1、Designation: A49 12Standard Specification forHeat-Treated Carbon Steel Joint Bars, Microalloyed JointBars, and Forged Carbon Steel Compromise Joint Bars1This standard is issued under the fixed designationA49; the number immediately following the designation indicates the year of originaladoption or,
2、 in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A superscriptepsilon () indicates an editorial change since the last revision or reapproval.This standard has been approved for use by agencies of the Department of Defense.1. Scope1.1
3、 This specification covers heat-treated carbon steel jointbars, microalloyed joint bars, and forged compromise joint barsfor general use in standard railroad track.1.2 The joint bars may be used for the production ofinsulated joints.1.3 The values stated in inch-pound units are to be regardedas the
4、standard. The values given in parentheses are forinformation only.2. Referenced Documents2.1 ASTM Standards:2A29/A29M Specification for Steel Bars, Carbon and Alloy,Hot-Wrought, General Requirements forA370 Test Methods and Definitions for Mechanical Testingof Steel ProductsA700 Practices for Packag
5、ing, Marking, and Loading Meth-ods for Steel Products for Shipment2.2 American Railway Engineering and Maintenance ofWay Association Manual for Railway Engineering33. Ordering Information3.1 Orders for joint bars under this specification shallinclude the following information as appropriate:3.1.1 Qu
6、antitynumber of pairs of bars,3.1.2 Typedesign or type bar along with section designa-tion and weight of rails being joined,3.1.3 Dimensionoverall length,3.1.4 Punchingtype (elliptical, oval, round, or combina-tions), size, number, location, spacing and elevation ofpunched holes, with dimensional dr
7、awing if necessary,3.1.5 Head Easementif required, and3.1.6 Certification and Test Report Requirements (see12.1).4. Manufacture4.1 The steel shall be made by one or both of the followingprocesses: basic-oxygen or electric-furnace.4.1.1 The steel may be cast by a continuous process, or iningots.4.2 H
8、eating and QuenchingQuenched carbon-steel jointbars and forged compromise joint bars shall be uniformlyheated for punching, slotting, shaping, and forging and subse-quently quenched. Maximum depth of decarburized layer offorged bars shall not exceed 0.040 in.4.3 Microalloyed joint bars shall be prod
9、uced from hotrolled steel sections. Bars shall be sheared or sawed cold, andholes shall be drilled. No reheating and quenching is required.5. Chemical Requirements5.1 The chemical composition of the quenched carbon-steeljoint bars and forged compromise joint bars determined asprescribed in 5.3 shall
10、 be within the limits shown in Table 1.5.2 The chemical composition of the microalloyed joint barsshall be agreed upon by the purchaser and the manufacturer.Microalloying shall be accomplished with columbium, vana-dium, and nitrogen, or combinations thereof.5.3 Heat or Cast AnalysisSeparate analysis
11、 shall be madefrom test samples representing one of the first three and one ofthe last three ingots or continuously cast blooms preferablytaken during the pouring of the heat. Determinations may bemade chemically or spectrographically. Any portion of the heatmeeting the chemical analysis requirement
12、s of Table 1 may beapplied. The first heat analysis shall be recorded as the officialheat analysis, but the purchaser shall have access to all ladleanalyses.Additionally, any material meeting the product analy-sis limits shown in Table 2 may be applied after testing suchmaterial in accordance with S
13、pecification A29/A29M.1This specification is under the jurisdiction of ASTM Committee A01 on Steel,Stainless Steel and Related Alloys and is the direct responsibility of SubcommitteeA01.01 on Steel Rails and Accessories.Current edition approved March 1, 2012. Published April 2012. Originallyapproved
14、 in 1915. Last previous edition approved in 2006 asA49 01 (2006). DOI:10.1520/A0049-12.2For 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 Summar
15、y page onthe ASTM website.3Available fromAmerican Railway Engineering and Maintenance of WayAssn.,10003 Derekwood Lane, Suite 210, Lanham, MD 20706.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.5.4 Product AnalysisWhen ladle tests
16、are not available,finished material representing the heat may be product tested.The product analysis allowance beyond the limits of thespecified ladle analysis shall be within the limits for productanalyses specified in Table 2.5.4.1 An analysis may be made by the purchaser from asample taken from a
17、 finished joint bar representing each heat orcast. The chemical composition thus determined shall conformto the requirements in Table 2.6. Tensile Requirements6.1 Properties:6.1.1 The material as represented by a tension test specimenshall conform to the tensile properties prescribed in Table 3.6.1.
18、2 The yield point prescribed in Table 3 may be deter-mined by the drop of the beam or halt of the gage of the testingmachine, or by use of dividers. Where a definite yield point isnot exhibited, the yield strength method defined in 6.1.3 shallbe used.6.1.3 The yield strength prescribed in Table 3 sh
19、all bedetermined by a strain gage or extensometer reading to 0.0002in. (0.005 mm). Yield strength may be defined as the stress at0.5 % total strain under load or as the stress at 0.2 % offset. Themethod described in Test Methods and Definitions A370 shallbe followed. After the yield point has been p
20、assed, theextensometer may then be removed and the test continued todetermine the tensile strength.6.2 Test SpecimensThe tension test specimen shall betaken from the middle of the head at the center of a finishedjoint bar, and shall be machined to the form and dimensions fora standard round tension
21、test specimen with 2-in., or 50-mmgage length as described in Test Methods and DefinitionsA370.6.3 Number of TestsOne tension test shall be made fromeach lot of 1000 bars or less, but not less than one test fromeach heat or cast on each day in which bars are heated andquenched. For microalloyed bars
22、, one tension test shall bemade from each heat or cast.6.4 Retests:6.4.1 If the results of the tension test of any test lot forquenched bars do not conform to the specified requirements,the manufacturer may retreat such lot not more than twice, inwhich case two additional tension tests shall be made
23、 fromsuch lot, and both shall conform to the requirements specifiedin Table 3.6.4.2 If the results of the tension test for microalloyed barsdo not conform to the specified requirements, a retest may bemade on two random samples from the heat or cast, and bothshall conform to the requirements specifi
24、ed in Table 3.6.4.3 If any test specimen fails because of mechanicalreasons such as failure of testing equipment or improperspecimen preparation, it may be discarded and another speci-men taken.7. Bending Requirements7.1 Properties:7.1.1 The material as represented by a bend test specimenshall confo
25、rm to the bend properties prescribed below.7.1.2 The bend test shall stand being bent cold through 90degrees without cracking on the outside of the bent portionaround a pin the diameter of which is not greater than threetimes the thickness of the specimen. If preferred the manufac-turer may get appr
26、oval by the purchaser to substitute a fullsection bar. It shall stand being bent cold through 45 degreeswithout cracking on the outside of the bent portion around a pinthe diameter of which is not greater than three times thegreatest thickness of the section. The test fixture used shallbend the bar
27、laterally about its center, with the outside surfaceof the bar being placed on the opposite side from the bendingpin.7.2 Test SpecimensThe bend test specimen shall be takenfrom the middle of the head at the center of a finished joint bar,and shall be machined to12 in. square in section or rectangula
28、rin section with two parallel faces as rolled and with cornersrounded to a radius not over116 in.7.3 Number of TestsOne bend test shall be made fromeach lot of 1000 bars or fraction thereof, but not less than onetest for each heat on each day on which quenched carbon steelbars are heated and quenche
29、d, or on which micro alloyed jointbars are sheared or sawed.7.4 RetestsIf a bend test fails a retest shall be permitted ontwo random specimens from the same lot. If the results of bothtest specimens meet the specified requirements, the lot shall beaccepted.7.4.1 If the results of the bend test of an
30、y test lot forquenched bars do not conform to the specified requirements,the manufacturer may retreat such lot not more than twice, inTABLE 1 Chemical RequirementsElement Composition, %Carbon 0.350.60Manganese, max 1.20Phosphorus, max 0.04Sulfur, max 0.050TABLE 2 Product AnalysesAllowance Beyond Lim
31、its of Specified Chemical AnalysisPercent undermin limitPercent overmax limitCarbon 0.04 0.04Manganese 0.06 0.06Phosphorus . . . 0.008Sulfur . . . 0.008TABLE 3 Tensile Requirementsksi MPaTensile strength, min 100 690Yield point or yieldstrength,minimumA70 485Elongation in 2 in. or 50mm, min,%12Reduc
32、tion in area, min, % 25ADetermination by either the 0.2 % offset method or the 0.5 % extension-under-load method.A49122which case two additional bend tests shall be made from suchlot, and both shall conform to the requirements specified inTable 3.7.4.2 If a bend test fails for mechanical reasons; su
33、ch asfailure of testing equipment or improper specimen preparation,or flaws in the specimen it may be discarded and anotherspecimen taken.8. Dimensions and Permissible Variations8.1 The joint bars shall be true to template and shallaccurately fit the rails for which they are intended.8.2 The joint b
34、ars shall be either sheared or sawed to length,punched to the dimensions specified by the purchaser andalignment adjusted, all subject to the permissible variationsprescribed in 8.3 and Table 4.8.3 Any variation from a straight line in a vertical planeshall be such as will make the bars high in the
35、center.9. Workmanship, Finish, and Appearance9.1 The joint bars shall be straight subject to the variationprescribed in 8.3 and Table 4.9.2 The general appearance with respect to soundness andsurface finish shall be consistent with good commercial prac-tice as determined by ordinary visual inspectio
36、n.10. Inspection10.1 The manufacturer shall afford the purchasers inspectorall reasonable facilities necessary to satisfy that the material isbeing produced and furnished in accordance with the specifi-cation. Mill inspection by the purchaser shall not interfereunnecessarily with the manufacturers o
37、perations. All tests andinspections shall be made at the place of manufacture, unlessotherwise agreed upon.11. Rejection and Rehearing11.1 Material that fails to conform to the requirements ofthis specification may be rejected. Rejections shall be reportedto the manufacturer or supplier promptly and
38、 in writing. In caseof dissatisfaction with the test results, the manufacturer orsupplier may make claim for a rehearing.12. Certification and Test Report12.1 When specified in the purchaser order or contract, amanufacturers certification shall be furnished to the purchaserthat the material was prod
39、uced and tested in accordance withthis specification and has been found to meet the requirements.12.2 When specified in the purchaser order or contract, areport of the chemical and mechanical test results shall befurnished.12.3 A Material Test Report, Certificate of Inspection, orsimilar document pr
40、inted from or used in electronic form froman electronic data interchange (EDI) transmission shall beregarded as having the same validity as a counterpart printed inthe certifiers facility. The content of the EDI transmitteddocument must meet the requirements of the invoked ASTMstandard(s) and confor
41、m to any existing EDI agreement be-tween the purchaser and the supplier.12.4 Notwithstanding the absence of a signature, the orga-nization submitting either a printed document (Material TestReport, Certificate of Inspection or similar document) or anEDI transmission is responsible for the content of
42、 the report.13. Product Marking13.1 The name or brand of the manufacturer, the sectiondesignation, and the year of manufacture shall be either rolledin raised letters and figures on the side of the rolled bars, anda portion of this marking shall appear on each finished joint baror hot stamped.13.2 F
43、or quenched bars, a serial number representing theheat or cast shall be hot stamped on the outside of the web ofeach bar, near one end.13.3 Each compromise joint bar shall also have the railsections shown at each end along with the word “gage” or“out” to indicate on which side of the rail the bar is
44、 to be used.(If the compromise joint bars are interchangeable, the words“gage” and “out” shall be omitted.)13.4 Bar Coding:13.4.1 The Automotive Industry Action Group (AIAG) BarCode Standard for Primary Metals for Steel Products may beconsidered as a possible auxiliary method of identification. Useo
45、f this method shall be by agreement between purchaser andsupplier.14. U. S. Government Procurement14.1 When specified in the contract or purchase order,material shall be prepared for shipment and storage in accor-dance with the requirements of Practices A700.15. Keywords15.1 joint bars; rails; railw
46、ay applications; steel railsTABLE 4 Permissible Variations in Dimensionsin. (mm)Specified size of holes 6 1/32 (0.8)Specified location of holes 6 1/16 (1.6)Specified length of bar 6 1/8 (3.2)Maximum camber in either plane (see 8.3)24-in. (610-mm) bars 1/32 (0.8)36-in. (914-mm) bars 1/16 1.6)A49123AS
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48、ntirely 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 invited either for revision of this standard or for additional standards
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