1、SAE Technical Standards Board Rules provide that: This report is published by SAE to advance the state of technical and engineering sciences. The use of this report is entirelyvoluntary, and its applicability and suitability for any particular use, including any patent infringement arising therefrom
2、, is the sole responsibility of the user.SAE reviews each technical report at least every five years at which time it may be reaffirmed, revised, or cancelled. SAE invites your written comments and suggestions.Copyright 2003 SAE InternationalAll rights reserved. No part of this publication may be re
3、produced, stored in a retrieval system or transmitted, in any form or by any means, electronic, mechanical, photocopying,recording, or otherwise, without the prior written permission of SAE.TO PLACE A DOCUMENT ORDER: Tel: 877-606-7323 (inside USA and Canada)Tel: 724-776-4970 (outside USA)Fax: 724-77
4、6-0790Email: custsvcsae.orgSAE WEB ADDRESS: http:/www.sae.orgSURFACEVEHICLERECOMMENDEDPRACTICEJ1442REV.SEP2003Issued 1984-06Revised 2003-09Superseding J1442 NOV1993(R) High-Strength, Hot-Rolled Steel BarsForewordHigh-strength steel discussed in this SAE Recommended Practice involves hot-rolled bars
5、only. Thestrength is achieved through chemical composition and rolling practice; it is not achieved through quenching andtempering or additional rolling operations.1. ScopeThis SAE Recommended Practice covers two levels of high strength structural low-alloy steel barshaving minimum Yield Points of 3
6、45 MPa (50 ksi) and 450 MPa (65 ksi).The two strength levels are 345 and 450 MPa or 50 and 65 ksi minimum yield point. Different chemicalcompositions are used to achieve the specified mechanical properties. In some cases there are significantdifferences in chemical composition for the same strength
7、level, depending on the fabricating requirements.It should be noted that although the mechanical properties for a steel grade sourced from different suppliersmay be the same, the chemical composition may vary significantly. The fabricator should be aware that certaincompositional differences may eff
8、ect the forming, welding, and/or service requirements of the material. It istherefore recommended that the fabricator consult with the producer to understand the effect of chemicalcomposition.The products within the scope of this document include bars of the following types and sizes:Rounds, squares
9、, and hexagons of all sizes (cut length only), flats 5.2 mm (0.203 in) and greater in thicknessbut not greater than 150 mm (6 in) wide, and flats greater than 5.8 mm (0.229 in) thick and over 150 mm (6 in)to 204 mm (8 in) wide.This document previously covered plates, structural shapes, and bar size
10、shapes of Grades 290A, 345A,415A, 450A, 345W, 345F, 415F, 485F, and 550F as well as bars of Grades 290A, 415A, and 345W. Theseproducts are no longer covered; requirements for these products and grades can be found in ASTMSpecifications as follows in Table 1:Copyright SAE International Provided by IH
11、S under license with SAENot for ResaleNo reproduction or networking permitted without license from IHS-,-SAE J1442 Revised SEP2003-2-2. References2.1 Applicable PublicationsThe following publications form a part of the specification to the extent specifiedherein.2.1.1 ASTM PUBLICATIONSAvailable from
12、 ASTM, 100 Barr Harbor Drive, West Conshohocken, PA 19428-2959.ASTM A 6/A 6MGeneral Requirements for Rolled Steel Plates, Shapes, Sheet Piling, and Bars ofStructural UseASTM A 370Standard Methods and Definitions for Mechanical Testing of Steel ProductsASTM A 572/A 572MSpecification for High-Strength
13、 Low-Alloy Columbium-Vanadium Steels ofStructural QualityASTM A 588/A 588MSpecification for High-Strength Low-Alloy Structural Steel with 50 ksi (345 MPa)Minimum Yield Point to 4 in thickASTM A 656/A 656MSpecification for Hot-Rolled Structural Steel, High-Strength Low-Alloy Plate withImproved Formab
14、ility2.2 Related PublicationsThe following publication is provided for information purposes only and is not arequired part of this specification. Unless otherwise indicated, the latest version of SAE publications shallapply.SAE J450Use of Terms Yield Strength and Yield Point3. General InformationThe
15、 specific grades are identified by the minimum yield point expressed in MPa, that is345 and 450 or in ksi, that is 50 and 65 ksi. Grades 345 and 450 are similar to grades contained in ASTM A572/A 572M. These Grades were previously covered under this specification as Grades 345A and 450A; the“A” suff
16、ix has been dropped in this revision.Because these steels are characterized by their special mechanical properties obtained in the as-rolledconditions, they are not intended for any heat treatment by the purchaser either before, during, or afterfabrication. The fabricator should not subject these st
17、eels to such heat treatments without assumingresponsibility for the resulting mechanical properties. For certain applications, these steels may be annealed,normalized, or stress relieved with some effect on the mechanical properties; it is recommended that prior tosuch heat treatments, the purchaser
18、 should consult the producer to determine the need for and the effect onmechanical properties.Both grades and chemical compositions discussed in the practice are weldable despite the differences incarbon, manganese, and alloying addition. Because of the aforementioned variations in composition from
19、oneproducer to another, it is advisable to discuss with the producers the features of their chemical compositionrelative to the various types of welding and any special consideration for each application.TABLE 1EQUIVALENT ASTM SPECIFICATIONSProduct Previous SAE Grade ASTM Specification/GradePlates,
20、Structural Shapes, Bar Size Shapes, Bars 290A A 572/A 572M, Grade 42Plates, Structural Shapes, Bar Size Shapes 345A A 572/A 572M, Grade 50Plates, Structural Shapes, Bar Size Shapes, Bars 415A A 572/A 572M, Grade 60Plates, Structural Shapes, Bar Size Shapes 450A A 57/A 572M, Grade 65Plates, Structura
21、l Shapes, Bar Size Shapes, Bars 345W A 588/A 588MPlates 345F A 656/A 656M, Grade 50Plates 415F A 656/A 656M, Grade 60Plates 485F A 656/A 656M, Grade 70Plates 550F A 656/A 656M, Grade 80Copyright SAE International Provided by IHS under license with SAENot for ResaleNo reproduction or networking permi
22、tted without license from IHS-,-SAE J1442 Revised SEP2003-3-These steels, because of their high strength-to-weight ratio, are adapted particularly for use in mobileequipment and other structures where substantial weight savings are generally desirable.4. Mechanical PropertiesThe mechanical propertie
23、s of these steels are shown in Table 2. If thicknessesgreater than those shown in the table are required, consultation with the producers regarding availability andcharacteristics is suggested.5. Chemical CompositionThe chemical composition (heat analysis) of steel furnished to this practice shallco
24、nform to Table 3.Because the chemical compositions vary significantly among the producers despite the required mechanicalproperties being the same, it is advisable for the purchaser to discuss specific compositions with eachproducer, especially if welding, and/or forming are critical factors. The co
25、mmonly used alloying elements are:chromium, columbium (niobium), copper, molybdenum, nickel, titanium, vanadium, and zirconium. Theselection and chemical ranges for any alloying elements not in Table 3, which are considered necessary toattain the required properties, may be specified by mutual agree
26、ment between purchaser and producer at thetime of ordering. Once specified, they may not be changed without both parties consent.6. Suggested Bending PracticeThe suggested minimum inside bend radii for cold forming are shown in Table4. The suggested radii listed in Table 4 should be used as minimums
27、 in typical shop fabrication. Material thatdoes not form satisfactorily when fabricated in accordance with Table 4 may be subject to rejection pendingnegotiation with the steel supplier. When tighter bends are required, the manufacturer should be consulted.the bend radius and the radius of the male
28、die should be as liberal as the finished part will permit. The widthacross the shoulders of the female die should be at least eight times the plate thickness. Higher strengthsteels require larger die openings. The surface of the dies in the area of radius should be smooth.Since cracks in cold bendin
29、g commonly originate from the outside edges, shear burrs and gas cut edgesshould be removed by grinding. Sharp corners on edges and on punched or gas cut holes should be removedby chamfering or grinding to a radius. It should be noted that all steel has a tendency to crack when bent on asheared or g
30、as cut edge. This is not to be considered a fault of the steel, but rather a function of the inducedcold work or heat affected zone. Where bends are to be made on a sheared edge, best performance isattained when the shear burr is located on the inside of the bend.If possible, parts should be formed
31、such that the bend line is perpendicular to the direction of final rolling. If itis necessary to bend with the bend line parallel to the direction of final rolling, a more generous radius issuggested (1-1/2 times applicable value given in Table 4 for bend lines perpendicular to the direction of roll
32、ing.)7. Dimensional TolerancesStandard manufacturing tolerances for dimensions, as shown in the latest editionof ASTM A 6/A 6M shall apply.Copyright SAE International Provided by IHS under license with SAENot for ResaleNo reproduction or networking permitted without license from IHS-,-SAE J1442 Revi
33、sed SEP2003-4-TABLE 2MECHANICALPROPERTIES(1)1.Mechanical testing (location,number of tests,preparation, and method) is to bein accordance with the latest revision of ASTM A 6/A 6M.GradeNominalMaximumThicknessmmNominalMaximumThicknessinYieldPoint(2)(3)MinimumMPa2.Yield point may bereported as yield s
34、trength as measured bythe 0.2%offset or 0.5%extension under loadmethod asagreed uponbetween the producer and thepurchaser.3.Only one set of units apply to yield and tensile and thereported value should be based on the unitsof the purchaseorder. In addition only one set ofelongation values50mm (2 in)
35、 or 200 mm (8in) need to bemet and reported.YieldPoint(2)(3)MinimumksiTensileStrength(3)(4)MinimumMPa4.Some applications may require a maximum tensile strength. In such cases,the following values must bedetermined from the producerfor acceptance prior to issuing a purchase order.TensileStrength(3)(4
36、)MinimumksiElongation(3)Minimum% Minimum200 mm(8 in)Elongation(3)(5)Minimum% Minimum50 mm(2 in)5.Refer to ASTM A 6/A 6M elongation requirement adjustments.TensileStrength,(4)Max MPaTensileStrength,(4)Maxksi34510043455045065182165595450321-1/445065550801517725105TABLE 3CHEMICALCOMPOSITION,HEAT ANALYS
37、IS, MAX, % BYWEIGHTGradeCMnSiPSOther3450.211.500.400.0400.050(1)1.Choice anduse ofalloying elements,combined with carbon, manganese,silicon, phosphorusand sulfur within the limits of Table 3 to givethe mechanical properties prescribedin Table 2, shall be made bythe manufacturer and included and repo
38、rted in the heat analysis to identify the type ofsteel applied. Element commonly added include: chromium, copper, molybdenum, nickel, niobium (columbium), vanadium, titanium, and zirco-nium.4500.261.650.400.0400.050(1)TABLE 4SUGGESTEDMINIMUM INSIDERADII FOR 90-DEGREE COLD BENDINGRATIO OF BEND RADIUS
39、 TO THICKNESSTHICKNESS OF MATERIAL, mm(in)Gradeto 20 (3/4) incl.Over 20 (3/4) to25(1) incl.Over 25 (1)to 50 (2) incl.Over 50 (2)3451.51.52.02.54501.51.53.03.5Copyright SAE International Provided by IHS under license with SAENot for ResaleNo reproduction or networking permitted without license from I
40、HS-,-SAE J1442 Revised SEP2003-5-8. Notes8.1 Marginal IndiciaThe change bar (I) located in the left margin is for the convenience of the user in locatingareas where technical revisions have been mae to the previous issue of the report. An (R) symbol to the left ofthe document title indicates a compl
41、ete revision of the report.PREPARED BY THE SAE IRON AND STEEL TECHNICAL COMMITTEE DIVISION 1 CARBON AND ALLOY STEELSCopyright SAE International Provided by IHS under license with SAENot for ResaleNo reproduction or networking permitted without license from IHS-,-SAE J1442 Revised SEP2003RationaleThi
42、s document has been revised to cover two grades of high-strength low-alloy steel bars havingminimum yield points of 345 MPa (50 ksi) and 450 MPa (65 ksi) respectively. Other products previouslycovered by this document (plates, structural shapes and bar shapes) are covered by ASTMspecifications.Relat
43、ionship of SAE Standard to ISO StandardNot applicable.ApplicationThis SAE Recommended Practice covers six levels of high strength carbon and high-strengthlow-alloy steel plates, bars, and shapes for structural use.Reference SectionASTM A 6/A 6MGeneral Requirements for Rolled Steel Plates, Shapes, Sh
44、eet Piling, and Bars ofStructural UseASTM A 370Standard Methods and Definitions for Mechanical Testing of Steel ProductsASTM A 572/A 572MSpecification for High-Strength Low-Alloy Columbium-Vanadium Steels ofStructural QualityASTM A 588/A 588MSpecification for High-Strength Low-Alloy Structural Steel
45、 with 50 ksi (345 MPa)Minimum Yield Point to 4 in thickASTM A 656/A 656MSpecification for Hot-Rolled Structural Steel, High-Strength Low-Alloy Plate withImproved FormabilityDeveloped by the SAE Iron and Steel Technical Committee Division 1Carbon and Alloy SteelsSponsored by the SAE Iron and Steel Technical CommitteeCopyright SAE International Provided by IHS under license with SAENot for ResaleNo reproduction or networking permitted without license from IHS-,-
