AASHTO T 244-2018 Standard Method of Test for Mechanical Testing of Steel Products.pdf

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1、 Standard Method of Test for Mechanical Testing of Steel Products AASHTO Designation: T 244-181Technical Section: TS 4f, Metals Release: Group 2 (June) ASTM Designation: A370-17a American Association of State Highway and Transportation Officials 444 North Capitol Street N.W., Suite 249 Washington, D

2、.C. 20001 TS-4f T 244-1 AASHTO Standard Method of Test for Mechanical Testing of Steel Products AASHTO Designation: T 244-181Technical Section: TS 4f, Metals Release: Group 2 (June) ASTM Designation: A370-17a 1. SCOPE 1.1. These test methods cover procedures and definitions for the mechanical testin

3、g of steel, stainless steels, and related alloys. The various mechanical tests herein described are used to determine properties required in the product specifications. Variations in testing methods are to be avoided and standard methods of testing are to be followed to obtain reproducible and compa

4、rable results. In those cases in which the testing requirements for certain products are unique or at variance with these general procedures, the product specification testing requirements shall control. 1.2. The following mechanical tests are described: Sections Tension 6 to 14 Bend 15 Hardness 16

5、Brinell 17 Rockwell 18 Portable 19 Impact 20 to 29 Keywords 30 1.3. Annexes covering details peculiar to certain products are appended to these test methods as follows: Bar products Annex A Tubular products Annex B Fasteners Annex C Round wire products Annex D Significance of notched-bar impact test

6、ing Annex E Converting percentage elongation of round specimens to equivalents for flat specimens Annex F Testing multiwire strand Annex G Rounding of test data Annex H Methods for testing steel reinforcing bars Annex I 2018 by the American Association of State Highway and Transportation Officials.

7、All rights reserved. Duplication is a violation of applicable law.TS-4f T 244-2 AASHTO Procedure for use and control of heat-cycle simulation Mechanical Pull Testing of Wire and Welded Wire Annex J Annex K 1.4. The values stated in SI (MPa) units are to be regarded as the standard. 1.5. When this do

8、cument is referenced in a metric product specification, the yield and tensile values may be determined in inch-pound (ksi) units then converted into SI (MPa) units. The elongation determined in inch-pound gauge lengths of 2 or 8 in. may be reported in SI unit gauge lengths of 50 or 200 mm, respectiv

9、ely, as applicable. Conversely, when this document is referenced in an inch-pound product specification, the yield and tensile values may be determined in SI units and then converted into inch-pound units. The elongation determined in SI unit gauge lengths of 50 or 200 mm may be reported in inch-pou

10、nd gauge lengths of 2 or 8 in., respectively, as applicable. 1.6. The specimen used to determine the original units must conform to the applicable tolerances of the original unit system given in the dimension table not that of the converted tolerance dimensions. Note 1This is due to the specimen SI

11、dimensions and tolerances being hard conversions when this is not a dual standard. The user is directed to Test Methods A1058 if the tests are required in SI units. 1.7. Attention is directed to R 18 when there may be a need for information on criteria for evaluation of testing laboratories. 1.8. Th

12、is standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. 2. REFERENCED DOCUME

13、NTS 2.1. AASHTO Standard: M170/M170M, Standard Specification for Reinforced Concrete Culvert, Storm Drain, and Sewer Pipe M199/M199M, Standard Specification for Precast Reinforced Concrete Manhole Sections M206/M206M, Standard Specification for Reinforced Concrete Arch Culvert, Storm Drain, and Sewe

14、r Pipe M207/M207M, Standard Specification for Reinforced Concrete Elliptical Culvert, Storm Drain, and Sewer Pipe R 18, Establishing and Implementing a Quality Management System for Construction Materials Testing Laboratories 2.2. ASTM Standards: A623, Standard Specification for Tin Mill Products, G

15、eneral Requirements A623M, Standard Specification for Tin Mill Products, General Requirements Metric A833, Standard Practice for Indentation Hardness of Metallic Materials by Comparison Hardness Testers A1064/A1064M, Standard Specification for Carbon-Steel Wire and Welded Wire Reinforcement, Plain a

16、nd Deformed, for Concrete C76, Standard Specification for Reinforced Concrete Culvert, Storm Drain, and Sewer Pipe 2018 by the American Association of State Highway and Transportation Officials. All rights reserved. Duplication is a violation of applicable law.TS-4f T 244-3 AASHTO C506/506M, Standar

17、d Specification for Reinforced Concrete Arch Culvert, Storm Drain, and Sewer Pipe C507/507M, Standard Specification for Reinforced Concrete Elliptical Culvert, Storm Drain, and Sewer Pipe E4, Standard Practices for Force Verification of Testing Machines E6, Standard Terminology Relating to Methods o

18、f Mechanical Testing E8/E8M, Standard Test Methods for Tension Testing of Metallic Materials E10, Standard Test Method for Brinell Hardness of Metallic Materials E18, Standard Test Methods for Rockwell Hardness of Metallic Materials E23, Standard Test Methods for Notched Bar Impact Testing of Metall

19、ic Materials E29, Standard Practice for Using Significant Digits in Test Data to Determine Conformance with Specifications E83, Standard Practice for Verification and Classification of Extensometer Systems E110, Standard Test Method for Rockwell and Brinell Hardness of Metallic Materials by Portable

20、 Hardness Testers E190, Standard Test Method for Guided Bend Test for Ductility of Welds E290, Standard Test Methods for Bend Testing of Material for Ductility 2.3. ASME Code: ASME Boiler and Pressure Vessel Code, Section VIII, Division I, Part UG-84.23. SIGNIFICANCE AND USE 3.1. The primary use of

21、these test methods is to determine the specified mechanical properties of steel, stainless steel, and related alloy products for the evaluation of conformance of such products to a material specification as designated by a purchaser in a purchase order or contract. 3.1.1. The material condition at t

22、he time of testing, sampling frequency, specimen location and orientation, reporting requirements, and other parameters are contained in the pertinent material specification or in a General Requirement Specification for the particular product form. 3.1.2. Some material specifications require the use

23、 of additional test methods not described herein; in such cases, the required test method is described in the material specification or by reference to another appropriate test method standard. 3.2. These test methods are also suitable to be used for testing steel, stainless steel, and related alloy

24、 materials for other purposes, such as incoming material acceptance testing by the purchaser or evaluation of components after service exposure. 3.2.1. As with any mechanical testing, deviations from either specication limits or expected as-manufactured properties can occur for valid reasons besides

25、 deciency of the original as-fabricated product. These reasons include, but are not limited to: subsequent service degradation from environmental exposure (for example, temperature, corrosion); static or cyclic service stress effects, mechanically-induced damage, material inhomogeneity, anisotropic

26、structure, natural aging of select alloys, further processing not included in the specication, sampling limitations, and measuring equipment calibration uncertainty. There is statistical variation in all aspects of mechanical testing and variations in test results from prior tests are expected. An u

27、nderstanding of possible reasons for deviation from specied or expected test values should be applied in interpretation of test results. 2018 by the American Association of State Highway and Transportation Officials. All rights reserved. Duplication is a violation of applicable law.TS-4f T 244-4 AAS

28、HTO 4. GENERAL PRECAUTIONS 4.1. Certain methods of fabrication, such as bending, forming, and welding, or operations involving heating, may affect the properties of the material under test. Therefore, the product specifications cover the stage of manufacture at which mechanical testing is to be perf

29、ormed. The properties shown by testing prior to fabrication may not necessarily be representative of the product after it has been completely fabricated. 4.2. Improperly machined specimens should be discarded and other specimens substituted. 4.3. Flaws in the specimen may also affect results. If any

30、 test specimen develops flaws, the retest provision of the applicable product specification shall govern. 4.4. If any test specimen fails because of mechanical reasons such as failure of testing equipment or improper specimen preparation, it may be discarded and another specimen taken. 5. ORIENTATIO

31、N OF TEST SPECIMENS 5.1. The terms “longitudinal test” and “transverse test” are used only in material specifications for wrought products and are not applicable to castings. When such reference is made to a test coupon or test specimen, the following definitions apply: 5.1.1. Longitudinal Test, unl

32、ess specifically defined otherwise, signifies that the lengthwise axis of the specimen is parallel to the direction of the greatest extension of the steel during rolling or forging. The stress applied to a longitudinal tension test specimen is in the direction of the greatest extension, and the axis

33、 of the fold of a longitudinal bend test specimen is at right angles to the direction of greatest extension (Figures 1, 2(a), and 2(b). 5.1.2. Transverse Test, unless specifically defined otherwise, signifies that the lengthwise axis of the specimen is at right angles to the direction of the greates

34、t extension of the steel during rolling or forging. The stress applied to a transverse tension test specimen is at right angles to the greatest extension, and the axis of the fold of a transverse bend test specimen is parallel to the greatest extension (Figure 1). Figure 1The Relation of Test Coupon

35、s and Test Specimens to Rolling Direction or Extension (Applicable to General Wrought Products) Longitudinal SpecimenLongitudinal FlatTensionTestLongitudinal RoundTensionTestLongitudinalBendTestLongitudinalImpactTestIndicates Rolling Directionor ExtensionTransverse SpecimenTransverse FlatTensionTest

36、TransverseBendTestTransverseImpactTest 2018 by the American Association of State Highway and Transportation Officials. All rights reserved. Duplication is a violation of applicable law.TS-4f T 244-5 AASHTO Figure 2Locations of Longitudinal Tension Test Specimens in Rings Cut from Tubular Products 5.

37、2. The terms “radial test” and “tangential test” are used in material specifications for some wrought circular products and are not applicable to castings. When such reference is made to a test coupon or test specimen, the following definitions apply: 5.2.1. Radial Test, unless specifically defined

38、otherwise, signifies that the lengthwise axis of the specimen is perpendicular to the axis of the product and coincident with one of the radii of a circle drawn with a point on the axis of the product as a center (Figure 2(a). 5.2.2. Tangential Test, unless specifically defined otherwise, signifies

39、that the lengthwise axis of the specimen is perpendicular to a plane containing the axis of the product and tangent to a circle drawn with a point on the axis of the product as a center (Figures 2(a), 2(b), 2(c), and 2(d). ProlongationProlongationProlongationProlongationProlongationProlongationProlo

40、ngationTangentialTestTangentialTestTangentialTestTangentialTestTangentialTestTangentialTest(d) Ring Forgings(c) Disk Forgings(b) Hollow Forgings(a) Shafts and RotorsRadialTestLongitudinalTestLongitudinalTest 2018 by the American Association of State Highway and Transportation Officials. All rights r

41、eserved. Duplication is a violation of applicable law.TS-4f T 244-6 AASHTO TENSION TEST 6. DESCRIPTION 6.1. The tension test related to the mechanical testing of steel products subjects a machined or full-section specimen of the material under examination to a measured load sufficient to cause ruptu

42、re. The resulting properties sought are defined in ASTM E6. 6.2. In general, the testing equipment and methods are given in ASTM E8/E8M. However, there are certain exceptions to ASTM E8/E8M practices in the testing of steel, and they are covered in these test methods. 7. TERMINOLOGY 7.1. For definit

43、ions of terms pertaining to tension testing, including tensile strength, yield point, yield strength, elongation, and reduction of area, reference should be made to ASTM E6. 8. TESTING APPARATUS AND OPERATIONS 8.1. Loading SystemsThere are two general types of loading systems, mechanical (screw powe

44、r) and hydraulic. These differ chiefly in the variability of the rate of load application. The older screw power machines are limited to a small number of fixed free-running crosshead speeds. Some modern screw power machines and all hydraulic machines permit stepless variation throughout the range o

45、f speeds. 8.2. The tension testing machine shall be maintained in good operating condition, used only in the proper loading range, and calibrated periodically in accordance with the latest revision to ASTM E4. Note 2Many machines are equipped with stress strain recorders for autographic plotting of

46、stressstrain curves. It should be noted that some recorders have a load measuring component entirely separate from the load indicator of the testing machine. Such recorders are calibrated separately. 8.3. LoadingIt is the function of the gripping or holding device of the testing machine to transmit

47、the load from the heads of the machine to the specimen under test. The essential requirement is that the load shall be transmitted axially. This implies that the centers of the action of the grips shall be in alignment, insofar as practicable, with the axis of the specimen at the beginning and durin

48、g the test, and that bending or twisting be held to a minimum. For specimens with a reduced section, gripping of the specimen shall be restricted to the grip section. In the case of certain sections tested in full size, nonaxial loading is unavoidable and in such cases shall be permissible. 8.4. Spe

49、ed of TestingThe speed of testing shall not be greater than that at which load and strain readings can be made accurately. In production testing, speed of testing is commonly expressed (1) in terms of free-running crosshead speed (rate of movement of the crosshead of the testing machine when not under load), or (2) in terms of rate of separation of the two heads of the testing machine under load, or (3) in terms of rate of stressing the specimen, or (4) in terms of rate of straining the specimen. The following limitation