1、Designation: A 769/A 769M 05Standard Specification forCarbon and High-Strength Electric Resistance Forge-Welded Steel Structural Shapes1This standard is issued under the fixed designation A 769/A 769M; the number immediately following the designation indicates the yearof original adoption or, in the
2、 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.1. Scope*1.1 This specification covers carbon and high-strength steelshapes of structural quality
3、manufactured by the electric-resistance forge-welding process from coils.1.2 The size range covered is described in nominal dimen-sions for columns, beams, and tees.Size Range, in. (mm)Web thickness 0.060 to 0.375 1.5 to 10Flange thickness 0.060 to 0.500 1.5 to 12.7Overall depth 2.00 to 24.00 50 to
4、600Flange width 0.50 to 12.00 12.7 to 3001.3 These shapes are intended for two classes of applica-tion:1.3.1 Class 1 General structural use where static loadingpredominates.1.3.2 Class 2Structural use where fatigue loading occursand is a principal design consideration.NOTE 1CautionBecause of the abs
5、ence of smooth, integral, largeradius fillets at the junctions of the webs and the flanges (see Fig. 1),fatigue limits of resistance forge-welded shapes in torsion, lateral loading,and flexure are usually lower than those for hot-rolled shapes of similarsize and material. Users should consult shape
6、manufacturers for recom-mended values of fatigue limits for each specific use, material, and size incases where dynamic loading is a principal design consideration.1.4 When the steel is to be welded, it is presupposed that awelding procedure suitable for the grade of steel and intendeduse or service
7、 will be utilized. See Appendix X3 of Specifica-tion A 6/A 6M for information on weldability.1.5 The values stated in either inch-pound units or SI unitsare to be regarded separately as standard. Within the text, theSI units are shown in brackets. The values stated in eachsystem are not exact equiva
8、lents. Therefore, each system mustbe used independently of the other. Combining values from thetwo systems may result in nonconformance with this specifi-cation.1.6 The following safety hazards caveat pertains only to thetest methods portion, Section 10, of this specification: Thisstandard does not
9、purport to address all of the safety concerns,if any, associated with its use. It is the responsibility of the userof this standard to establish appropriate safety and healthpractices and determine the applicability of regulatory limita-tions prior to use.2. Referenced Documents2.1 ASTM Standards:A
10、6/A6M Specification for General Requirements forRolled Structural Steel Bars, Plates, Shapes, and SheetPilingA 370 Test Methods and Definitions for Mechanical Testingof Steel ProductsA 568/A568M Specification for Steel, Sheet, Carbon, andHigh-Strength, Low-Alloy, Hot-Rolled and Cold-Rolled,General R
11、equirements forA 700 Practices for Packaging, Marking, and LoadingMethods for Steel Products for Domestic Shipment2.2 American Welding Society Standard:AWS Specification D 1.1, Structural Welding Code23. Ordering Information3.1 Orders for material under this specification shouldinclude the following
12、, as required, to describe the desiredmaterial adequately:3.1.1 Quantity (total number of feet (metres) or lengths),3.2 ASTM designation and year of issue, grade, and class,3.3 Shape and size,3.4 Length of each piece,3.5 Information on intended application,3.6 Other special requirements, and3.7 Requ
13、ired certification and test reports.4. Materials and Manufacture4.1 The shapes shall be manufactured from coils by theelectric-resistance forge-welding process. All components of ashape shall be furnished to the same grade unless otherwisespecified.4.2 For Class 1 shapes the average width of weld at
14、 thejoint to the flange shall be more than 110 % of the nominal web1This specification 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 Ship
15、s.Current edition approved Sept. 1, 2005. Published September 2005. Originallyapproved in 1979. Last previous edition approved in 2000 as A 769/A 769M 00.2Available from American Welding Society, 550 N. W. LaJeune Rd., Miami, FL33135.1*A Summary of Changes section appears at the end of this standard
16、.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.thickness (see Fig. 1(b). The acceptability of coil-splice weldsin webs and flanges shall be subject to negotiation between thepurchaser and the manufacturer.4.3 For Class 2 shapes the
17、average width of weld at thejoint to the flange shall be more than 130 % of the nominal webthickness (see Fig. 1(b). Coil-splice welds shall not bepermitted.4.4 Flash caused by welding will not be removed unlessindicated on the purchase order.5. Chemical Composition5.1 An analysis of each heat of st
18、eel shall be made by thesteel manufacturer. The chemical composition thus determinedshall conform to the requirements of Table 1, subject to theproduct analysis tolerances in Specification A 6/A 6M for platesteels or Specification A 568/A 568M for sheet steels. Heatanalysis reports shall be furnishe
19、d by the shape manufacturerupon request.5.2 The steel supplier, shape manufacturer, and the shapepurchaser shall establish a chemical composition, which willassure the purchaser of the desired properties while providingthe shape manufacturer with material that is weldable by theelectric-resistance w
20、elding process.6. Tension Test Tension Test6.1 The material as represented by the test specimen shallconform to the requirements of tensile properties prescribed inTable 2.6.2 The shape manufacturer shall furnish, upon request, testreports of tensile properties determined in accordance withSections
21、8, 9, and 10.7. Permissible Variations in Dimensions7.1 Unless otherwise agreed upon by the shape manufac-turer and the purchaser, dimensional variations shall conformto Specification A 6/A 6M (13.3 and Tables 16 to Tables 24inclusive) for shapes of similar dimensions. Thicknesses of theshape compon
22、ents shall be based on nominal thicknessesconforming to Specification A 6/A 6M (Table 1, plate) orSpecification A 568/A 568M (Tables 4 and Tables 5 , sheet).Nominal thickness shall be defined as the minimum thicknessspecified plus one half the allowable thickness tolerance asshown in the tables. The
23、 nominal weight per foot of the shapeshall be calculated based on the nominal thickness and allow-able variations in weight shall be equivalent to allowablevariations in thickness.8. Number of Tests8.1 Tension Tests:FIG. 1 Appearance of Peel Test CriteriaTABLE 1 Chemical RequirementsAGeneral Limitat
24、ions, %Carbon 0.26 maxManganese 0.30 min to 1.65 maxPhosphorus 0.04 maxSulfur 0.05 maxSilicon 0.60 maxAThe choice and use of alloying elements (combined with carbon, manganese,phosphorus, and sulfur within the limits prescribed) to provide the specifiedmechanical properties, or to enhance the atmosp
25、heric corrosion resistance, orboth, may vary with manufacturer and thickness of material. Elements commonlyadded include: boron, chromium, copper, molybdenum, nickel, silicon, vanadium,titanium, zirconium, and columbium. The heat analysis, including the alloyingelements intentionally added, shall be
26、 reported to the purchaser. Permittedvariations in product analysis shall be within the limits established in Table B ofSpecification A 6/A 6M.A 769/A 769M 0528.1.1 For steel ordered from the steel manufacturer as coiledsheet to minimum mechanical properties (ASTM or equiva-lent), the shape manufact
27、urer may certify his steel based onmanufacturers test reports of mechanical properties. Twotension tests, taken longitudinally, shall be made by the steelmanufacturer from each heat, unless the finished material froma heat is less than 50 ton 50 Mg, in which case one tensiontest will be sufficient.
28、When material rolled from one heatdiffers 0.050 in. 1.2 mm or more in thickness, one tension testshall be made from both the thickest and thinnest materialrolled regardless of the weight represented.8.1.2 For heavy thickness coils ordered to minimum me-chanical properties, make one tension test of t
29、he end lap eitherby the steel manufacturer as in 8.1.1 or by the shape manufac-turer.8.1.2.1 In addition, the shape manufacturer shall make onetension test using a specimen which is representative of theapproximate middle of the original coil length. Make thesetests on the product of two coils from
30、each heat for eachnominal thickness which differs by more than 0.050 in. 1.2mm from the thickness already tested for that heat.8.1.3 For all steel not made to minimum mechanical prop-erties, regardless of thickness, the shape manufacturer shallmake the tests as in 8.1.2 for each coil. Specimens take
31、n fortesting from the middle of the original coil length shall, inaddition, be taken from the approximate quarter point of theoriginal coil width.8.2 Peel Tests:8.2.1 One peel test, 8.2, is required on both sides of eachbutt weld on the flanges and web. A short (2 to 5 ft) sampleshall be cut from th
32、e section and a peel test shall be performedon both ends of the section, on both welds.8.3 Tee Tension TestsOne tee tension test, 8.3, is requiredof each weld for each lot.8.3.1 A lot consists of not more than1hofwelding ofmaterial of unchanged dimensions and heat number. A new lotwill be started in
33、 the event of a dimension change or start of anew heat of steel for any component of the shape.9. Retests9.1 If one tension test fails, run two more tension tests froman adjacent location of the same parent coil. Both retests shallconform to the requirements prescribed in this specification;otherwis
34、e, the product of all coils represented by those testsshall stand rejected.9.2 If the results of the peel tests and tee tension testsrepresenting any lot do not meet a requirement as specified inSection 10, make two retests, one on each side of and adjacentto the original test, from the same lot. Ea
35、ch retest shall meet therequirements specified, or the lot represented by the retestsshall be rejected.10. Test Methods10.1 Tension Test:10.1.1 The tension specimens required by this specificationshall conform to those described in the latest issue of TestMethods A 370.10.1.2 Take all tension test s
36、pecimens longitudinally. Re-move all burrs from the specimens and ensure that there are nosurface imperfections that would interfere with proper deter-mination of the tensile properties of the metal.10.1.3 Determine the mechanical properties, Table 2,inaccordance with one of the methods described in
37、 Test MethodsA 370.10.2 Peel Test The peel test is conducted to determineweld width and ductility. In this test it is necessary to separatethe flange from the web and the flange from the stem of teesections mechanically for a length of approximately 2 in. (50mm) by any method that places the weld bo
38、nd plane inprogressive, peeling tension. A slotted bending hook, Fig. 2(a),is preferred. Fracture may be initiated on the bond plane by anotch pressed or sawed into the end of the specimen along theweld bond plane (Fig. 2(c). Striking of the inner surface of theflange on alternate sides of the weld
39、with a hammer may beused to perform the peel test, if necessary, in cases where abending hook is not appropriate. Appearance and width of thefracture are the bases for evaluating weld quality.10.2.1 Flange Pullout The usual mode of fracture causesa pullout of the surface of the flange under the weld
40、. This isevidence of an acceptable metallurgical bond. The averagewidth of the pullout material (Fig. 1(b) expressed as apercentage of the nominal web thickness shall be: for Class 1shapes, more than 110 %; and for Class 2 shapes, more than130 %. Typically, the appearance of pulled out material isro
41、ugh, often having a woody texture. A general nonorientedroughness or granular appearance is acceptable. Measure theweld width using an appropriate steel scale or caliper. Somevariation of width is to be expected. Fracture that results in arelatively smooth surface shall be taken as an indication of
42、abrittle or poorly bonded weld, and is unacceptable. Regions ofthis appearance that lie adjacent to pulled-out flange materialare not to be included in estimating width of pulled-outmaterial (see Weld Margin in Fig. 1(b).TABLE 2 Mechanical PropertiesGrade 36 45 45WA50 50WA60 80Tensile strength, min,
43、 psi MPa 53 00036560 00041565 00045065 00045070 00048575 00052090 000620Yield point, min, psi MPa 36 00025045 00031045 00031050 00034550 00034560 00041580 000550Elongation, min, %in 2 in. 50 mm 22 19 19 17 17 17 17in 8 in. 200 mmB15 14 14 12 12 12 12AThe suffix “W indicates steel grades having atmos
44、pheric corrosion resistance approximately two times that of carbon structural steel with copper.BSee elongation requirement adjustments under the Tension Tests section of Specification A 6/A 6M. See specimen orientation in the Tension Tests section ofSpecification A 6/A 6M.A 769/A 769M 05310.2.2 Web
45、 Fracture Fracture will ordinarily not occur inthe web or stem unless (1) that member is made of significantlyweaker steel than the flange, or (2) the weld width is over150 % of web thickness for similar materials. For (1) the test isnot applicable, and the weld is considered acceptable. For (2)the
46、weld is considered acceptable.10.2.3 Flange Shearing Flange shearing-fracture mayoccur by shearing the flange on both sides of the weld. In suchcases, the weld is acceptable.10.3 Tee Tension Test:10.3.1 The purpose of the tee tension test is to compare thestatic tensile strength of the weld to the t
47、ensile strength of theweb and the strength of the flange in shear.10.3.2 The test is conducted by clamping the flange of ashort length of section in a slotted holder, Fig. 3. The width ofthe slot should not exceed 1.5 times the flange thickness, andthe flange must be clamped adequately in order to m
48、inimizebending of the flange. Welding flash must be removed if itinterferes with the holder. The length of the specimen isnormally about 1 in. (25 mm), but other lengths may be used.10.3.3 The web shall be held in tapered jaw grips ofsuitable shape to avoid fracture in the grips.10.3.3.1 Fracture of
49、 the specimen in web tension or flangeshear is acceptable.10.3.3.2 Fracture of the specimen in the flange near theweld is acceptable if weld width requirements are met.10.3.3.3 Fracture in the weld bond plane is not acceptable.10.4 Test Specimen Preparation:10.4.1 Prepare the specimens for mechanical tests in such away that the areas of interest are not significantly affected bythe thermal or mechanical consequences of cutting. The areasof interest are the weld zone at the tested end of the peel testspecimen and the e
