1、Designation: A242/A242M 13 (Reapproved 2018) American Association StateHighway and Transportation OfficialsStandard AASHTO No.: M 161Standard Specification forHigh-Strength Low-Alloy Structural Steel1This standard is issued under the fixed designation A242/A242M; the number immediately following the
2、 designation indicates the yearof original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval.A superscript epsilon () indicates an editorial change since the last revision or reapproval.This standard has been approved for u
3、se by agencies of the U.S. Department of Defense.1. Scope1.1 This specification covers high-strength low-alloy struc-tural steel shapes, plates, and bars for welded, riveted, or boltedconstruction intended primarily for use as structural memberswhere savings in weight mass or added durability areimp
4、ortant. The atmospheric corrosion resistance of the steel inmost environments is substantially better than that of carbonstructural steels with or without copper addition. When prop-erly exposed to the atmosphere, this steel can be used bare(unpainted) for many applications (see Note 1). This specif
5、i-cation is limited to material up to 4 in. 100 mm, inclusive, inthickness.NOTE 1For methods of estimating the atmospheric corrosion resis-tance of low-alloy steels, see Guide G101.1.2 When the steel is to be welded, it is presupposed that awelding procedure suitable for the grade of steel and inten
6、deduse or service will be utilized. See Appendix X3 of Specifica-tion A6/A6M for information on weldability.1.3 The values stated in either inch-pound units or SI unitsare to be regarded as standard. Within the text, the SI units areshown in brackets. The values stated in each system are notexact eq
7、uivalents; therefore, each system must be used inde-pendently of the other. Combining values from the two systemsmay result in nonconformance with the specification.1.4 For structural products produced from coil and fur-nished without heat treatment or with stress relieving only, theadditional requi
8、rements, including additional testing require-ments and the reporting of additional test results, of Specifi-cation A6/A6M apply.1.5 This international standard was developed in accor-dance with internationally recognized principles on standard-ization established in the Decision on Principles for t
9、heDevelopment of International Standards, Guides and Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trade (TBT) Committee.2. Referenced Documents2.1 ASTM Standards:2A6/A6M Specification for General Requirements for RolledStructural Steel Bars, Plates, Shapes, and Sheet
10、PilingG101 Guide for Estimating the Atmospheric Corrosion Re-sistance of Low-Alloy Steels3. General Requirements for Delivery3.1 Structural products furnished under this specificationshall conform to the requirements of the current edition ofSpecification A6/A6M, for the specific structural producto
11、rdered, unless a conflict exists, in which case this specificationshall prevail.3.2 Coils are excluded from qualification to this specifica-tion until they are processed into a finished structural product.Structural products produced from coil means structural prod-ucts that have been cut to individ
12、ual lengths from a coil. Theprocessor directly controls, or is responsible for, the operationsinvolved in the processing of a coil into a finished structuralproduct. Such operations include decoiling, leveling orstraightening, hot-forming or cold-forming (if applicable),cutting to length, testing, i
13、nspection, conditioning, heat treat-ment (if applicable), packaging, marking, loading for shipment,and certification.NOTE 2For structural products produced from coil and furnishedwithout heat treatment or with stress relieving only, two test results are tobe reported for each qualifying coil. Additi
14、onal requirements regardingstructural products produced from coil are described in SpecificationA6/A6M.4. Materials and Manufacture4.1 The steel shall be killed.1This specification is under the jurisdiction of ASTM Committee A01 on Steel,Stainless Steel and Related Alloys and is the direct responsib
15、ility of SubcommitteeA01.02 on Structural Steel for Bridges, Buildings, Rolling Stock and Ships.Current edition approved March 1, 2018. Published March 2018. Originallyapproved in 1941. Last previous edition approved in 2013 as A242/A242M 13.DOI: 10.1520/A0242_A0242M-13R18.2For referenced ASTM stand
16、ards, 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.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA
17、 19428-2959. United StatesThis international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for theDevelopment of International Standards, Guides and Recommendations issued by the World Trade Organization T
18、echnical Barriers to Trade (TBT) Committee.15. Chemical Composition5.1 The heat analysis shall conform to the requirementsprescribed in Table 2.5.2 The steel shall conform on product analysis to therequirements prescribed in Table 2, subject to the productanalysis tolerances in Specification A6/A6M.
19、5.3 Choice and use of alloying elements, combined withcarbon, manganese, phosphorus, sulfur, and copper within thelimits prescribed in 5.1 to give the mechanical propertiesprescribed in Section 6 and to provide the atmospheric corro-sion resistance of 1.1, shall be made by the manufacturer andinclud
20、ed and reported in the heat analysis to identify the typeof steel applied. Elements commonly added include:chromium, nickel, silicon, vanadium, titanium, and zirconium.5.4 The atmospheric corrosion-resistance index, calculatedon the basis of the heat analysis of the steel, as described inGuide G101P
21、redictive Method Based on the Data of Larabeeand Coburn, shall be 6.0 or higher.NOTE 3The user is cautioned that the Guide G101 predictive equation(Predictive Method Based on the Data of Larabee and Coburn) forcalculation of an atmospheric corrosion-resistance index has only beenverified for the com
22、position limits stated in the guide.5.5 When required, the manufacturer shall supply evidenceof corrosion resistance satisfactory to the purchaser.6. Tension Test6.1 The material as represented by the test specimens shallconform to the requirements as to tensile properties prescribedin Table 1.7. Ke
23、ywords7.1 atmospheric corrosion resistance; bars; bolted construc-tion; durability; high-strength; low-alloy; plates; riveted con-struction; shapes; steel; structural steel; weight; welded con-structionSUPPLEMENTARY REQUIREMENTSStandardized supplementary requirements for use at the option of the pur
24、chaser are listed inSpecification A6/A6M. Those that are considered suitable for use with this specification are listed bytitle:S2. Product Analysis,S3. Simulated Post-Weld Heat Treatment of MechanicalTest Coupons,S5. Charpy V-Notch Impact Test,S6. Drop Weight Test (for Material 0.625 in. 16 mm ando
25、ver in Thickness),S8. Ultrasonic Examination, andS15. Reduction of Area Measurement.S32. Single Heat Bundles.TABLE 1 Tensile RequirementsPlates and BarsAStructural ShapesForthicknesses34 in.20 mm,andunderFor thicknessesover34 to 112 in.20to40mm, inclFor thicknessesover112 to4in.40to100mm, inclFor fl
26、ange orleg thicknesses1.5 in. 40 mmand underFor flangethicknessesover 1.5in.40 mm to2 in. 50mm, inclFor flangethicknessesover 2 in.50 mmTensile strength, min, ksi MPa 70 480 67 460 63 435 70 485 67 460 63 435Yield point, min, ksi MPa 50 345 46 315 42 290 50 345 46 315 42 290Elongation in 8 in. 200 m
27、m, min, % 18B,C18B,C18B,C18C18 18Elongation in 2 in. 50 mm, min, % 21C21C21C21 21 21DASee the Orientation subsection in the Tension Tests section of Specification A6/A6M.BElongation not required to be determined for floor plate.CFor plates wider than 24 in. 600 mm the elongation requirement is reduc
28、ed two percentage points. See the Elongation Requirement Adjustments subsectionintheTension Tests section of Specification A6/A6M.DFor wide flange shapes over 426 lb/ft 634 kg/m, elongation in 2 in. 50 mm of 18 % minimum applies.TABLE 2 Chemical Requirements (Heat Analysis)ElementComposition, %Type
29、1Carbon, max 0.15Manganese, max 1.00Phosphorus, max 0.15Sulfur, max 0.05Copper, min 0.20A242/A242M 13 (2018)2ASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this standard are expressly advised
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