1、Designation: B557 14Standard Test Methods forTension Testing Wrought and Cast Aluminum- andMagnesium-Alloy Products1This standard is issued under the fixed designation B557; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year
2、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 U.S. Department of Defense.1. Scope*1.1 These test methods cover the
3、 tension testing of wroughtand cast aluminum- and magnesium-alloy products, exceptingaluminum foil2, and are derived from Test Methods E8, whichcover the tension testing of all metallic materials.1.2 The values stated in inch-pound units are to be regardedas standard. No other units of measurement a
4、re 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 applica-bility of regulatory limitations
5、prior to use.NOTE 1Exceptions to the provisions of these test methods may needto be made in individual specifications or test methods for a particularmaterial.NOTE 2Acomplete metric companion to Test Methods B557 has beendevelopedTest Methods B557M; therefore, no metric equivalents arepresented in t
6、hese test methods.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 TestingE8 Test Methods for Tension Testing of Metallic MaterialsE29 Pr
7、actice 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 Interlaboratory Study toDetermine the Precision of
8、 a Test MethodE1012 Practice for Verification of Testing Frame and Speci-men Alignment Under Tensile and Compressive AxialForce Application3. Terminology3.1 The definitions of terms relating to tension testingappearing in Terminology E6 shall be considered as applyingto the terms used in these test
9、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 circum-stances.4.2 The results of ten
10、sion 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 methods are considered satisfactory for a
11、c-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 strength and yield strength shall bewithin
12、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 tensile stresswithin the gage length
13、, the axis of the test specimen mustcoincide with the centerline of the heads of the testingmachine. Any departure from this requirement may introduce1These test methods are under the jurisdiction of ASTM Committee B07 onLight Metals and Alloys and are the direct responsibility of Subcommittee B07.0
14、5on Testing.Current edition approved May 15, 2014. Published July 2014. Originallyapproved in 1971. Last previous edition approved in 2010 as B557 10. DOI:10.1520/B0557-14.2For test methods of tension testing of aluminum foil, see Test Methods E345.3For referenced ASTM standards, visit the ASTM webs
15、ite, 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.*A Summary of Changes section appears at the end of this standardCopyright ASTM International, 100 Barr Harbor D
16、rive, PO Box C700, West Conshohocken, PA 19428-2959. United States1bending stresses that are not included in the usual stresscomputation (load divided by cross-sectional area).NOTE 3The effect of this eccentric loading may be illustrated bycalculating the bending moment and stress thus added. For a
17、standard0.500-in. diameter specimen, the stress increase is 1.5 percentage pointsfor each 0.001 in. of eccentricity. This error increases to 2.24 percentagepoints/0.001 in. for a 0.350-in. diameter specimen and to 3.17 percentagepoints/0.001 in. for a 0.250-in. diameter specimen.NOTE 4Alignment meth
18、ods are given in Practice E1012.5.2.2 Wedge GripsTesting machines usually are equippedwith wedge grips. These wedge grips generally furnish asatisfactory means of gripping long specimens of ductile metal.If, however, for any reason, one grip of a pair advances fartherthan the other as the grips tigh
19、ten, 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 best results, the wedges should besupported over their entire length by the heads of the testingmachine. This requires that lin
20、ers 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 be in contact with the specimen. Properalignment of wedge grips and liners is illustrated in Fig. 1. Forshort specimens it is
21、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 uniformly distributed pure axial tension (see 5.2.3, 5.2.4, and5.2.5).5.2.3 Grips for Threaded and Shouldered SpecimensAschematic di
22、agram 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 should be attached to the heads of the testingmachine through properly lubricated spherical-seated bearings.The distance betw
23、een spherical bearings should be as great asfeasible.5.2.4 Grips for Sheet MaterialsThe self-adjusting gripsshown in Fig. 4 have proved satisfactory for testing sheetmaterials that cannot be tested satisfactorily in the usual type ofwedge grips.5.2.5 Grips for WireGrips of either the wedge or snubbi
24、ngtypes 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 accurateand precise to at least one half the smallest unit to which theindividual dimension is required to be measured.5.4 Ex
25、tensometersExtensometers used in tensile testingshall conform to the requirements of Practice E83 for theclassifications specified by the procedure section of these testmethods. Extensometers shall be used and verified to includethe strains corresponding to the yield strength and elongation atfractu
26、re (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 figures) maybe used to determine the yield behavior. For measuringelongation at fracture with an appropriate extensometer, t
27、hegage 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 the full section of thematerial whenever practical. Otherwise, machined specimensof rectangular or round cross section shall
28、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 preparationof specimens, particularly in the machining, to ensure thedesired precision and bias in test results.FIG. 1 Wedge Gr
29、ips with Liners for Flat SpecimensFIG. 2 Gripping Device for Threaded-End SpecimensB557 1426.1.3 The cross-sectional area of the specimen should besmallest at the center of the reduced section to ensure fracturewithin the gage length. For this reason, a small taper ispermitted in the reduced section
30、 of each of the specimensdescribed in the following sections.6.1.4 Rectangular specimens shall be 0.500 in. wide inaccordance with Fig. 6 or Fig. 7 (for tubular products), andshall be of the full thickness of the material when practical.When necessary, 0.250-in. wide subsize specimens as shown inFig
31、. 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 buckling in tests of thin and high-strength materials, itmay be necessary to use stiffening plates at the grip ends.6.1.5 Round
32、 specimens shall be the standard 0.500-in.diameter specimen in Fig. 9, except when the dimensions of theproduct make this impossible. In such cases, small-size speci-mens proportional to the standard specimen shown in Fig. 9may be used. Unless otherwise specified in the productspecification, the sel
33、ection of round tension specimens shall beas specified in Table 1. Unless permitted by the productspecification, the dimensions of the smallest specimen usedshall not be less than the following:Wrought CastDiameter of reduced section, in. 0.160 0.250Length of reduced section, in.34 114Radius of fill
34、et, in.18316Diameter of end section, in.156438Overall length, in.With shouldered ends 112 238With threaded ends 2 3With plain cylindrical ends 3 46.1.5.1 The shape of the ends of the specimens outside ofthe gage length shall be suitable to the material and of a shapeto fit the holders or grips of th
35、e testing machine so that theloads are applied axially. Fig. 10 shows specimens with varioustypes of 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 applie
36、d and the amount ofheat generated) and testing (for example, eccentricity 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 m
37、ay be more variable dueto the increasing significance of variations in metallic structureFIG. 3 Gripping Device for Shouldered-End SpecimensFIG. 4 Gripping Devices for Sheet and Wire SpecimensFIG. 5 Snubbing Device for Testing WireB557 143Dimensions, in.Standard Specimen Sheet-Type,12-in. WideSubsiz
38、e Specimen14-in. WideGGage length 2.000 0.005 1.000 0.003WWidth (Note 1 and Note 2) 0.500 0.010 0.250 0.002TThickness (Note 3) thickness of material thickness of materialRRadius of fillet, minLOverall length, min (Note 4)128144ALength of reduced section, min 214 114BLength of grip section, min (Note
39、 5) 2114CWidth of grip section, approximate(Note 2 and Note 6)3438NOTE 1The ends of the reduced section shall not differ in width by more than 0.002 in. for the 2.00-in. gage length specimen or 0.001 in. for the1.00-in. gage length specimen. There may be a gradual taper in width from the ends of the
40、 reduced section to the center, but the width at each end shallnot be more than 1 % greater than the width at the center.NOTE 2For each of the specimens, narrower widths (W and C) may be used when necessary. In such cases the width of the reduced section shouldbe as large as the width of the materia
41、l being tested permits; however, unless stated specifically, the requirements for elongation in a product specificationshall not apply when these narrower specimens are used. If the width of the material is less than W, the sides may be parallel throughout the length ofthe specimen.NOTE 3The dimensi
42、on T is the thickness of the test specimen as stated in the applicable material specifications. Maximum nominal thicknesses of12-in. and14-in. wide specimens shall be12 in. and14 in., respectively.NOTE 4To aid in obtaining axial loading during testing of14-in. wide specimens, the overall length shou
43、ld be as large as the material will permit,up to 8 in.NOTE 5It is desirable, if possible, to make the length of the grip section large enough to allow the specimen to extend into the grips a distance equalto two thirds or more of the length of the grips. If the thickness of12-in. wide specimens is o
44、ver38 in., longer grips and correspondingly longer gripsections of the specimen may be necessary to prevent failure in the grip section.NOTE 6The grip-end centerline of the12 in. wide and14 in. wide specimens shall coincide with the centerline of the reduced section within 0.01and 0.005 in., respect
45、ively.FIG. 6 Rectangular Tension Test SpecimensDimensions, in.GGage length 2.000 0.005WWidth (Note 1) 0.500 0.010TMeasured thickness of specimen Note 2RRadius of fillet, min12ALength of reduced section, min 214BLength of grip section, min (Note 3) 3CWidth of grip section, approximate (Note 4)1116NOT
46、E 1The ends of the reduced section shall not differ in width by more than 0.002 in. There may be a gradual taper in width from the ends of thereduced section to the center, 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 thicknes
47、s 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 to allow the specimen to extend into the grips a distance equalto two thirds or more of the length of the grips.NOTE 4The grip-en
48、d centerline of the specimen shall coincide with the centerline of the reduced section within 0.05 in.NOTE 5For circular segment, the cross-sectional area shall be calculated using the formula shown in 7.2.3NOTE 6The radii of all fillets shall be equal to each other within a tolerance of 0.05 in., a
49、nd the centers of curvature of the two fillets at a particularend shall be located across from each other (on a line perpendicular to the centerline) within a tolerance of 0.10 in.FIG. 7 Longitudinal Tension Test Specimens for Large-Diameter Tubular ProductsB557 144Dimensions, in.GGage length 2.000 0.005WWidth (Note 1) 0.500 0.010TThickness, max (Note 2)58RRadius of fillet, min (Note 3)12LOverall length, minALength of reduced section, min8214B Length of grip section, min 2C Width of
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