1、Designation: F1574 03a (Reapproved 2017)Standard Test Method forCompressive Strength of Gaskets at ElevatedTemperatures1This standard is issued under the fixed designation F1574; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the
2、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. Scope1.1 This test method covers the determination of compres-sive strength characteristics (crush-extrusion resistance
3、) ofgasket materials at elevated temperature.1.2 The values stated in SI units are to be regarded as thestandard. The values in parentheses are for information only.1.3 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of th
4、e user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.1.4 This international standard was developed in accor-dance with internationally recognized principles on standard-ization established in the Decisio
5、n on Principles for theDevelopment of International Standards, Guides and Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trade (TBT) Committee.2. Referenced Documents2.1 ASTM Standards:2F104 Classification System for Nonmetallic Gasket Materi-alsF1315 Test Method for De
6、nsity of a Sheet Gasket Material3. Summary of the Test Method3.1 Specimens cut from gasket material are subjected tovarious stresses perpendicular to the flat surface of the speci-mens for a specified time at 150C (302F). Dimensionalchanges to the thickness and in the plane of the specimen aredeterm
7、ined while it is under stress and after the stress has beenremoved. A graphical display of percent deformation plottedagainst the applied stress will enable determination of acompressive yield stress point beyond which the material willno longer decrease in thickness without also extruding in thepla
8、nar dimensions. This condition is also revealed by physicalmeasurements of the change in size of the specimens in theplanar dimensions. Tests may be performed at varioustemperatures, as agreed upon between the producer and theuser, to determine the relationship between temperature andcompressive beh
9、avior.4. Significance and Use4.1 The compressive strength or crush-extrusion resistanceof a gasket material is a major factor with regard to theselection of a given material for use in a particular sealingapplication. The significance of the test method is based, inpart, on the assumption that a mat
10、erial, once it has beencrushed or extruded, will no longer function as effectively as aseal. This assumption can only be used as a guide, however,since exact yield or failure points are difficult to define forgasket materials (which are usually viscoelastic in nature). Twoor more materials can be co
11、mpared to determine differences intheir resistance to compressive stress. A sample of material canbe compared to an established standard or previously deter-mined characteristics on original lots of the same material, forquality assurance purposes. See 6.2 for discussion of specimenarea and geometry
12、 effects.5. Apparatus5.1 Testing Machine3, for applying a known value of com-pressive stresses to specimens. The machine should be capableof applying a stress of up to 520 MPa (75 400 psi) (toleranceof 65 %), depending on the indent resistance of the steelplatens and the means of reading the applied
13、 load.5.2 Hardened Steel Platens, Two (Rockwell of C35 to 40 orequivalent), circular shape, larger than the specimen diameter.A suitable size is a diameter of approximately 100 mm (3.94in.). The surface finish shall be RMS 0.25 to 0.50 m (10 to 20m). Fig. 1 shows a suitable arrangement of steel plat
14、ens andtest specimen.1This test method is under the jurisdiction of ASTM Committee F03 on Gasketsand is the direct responsibility of Subcommittee F03.20 on Mechanical TestMethods.Current edition approved May 1, 2017. Published July 2017. Originally approvedin 1995. Last previous edition approved in
15、2009 as F1574 03a (2009). DOI:10.1520/F1574-03AR17.2For 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 Document Summary page onthe ASTM website.3Examples
16、of such equipment include Baldwin-Southwark, Instron, Tinius-Olsen, MTS, or any type of pressing device which has been properly calibrated toapply a known force.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United StatesThis international standar
17、d was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for theDevelopment of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.15.3 Devi
18、ce forApplying Heat to Platens sufficient to achievea desired temperature at interface with gasket material speci-mens. An example of this device is also shown in Fig. 1, wherea resistance heater surrounds the hardened platens. In somecases, the loading device itself may be heated, such as with ahot
19、 press. Any appropriate means is acceptable. The recom-mended elevated temperature is 150 6 5C (302 6 9F). Othertemperatures may be employed as desired, or as agreed uponbetween the producer and the user.5.4 Temperature Measuring Device for use at interface, suchas a thermocouple assembly and a mean
20、s for recording thevoltage.5.5 DiesCutting dies for specimens of desired size andshape. The inside faces of the dies shall be polished and beperpendicular to the plane formed by the cutting edges for adepth sufficient to prevent any bevel on the edge. The die shallbe sharp and free of nicks in order
21、 to prevent ragged edges onthe specimen. The bore and outside diameter shall be concen-tric.5.6 Lead Pellets, Solder Plugs, or Similar Soft MetallicParticles, approximately 1.6 mm 0.063 in. in diameter.5.7 Micrometer, for making specimen thickness measure-ments in accordance with Classification F104
22、.5.8 Micrometer, for measuring metallic particle thickness.5.9 Vernier Calipers or other suitable device for makinglinear dimensional measurements in the plane of thespecimens, capable of reading to the nearest 0.025 mm (0.001in.) or less.6. Test Specimens6.1 The gasket shall be die cut in the shape
23、 of an annulus,which may be considered indicative of an area of a gasket. Thearea shall be sufficiently small as to allow an applied stress ofup to 520 MPa (75 400 psi) (65 %). Three specimens shouldbe prepared for each applied stress at which the material is tobe evaluated.6.2 The recommended annul
24、ar specimen size is 23.8 6 0.5mm (0.937 6 0.02 in.) outside diameter by 12.7 6 0.5 mm(0.500 6 0.02 in.) inside diameter. Therefore, this size willhave an annular width of approximately 5.5 mm (0.219 in.),where the annular width is the difference between the outer andinner radius. The area will be ap
25、proximately 323 mm2(0.5in.2). If, because of loading capacity or agreement between theproducer and the user, a specimen of different area is tested, itis recommended that the annulus width be kept constant at 5.5mm (0.219 in.) so as not to introduce additional variation to thetest. If comparisons be
26、tween two or more laboratories are to bemade, the specimen area and annulus width should be thesame.6.3 The recommended test specimen thickness may varydepending on the type of testing machine employed, type ofmaterial being evaluated, and the application to which theresults are directed. The exact
27、effect of specimen thickness onthe test results is not being addressed in this test method, otherthan to acknowledge it will most likely influence the resultsand should be a part of the report as specified in Section 10.See Table 3 in Classification F104 for recommended thick-nesses for different ty
28、pes of materials.7. Conditioning7.1 Condition the cut specimens in accordance with theappropriate procedure specified in Classification F104 withrespect to the type of gasket material from which the specimensare cut.8. Procedure8.1 Determine applied stress at which the gasket materialwill be evaluat
29、ed. It should be representative of typicaloperating conditions for the gaskets made of the material, andshould include additional higher and lower stress conditionswhen a full range evaluation of the material is desired. Severaldifferent stresses should be selected to cover the entire range.A series
30、 of stresses in increments of 70 MPa (10 152 psi) isrecommended, to a maximum of 520 MPa (57 400 psi) or untilFIG. 1 Device for Testing Gasket for Compressive Strength at Elevated TemperatureF1574 03a (2017)2extrusion has obviously occurred. Smaller steps may be re-quired for some materials to more
31、accurately define theextrusion range. The tolerance for each stress employed shouldbe no more than 65%.8.2 Prepare the testing machine by arranging the steelplatens to accommodate the test specimens. Verify that thetemperature of the platen interface is at 150 6 5C (302 69F), as required for the tes
32、t.8.3 Measure and record the original thicknesses of eachspecimen, in accordance with the method described in Classi-fication F104 for the particular type of material. Weigh eachspecimen, calculate and record the density in accordance withTest Method F1315 to the nearest 0.001 g. The density of alls
33、amples used should be within 1 % of each other.8.4 Measure the initial annulus width of the test specimen atfour locations 90 apart, taking the average, and record this asthe initial annulus width. For materials of the samecomposition, and cut with the same die, the measurement onone or two specimen
34、s can be considered representative of allspecimens prior to testing. The annulus width can best bedetermined with a set of vernier calipers which can be used tomeasure the difference between the outer and inner radii. Formaterials of the same composition and cut with the same die,the measurements ma
35、de on one or two specimens can beconsidered representative of all specimens prior to testing.8.5 Open the testing device and place a test specimen on thecenter of the lower platen. Place four lead pellets or solderplugs (approximately 1.6 mm (0.063 in.) in diameter) on theplaten approximately 6 mm (
36、0.24 in.) from the outer edge ofthe specimen, 90 apart.8.6 Close the testing device with the upper platen in positionover the specimen and lower the platen, using minimal contactforce. When performing tests at elevated temperature, hold inthis position for 30 s to enable heating of the specimen.8.7
37、Apply the desired load at a rate of 45 000 N (10 116lb)/min until the desired load is achieved; then remove the loadfrom the test specimen within 5 s. (See 8.1 for description ofdesired stress.)8.8 Remove the test specimen from the device, and measureand record the final thickness in the same manner
38、 as was donefor the original thickness.8.9 Measure the final annulus width of the test specimen atfour locations 90 apart, taking the average, and record this asthe extruded annulus width.8.10 Measure the thickness of the lead pellets or solderplugs, take the average of the four plugs, and record th
39、is as thespecimen thickness under stress, as it will be equivalent to thatcharacteristic since the metal particles will not recover inthickness when the applied stress is removed.8.11 After each test, clean the platens appropriately torestore them to their original condition. Wipe the surfaces witha
40、 solvent, such as acetone, using a soft cotton cloth to ensurethat the surface is clean.8.12 Repeat the test procedure on two additional specimensof the same material at the same applied stress, until thesespecimens have been so evaluated at each selected stress.8.13 Repeat the test procedure on thr
41、ee new specimens ofthe material being evaluated, at each additional level of appliedstress to be studied. A series of stresses in steps of 70 MPa(10 152 psi) is recommended, to a maximum of 520 MPa(75 400 psi) or until extrusion has obviously occurred. Smallersteps may be required for some materials
42、 to more accuratelydefine the extrusion range. The tolerance for each reportedstress should be no more than 65%.9. Calculation9.1 Determine the percent deformation (thickness reduc-tion) under applied stress for each specimen, as follows:Ds5 To2 Ts(1)% Ds5To2 TsTo3100% (2)where:Ds= deformation under
43、 applied stress,To= original thickness, andTs= thickness under stress.9.2 Determine the percent final deformation for each speci-men as follows:Df5 To2 Tf(3)% Df5To2 TfTo3100% (4)where:Df= final deformation,To= original thickness, andTf= final thickness.9.3 Determine the percent annular deformation
44、for eachspecimen as follows:AD 5 Wf2 Wo(5)% AD 5Wf2 WoWo3100% (6)where:AD = annular deformation,Wo= original annulus width, andWf= final annulus width.9.3.1 Record the results for each of the given calculationsfor the three specimens tested at a given stress, and determinethe average values.9.4 Repe
45、at the calculations on the specimens tested at eachadditional stress, again determining the average figures.9.5 If a graphical display of test results is desired, plot theapplied stress on the x-axis. The y-axis may include: (1) thepercent deformation under stress; (2) the percent finaldeformation,
46、or (3) the percent annular deformation. Thecompressive yield stress point will be observed on the graph asthe point where there is a change in slope of the line. Thischange may be large or small, depending on the nature of thegasket material.F1574 03a (2017)310. Report10.1 Report the following infor
47、mation for each materialtested:10.1.1 Material identification,10.1.2 Size, shape, and density of the specimens, and10.1.3 Temperature of the test.10.2 Report the following for each applied stress at whichmaterial was tested:10.2.1 Applied stress,10.2.2 Original thickness,10.2.3 Thickness under stres
48、s,10.2.4 Final thickness,10.2.5 Percent deformation under stress,10.2.6 Percent final deformation,10.2.7 Percent annular deformation,10.2.8 Graphical display of results if desired, and10.2.9 Compressive yield stress point determined fromplotted curves.10.3 Tested specimens may be mounted on a displa
49、y sheetto illustrate the degree of extrusion.11. Precision and Bias11.1 PrecisionThe precision of this test method is beingdetermined.11.2 BiasSince there is no accepted reference materialsuitable for determining the bias for this test method, nostatement on bias is available.12. Keywords12.1 annulus; compression; compressive strength; compres-sive yield; crush-extrusion; deformation; failure; gasket mate-rial; stressASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. User
