchaser and the seller.NOTE 4Application, metal preparation, and film thickness measurement methods are given in the following ASTM Practices: D609, D823 and D2201,and Test Methods D1005, D1186, D1400, and D1733.7. Procedure7.1 Condition the specimens for a m
29、inimum of 1 h at the specified test temperature in the equipment specified in 5.4. Makecertain the test specimens are separated and have free access to the conditioning environment so that optimum heat transfer occurs.7.2 Adjust the air pressure on the gravel apparatus to 480 6 20 kPa (70 6 3 psi) w
30、ith the air valve open.NOTE 5For cabinet type gravelometers, keep the lid to the gravel chamber closed during this operation as a safety precaution. Other air pressurescan be used as agreed upon by the contractual parties.7.3 Cabinet Style Gravelometer:7.3.1 After adjusting the air pressure, shut of
31、f the air valve, open the lid to the gravel chamber and collect 550 mL (1 pt) 473mL (1.00 US Liquid Pint) of graded gravel (approx 250 to 3000300 stones) in a suitable container. Collect the gravel by scrapingacross the screen to allow fines to fall through.7.3.2 Place one test specimen at the desir
32、ed test temperature in 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 the one pint container obtained from 7.3.1 into the top of the gravelhopper. Do not allow gravel to fall into the
33、nozzle entrance.7.3.4 Open the air valve to allow the air to project the gravel at the specimen.NOTE 6The gravel hopper must empty in 7 to 10 s. If gravel remains in the hopper after 10 s, stop the test and investigate the cause. The operatorshould not touch the gravel during the test or otherwise p
34、hysically help the gravel into the funnel.NOTE 7It is important to know that the vibrator may become frozen when the chamber is installed in a cold room or freezer. If the vibrator is frozen,discontinue the test until the vibrator has thawed and is operating correctly.7.3.5 Shut the air valve, open
35、the lid to the specimen chamber 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) 473 mL(1.00 US Liquid Pint) of graded gravel (approx. 250 to 3000300 stones) into the top of
36、 the gravel hopper.7.4.2 Pull back on the specimen mounting clamp to open the specimen holder on the holder assembly. Place one test specimenat the desired test temperature in the panel holder with the coated side facing the front of the apparatus. Clamp to close thespecimen holder.7.4.3 Set the tes
37、t timer.NOTE 8There are two ways to operate a test on the Modular style gravelometer. A timed test is a test that shuts off the machine after a preset amountof time has passed. A manual test requires the operator to shut off the machine after the desired amount of time has passed.7.4.3.1 Timed Test:
38、(a) Make sure that the control switch is set to stop.(b) Set the test timer to the desired test time. A typical test time is 10 s.(c) Turn the main power switch on.(d) Turn the control switch to Timed Start.7.4.3.2 Manual Test:(a) Make sure that the control switch is set to stop.(b) Turn the main po
39、wer switch on.(c) Turn the control switch to Manual.(d) After the desired amount of time has passed turn the control switch to Off.NOTE 9Manual mode requires the operator to manually stop the test. Once started, the test will not stop by itself.9 The sole source of supply of Chipping Rating Standard
40、s, Part #AE-400, known to the committee at this time is the Society of Automotive Engineers, 400 CommonwealthDr., Warrendale, PA 15096.D3170 1247.4.4 When the test has been completed, remove the test panel from the specimen holder by pulling back on the SpecimenMounting Clamp and removing the test s
41、pecimen.7.4.5 Remove the gravel from the return receptacle and screen before reuse.7.5 Allow the test specimens to return to room temperature and dry with a soft cloth to remove any condensation.7.6 Use the tape referenced in 5.3 to remove all loose or damaged paint.7.6.1 Cover the test area of the
42、specimen with a strip(s) of tape. Apply uniform pressure to ensure that the tape is firmly adheredto the specimen. There should not be any air bubbles trapped beneath the tape.NOTE 10Uniform pressure can be applied by using a pencil eraser or tongue depressor.7.6.2 Remove the tape by pulling straigh
43、t 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 opposite direction to 7.6.2.7.6.5 Continue this procedure using new strips of tape until all loose or damaged paint is removed.NOTE 11Other tapes or loose paint removal methods may be used a
44、s agreed upon by contractual parties.8. Chip Rating Systems8.1 There are two generally accepted methods for determining the degree of chipping on the test panel. In the first method, theexact number of chips in each size range is tabulated for the test area. The second method utilizes a visual compa
45、rison of the testpanel to the Chipping Rating Standards.9 An example of the chipping standards is shown in Fig. 2.NOTE 12The first method, while the most time consuming, is the most precise and should be used where definitive accuracy is required or as thereferee method in case differences arise bet
46、ween laboratories. The second method, while more of an approximation than the first method, can be usedfor many routine laboratory evaluations where the accuracy of the first method is not required. The second method also lends itself to field survey workwhere the chipped areas can be rated by direc
47、t comparison with the Chipping Rating Standards.NOTE 13Other rating methods may be employed as agreed upon by contractual parties. The evaluation may also be carried out using digital opticalimaging which offers further possibilities of evaluation and reproducibility. A guide for use of digital opti
48、cal imaging is being prepared by ASTMSubcommittee D01.25.8.2 The chipped area to be evaluated on the test specimen should be the 10.2 by 10.2 cm (4 by 4 in) square that is the centerof the chipped area.8.3 The chip rating system consists of one or more number-letter combinations in which the numbers
49、 indicate the number ofchips and the letters designate the size of the corresponding chips. A point of failure notation may also be included in the ratingif a 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 10.2 by 10.2cm (4 by 4 in) test area.8.3.2 Size of ChipsA letter, as shown in Table 2, from AD that is used to indicate the size of the chip. Due to the irregularnature of chipping, the size cannot always be measured exactly so it has to be app
