1、Designation: D6546 00 (Reapproved 2010)D6546 15Standard Test Methods forand Suggested Limits for Determining Compatibility ofElastomer Seals for Industrial Hydraulic Fluid Applications1This standard is issued under the fixed designation D6546; the number immediately following the designation indicat
2、es the year oforiginal adoption or, in the case of revision, the year of 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. Scope Scope*1.1 These test methods cover the procedure
3、 for measuring physical properties of elastomer seals in the form of O-rings afterexposure to industrial hydraulic fluids and thermal aging. The measured properties are then compared to the physical propertiesof elastomer seals that have not been exposed to the industrial hydraulic fluids and therma
4、l aging. The changes in these propertiesform a basis for assessing compatibility when these changes are compared against the suggested limits in Table 1.1.2 While these test methods involve the use of O-rings, they can also be used to evaluate the compatibility of the elastomericcompounds of special
5、ty seals with industrial hydraulic fluids and their resistance to thermal aging. The compounds can be moldedinto O-rings for evaluation purposes.1.3 These test methods provide procedures for exposing O-ring test specimens to industrial hydraulic fluids under definiteconditions of temperature and tim
6、e. The resulting deterioration of the O-ring material is determined by comparing the changes inwork function, hardness, physical properties, compression set, and seal volume after immersion in the test fluid to thepre-immersion values.1.4 The values stated in SI units are to be regarded as the stand
7、ard. The values given in parentheses are for information only.1.4.1 ExceptionThe values given in parentheses are for information only.1.5 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 est
8、ablish appropriate safety and health practices and determine the applicability of regulatorylimitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D395 Test Methods for Rubber PropertyCompression SetD412 Test Methods for Vulcanized Rubber and Thermoplastic ElastomersTensionD471 Test Met
9、hod for Rubber PropertyEffect of LiquidsD1414 Test Methods for Rubber O-RingsD2000 Classification System for Rubber Products in Automotive ApplicationsD2240 Test Method for Rubber PropertyDurometer HardnessD3677 Test Methods for RubberIdentification by Infrared SpectrophotometryD3767 Practice for Ru
10、bberMeasurement of DimensionsD5028 Test Method for Curing Properties of Pultrusion Resins by Thermal AnalysisE1131 Test Method for Compositional Analysis by Thermogravimetry2.2 SAE Standard:3AS568A O-ring Sizes3. Terminology3.1 Definitions:3.1.1 batchall the O-rings molded from the same lot of mater
11、ial and presented for inspection at one time.1 These test methods are under the jurisdiction of ASTM Committee D02 on Petroleum Products, Liquid Fuels, and Lubricants and is the direct responsibility ofSubcommittee D02.N0.09D02.N0 on CompatibilityHydraulic Fluids.Current edition approved Oct. 1, 201
12、0Dec. 1, 2015. Published November 2010February 2016. Originally approved in 2000. Last previous edition approved in 20052010as D654600(2005).D6546 00 (2010). DOI: 10.1520/D6546-00R10.10.1520/D6546-15.2 For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service
13、 at serviceastm.org. For Annual Book of ASTM Standardsvolume information, refer to the standards Document Summary page on the ASTM website.3 Available from Society of Automotive Engineers, 400 Commonwealth Drive, Warrendale, PA 15096.This document is not an ASTM standard and is intended only to prov
14、ide the user of an ASTM standard an indication of what changes have 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
15、standard as published by ASTM is to be considered the official document.*A Summary of Changes section appears at the end of this standardCopyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States13.1.2 compounda fully formulated elastomer materi
16、al containing all fillers and cross-linking agents.3.1.3 fluid saturation effectthe absorption of fluid by the elastomer until an equilibrium swell value is reached at a particulartemperature.3.1.4 O-ringa rubber seal of homogeneous composition molded in one piece to the configuration of a torus wit
17、h circular crosssection.3.1.4.1 DiscussionO-rings are used as both dynamic and static seals. The size of the O-ring is normally designated by a dash number correspondingto the size tables listed in AS568A. The dimensions for the O-rings used in these test methods are listed in Annex A2.3.1.5 ultimat
18、e elongationthe amount of stretch that the O-ring is exposed to before breaking.3.1.6 work functionwork done on a test specimen to cause 20 % deformation.4. Significance and Use4.1 When more than one elastomer seal material is tested, the test methods yield comparative data on which to base judgemen
19、tsas to expected service quality. Suggested in-service property change limits are provided. Property changes beyond these limits willindicate limited service life of the elastomer seal.4.2 These test methods attempt to simulate service conditions through controlled aging and evaluation of property c
20、hanges butmay not give any direct correlations with actual part performance since actual service conditions vary widely. These test methodsyield comparative data and indications of property changes of the elastomeric seal material under ideal service conditions. Thesetest methods can be used for qua
21、lity control purposes, for engineering assessments, for service evaluation, and for manufacturingcontrol. The information from these test methods can be used to anticipate expected service quality.5. General Test Methods5.1 Except as otherwise specified, the test methods for rubber O-rings referred
22、to in 5.1.1 5.1.6, which are applicable in generalto vulcanized rubber, shall be complied with as required and are hereby made a part of these test methods.5.1.1 Tension TestTest Methods D412 and D1414.5.1.2 Compression SetTest Methods D395 and D1414.5.1.3 Fluid AgingTest Method D471 and Test Method
23、s D1414.5.1.4 HardnessTest Method D2240.5.1.5 Compositional AnalysisTest Methods D3677 and Test Method E1131.5.1.6 Degree of CureTest Method D5028.5.2 In case of conflict between the provisions of the ASTM test methods referenced in 5.1.1 5.1.6 and the detailed provisionsof the test methods in Test
24、Methods D6546, the latter shall take precedence.6. Test Conditions6.1 TemperatureThe test temperature shall be the maximum sustained temperature anticipated in service.6.2 Immersion PeriodsThe following immersion periods are recommended: 24 h, 72 h, 100 h, 250 h, 500 h, and 1000 h. Thefinal immersio
25、n period will depend upon the results of the previous immersion period. If the changes in the physical propertieshave deteriorated beyond the suggested limits, then further testing is not required. The tolerance for any immersion period shallbe 61 % of the immersion period.7. Test Fluids7.1 For reli
26、able compatibility assessments, it is desirable to use the fluid with which the elastomer will come in contact in actualservice. For comparative tests, samples of fluid from the same drum or shipment shall be used.TABLE 1 Property Change LimitsTime, h MaximumVolumeSwell,%MaximumVolumeShrinkage,%Hard
27、nessChange,Shore APointsMaximumTensileStrengthChange,%MaximumElongationChange,%MaximumWorkFunctionChange,%MaximumCompressionSet, %24 15 3 7 20 20 12 . . .70 15 3 7 20 20 12 20100 15 3 8 20 20 12 20250 15 4 8 20 20 12 25500 20 4 10 25 25 17 301000 20 5 10 30 30 20 35D6546 1528. Test Specimen8.1 The t
28、est specimens shall be O-rings molded from the same compound batch from which the actual seals will be molded.The test samples should approximate the cross section of the actual seal to be used so that the fluid saturation effect is properlyconsidered. The test samples should be either -021, -120, -
29、214, or -320 O-rings, in accordance with AS568A. These have anapproximate inside diameter of 25.4 mm (1 in.) 25.4 mm (1 in.) and represent the most popular cross sections of seals used inindustrial systems. The actual dimensions of each O-ring size are listed in Annex A2.8.2 Test specimens shall be
30、wiped clean of external contaminants prior to testing by using a clean dry wipe.9. Suggested Compatibility Test Limits9.1 For a critical seal application, property change limits, as described in Table 1, should be observed.9.2 All values are in reference to soak time in the operational fluid at the
31、operating temperature of the application. Values reflectchanges from the determined pre-immersion original physical property values of the test specimens.9.3 If the changes are within these limits, the elastomer should be considered compatible. Once a seal material is found to becompatible, all seal
32、s for that system should be ordered by specific compound or specification and not by Classification D2000 callout number or generic polymer designation.10. Procedure for Change in Volume10.1 Apparatus:10.1.1 Test Container, a Mason jar (quart size) fitted with a lid to prevent liquid and vapor from
33、escaping. The lid shall notcontaminate the test liquid. Cover the lid with aluminum foil.10.1.2 Heating Device, a forced air oven, aluminum block heater, or oil bath heater. Maintain the temperature within 61C(1.8F).61 C (1.8 F).10.1.3 Test SpecimenThe test specimen shall consist of an entire O-ring
34、. The same specimen may be used for all tests withhardness and volume determinations made prior to stress-strain tests. Place the test specimen in the test liquid so that it is notdistorted or in contact with the sides of the test container or with the other test specimens. Test a minimum of three t
35、est specimensat one time. It is also important that only O-rings of one size and one material compound be placed in the test container.10.1.4 Analytical Balance, an analytical balance capable of allowing a test specimen to be weighed whether in air or whilesubmerged in water.10.2 Volume ChangeTest t
36、hree specimens.10.2.1 Weigh each test specimen in air, M1, to the nearest 1 mg, 1 mg, and then weigh each specimen immersed in water, M2,at room temperature. It is important that all air bubbles clinging to the test specimen be removed before reading the weight in water.Blot the specimen dry.10.2.2
37、Suspend the specimens in the glass jar by the use of corrosion-resistant wire. Separate the specimens by bending smallloops in the wire or by locating them in different locations so that they do not contact each other.10.2.3 Suspend the specimen vertically so that 25.4 mm (1 in.) 25.4 mm (1 in.) of
38、test fluid is between the lower extremity ofthe specimen and the bottom of the apparatus. Add enough test fluid to cover the specimen to a depth of 25.4 mm (1 in.) 25.4 mm(1 in.) over the upper extremity of the specimen.10.2.4 Place the test apparatus in the heating device adjusted to maintain the s
39、ample at the test temperature for the requiredlength of time. At the end of the required immersion period, remove the specimen from the apparatus. Cool the specimen to roomtemperature by immersing it in a cool, fresh amount of the test fluid for 45 min.10.2.5 At the end of the cooling period, remove
40、 the specimen from the fluid, wipe with a cloth dipped in acetone, and blot dry.Weigh each test specimen in air, M3, and then weigh each specimen immersed in water, M4.10.2.6 Some oils can be very viscous and may be difficult to remove with an acetone wipe. Since these oils do not readilyvolatize, s
41、pecimens exposed to these oils can be cooled by suspending them for 45 min 45 min in air at room temperature shieldedfrom draft. This will allow the majority of the oil to drip off the surface of the specimen. Then proceed with the acetone wipe andweighing process described in 10.2.5. Report when th
42、is alternate method of specimen cooling is used.10.2.7 The change in volume is calculated as follows:V,%5M32M4!2M12M2!M12M2!3100 (1)where:M1 = initial mass of specimen in air, g,M2 = initial mass of specimen in water, g,M3 = mass of specimen in air after immersion, g, andM4 = mass of specimen in wat
43、er after immersion, g.10.3 Volume Shrinkage-Simulated Dry Out (Optional Test Method)Test three specimens.D6546 15310.3.1 In some situations when long downtimes are expected, the O-ring should not shrink beyond 5 % of its previous volumechange value since this can affect its ability to be an effectiv
44、e seal when the system is restarted. In those cases in which a positivevolume change was obtained in 10.2 and long system down times are anticipated, it is recommended that volume shrinkage bedetermined. To perform this optional test method, additional O-rings will have to be tested in accordance wi
45、th 10.2 and then testedin accordance with 10.3 since the normal test for volume change is immediately followed by the destructive tensile test.10.3.2 The test specimen shall consist on an entire O-ring. The specimen must first be submitted for the volume swell test. Thisspecimen is only to be used f
46、or this test sequence and not for any other testing.10.3.3 Place the test specimen from the volume swell test in a forced-air oven that allows air circulation around the testspecimen, and maintain the oven at a test temperature of 23 6 1C (73.4 6 1.8F) for 22 6 0.25 h. 23 C 6 1 C(73.4 F 6 1.8 F) for
47、 22 h 6 0.25 h.At the end of the required period, remove the specimen from the oven and allow it to air cool.10.3.4 Weigh each test specimen in air, M5, and then weigh each specimen immersed in water, M6.10.3.5 The change in volume or shrinkage is calculated as follows:V,%5M52M6!2M32M4!M32M4!3100 (2
48、)where:M3 = initial mass of volume swell specimen in air after immersion, g,M4 = initial mass of volume swell specimen in water after immersion, g,M5 = mass of volume swell specimen in air after dry out, g, andM6 = mass of volume swell specimen in water after dry out, g.11. Changes in Tensile Streng
49、th, Work Function, Elongation, and Hardness11.1 Original PropertiesThe original tensile strength, work function, ultimate elongation, and hardness shall be determinedusing a duplicate set of specimens of O-rings of the same cross section as those that are to be immersed in the test fluid.The O-ringsshall be from the same batch as those that are to be immersed in the test fluid.11.2 Properties After Exposure to the Test Fluid, for determining the tensile strength, work function, ultimate elongation, an
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