1、Designation: B557M 10Standard Test Methods forTension Testing Wrought and Cast Aluminum- andMagnesium-Alloy Products (Metric)1This standard is issued under the fixed designation B557M; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision
2、, 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.This standard has been approved for use by agencies of the Department of Defense.1. Scope*1.1 These test methods cov
3、er the tension testing of wroughtand cast aluminum- and magnesium-alloy products, exceptingaluminum foil2, and are derived from Test Methods E8M,which cover the tension testing of all metallic materials.NOTE 1These metric test methods are the equivalents of those in TestMethods B557, and are compati
4、ble in technical content except for therequirement of longer gage lengths for round specimens.NOTE 2Exceptions to the provisions of these test methods may needto be made in individual specifications or test methods for a particularmaterial.1.2 The values stated in SI units are to be regarded asstand
5、ard. No other units of measurement are included in thisstandard.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 appli
6、ca-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:3B209 Specification for Aluminum and Aluminum-AlloySheet and PlateE4 Practices for Force Verification of Testing MachinesE6 Terminology Relating to Methods of Mechanical TestingE8M Test Methods for Tension Tes
7、ting of Metallic Materi-als Metric4E29 Practice for Using Significant Digits in Test Data toDetermine Conformance with SpecificationsE83 Practice for Verification and Classification of Exten-someter SystemsE345 Test Methods of Tension Testing of Metallic FoilE691 Practice for Conducting an Interlabo
8、ratory Study toDetermine the Precision of a Test MethodE1012 Practice for Verification of Test Frame and SpecimenAlignment Under Tensile and Compressive Axial ForceApplication3. Terminology3.1 The definitions of terms relating to tension testingappearing in Terminology E6 shall be considered as appl
9、yingto the terms used in these test methods.4. Significance and Use4.1 Tension tests provide information on the strength andductility of materials under uniaxial tensile stresses. Thisinformation may be useful in comparisons of materials, alloydevelopment, quality control, and design under certain c
10、ircum-stances.4.2 The results of tension tests of specimens machined tostandardized dimensions from selected portions of a part ormaterial may not totally represent the strength and ductilityproperties of the entire end product or its in-service behavior indifferent environments.4.3 These test metho
11、ds are considered satisfactory for ac-ceptance testing of commercial shipments and have been usedextensively in the trade for this purpose.5. Apparatus5.1 Testing MachinesMachines used for tension testingshall conform to the requirements of Practices E4. The forcesused in determining tensile strengt
12、h and yield strength shall bewithin the verified force application range of the testingmachine as defined in Practices E4.5.2 Gripping Devices:5.2.1 GeneralVarious types of gripping devices may beused to transmit the measured load applied by the testingmachine to the test specimens. To ensure axial
13、tensile stresswithin the gage length, the axis of the test specimen mustcoincide with the centerline of the heads of the testing1These test methods are under the jurisdiction of ASTM Committee B07 onLight Metals and Alloys and are the direct responsibility of Subcommittee B07.05on Testing.Current ed
14、ition approved July 1, 2010. Published August 2010. Originallyapproved in 1976. Last previous edition approved in 2007 as B557M 071. DOI:10.1520/B0557M-10.2For test methods of tension testing of aluminum foil, see Test Methods E345.3For referenced ASTM standards, visit the ASTM website, www.astm.org
15、, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.4Withdrawn. The last approved version of this historical standard is referencedon www.astm.org.1*A Summary of Changes section app
16、ears at the end of this standard.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.machine. Any departure from this requirement may introducebending stresses that are not included in the usual stresscomputation (load divided by cross-se
17、ctional area).NOTE 3The effect of this eccentric loading may be illustrated bycalculating the bending moment and stress thus added. For a standard12.50-mm diameter specimen, the stress increase is 1.5 percentage pointsfor each 0.025 mm of eccentricity. This error increases to about 2.3percentage poi
18、nts/0.025 mm for a 9-mm diameter specimen and to 3.25percentage points /0.025-mm for a 6-mm diameter specimen.NOTE 4Alignment methods are given in Practice E1012.5.2.2 Wedge GripsTesting machines usually are equippedwith wedge grips. These wedge grips generally furnish asatisfactory means of grippin
19、g long bars of ductile metal. If,however, for any reason, one grip of a pair advances fartherthan the other as the grips tighten, an undesirable bendingstress may be introduced. When liners are used behind thewedges, they must be of the same thickness and their facesmust be flat and parallel. For be
20、st results, the wedges should besupported over their entire length by the heads of the testingmachine. This requires that liners of several thicknesses beavailable to cover the range of specimen thickness. For propergripping, it is desirable that the entire length of the serratedface of each wedge b
21、e in contact with the specimen. Properalignment of wedge grips and liners is illustrated in Fig. 1. Forshort specimens it is generally necessary to use machined testspecimens and to use a special means of gripping to ensure thatthe specimens, when under load, shall be as nearly as possiblein uniform
22、ly distributed pure axial tension (see 5.2.3, 5.2.4, and5.2.5).5.2.3 Grips for Threaded and Shouldered SpecimensAschematic diagram of a gripping device for threaded-endspecimens is shown in Fig. 2, while Fig. 3 shows a device forgripping specimens with shouldered ends. Both of thesegripping devices
23、should be attached to the heads of the testingmachine through properly lubricated spherical-seated bearings.The distance between spherical bearings should be as large asfeasible.5.2.4 Grips for Sheet MaterialsThe self-adjusting gripsshown in Fig. 4 have proved satisfactory for testing sheetmaterials
24、 that cannot be tested satisfactorily in the usual type ofwedge grips.5.2.5 Grips for WireGrips of either the wedge or snubbingtypes as shown in Fig. 4 and Fig. 5 or flat wedge grips may beused.5.3 Dimension-Measuring DevicesMicrometers and otherdevices used for measuring linear dimensions shall be
25、accurateand precise to at least one half the smallest unit to which theindividual dimension is required to be measured.5.4 ExtensometersExtensometers used in tensile testingshall conform to the requirements of Practice E83 for theclassifications specified by the procedure section of these testmethod
26、s. Extensometers shall be used and verified to includethe strains corresponding to the yield strength and elongation atfracture (if determined).5.4.1 Extensometers with gage lengths equal to or shorterthan the nominal gage length of the specimen (dimensionshown as “G-gage Length” in the accompanying
27、 figures) maybe used to determine the yield behavior. For measuringelongation at fracture with an appropriate extensometer, thegage length of the extensometer shall be equal to the nominalgage length required for the specimen being tested.6. Test Specimen6.1 General:6.1.1 Test specimens shall be of
28、the full section of thematerial whenever practical. Otherwise, machined specimensof rectangular or round cross section shall be used.6.1.2 Improperly prepared test specimens often are thereason for unsatisfactory and incorrect test results. It isimportant, therefore, that care be exercised in the pr
29、eparationof specimens, particularly in the machining, to ensure thedesired precision and bias in test results.6.1.3 The cross-sectional area of the specimen should besmallest at the center of the reduced section to ensure fractureFIG. 1 Wedge Grips with Liners for Flat SpecimensFIG. 2 Gripping Devic
30、e for Threaded-End SpecimensB557M 102within the gage length. For this reason, a small taper ispermitted in the reduced section of each of the specimensdescribed in the following sections.6.1.4 Rectangular specimens shall be 12.50 mm wide inaccordance with Fig. 6 or Fig. 7 (for tubular products), and
31、shall be of the full thickness of the material when practical.When necessary, 6.00-mm wide subsize specimens as shown inFig. 6 may be used, but elongation values from such specimensare not applicable to specification requirements.6.1.4.1 Pin ends as shown in Fig. 8 may be used. In order toavoid buck
32、ling in tests of thin and high-strength materials, itmay be necessary to use stiffening plates at the grip ends.6.1.5 Round specimens shall be the standard 12.50-mmdiameter specimen in Fig. 9, except when the dimensions of theproduct make this impossible. In such cases, small-size speci-mens proport
33、ional to the standard specimen shown in Fig. 9may be used. Unless otherwise specified in the productspecification, the selection of round tensile specimens shall beas specified in Table 1. Unless permitted by the productspecification, the diameter of the reduced section of thesmallest specimen used
34、shall not be less than 4 mm for wroughtproducts and 6 mm for cast products.6.1.5.1 The shape of the ends of the specimen outside of thegage length shall be suitable to the material and of a shape tofit the holders or grips of the testing machine so that the loadsare applied axially. Fig. 10 shows sp
35、ecimens with various typesof ends that have given satisfactory results.6.1.6 Special care is required in the manufacture and testingof smaller specimens because the effects of machining (forexample, the amount of end load applied and the amount ofheat generated) and testing (for example, eccentricit
36、y and gagemarking) variables are greater upon them than upon largerspecimens. Therefore, the largest practical specimen shallalways be used. With some types of materials, notably castings,the result of tests of small specimens may be more variable dueto the increasing significance of variations in m
37、etallic structureor the character of the surfaces. Low values derived from smallspecimens should be carefully evaluated in accordance with8.1 to be certain that the results are valid.6.1.7 While tensile strengths and yield strengths can prop-erly be compared with results derived from test specimens
38、ofvarious dimensions, elongation values may vary with specimensize and type. Therefore, elongation values should be obtainedwith specimens of the type from which the published tensileproperties were established.FIG. 3 Gripping Device for Shouldered-End SpecimensFIG. 4 Gripping Devices for Sheet and
39、Wire SpecimensFIG. 5 Snubbing Device for Testing WireB557M 103Dimensions, mmStandard Specimen Sheet-Type12.5mmWideSubsize Specimen 6 mm WideGgage length 50.0 6 0.1 25.0 6 0.1WWidth (Note 1 and Note 2) 12.5 6 0.2 6.0 6 0.1TThickness (Note 3) thickness of material thickness of materialRRadius of fille
40、t, min 12.5 6LOverall length, min (Note 4) 200 100ALength of reduced section, min 57 32BLength of grip section, min (Note 5) 50 30CWidth of grip section, approximate (Note 2 and Note 6) 20 10NOTE 1The ends of the reduced section shall not differ in width by more than 0.06 mm for the 50.00-mm gage le
41、ngth specimen or 0.025 mm forthe 25.00-mm gage length specimen. There may be a gradual taper in width from the ends of the reduced section to the center, but the width at each endshall not be more than 1 % greater than the width at the center.NOTE 2For each of the specimens, narrower widths (W and C
42、) may be used when necessary. In such cases the width of the reduced section shouldbe as large as the width of the material being tested permits: however, unless stated specifically, the requirements for elongation in a product specificationshall not apply when these narrower specimens are used. If
43、the width of the material is less than W, the sides may be parallel throughout the length ofthe specimen.NOTE 3The dimension T is the thickness of the test specimen as stated in the applicable material specifications. Maximum nominal thicknesses of12.5-mm and 6-mm wide specimens shall be 12.5 mm and
44、 6 mm, respectively.NOTE 4To aid in obtaining axial loading during testing of 6-mm wide specimens, the overall length should be as large as the material will permit,up to 200 mm.NOTE 5It is desirable, if possible, to make the length of the grip section large enough to allow the specimen to extend in
45、to the grips a distance equalto two thirds or more of the length of the grips. If the thickness of 12.5-mm wide specimens is over 9 mm, longer grips and correspondingly longer gripsections of the specimens may be necessary to prevent failure in the grip section.NOTE 6The grip-end centerline of the 1
46、2.5-mm wide and 6-mm wide specimens shall coincide with the centerline of the reduced section within 0.2mm and 0.1 mm, respectively.FIG. 6 Rectangular Tension Test SpecimensDimensions, mmGgage length 50.00 6 0.10WWidth (Note 1) 12.50 6 0.25TMeasured thickness of specimen Note 2RRadius of fillet, min
47、 12.5ALength of reduced section, min 57BLength of grip section, min (Note 3) 75CWidth of grip section, approximate (Note 4) 20NOTE 1The ends of the reduced section shall not differ in width by more than 0.06 mm. There may be a gradual taper in width from the ends ofthe reduced section to the center,
48、 but the width at each end shall not be more than 1 % greater than the width at the center.NOTE 2The dimension T is the thickness of the tubular section as provided for in the applicable material specifications.NOTE 3It is desirable, if possible, to make the length of the grip section great enough t
49、o allow the specimen to extend into the grips a distance equalto two thirds or more of the length of the grips.NOTE 4The grip-end centerline of the specimen shall coincide with the centerline of the reduced section within 1.00 mm.NOTE 5For circular segments, the cross-sectional area shall be calculated using the formula shown in 7.2.3.NOTE 6The radii of all fillets shall be equal to each other within a tolerance of 1.00 mm, and the centers of curvature of the two fillets at a particularend shall be located across from each other (on a line
