1、Designation: A 847/A 847M 05Standard Specification forCold-Formed Welded and Seamless High-Strength, Low-Alloy Structural Tubing with Improved AtmosphericCorrosion Resistance1This standard is issued under the fixed designation A 847/A 847M; the number immediately following the designation indicates
2、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.1. Scope*1.1 This specification covers cold-formed welded a
3、nd seam-less high-strength, low-alloy round, square, rectangular, orspecial shaped structural tubing for welded, riveted, or boltedconstruction of bridges and buildings and for general structuralpurposes where high strength and enhanced atmospheric cor-rosion resistance are required (Note 1). The at
4、mosphericcorrosion resistance of this steel in most environments issubstantially better than carbon steel with or without copperaddition (Note 2). When properly exposed to the atmosphere,this steel can be used bare (unpainted) for many applications.When this steel is used in welded construction, the
5、 weldingprocedure shall be suitable for the steel and the intendedservice.1.2 This tubing is produced in welded sizes with a maxi-mum periphery of 64 in. 1626 mm and a maximum wall of0.625 in. 15.9 mm, and in seamless with a maximumperiphery of 32 in. 813 mm and a maximum wall of 0.500 in.12.7 mm. T
6、ubing having other dimensions may be furnishedprovided such tubing complies with all other requirements ofthis specification.1.3 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
7、 eachsystem are not exact equivalents; therefore, each system is tobe used independently of the other, without combining valuesin any way.NOTE 1Products manufactured to this specification may not besuitable for those applications where low temperature notch toughnessproperties may be important, such
8、 as dynamically loaded elements inwelded structures, etc.NOTE 2For methods of estimating the atmospheric corrosion resis-tance of low alloy steels see Guide G 101 or actual data.2. Referenced Documents2.1 ASTM Standards:2A 370 Test Methods and Definitions for Mechanical Testingof Steel ProductsA 700
9、 Practices for Packaging, Marking, and LoadingMethods for Steel Products for ShipmentA 751 Test Methods, Practices, and Terminology forChemical Analysis of Steel ProductsG 101 Guide For Estimating the Atmospheric CorrosionResistance of Low-Alloy Steels3. Ordering Information3.1 Orders for material u
10、nder this specification shouldinclude the following, as required, to describe the desiredmaterial adequately:3.1.1 ASTM specification number,3.1.2 Quantity (feet, metres, or number of lengths),3.1.3 Name of material (cold-formed tubing),3.1.4 Method of manufacture (welded or seamless),3.1.5 Size (ou
11、tside diameter and nominal wall thickness forround tubing and the outside dimensions and nominal wallthickness for square and rectangular tubing),3.1.6 Length (specific or random, see 10.3),3.1.7 End condition (see 14.2),3.1.8 Burr removal (see 14.2),3.1.9 Certification (see Section 17),1This specif
12、ication is under the jurisdiction of ASTM Committee A01 on Steel,Stainless Steel, and Related Alloys and is the direct responsibility of SubcommitteeA01.09 on Carbon Steel Tubular Products.Current edition approved October 1, 2005. Published November 2005. Originallyapproved in 1985. Last previous ed
13、ition approved in 2003 as A 847 99a(2003).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 Chan
14、ges section appears at the end of this standard.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.3.1.10 End use, and3.1.11 Special requirements.4. Process4.1 The steel shall be made by one or more of the followingprocesses: open hearth
15、, basic oxygen, or electric furnace.5. Manufacture5.1 The tubing shall be made by a welded or seamlessprocess.5.2 Welded tubing shall be made from flat-rolled steel bythe electric-resistance welding or electric-fusion welding pro-cess. The longitudinal butt joint shall be welded across itsthickness
16、in such a manner that the structural design strength ofthe tubing section is assured.5.2.1 Structural tubing welded by the electric-resistancemethod is normally furnished without removal of inside flash.5.3 The tubing may be stress relieved or annealed, as isconsidered necessary by the tubing manufa
17、cturer, to conformto the requirements of this specification.6. Chemical Composition6.1 The choice and use of alloying elements combined withcarbon, manganese, phosphorus, sulphur, and copper shall bewithin the limits prescribed in Section 7 to give the mechanicalproperties prescribed in Table 1 and
18、to provide the atmosphericcorrosion resistance of 1.1. The choice and use of theseelements shall be made by the manufacturer and included andreported in the heat analysis to identify the type of steelapplied. Elements commonly added include chromium, nickel,silicon, vanadium, titanium, and zirconium
19、. For SpecificationA 847 material, the atmospheric corrosion-resistance index,calculated on the basis of the chemical composition of the steelas described in Guide G 101, shall be 6.0 or higher.NOTE 3The user is cautioned that the Guide G 101 predictiveequation for calculation of an atmospheric corr
20、osion-resistance index hasbeen verified only for the composition limits stated in that guide.7. Heat Analysis7.1 Each heat analysis shall conform to the requirementsgiven in Table 2 for heat analysis.8. Product Analysis8.1 The tubing shall be capable of comforming to therequirements given in Table 2
21、 for product analysis.8.2 If product analyses are made, they shall be made usingtest specimens taken from two lengths of tubing from each lotof 500 lengths, or a fraction thereof, or two pieces of flat-rolledstock from each lot of a corresponding quantity of flat-rolledstock. Methods and practices r
22、elating to chemical analysis shallbe in accordance with Test Methods, Practices, and Terminol-ogy A 751. Such product analyses shall conform to therequirements specified in Table 2 for product analysis.8.3 If both product analyses representing a lot fail toconform to the specified requirements, the
23、lot shall be rejected.8.4 If only one product analysis representing a lot fails toconform to the specified requirements, product analyses shallbe made using two additional test specimens taken from the lot.Both additional product analyses shall conform to the specifiedrequirements or the lot shall b
24、e rejected.9. Tensile Requirements9.1 The material, as represented by the test specimen, shallconform to the tensile property requirements prescribed inTable 1.10. Permissible Variations and Dimensions10.1 Outside Dimensions:10.1.1 Round Structural TubingThe outside diametershall not vary from the s
25、pecified outside diameter by more than6 0.5 %, rounded to the nearest 0.005 in. 0.1 mm, forspecified outside diameters 1.900 in. 48.3 mm and smaller;6 0.75 %, rounded to the nearest 0.005 in., for specifiedoutside diameters 2 in. 50 mm and larger. The outsidediameter measurements shall be made at po
26、sitions at least 2 in.50 mm from either end of the tubing.10.1.2 Square and Rectangular Structural TubingThespecified dimensions, measured across the flats at a position atleast 2 in. 50 mm from either end of the tubing and includingan allowance for convexity or concavity, shall not exceed theplus a
27、nd minus tolerances shown in Table 3.10.2 Wall ThicknessThe minimum wall thickness at anypoint of measurement on the tubing shall be not more than10 % less than the specified wall thickness. The maximum wallthickness, excluding the weld seam of welded tubing, shall benot more than 10 % greater than
28、the specified wall thickness.TABLE 1 Tensile Requirements for Round and Shaped TubingTensile strength, min, psi MPa 70 000 485Yield strength, min, psi MPa 50 000 345Elongation in 2 in. or 50 mm min, % 19AAApplies to specified wall thicknesses 0.120 in. 3.0 mm and over. For lighterwall thicknesses, e
29、longation shall be by agreement with the manufacturer.TABLE 2 Chemical RequirementsElements Heat Analysis Product AnalysisCarbon, max 0.20 0.24Manganese, max 1.35 1.40Phosphorus, max 0.15ASulphur, max 0.05 0.06Copper, min 0.20B0.18BABecause of the degree to which phosphorus segregates, product analy
30、sis forthis element is not technologically appropriate for rephosphorized steels unlessmisapplication is clearly indicated.BIf chromium and silicon contents are each 0.50 minimum, then the copperminimums do not apply.TABLE 3 Outside Dimension Tolerances for Square andRectangular TubingLargest outsid
31、e dimensionacross flats, in. mmTolerance, 6 in. mmA212 63.5 and under 0.020 0.5Over 212 63.5 to 312 88.9, incl 0.025 0.6Over 312 88.9 to 512 139.7, incl 0.030 0.7Over 512 139.7 1 %ATolerances include allowance for convexity or concavity. For rectangularsections, the tolerance calculated for the larg
32、er flat dimension shall also apply tothe smaller flat dimension. This tolerance may be increased 50 % when applied tothe smaller dimension if the ratio of the external sides is in the range of 1.5 to 3,inclusive; the tolerance may be increased 100 % when the ratio exceeds 3.A 847/A 847M 052The wall
33、thickness on square and rectangular tubing is to bemeasured at the center of the flat.10.3 LengthStructural tubing is normally produced inrandom mill lengths 5 ft 1.5 m and over, in multiple lengths,and in specified mill lengths (see Section 3). When specifiedmill lengths are ordered, the length tol
34、erance shall be inaccordance with Table 4.10.4 StraightnessThe permissible variation for straight-ness of structural tubing shall be18 in. times the number of feet10.4 mm times the number of metres of total length dividedby 5.10.5 Squareness of SidesFor square and rectangular struc-tural tubing, adj
35、acent sides may deviate from 90 by atolerance of 6 2 maximum.10.6 Radius of CornersFor square or rectangular struc-tural tubing, the radius of any outside corner of the sectionshall not exceed three times the specified wall thickness.10.7 TwistThe tolerances for twist, or variation withrespect to ax
36、ial alignment of the section, for square andrectangular structural tubing shall be as shown in Table 5.Twist is measured by holding down on a flat surface plate oneend of a square or rectangular tube, with the bottom side of thetube parallel to the surface plate and either (1) noting thedifference i
37、n height above the surface plate of the two cornersat the opposite end of the bottom side of the tube, or (2)bymeasuring this difference on the heavier sections by a suitablemeasuring device. The difference in the height of the cornersshall not exceed the values of Table 5. Twist measurements arenot
38、 to be taken within 2 in. 50 mm of either end of theproduct.11. Special Shaped Structural Tubing11.1 The dimensions and tolerances of special shaped struc-tural tubing are available by inquiry and negotiation with themanufacturer.12. Flattening Test12.1 The flattening test shall be made on round str
39、ucturaltubing. A flattening test is not required for shaped structuraltubing.12.2 For welded round structural tubing, a specimen at least4 in. 100 mm in length shall be flattened cold betweenparallel plates in three steps, with the weld located at 90 fromthe line of direction of force. During the fi
40、rst step, which is atest for ductility of the weld, no cracks or breaks on the insideor outside surfaces shall occur before the distance between theplates is less than two thirds of the original outside diameter ofthe tubing. As a second step, the flattening shall be continued.During the second step
41、, which is a test for ductility exclusiveof the weld, no cracks or breaks on the inside or outsidesurfaces, except as provided for in 12.4, shall occur before thedistance between the plates is less than one half of the originaloutside diameter of the tubing, but not less than five times thewall thic
42、kness of the tubing. During the third step, which is atest for soundness, continue the flattening until the specimenbreaks or the opposite walls of the tubing meet. Evidence oflaminated or unsound material or of incomplete weld that isrevealed during the entire flattening test shall be cause forreje
43、ction.12.3 For seamless round structural tubing of 238 in. 60.3mm specified outside diameter and larger, a section not lessthan 212 in. 60 mm in length shall be flattened cold betweenparallel plates in two steps. During the first step, which is a testfor ductility, no cracks or breaks on the inside
44、or outsidesurfaces, except as provided for in 12.4, shall occur before thedistance between the plates is less than the value of H,calculated by the following equation:H 5 1 1 e!t/e 1 t/D!where:H = distance between flattening plates, in. mm,e = deformation per unit length, 0.06,t = nominal wall thick
45、ness of tubing, in. mm, andD = actual outside diameter of tubing, in. mm.12.3.1 During the second step, which is a test for soundness,continue the flattening until the specimen breaks or theopposite walls of the tubing meet. Evidence of laminated orunsound material that is revealed during the entire
46、 flatteningtest shall be cause for rejection.12.4 Surface imperfections not found in the test specimenbefore flattening, but revealed during the first step of theflattening test, shall be judged in accordance with Section 14.12.5 When low D-to- t-ratio tubulars are tested, the strainimposed due to g
47、eometry is unreasonably high on the insidesurface at the 6 to 12 oclock locations; therefore, cracks atthese locations shall not be cause for rejection if the D-to-t-ratio is less than 10.13. Test Methods13.1 The tension specimens required by this specificationshall conform to those described in the
48、 latest issue of Methodsand Definitions A 370, Supplementary Requirements II.13.2 The tension test specimens shall be taken longitudi-nally from a section of the finished tubing at a location at least90 from the weld in the case of welded tubing, and shall notbe flattened between gage marks. If desi
49、red, the tension testsmay be made on the full section of the tubing; otherwise, aTABLE 4 Specified Mill LengthTolerances for Structural Tubing22 ft 6.7 m and under Over 22 ft 6.7 mOver Under Over UnderLength tolerancefor specified milllength, in. mm1212.7146.43419.0146.4TABLE 5 Twist Tolerances for Square and RectangularStructural TubingSpecified dimensionof longest side, in. mmMaximum twist in the first 3 ft 1 mand in each additional 3 ftin. mm112 38.1 and underO
