1、Designation: A370 15Standard Test Methods and Definitions forMechanical Testing of Steel Products1This standard is issued under the fixed designation A370; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision.
2、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 methods2cover procedures and defini
3、tionsfor the mechanical testing of steels, stainless steels, and relatedalloys. The various mechanical tests herein described are usedto determine properties required in the product specifications.Variations in testing methods are to be avoided, and standardmethods of testing are to be followed to o
4、btain reproducibleand comparable results. In those cases in which the testingrequirements for certain products are unique or at variance withthese general procedures, the product specification testingrequirements shall control.1.2 The following mechanical tests are described:SectionsTension 6 to 14B
5、end 15Hardness 16Brinell 17Rockwell 18Portable 19Impact 20 to 29Keywords 301.3 Annexes covering details peculiar to certain productsare appended to these test methods as follows:AnnexBar Products A1.1Tubular Products Annex A2Fasteners Annex A3Round Wire Products Annex A4Significance of Notched-Bar I
6、mpact Testing Annex A5Converting Percentage Elongation of Round Specimens toEquivalents for Flat SpecimensAnnex A6Testing Multi-Wire Strand Annex A7Rounding of Test Data Annex A8Methods for Testing Steel Reinforcing Bars Annex A9Procedure for Use and Control of Heat-Cycle Simulation Annex A101.4 The
7、 values stated in inch-pound units are to be regardedas the standard.1.5 When this document is referenced in a metric productspecification, the yield and tensile values may be determined ininch-pound (ksi) units then converted into SI (MPa) units. Theelongation determined in inch-pound gauge lengths
8、 of 2 or8 in. may be reported in SI unit gauge lengths of 50 or 200 mm,respectively, as applicable. Conversely, when this document isreferenced in an inch-pound product specification, the yieldand tensile values may be determined in SI units then con-verted into inch-pound units. The elongation dete
9、rmined in SIunit gauge lengths of 50 or 200 mm may be reported ininch-pound gauge lengths of 2 or 8 in., respectively, asapplicable.1.5.1 The specimen used to determine the original unitsmust conform to the applicable tolerances of the original unitsystem given in the dimension table not that of the
10、 convertedtolerance dimensions.NOTE 1This is due to the specimen SI dimensions and tolerancesbeing hard conversions when this is not a dual standard. The user isdirected to Test Methods A1058 if the tests are required in SI units.1.6 Attention is directed to ISO/IEC 17025 when there maybe a need for
11、 information on criteria for evaluation of testinglaboratories.1.7 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 applic
12、a-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:3A623 Specification for Tin Mill Products, General Require-mentsA623M Specification for Tin Mill Products, General Re-quirements MetricA833 Practice for Indentation Hardness of Metallic Materi-als by Comparison
13、 Hardness TestersA956 Test Method for Leeb Hardness Testing of SteelProducts1These test methods and definitions are under the jurisdiction of ASTMCommittee A01 on Steel, Stainless Steel and Related Alloys and are the directresponsibility of Subcommittee A01.13 on Mechanical and Chemical Testing andP
14、rocessing Methods of Steel Products and Processes.Current edition approved Nov. 1, 2015. Published November 2015. Originallyapproved in 1953. Last previous edition approved in 2014 as A370 14. DOI:10.1520/A0370-15.2For ASME Boiler and Pressure Vessel Code applications see related Specifi-cation SA-3
15、70 in Section II of that Code.3For 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.*A Summary of Changes section a
16、ppears at the end of this standardCopyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States1A1038 Test Method for Portable Hardness Testing by theUltrasonic Contact Impedance MethodA1058 Test Methods for Mechanical Testing of SteelProductsMetri
17、cE4 Practices for Force Verification of Testing MachinesE6 Terminology Relating to Methods of Mechanical TestingE8/E8M Test Methods for Tension Testing of Metallic Ma-terialsE10 Test Method for Brinell Hardness of Metallic MaterialsE18 Test Methods for Rockwell Hardness of Metallic Ma-terialsE23 Tes
18、t Methods for Notched Bar Impact Testing of Me-tallic MaterialsE29 Practice for Using Significant Digits in Test Data toDetermine Conformance with SpecificationsE83 Practice for Verification and Classification of Exten-someter SystemsE110 Test Method for Rockwell and Brinell Hardness ofMetallic Mate
19、rials by Portable Hardness TestersE190 Test Method for Guided Bend Test for Ductility ofWeldsE290 Test Methods for Bend Testing of Material for Ductil-ity2.2 ASME Document:4ASME Boiler and Pressure Vessel Code, Section VIII,Division I, Part UG-82.3 ISO Standard:5ISO/IEC 17025 General Requirements fo
20、r the Competenceof Testing and Calibration Laboratories3. Significance and Use3.1 The primary use of these test methods is testing todetermine the specified mechanical properties of steel, stainlesssteel and related alloy products for the evaluation of confor-mance of such products to a material spe
21、cification under thejurisdiction of ASTM Committee A01 and its subcommitteesas designated by a purchaser in a purchase order or contract.3.1.1 These test methods may be and are used by otherASTM Committees and other standards writing bodies for thepurpose of conformance testing.3.1.2 The material co
22、ndition at the time of testing, samplingfrequency, specimen location and orientation, reportingrequirements, and other test parameters are contained in thepertinent material specification or in a General RequirementSpecification for the particular product form.3.1.3 Some material specifications requ
23、ire the use of addi-tional test methods not described herein; in such cases, therequired test method is described in that material specificationor by reference to another appropriate test method standard.3.2 These test methods are also suitable to be used fortesting of steel, stainless steel and rel
24、ated alloy materials forother purposes, such as incoming material acceptance testingby the purchaser or evaluation of components after serviceexposure.3.2.1 As with any mechanical testing, deviations from eitherspecification limits or expected as-manufactured properties canoccur for valid reasons be
25、sides deficiency of the originalas-fabricated product. These reasons include, but are notlimited to: subsequent service degradation from environmentalexposure (for example, temperature, corrosion); static or cyclicservice stress effects, mechanically-induced damage, materialinhomogeneity, anisotropi
26、c structure, natural aging of selectalloys, further processing not included in the specification,sampling limitations, and measuring equipment calibrationuncertainty. There is statistical variation in all aspects ofmechanical testing and variations in test results from prior testsare expected. An un
27、derstanding of possible reasons for devia-tion from specified or expected test values should be applied ininterpretation of test results.4. General Precautions4.1 Certain methods of fabrication, such as bending,forming, and welding, or operations involving heating, mayaffect the properties of the ma
28、terial under test. Therefore, theproduct specifications cover the stage of manufacture at whichmechanical testing is to be performed. The properties shown bytesting prior to fabrication may not necessarily be representa-tive of the product after it has been completely fabricated.4.2 Improperly machi
29、ned specimens should be discardedand other specimens substituted.4.3 Flaws in the specimen may also affect results. If any testspecimen develops flaws, the retest provision of the applicableproduct specification shall govern.4.4 If any test specimen fails because of mechanical reasonssuch as failure
30、 of testing equipment or improper specimenpreparation, it may be discarded and another specimen taken.5. Orientation of Test Specimens5.1 The terms “longitudinal test” and “transverse test” areused only in material specifications for wrought products andare not applicable to castings. When such refe
31、rence is made toa test coupon or test specimen, the following definitions apply:5.1.1 Longitudinal Test, unless specifically definedotherwise, signifies that the lengthwise axis of the specimen isparallel to the direction of the greatest extension of the steelduring rolling or forging. The stress ap
32、plied to a longitudinaltension test specimen is in the direction of the greatestextension, and the axis of the fold of a longitudinal bend testspecimen is at right angles to the direction of greatest extension(Fig. 1, Fig. 2a, and Fig. 2b).5.1.2 Transverse Test, unless specifically defined otherwise
33、,signifies that the lengthwise axis of the specimen is at rightangles to the direction of the greatest extension of the steelduring rolling or forging. The stress applied to a transversetension test specimen is at right angles to the greatestextension, and the axis of the fold of a transverse bend t
34、estspecimen is parallel to the greatest extension (Fig. 1).4Available from American Society of Mechanical Engineers (ASME), ASMEInternational Headquarters, Two Park Ave., New York, NY 10016-5990, http:/www.asme.org.5Available from American National Standards Institute (ANSI), 25 W. 43rd St.,4th Floo
35、r, New York, NY 10036, http:/www.ansi.org.A370 1525.2 The terms “radial test” and “tangential test” are used inmaterial specifications for some wrought circular products andare not applicable to castings. When such reference is made toa test coupon or test specimen, the following definitions apply:5
36、.2.1 Radial Test, unless specifically defined otherwise,signifies that the lengthwise axis of the specimen is perpen-dicular to the axis of the product and coincident with one of theradii of a circle drawn with a point on the axis of the productas a center (Fig. 2a).5.2.2 Tangential Test, unless spe
37、cifically defined otherwise,signifies that the lengthwise axis of the specimen is perpen-dicular to a plane containing the axis of the product and tangentto a circle drawn with a point on the axis of the product as acenter (Fig. 2a, Fig. 2b, Fig. 2c, and Fig. 2d).TENSION TEST6. Description6.1 The te
38、nsion test related to the mechanical testing of steelproducts subjects a machined or full-section specimen of thematerial under examination to a measured load sufficient tocause rupture. The resulting properties sought are defined inTerminology E6.6.2 In general, the testing equipment and methods ar
39、e givenin Test Methods E8/E8M. However, there are certain excep-tions to Test Methods E8/E8M practices in the testing of steel,and these are covered in these test methods.7. Terminology7.1 For definitions of terms pertaining to tension testing,including tensile strength, yield point, yield strength,
40、elongation, and reduction of area, reference should be made toTerminology E6.8. Testing Apparatus and Operations8.1 Loading SystemsThere are two general types of load-ing systems, mechanical (screw power) and hydraulic. Thesediffer chiefly in the variability of the rate of load application.The older
41、 screw power machines are limited to a small numberof fixed free running crosshead speeds. Some modern screwpower machines, and all hydraulic machines permit steplessvariation throughout the range of speeds.8.2 The tension testing machine shall be maintained in goodoperating condition, used only in
42、the proper loading range, andcalibrated periodically in accordance with the latest revision ofPractices E4.NOTE 2Many machines are equipped with stress-strain recorders forautographic plotting of stress-strain curves. It should be noted that somerecorders have a load measuring component entirely sep
43、arate from theload indicator of the testing machine. Such recorders are calibratedseparately.8.3 LoadingIt is the function of the gripping or holdingdevice of the testing machine to transmit the load from theheads of the machine to the specimen under test. The essentialrequirement is that the load s
44、hall be transmitted axially. Thisimplies that the centers of the action of the grips shall be inalignment, insofar as practicable, with the axis of the specimenat the beginning and during the test and that bending ortwisting be held to a minimum. For specimens with a reducedsection, gripping of the
45、specimen shall be restricted to the gripsection. In the case of certain sections tested in full size,nonaxial loading is unavoidable and in such cases shall bepermissible.8.4 Speed of TestingThe speed of testing shall not begreater than that at which load and strain readings can be madeaccurately. I
46、n production testing, speed of testing is commonlyexpressed: (1) in terms of free running crosshead speed (rate ofmovement of the crosshead of the testing machine when notunder load), (2) in terms of rate of separation of the two headsof the testing machine under load, (3) in terms of rate ofstressi
47、ng the specimen, or (4) in terms of rate of straining thespecimen. The following limitations on the speed of testing arerecommended as adequate for most steel products:NOTE 3Tension tests using closed-loop machines (with feedbackcontrol of rate) should not be performed using load control, as this mo
48、deof testing will result in acceleration of the crosshead upon yielding andelevation of the measured yield strength.8.4.1 Any convenient speed of testing may be used up toone half the specified yield point or yield strength. When thispoint is reached, the free-running rate of separation of thecrossh
49、eads shall be adjusted so as not to exceed116 in. per minper inch of reduced section, or the distance between the gripsfor test specimens not having reduced sections. This speedshall be maintained through the yield point or yield strength. Indetermining the tensile strength, the free-running rate ofseparation of the heads shall not exceed12 in. per min per inchof reduced section, or the distance between the grips for testspecimens not having reduced sections. In any event, theminimum speed of testing shall not be less than110 thespecified maximum rates for determining
