1、Designation: A 242/A 242M 04e1American Association StateHighway and Transportation OfficialsStandard AASHTO No.: M 161Standard Specification forHigh-Strength Low-Alloy Structural Steel1This standard is issued under the fixed designation A 242/A 242M; the number immediately following the designation
2、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 (e) indicates an editorial change since the last revision or reapproval.This standard has been approved for use by agenci
3、es of the Department of Defense.e1NOTEThe numbering for Tables 1 and 2 was corrected editorially in October 2005.1. Scope*1.1 This specification covers high-strength low-alloy struc-tural steel shapes, plates, and bars for welded, riveted, or boltedconstruction intended primarily for use as structur
4、al memberswhere savings in weight mass or added durability areimportant. 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 use
5、d bare(unpainted) for many applications (see Note 1). This specifi-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 G 101.1.2 When the steel is to be welded, it is presupposed
6、 that awelding procedure suitable for the grade of steel and intendeduse 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 ar
7、eshown in brackets. The values stated in each system are notexact equivalents; 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 witho
8、ut heat treatment or with stress relieving only, theadditional requirements, 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
9、Structural Steel Bars, Plates, Shapes, and SheetPilingG 101 Guide for 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 ofSpecificati
10、on A 6/A 6M, for the specific structural productordered, 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 s
11、tructural prod-ucts that have been cut to individual 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-form
12、ing (if applicable),cutting to length, testing, inspection, 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 a
13、re tobe reported for each qualifying coil. Additional requirements regardingstructural products produced from coil are described in SpecificationA 6/A 6M.4. Materials and Manufacture4.1 The steel shall be semi-killed or killed.1This specification is under the jurisdiction of ASTM Committee A01 on St
14、eel,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, 2004. Published May 2004. Originallyapproved in 1941. Last previous edition approved in 2003 as A 242/A
15、242M 03a.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 website.1*A Summary of Changes section appears at the end of
16、 this standard.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.5. 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 pres
17、cribed 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 propertiesprescribed in Section 6 and to provide th
18、e atmospheric corro-sion resistance of 1.1, shall be made by the manufacturer andincluded and reported in the heat analysis to identify the typeof steel applied. Elements commonly added include: chro-mium, nickel, silicon, vanadium, titanium, and zirconium.5.4 The atmospheric corrosion-resistance in
19、dex, calculatedon the basis of the heat analysis of the steel, as described inGuide G 101Predictive Method Based on the Data of Larabeeand 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
20、 calculation of an atmospheric corrosion-resistance index has only beenverified for the composition 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 spe
21、cimens shallconform to the requirements as to tensile properties prescribedin Table 1.7. Keywords7.1 atmospheric corrosion resistance; bars; bolted construc-tion; durability; high-strength; low-alloy; plates; riveted con-struction; shapes; steel; structural steel; weight; weldedconstructionSUPPLEMEN
22、TARY REQUIREMENTSStandardized supplementary requirements for use at the option of the purchaser are listed inSpecification A 6/A 6M. Those that are considered suitable for use with this specification are listed bytitle:S2. Product Analysis,S3. Simulated Post-Weld Heat Treatment of MechanicalTest Cou
23、pons,S5. Charpy V-Notch Impact Test,S6. Drop Weight Test (for Material 0.625 in. 16 mm andover in Thickness),S8. Ultrasonic Examination, andS15. Reduction of Area Measurement.S32. Single Heat Bundles.TABLE 1 Tensile RequirementsPlates and BarsAStructural ShapesFor thick-nesses34 in.20 mm, andunderFo
24、r thick-nesses over34 to 112 in.20to40mm, inclFor thick-nesses over112 to4in.40to100mm, inclFor flange orleg thicknesses1.5 in. 40 mmand underFor flangethicknessesover 1.5 in.40 mm to2 in. 50mm, inclFor flangethicknessesover 2 in. 50mmTensile strength, min, ksi MPa 70 480 67 460 63 435 70 485 67 460
25、 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 18Elongation in 2 in. 50 mm, min, % 21C21C21C21 21 21DASee the Orientation subsection in the Tension Tests section of Specification A 6/A 6M.BElongation not required to b
26、e determined for floor plate.CFor plates wider than 24 in. 600 mm the elongation requirement is reduced two percentage points. See the Elongation Requirement Adjustments subsectionintheTension Tests section of Specification A 6/A 6M.DFor wide flange shapes over 426 lb/ft 634 kg/m, elongation in 2 in
27、. 50 mm of 18 % minimum applies.TABLE 2 Chemical Requirements (Heat Analysis)Element Composition, %Type 1Carbon, max 0.15Manganese, max 1.00Phosphorus, max 0.15Sulfur, max 0.05Copper, min 0.20A 242/A 242M 04e12SUMMARY OF CHANGESCommittee A01 has identified the location of selected changes to this st
28、andard since the last issue (A 242/A242M 03a) that may impact the use of this standard (approved April 1, 2004).(1) Added Supplementary Requirement S32.Committee A01 has identified the location of selected changes to this standard since the last issue (A 242/A 242M-03) thatmay impact the use of this
29、 standard (approved May 10, 2003).(1) Table 2 was revised.Committee A01 has identified the location of selected changes to this standard since the last issue (A 242/A 242M-01) thatmay impact the use of this standard (approved April 10, 2003).(1) 1.4, 3.1, 3.1.1 (renumbered as 3.2), and Note 2 have b
30、eenrevised to be consistent with the terminology and requirementsof A 6/A 6M.ASTM 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 validi
31、ty of any 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 commen
32、ts are invited 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 no
33、t received 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 04e13
