1、Designation: B 557M 07METRICStandard Test Methods forTension Testing Wrought and Cast Aluminum- andMagnesium-Alloy Products Metric1This standard is issued under the fixed designation B 557M; the number immediately following the designation indicates the year oforiginal adoption or, in the case of re
2、vision, 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.This standard has been approved for use by agencies of the Department of Defense.1. Scope*1.1 These test meth
3、ods cover 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 B 557, and are
4、 compatible in technical content except for therequirement of longer gauge 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 This standard does not purport to address all o
5、f 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 prior to use.2. Referenced Documents2.1 The following documents of the issue in
6、 effect at thetime of reference form a part of these test methods to the extentreferenced herein:2.2 ASTM Standards:3B 209 Specification for Aluminum and Aluminum-AlloySheet and PlateE4 Practices for Force Verification of Testing MachinesE6 Terminology Relating to Methods of Mechanical Test-ingE8M T
7、est Methods for Tension Testing of Metallic Mate-rials MetricE29 Practice for Using Significant Digits in Test Data toDetermine Conformance with SpecificationsE83 Practice for Verification and Classification of Exten-someter SystemsE 345 Test Methods of Tension Testing of Metallic FoilE 691 Practice
8、 for Conducting an Interlaboratory Study toDetermine the Precision of a Test MethodE 1012 Practice for Verification of Test Frame and Speci-men Alignment Under Tensile and Compressive AxialForce Application3. Terminology3.1 The definitions of terms relating to tension testingappearing in Terminology
9、 E6shall be considered as applyingto 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 contr
10、ol, and design under certain circum-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 env
11、ironments.4.3 These test methods 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
12、in determining tensile strength and yield strength shall be1These 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 edition approved Sept. 1, 2007. Published September 2007. Originallyapp
13、roved in 1976. Last previous edition approved in 2006 as B 557M 06.2For test methods of tension testing of aluminum foil, see Test Methods E 345.3For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards
14、volume information, refer to the standards Document Summary page onthe ASTM website.1*A Summary of Changes section appears at the end of this standard.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.within the verified force applicati
15、on 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 gauge length, the axis of the test spec
16、imen mustcoincide with the centerline of the heads of the testingmachine. Any departure from this requirement may introducebending 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 bycalc
17、ulating 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 points/0.025 mm for a 9-mm diameter specimen and to 3.25percentage points /0.025-mm f
18、or a 6-mm diameter specimen.NOTE 4Alignment methods are given in Practice E 1012.5.2.2 Wedge GripsTesting machines usually are equippedwith wedge grips. These wedge grips generally furnish asatisfactory means of gripping long bars of ductile metal. If,however, for any reason, one grip of a pair adva
19、nces 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 best results, the wedges should besupported over their entire length by the heads o
20、f 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 be in contact with the specimen. Properalignment of wedge grips and liners is illu
21、strated 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 uniformly distributed pure axial tension (see 5.2.3, 5.2.4, and5.2.5).5.2.3 Grips for Th
22、readed 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 should be attached to the heads of the testingmachine through properly lubricated
23、 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 that cannot be tested satisfactorily in the usual type ofwedge grips.5.2.5 Grips
24、 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 accurateand precise to at least one half the smallest unit to which theindividual
25、 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 testmethods. Extensometers shall be used and verified to includethe strains corresponding t
26、o the yield strength and elongation atfracture (if determined).5.4.1 Extensometers with gauge lengths equal to or shorterthan the nominal gauge length of the specimen (dimensionshown as “G-gauge Length” in the accompanying figures) maybe used to determine the yield behavior. For measuringelongation
27、at fracture with an appropriate extensometer, thegauge length of the extensometer shall be equal to the nominalgauge length required for the specimen being tested.FIG. 1 Wedge Grips with Liners for Flat SpecimensFIG. 2 Gripping Device for Threaded-End SpecimensB557M0726. Test Specimen6.1 General:6.1
28、.1 Test specimens shall be of 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, th
29、at care be exercised in the preparationof 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 fracturewithin the gauge length. For this reason
30、, 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), andshall be of the full thickness of the material when practical.When necessary
31、, 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 buckling in tests of thin and high-strength materials, itmay be necessary to use
32、 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 proportional to the standard specimen shown in Fig. 9may be used. Unless otherwise
33、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 shall not be less than 4 mm for wroughtproducts and 6 mm for cast products.6
34、.1.5.1 The shape of the ends of the specimen outside of thegauge 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 specimens with various typesof ends that have given satisfactory results.6.1.
35、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, eccentricity andgauge marking) variables are greater upon them than uponlarger specime
36、ns. Therefore, the largest practical specimenFIG. 3 Gripping Device for Shouldered-End SpecimensFIG. 4 Gripping Devices for Sheet and Wire SpecimensFIG. 5 Snubbing Device for Testing WireB557M073Dimensions, mmStandard Specimen Sheet-Type12.5mmWideSubsize Specimen 6 mm WideGGauge length 50.0 6 0.1 25
37、.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 fillet, 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
38、(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 gauge length specimen or 0.025 mm forthe 25.00-mm gauge length specimen. There may be a gradual taper in width from the ends of the reduced section to the center, but the wi
39、dth at eachend shall not 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 material being tested permits: however, unless st
40、ated 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 dimension T is the thickness of the test specimen
41、 as stated in the applicable material specifications. Maximum nominal thicknesses of12.5-mm and 6-mm wide specimens shall be 12.5 mm and 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
42、,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 into 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 correspondi
43、ngly longer gripsections of the specimens may be necessary to prevent failure in the grip section.NOTE 6The grip-end centerline of the 12.5-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
44、SpecimensDimensions, mmGgauge length 50.00 6 0.10WWidth (Note 1) 12.50 6 0.25TMeasured thickness of specimen Note 2RRadius of fillet, min 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
45、 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, 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 provide
46、d 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-end centerline of the specimen shall
47、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
48、 two fillets at a particularend shall be located across from each other (on a line perpendicular to the centerline) within a tolerance of 2.00 mm.FIG. 7 Longitudinal Tension Specimens for Large-Diameter Tubular ProductsB557M074Dimensions, mmGgauge length 50.00 6 0.10WWidth (Note 1) 12.506 0.25TThick
49、ness, max (Note 2) 12.5RRadius of fillet, min (Note 3) 13LOverall length, min 200ALength of reduced section, min 57BLength of grip section, min 50CWidth of grip section, approximate 50DDiameter of hole for pin, min (Note 4) 13EEdge distance from pin, approximate 40FDistance from hole to fillet, min 15NOTE 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, but the width at each end shall not be more than 1 % grea
