1、Designation: E 209 00 (Reapproved 2005)Standard Practice forCompression Tests of Metallic Materials at ElevatedTemperatures with Conventional or Rapid Heating Ratesand Strain Rates1This standard is issued under the fixed designation E 209; the number immediately following the designation indicates t
2、he 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 (e) indicates an editorial change since the last revision or reapproval.1. Scope1.1 This practice covers compression test in which t
3、hespecimen is heated to a constant and uniform temperature andheld at temperature while an axial force is applied at acontrolled rate of strain.NOTE 1In metals with extremely high elastic limit or low modulus ofelasticity it is conceivable that 1.5 percent total strain under load could bereached bef
4、ore the 0.2 percent-offset yield strength is reached. In thisevent the 0.2 percent-offset yield strength will be the end point of the testunless rupture occurs before that point.NOTE 2For acceptable compression tests it is imperative that thespecimens not buckle before the end point is reached. For
5、this reason theequipment and procedures, as discussed in this recommended practice,must be designed to maintain uniform loading and axial alignment.1.2 Preferred conditions of testing are recommended so thatdata from different sources conducting the tests will becomparable.1.3 The values stated in i
6、nch-pound units are to be regardedas the standard.1.4 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 r
7、egulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2E4 Practices for Force Verification of Testing MachinesE9 Test Methods of Compression Testing of Metallic Ma-terials at Room TemperatureE21 Test Methods for Elevated Temperature Tension Testsof Metallic MaterialsE83 Practi
8、ce for Verification and Classification of Exten-someter System3. Apparatus3.1 Testing MachinesMachines used for compression test-ing shall conform to the requirements of Practices E4.3.2 Bearing Blocks and Loading AdaptersLoad both endsof the compression specimens through bearing blocks orthrough pi
9、n-type adapters that are part of the compression-testing assembly. Bearing blocks may be designed with flatbearing faces for sheet- or bar-type specimens. Sheet speci-mens may also be loaded through pin-type adapters that areclamped rigidly to the grip sections of specimens designed forthese adapter
10、s (1).3The main requirement is that the method ofapplying the force be consistent with maintaining axial align-ment and uniform loading on the specimen throughout the test.When bearing blocks with flat faces are used, the load-bearingsurfaces should be smooth and parallel within very close limits.Th
11、e tolerance for parallelism for these surfaces should be equalto or closer than that specified for the loaded ends of thespecimens. The design of the equipment should provideadequate rigidity so that parallelism is maintained duringheating and loading. The bearing blocks or pin-type adaptersshould b
12、e made of a material that is sufficiently hard at thetesting temperature to resist plastic indentation at maximumforce. They should also be of a material or coated with amaterial that is sufficiently oxidation resistant at the maximumtesting temperature to prevent the formation of an oxidecoating th
13、at would cause misalignment. In any compressiontest it is important that the specimen be carefully centered withrespect to the bearing blocks, which in turn should be centeredwith respect to the testing machine heads.NOTE 3Bearing blocks with straight cylindrical or threaded holesdepending on specim
14、en design may be used for bar-type specimensproviding the apparatus qualifies in accordance with Section 9.NOTE 4Bearing blocks of an adjustable type to provide parallelloading surfaces are discussed in Test Methods E9. Bearing blocks witha spherical seat for the upper block are also shown.3.3 Subpr
15、essesA subpress or other alignment device isnecessary in order to maintain suitable alignment when testingspecimens that are not laterally supported, unless the testingmachine has been designed specifically for axial alignment and1This practice is under the jurisdiction ofASTM Committee E28 on Mecha
16、nicalTesting and is the direct responsibility of Subcommittee E28.04 on Uniaxial Testing.Current edition approved Dec. 1, 2005 Published December 2005. Originallyapproved in 1963. Last previous edition, approved in 2000 as E 20900e1.2For referenced ASTM standards, visit the ASTM website, www.astm.or
17、g, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.3Boldface numbers in parentheses refer to references at the end of this practice.1Copyright ASTM International, 100 Barr Harbor
18、Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.uniform application of force in elevated-temperature compres-sion testing. A subpress for room-temperature testing is shownin Test Methods E9. For elevated-temperature compressiontesting, the subpress must accommodate the heating an
19、dloading devices and the temperature-sensing elements. Thedesign of the subpress is largely dependent on the size andstrength of the specimens, the temperatures to be used, theenvironment, and other factors. It must be designed so the ramdoes not jam or tilt the frame as a result of heating orapplic
20、ation of force. If the bearing faces of the subpress, theopposite faces of both bearing blocks, and the ends of thespecimen are respectively plane and parallel within very closelimits, it is unnecessary to use adjustable or spherical seats. Inany case, the specimen should be properly centered in the
21、subpress.3.4 Compression Testing JigsWhen testing sheet material,buckling of the specimen during application of compessiveforces must be prevented. This may be accomplished by usinga jig containing side-support plates that bear against the facesof the specimen. The jig must afford a suitable combina
22、tion oflateral-support pressure and spring constant to prevent buck-ling without interfering with axial deformation of the specimen(1). Although suitable combinations vary somewhat withvariations in specimen material and thickness, testing tempera-ture, and accuracy of alignment, acceptable results
23、can beobtained with rather wide ranges of lateral-support pressureand spring constant for any given test conditions. Generally,the higher the spring constant of the jig, the lower thelateral-support pressure that is required. Proper adjustment ofthese test variables may be established in preliminary
24、 verifi-cation tests for the equipment (Section 9).3.4.1 This practice does not intend to designate specificcompression jigs for testing sheet metals, but merely to providea few illustrations and references to jigs that have been usedsuccessfully. Many other jigs are acceptable provided theyprevent
25、buckling and pass the qualification tests set forth inSection 9. Satisfactory results have been obtained in room-temperature testing using the jigs illustrated in Test MethodsE9. These jigs usually require that the specimen be lubricatedto permit normal compression on loading. For elevated-temperatu
26、re testing, modified jigs that accommodate the heat-ing and strain-measuring equipment as well as the temperature-sensing elements must be used. A number of compression-testing jigs have been evaluated specifically for performance inelevated-temperature tests (2, 3). The preferred type dependson the
27、 material, its thickness, and the temperatures involved.For moderately elevated temperatures, one of the room-temperature designs may be used in an oven in which the air iscirculated to provide uniform heating. One design for side-support plates that has been found satisfactory for use attemperature
28、s up to 1000F (538C) when lubricated withgraphite is shown in Fig. 1( a) (4). Longitudinal grooves are cutin each plate with the grooves offset across the thickness of thespecimen. These plates are made of titanium carbide.Atype ofside-support plate that has been used in compression jigs to1800F (98
29、2C) is shown in Fig. 1(b) (4). This is an assemblyof small titanium carbide balls backed up by a titanium carbideplate. The balls protrude through holes in the front retainingplate. The holes for the balls are large enough to allow rotationand translation of each ball while at the same time retainin
30、g theballs in the plate assembly. The spacing of the balls, which isnormally about18 in. (3.2 mm), determines the minimumspecimen thickness that can be tested without buckling be-tween the balls. Rational values of the ball spacing can beobtained from calculations based upon the plastic buckling ofs
31、imply supported plates where the plate width can be taken asthe ball spacing. Another type of jig has a number of leaf-spring supports on each side of the specimen (3, 5). This designis limited to a temperature range in which the metal leaf-springelements can support the specimen satisfactorily. Jig
32、s for usewith specimens that are heated by self resistance are discussedin Ref 1, 6 and 7, which also provide quantitative informationon the effects of lubrication, lateral-support pressure, springconstant, and misalignment.3.4.2 The side-support plates are assembled in a frame thatis part of the ji
33、g. A typical frame and jig assembly is shown inFig. 2.Afurnace is placed around the jig after the specimen andextensometer are assembled in the jig. The holes in the supportblocks are for auxiliary cartridge-type heaters.4. Heating Apparatus4.1 The apparatus and method for heating the specimens aren
34、ot specified, but in present practice the following are mainlyused.4.1.1 The resistance of the specimen gage length to thepassage of an electric current,4.1.2 Resistance heating supplemented by radiant heating,4.1.3 Radiant heating,4.1.4 Induction heating, or4.1.5 Convection heating with circulating
35、-air furnace.4.2 The apparatus must be suitable for heating the specimenunder the conditions specified in Section 5.5. Test Specimen5.1 The size and shape of the test specimen should be basedon three requirements as follows:5.1.1 The specimen should be representative of the materialbeing investigate
36、d and should be taken from the materialproduced in the form and condition in which it will be used,5.1.2 The specimen should be adapted to meet the require-ments on temperature control and rates of heating and strain-ing, andFIG. 1 Specimen Side Support Plates (Ref 4)E 209 00 (2005)25.1.3 The specim
37、en should be conducive to the maintenanceof axial alignment uniform application of force, and freedomfrom buckling when loaded to the end point in the apparatusused.5.2 The specimens are divided into two general classifica-tions: those with rectangular cross sections and those withround cross sectio
38、ns. The dimensions of the specimens areoptional. The specimen must be long enough to be compressedto the required deformation without interference from a sup-porting jig but not long enough to permit buckling where it isunsupported. The end allowance (dimension between the gagepoints and the adjacen
39、t end of the uniform section) should bea minimum of one half the width of rectangular specimens orone half the diameter of round specimens. Typical acceptablespecimens are illustrated in Fig. 3 and Fig. 4.5.3 When the dimensions of the test material permit, roundspecimens should be used. Round speci
40、mens should be de-signed to be free from buckling up to the end point of the testwithout lateral support. Rectangular specimens up to 0.250 in.(6.35 mm) thick normally require lateral support; with greaterthicknesses lateral support may not be required in well-alignedequipment. The methods covered b
41、y this specification arenormally satisfactory for testing sheet specimens down to0.020 in. (0.51 mm) thick. With smaller thicknesses inaccura-cies resulting from buckling and nonuniform straining tend toincrease; consequently, extra care in the design, construction,and use of the test equipment is r
42、equired to obtain valid resultsfor specimens in this thickness range. All compression speci-mens should be examined after they are tested; any evidence ofbuckling invalidates the results for that specimen.5.4 The width and thickness of rectangular specimens anddiameter of round specimens at any poin
43、t in the gage lengthshould not vary from the average by more than 0.001 in. (0.025mm) for dimensions up to 1 in. (25.4 mm) or by more than 0.1percent for dimensions above 1 in.5.5 The ends of end-loaded specimens should be parallelwithin 0.00025 in. (0.0064 mm) for widths, thicknesses, anddiameters
44、up to12 in. (12.7 mm) and within 0.05 percent forwidths, thicknesses, and diameters above12 in. The ends ofend-loaded specimens should be perpendicular to the sideswithin14 of a degree. All machined surfaces should have anaverage surface finish of 63 in. or better. Rectangularspecimens should have a
45、 width of material, equal to at least thethickness of the specimen, machined from all sheared orstamped edges.5.6 Shouldered specimens may be used in lieu of specimenswith uniform width or diameter, provided the method ofapplying force is consistent with requirements of axial align-ment, uniform app
46、lication of force, and freedom from buck-ling.5.7 The surfaces of the rectangular specimens in contactwith the supporting jig should be lubricated to reduce friction.The lubricant should have negligible reaction with the surfaceof the specimen for the test temperature and time chosen andshould retai
47、n its lubricating properties for the duration of theFIG. 2 Typical Compression Testing Jig for Sheet SpecimensMounted on Support Jig (Ref 3)DimensionsSpecimen 1 Specimen 2 Specimen 3G.L.Gage Length, in. (mm) 1.000 6 0.005(25.46 0.13)2.000 6 0.005(50.86 0.13)2.000 6 0.005(50.86 0.13)LUniform Section,
48、 in. (mm) 2.500 6 0.005(63.56 0.13)3.000 6 0.005(76.26 0.13)2.50 min(63.5)WWidth, in. (mm) 0.625 6 0.010(15.96 0.25)1.000 6 0.010(25.46 0.25)0.500 6 0.010(12.76 0.25)E.A.End Allowance, in. (mm) 0.75 (19) 0.50 (12.7) 0.25 min (6.35)FIG. 3 Dimensions of Typical Rectangular SpecimensE 209 00 (2005)3tes
49、t. Molybdenum disulfide and graphite are examples oflubricants that are used.5.8 Specimen dimensions above 0.100 (2.54 mm) in. shouldbe measured to the nearest 0.001 in. (0.025 mm) or less;dimensions under 0.100 in. should be measured to the nearest1 percent or less. The average cross-sectional area of the gagelength should be used for calculation of stress.6. Temperature Control6.1 Conventional HeatingWhen a conventional-heatingrate is desired, variations in indicated temperature within thegage length of the specimen should not exceed the followinglimits duri
