1、Designation: A847/A847M 11 A847/A847M 12Standard 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
2、indicates 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 () indicates an editorial change since the last revision or reapproval.1. Scope*1.1 This specification covers cold-formed
3、 welded and seamless high-strength, low-alloy round, square, rectangular, or specialshaped structural tubing for welded, riveted, or bolted construction of bridges and buildings and for general structural purposeswhere high strength and enhanced atmospheric corrosion resistance are required (Note 1)
4、. The atmospheric corrosion resistanceof this steel in most environments is substantially better than carbon steel with or without copper addition (Note 2). When properlyexposed to the atmosphere, this steel can be used bare (unpainted) for many applications. When this steel is used in weldedconstru
5、ction, the welding procedure shall be suitable for the steel and the intended service.1.2 This tubing is produced in welded sizes with a maximum periphery of 64 in. 1626 mm and a maximum wall of 0.625 in.15.9 mm, and in seamless with a maximum periphery of 32 in. 813 mm and a maximum wall of 0.500 i
6、n. 12.7 mm. Tubinghaving other dimensions may be furnished provided such tubing complies with all other requirements of this specification.1.3 The values stated in either SI units or inch-pound units are to be regarded separately as standard. Within the text, the SI unitsare shown in brackets. The v
7、alues stated in each system may not be exact equivalents; therefore, each system shall be usedindependently of the other. Combining values from the two systems may result in non-conformance with the standard.NOTE 1Products manufactured to this specification may not be suitable for those applications
8、 where low temperature notch toughness properties maybe important, such as dynamically loaded elements in welded structures, etc.NOTE 2For methods of estimating the atmospheric corrosion resistance of low alloy steels see Guide G101 or actual data.2. Referenced Documents2.1 ASTM Standards:2A370 Test
9、 Methods and Definitions for Mechanical Testing of Steel ProductsA700 Practices for Packaging, Marking, and Loading Methods for Steel Products for ShipmentA751 Test Methods, Practices, and Terminology for Chemical Analysis of Steel ProductsG101 Guide for Estimating the Atmospheric Corrosion Resistan
10、ce of Low-Alloy Steels3. Ordering Information3.1 Orders for material under this specification should include the following, as required, to describe the desired materialadequately:3.1.1 ASTM specification number,3.1.2 Quantity (feet, metres, or number of lengths),3.1.3 Name of material (cold-formed
11、tubing),3.1.4 Method of manufacture (welded or seamless),3.1.5 Size (outside diameter and nominal wall thickness for round tubing and the outside dimensions and nominal wall thicknessfor square and rectangular tubing),3.1.6 Length (specific or random, see 10.3),3.1.7 End condition (see 14.2),1 This
12、specification is under the jurisdiction of ASTM Committee A01 on Steel, Stainless Steel and Related Alloys and is the direct responsibility of Subcommittee A01.09on Carbon Steel Tubular Products.Current edition approved April 1, 2011Nov. 1, 2012. Published May 2011November 2012. Originally approved
13、in 1985. Last previous edition approved in 20052011 asA847/A847M05.11. DOI: 10.1520/A0847_A0847M-11.10.1520/A0847_A0847M-12.2 For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standardsvolume information,
14、 refer to the standards Document Summary page on the ASTM website.This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Becauseit may not be technically possible to adequately depict al
15、l changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current versionof the standard as published by ASTM is to be considered the official document.*A Summary of Changes section appears at the end of this standardCopyright ASTM International, 1
16、00 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States13.1.8 Burr removal (see 14.2),3.1.9 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 moreboth of the following processes: open hearth, basic
17、 oxygen,oxygen or electricfurnace.5. Manufacture5.1 The tubing shall be made by a welded or seamless process.5.2 Welded tubing shall be made from flat-rolled steel by the electric-resistance welding or electric-fusion welding process. Thelongitudinal butt joint shall be welded across its thickness i
18、n such a manner that the structural design strength of the tubing sectionis assured.5.2.1 Structural tubing welded by the electric-resistance method is normally furnished without removal of inside flash.5.3 The tubing may be stress relieved or annealed, as is considered necessary by the tubing manuf
19、acturer, to conform to therequirements of this specification.6. Chemical Composition6.1 The choice and use of alloying elements combined with carbon, manganese, phosphorus, sulphur, and copper shall be withinthe limits prescribed in Section 7 to give the mechanical properties prescribed in Table 1 a
20、nd to provide the atmospheric corrosionresistance of 1.1. The choice and use of these elements shall be made by the manufacturer and included and reported in the heatanalysis to identify the type of steel applied. Elements commonly added include chromium, nickel, silicon, vanadium, titanium,and zirc
21、onium. For Specification A847 material, the atmospheric corrosion-resistance index, calculated on the basis of thechemical composition of the steel as described in Guide G101, shall be 6.0 or higher.NOTE 3The user is cautioned that the Guide G101 predictive equation for calculation of an atmospheric
22、 corrosion-resistance index has been verifiedonly for the composition limits stated in that guide.7. Heat Analysis7.1 Each heat analysis shall conform to the requirements given in Table 2 for heat analysis.8. Product Analysis8.1 The tubing shall be capable of conforming to the requirements given in
23、Table 2 for product analysis.8.2 If product analyses are made, they shall be made using test specimens taken from two lengths of tubing from each lot of500 lengths, or a fraction thereof, or two pieces of flat-rolled stock from each lot of a corresponding quantity of flat-rolled stock.Methods and pr
24、actices relating to chemical analysis shall be in accordance with Test Methods, Practices, and Terminology A751.Such product analyses shall conform to the requirements specified in Table 2 for product analysis.8.3 If both product analyses representing a lot fail to conform to the specified requireme
25、nts, the lot shall be rejected.8.4 If only one product analysis representing a lot fails to conform to the specified requirements, product analyses shall be madeusing two additional test specimens taken from the lot. Both additional product analyses shall conform to the specifiedrequirements or the
26、lot shall be rejected.9. Tensile Requirements9.1 The material, as represented by the test specimen, shall conform to the tensile property requirements prescribed in Table 1.10. Permissible Variations and Dimensions10.1 Outside Dimensions:TABLE 1 Tensile Requirements for Round and Shaped TubingTensil
27、e strength, min, psi MPa 70 000 485Yield strength, min, psi MPa 50 000 345Elongation in 2 in. or 50 mm min, % 19AA Applies to specified wall thicknesses 0.120 in. 3.0 mm and over. For lighter wallthicknesses, elongation shall be by agreement with the manufacturer.A847/A847M 12210.1.1 Round Structura
28、l TubingThe outside diameter shall not vary from the specified outside diameter by more than 6 0.5%, rounded to the nearest 0.005 in. 0.1 mm, for specified outside diameters 1.900 in. 48.3 mm and smaller; 6 0.75 %, roundedto the nearest 0.005 in., for specified outside diameters 2 in. 50 mm and larg
29、er. The outside diameter measurements shall be madeat positions at least 2 in. 50 mm from either end of the tubing.10.1.2 Square and Rectangular Structural TubingThe specified dimensions, measured across the flats at a position at least 2in. 50 mm from either end of the tubing and including an allow
30、ance for convexity or concavity, shall not exceed the plus andminus tolerances shown in Table 3.10.2 Wall ThicknessThe minimum wall thickness at any point of measurement on the tubing shall be not more than10 % less than the specified wall thickness. The maximum wall thickness, excluding the weld se
31、am of welded tubing, shall be notmore than 10 % greater than the specified wall thickness. The wall thickness on square and rectangular tubing is to be measuredat the center of the flat.10.3 LengthStructural tubing is normally produced in random mill lengths 5 ft 1.5 m and over, in multiple lengths,
32、 and inspecified mill lengths (see Section 3). When specified mill lengths are ordered, the length tolerance shall be in accordance withTable 4.10.4 StraightnessThe permissible variation for straightness of structural tubing shall be 18 in. times the number of feet 10.4mm times the number of metres
33、of total length divided by 5.10.5 Squareness of SidesFor square and rectangular structural tubing, adjacent sides may deviate from 90 by a tolerance of6 2 maximum.10.6 Radius of CornersFor square or rectangular structural tubing, the radius of any outside corner of the section shall notexceed three
34、times the specified wall thickness.10.7 TwistThe tolerances for twist, or variation with respect to axial alignment of the section, for square and rectangularstructural tubing shall be as shown in Table 5. Twist is measured by holding down on a flat surface plate one end of a square orrectangular tu
35、be, with the bottom side of the tube parallel to the surface plate and either ( 1) noting the difference in height abovethe surface plate of the two corners at the opposite end of the bottom side of the tube, or (2) by measuring this difference on theheavier sections by a suitable measuring device.
36、The difference in the height of the corners shall not exceed the values of Table5. Twist measurements are not to be taken within 2 in. 50 mm of either end of the product.11. Special Shaped Structural Tubing11.1 The dimensions and tolerances of special shaped structural tubing are available by inquir
37、y and negotiation with themanufacturer.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 0.06Sulphur, max 0.035 0.045Copper, min 0.20A 0.18AA If chromium and silicon contents are each 0.50 minim
38、um, then the copperminimums do not apply.TABLE 3 Outside Dimension Tolerances for Square andRectangular TubingLargest outside dimensionacross flats, in. mm Tolerance, 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
39、1 %A Tolerances 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
40、 in the range of 1.5 to 3,inclusive; the tolerance may be increased 100 % when the ratio exceeds 3.A847/A847M 12312. Flattening Test12.1 The flattening test shall be made on round structural tubing. A flattening test is not required for shaped structural tubing.12.2 For welded round structural tubin
41、g, a specimen at least 4 in. 100 mm in length shall be flattened cold between parallelplates in three steps, with the weld located at 90 from the line of direction of force. During the first step, which is a test for ductilityof the weld, no cracks or breaks on the inside or outside surfaces shall o
42、ccur before the distance between the plates is less thantwo thirds of the original outside diameter of the tubing. As a second step, the flattening shall be continued. During the second step,which is a test for ductility exclusive of the weld, no cracks or breaks on the inside or outside surfaces, e
43、xcept as provided for in12.4, shall occur before the distance between the plates is less than one half of the original outside diameter of the tubing, but notless than five times the wall thickness of the tubing. During the third step, which is a test for soundness, continue the flatteninguntil the
44、specimen breaks or the opposite walls of the tubing meet. Evidence of laminated or unsound material or of incompleteweld that is revealed during the entire flattening test shall be cause for rejection.12.3 For seamless round structural tubing of 238 in. 60.3 mm specified outside diameter and larger,
45、 a section not less than212 in. 60 mm in length shall be flattened cold between parallel plates in two steps. During the first step, which is a test forductility, no cracks or breaks on the inside or outside surfaces, except as provided for in 12.4, shall occur before the distancebetween the plates
46、is less than the value of H, calculated by the following equation:H 511e!t/e1t/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, wh
47、ich is a test for soundness, continue the flattening until the specimen breaks or the oppositewalls of the tubing meet. Evidence of laminated or unsound material that is revealed during the entire flattening test shall be causefor rejection.12.4 Surface imperfections not found in the test specimen b
48、efore flattening, but revealed during the first step of the flatteningtest, shall be judged in accordance with Section 14.12.5 When low D-to- t-ratio tubulars are tested, the strain imposed due to geometry is unreasonably high on the inside surfaceat the 6 to 12 oclock locations; therefore, cracks a
49、t these locations shall not be cause for rejection if the D-to-t-ratio is less than10.13. Test Methods13.1 The tension specimens required by this specification shall conform to those described in the latest issue of Methods andDefinitions A370, Annex A2.TABLE 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
