1、Designation: A847/A847M 11Standard Specification forCold-Formed Welded and Seamless High-Strength, Low-Alloy Structural Tubing with Improved AtmosphericCorrosion Resistance1This standard is issued under the fixed designation A847/A847M; the number immediately following the designation indicates the
2、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 () indicates an editorial change since the last revision or reapproval.1. Scope*1.1 This specification covers cold-formed welded and se
3、am-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 atmosph
4、ericcorrosion 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 weld
5、ingprocedure 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. Tubing
6、 having other dimensions may be furnishedprovided such tubing complies with all other requirements ofthis specification.1.3 The values stated in either SI units or inch-pound unitsare to be regarded separately as standard. Within the text, theSI units are shown in brackets. The values stated in each
7、system may not be exact equivalents; therefore, each systemshall be used independently of the other. Combining valuesfrom the two systems may result in non-conformance with thestandard.NOTE 1Products manufactured to this specification may not besuitable for those applications where low temperature n
8、otch toughnessproperties may be important, such as dynamically loaded elements inwelded structures, etc.NOTE 2For methods of estimating the atmospheric corrosion resis-tance of low alloy steels see Guide G101 or actual data.2. Referenced Documents2.1 ASTM Standards:2A370 Test Methods and Definitions
9、 for Mechanical Testingof Steel ProductsA700 Practices for Packaging, Marking, and Loading Meth-ods for Steel Products for ShipmentA751 Test Methods, Practices, and Terminology for Chemi-cal Analysis of Steel ProductsG101 Guide for Estimating the Atmospheric CorrosionResistance of Low-Alloy Steels3.
10、 Ordering Information3.1 Orders for material under 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 m
11、anufacture (welded or seamless),3.1.5 Size (outside 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
12、.9 Certification (see Section 17),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, basic oxygen, or electric furnace.5. Manufacture5.1 The tubing shall be made by a welded or seamlessprocess.1This specificatio
13、n 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 April 1, 2011. Published May 2011. Originallyapproved in 1985. Last previous edition approved
14、 in 2005 as A847/A847M05.DOI: 10.1520/A0847_A0847M-11.2For 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 Sum
15、mary of Changes 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.5.2 Welded tubing shall be made from flat-rolled steel bythe electric-resistance welding or electric-fusion welding pro-cess.
16、The longitudinal butt joint shall be welded across itsthickness 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 reli
17、eved or annealed, as isconsidered necessary by the tubing manufacturer, 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 Secti
18、on 7 to give the mechanicalproperties prescribed in Table 1 and 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 inc
19、lude chromium, nickel,silicon, vanadium, titanium, and zirconium. For SpecificationA847 material, the atmospheric corrosion-resistance index,calculated on the basis of the chemical composition of the steelas described in Guide G101, shall be 6.0 or higher.NOTE 3The user is cautioned that the Guide G
20、101 predictive equationfor calculation of an atmospheric corrosion-resistance index has beenverified 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
21、 be capable of conforming to therequirements given in Table 2 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 corres
22、ponding quantity of flat-rolledstock. Methods and practices relating to chemical analysis shallbe in accordance with Test Methods, Practices, and Terminol-ogy A751. Such product analyses shall conform to the require-ments specified in Table 2 for product analysis.8.3 If both product analyses represe
23、nting a lot fail toconform to the specified requirements, the 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
24、 shall conform to the specifiedrequirements or the lot shall be 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
25、Structural TubingThe outside diametershall not vary from the specified 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 an
26、d larger. The outsidediameter measurements shall be made at positions 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 al
27、lowance for convexity or concavity, shall not exceed theplus and 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 s
28、eam of welded tubing, shall benot more than 10 % greater than the specified wall thickness.The wall 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,a
29、nd in specified mill lengths (see Section 3). When specifiedmill lengths are ordered, the length tolerance 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
30、 total length dividedby 5.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, elon
31、gation 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 0.04 0.04Sulphur, max 0.05 0.06Copper, min 0.20A0.18AAIf chromium and silicon contents are each 0.50 minimum, then the c
32、opperminimums do not apply.TABLE 3 Outside Dimension Tolerances for Square andRectangular TubingLargest outside 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 %ATolerance
33、s include allowance for convexity or concavity. For rectangularsections, the tolerance calculated for the larger 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
34、of 1.5 to 3,inclusive; the tolerance may be increased 100 % when the ratio exceeds 3.A847/A847M 11210.5 Squareness of SidesFor square and rectangular struc-tural tubing, adjacent sides may deviate from 90 by atolerance of 6 2 maximum.10.6 Radius of CornersFor square or rectangular struc-tural tubing
35、, 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 axial alignment of the section, for square andrectangular structural tubing shall be as shown in Table 5.Twist is measured by hol
36、ding 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 in height above the surface plate of the two cornersat the opposite end of the bottom side of the tube, or (2)bymeasuring this d
37、ifference 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 to be taken within 2 in. 50 mm of either end of theproduct.11. Special Shaped Structural Tubing11.1 The dimensions and toleran
38、ces 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 structuraltubing. A flattening test is not required for shaped structuraltubing.12.2 For welded round structural tubing, a specime
39、n 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 first step, which is atest for ductility of the weld, no cracks or breaks on the insideor outside surfaces shall occur before the
40、 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, which is a test for ductility exclusiveof the weld, no cracks or breaks on the inside or outsidesurfaces, except as provided
41、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 thickness of the tubing. During the third step, which is atest for soundness, continue the flattening until the specimenbreaks or t
42、he 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 forrejection.12.3 For seamless round structural tubing of 238 in. 60.3mm specified outside diameter and larger, a section not lessthan
43、 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 or outsidesurfaces, except as provided for in 12.4, shall occur before thedistance between the plates is less than the value of
44、 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 thickness of tubing, in. mm, andD = actual outside diameter of tubing, in. mm.12.3.1 During the second step, which is a test for sou
45、ndness,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 flatteningtest shall be cause for rejection.12.4 Surface imperfections not found in the test specimenbefore flattening, but re
46、vealed 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 geometry is unreasonably high on the insidesurface at the 6 to 12 oclock locations; therefore, cracks atthese locations shall no
47、t 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 latest issue of Methodsand Definitions A370, Annex A2.13.2 The tension test specimens shall be taken longitudi-nally from a se
48、ction 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 desired, the tension testsmay be made on the full section of the tubing; otherwise, alongitudinal strip-test specimen as prescribed in Test Methodsand De
49、finitions A370, Annex A2, shall be used. The specimensshall have all burrs removed and shall not contain surfaceimperfections which would interfere with proper determinationof the tensile properties of the metal.13.3 The yield strength corresponding to a permanent offsetof 0.2 % of the gage length of the specimen, or to a totalextension of 0.5 % of the gage length under load, shall bedetermined.TABLE 4 Specified Mill LengthTolerances for Structural Tubing22 ft 6.7 m and under Over 22 ft
