1、Designation: A 242/A 242M 04 (Reapproved 2009)American Association StateHighway and Transportation OfficialsStandard AASHTO No.: M 161Standard Specification forHigh-Strength Low-Alloy Structural Steel1This standard is issued under the fixed designationA 242/A 242M; the number immediately following t
2、he 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
3、 use by agencies of the 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 areimport
4、ant. 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 specifi-c
5、ation 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 G 101.1.2 When the steel is to be welded, it is presupposed that awelding procedure suitable for the grade of steel and intende
6、duse or service will be utilized. See Appendix X3 of Specifica-tion A 6/A 6M 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 A 6/A 6M apply.2. Referenced Documents2.1 ASTM Standards:2A 6/A 6M Specification for General Requirements forRolled Structural Steel Bars, Plates, Shapes, and SheetPilingG 101 Guide fo
9、r Estimating the Atmospheric CorrosionResistance of Low-Alloy Steels3. General Requirements for Delivery3.1 Structural products furnished under this specificationshall conform to the requirements of the current edition ofSpecification A 6/A 6M, for the specific structural productordered, unless a co
10、nflict 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 individual lengths from a
11、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, inspection, conditio
12、ning, 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. Additional requirements r
13、egardingstructural products produced from coil are described in SpecificationA 6/A 6M.4. Materials and Manufacture4.1 The steel shall be semi-killed or killed.5. Chemical Composition5.1 The heat analysis shall conform to the requirementsprescribed in Table 2.5.2 The steel shall conform on product an
14、alysis to therequirements prescribed in Table 2, subject to the productanalysis tolerances in Specification A 6/A 6M.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 properties1This speci
15、fication is under the jurisdiction of ASTM Committee A01 on Steel,Stainless Steel and Related Alloys and is the direct responsibility of SubcommitteeA01.02 on Structural Steel for Bridges, Buildings, Rolling Stock and Ships.Current edition approved April 1, 2009. Published May 2009. Originallyapprov
16、ed in 1941. Last previous edition approved in 2004 as A 242/A 242M041.2For 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
17、 website.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.prescribed in Section 6 and to provide the atmospheric corro-sion resistance of 1.1, shall be made by the manufacturer andincluded and reported in the heat analysis to identify
18、 the typeof steel applied. Elements commonly added include: chro-mium, 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 G 101Predictive Method Based on the Data of Larabee
19、and Coburn, shall be 6.0 or higher.NOTE 3The user is cautioned that the Guide G 101 predictiveequation (Predictive Method Based on the Data of Larabee and Coburn)for calculation of an atmospheric corrosion-resistance index has only beenverified for the composition limits stated in the guide.5.5 When
20、 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. Keywords7.1 atmospheric corrosion resistance;
21、bars; bolted construc-tion; durability; high-strength; low-alloy; plates; riveted con-struction; shapes; steel; structural steel; weight; weldedconstructionSUPPLEMENTARY REQUIREMENTSStandardized supplementary requirements for use at the option of the purchaser are listed inSpecification A 6/A 6M. Th
22、ose 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 andover in Thickness),S8. Ultrasonic Examination
23、, andS15. Reduction of Area Measurement.S32. Single Heat Bundles.TABLE 1 Tensile RequirementsPlates and BarsAStructural ShapesFor thicknesses34 in.20 mm,andunderFor thicknessesover34 to 112 in.20to40mm, inclFor thicknessesover112 to4in.40to100mm, inclFor flange orleg thicknesses1.5 in. 40 mmand unde
24、rFor flangethicknessesover 1.5 in.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 mm, min, % 18B,C18B,C18B,C18C18 18Elongatio
25、n 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 reduced two percentage points. See the Elongati
26、on 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 1Carbon, max 0.15Manganese, max 1.00Phosph
27、orus, max 0.15Sulfur, max 0.05Copper, min 0.20A 242/A 242M 04 (2009)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 that determination of the validity of an
28、y such patent rights, and the riskof infringement of such rights, are entirely their own responsibility.This standard is subject to revision at any time by the responsible technical committee and must be reviewed every five years andif not revised, either reapproved or withdrawn. Your comments are i
29、nvited either for revision of this standard or for additional standardsand should be addressed to ASTM International Headquarters. Your comments will receive careful consideration at a meeting of theresponsible technical committee, which you may attend. If you feel that your comments have not receiv
30、ed a fair hearing you shouldmake your views known to the ASTM Committee on Standards, at the address shown below.This standard is copyrighted by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,United States. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the aboveaddress or at 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.org).A 242/A 242M 04 (2009)3
