1、Designation: B957/B957M 081B957/B957M 16Standard Specification forExtra-High-Strength and Ultra-High-Strength Zinc-Coated(Galvanized) Steel Core Wire for Overhead ElectricalConductors1This standard is issued under the fixed designation B957/B957M; the number immediately following the designation ind
2、icates 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 NOTEDesignation was corrected editorially in Octobe
3、r 2013.1. Scope1.1 This specification covers round, extra-high-strength and ultra-high-strength, Class A zinc-coated (galvanized), steel corewire used for use in Overhead Electrical Conductors.1.2 This specification covers wire of diameter from 0.0500 to 0.1900 in. inclusive or 1.27 to 4.82 mm inclu
4、sive.1.3 The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in eachsystem may not be exact equivalents; therefore, each system shall be used independently of the other. Combining values from thetwo systems may result in non-conforman
5、ce with the standard.1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibilityof the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatorylimitations prior to
6、use.2. Referenced Documents2.1 ASTM Standards:2A90/A90M Test Method for Weight Mass of Coating on Iron and Steel Articles with Zinc or Zinc-Alloy CoatingsA370 Test Methods and Definitions for Mechanical Testing of Steel ProductsA751 Test Methods, Practices, and Terminology for Chemical Analysis of S
7、teel ProductsB6 Specification for ZincB193 Test Method for Resistivity of Electrical Conductor MaterialsE29 Practice for Using Significant Digits in Test Data to Determine Conformance with Specifications3. Terminology3.1 Definitions of Terms Specific to This Standard:3.1.1 Lot, nUnless otherwise spe
8、cified in the contract or order, a lot shall consist of all coils of wire of the same diameter andunit lengths submitted for inspection at the same time.3.1.2 Product Code, nDefines product coating type, coating class and strength grade. Extra High Strength Grade Zinc, Class A Coated, use Code GA4.
9、Ultra High Strength Grade Zinc, Class A Coated, use Code GA5.3.1.2.1 Extra High Strength Grade Zinc, Class A Coateduse Code GA4.3.1.2.2 Ultra High Strength Grade Zinc, Class A Coateduse Code GA5.4. Ordering Information4.1 Orders for material under this specification shall include the following infor
10、mation:4.1.1 Quantity of each size,1 This test method specification is under the jurisdiction of ASTM Committee B01 on Electrical Conductors and is the direct responsibility of Subcommittee B01.05 onConductors of Ferrous Metals.Current edition approved Nov. 1, 2008Dec. 1, 2016. Published December 20
11、08December 2016. Originally approved in 2008. Last previous edition approved in 2008 asB957 081. DOI: 10.1520/B0957_B0957M-08E01.10.1520/B0957_B0957M-16.2 For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at serviceastm.org. For Annual Book of ASTM St
12、andardsvolume information, 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 possib
13、le to adequately depict all 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.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West
14、 Conshohocken, PA 19428-2959. United States14.1.2 Wire diameter in inches or millimeter (Section 13),4.1.3 Certification, if required (Section 18),4.1.4 Test report, if required (Section 18), and4.1.5 Package size (Section 19).4.1.6 Strength GradeGrade.5. Materials and Manufacture5.1 The base metal
15、shall be steel produced by the open-hearth, electric-furnace, or basic-oxygen process.5.2 The wire shall be cold drawn and coated with zinc to produce the desired properties.5.3 The slab zinc used for coating shall be high grade or better, conforming to Specification B6.6. Chemical Composition6.1 Th
16、e steel shall conform to the requirements prescribed in Table 1.6.2 Chemical analysis shall be conducted in accordance with Test Methods, Practices, and Terminology A751.7. Tensile Test7.1 The zinc-coated steel core wire shall conform to the tensile and elongation requirements prescribed in Table 2,
17、 Table 3,Table 4, or Table 5 depending on the strength grade and unit base ordered.7.2 Tensile tests shall be conducted in accordance with Test Methods and Definitions A370, using the initial settings fordetermining stress at 1 % extension given in Table 6 or Table 7 of this specification.7.3 Test S
18、pecimensThe test specimens shall be free of bends or kinks other than the curvature resulting from the usual coilingoperations. Any hand straightening necessary to permit insertion of the specimen in the jaws of the testing machine shall beperformed by drawing between wood blocks or by some other eq
19、ually satisfactory means.7.4 The nominal diameter requested shall be used to determine the applicable strength specification.8. Wrap Test8.1 The material, as represented by the test specimens, shall not fracture when the galvanized wire is wrapped at a rate notexceeding 15 turns/min in a close helix
20、 of at least eight turns around a cylindrical mandrel with a diameter equal to four times thespecified diameter of the wire under test, 6 5 %.9. Coating Test9.1 The zinc-coated wire shall conform to the coating requirements prescribed in Table 8 or Table 9.9.2 The coating test shall be conducted in
21、accordance with Test Method A90/A90M.10. Adherence of Coating Test10.1 The zinc-coated wire shall be capable of being wrapped in a close helix at a rate not exceeding 15 turns/min around acylindrical mandrel having a diameter as prescribed in Table 10 or Table 11, without cracking or flaking the zin
22、c coating to suchan extent that any zinc can be removed by rubbing with the bare fingers.11. Joints11.1 No joints shall be made in the finished wire.11.2 Joints may be made at any stage of processing prior to final cold drawing, by the electric butt-weld or flash-weldingprocess.11.3 Welding equipmen
23、t and procedure shall be such that it can be demonstrated that the ultimate tensile strength of a finishedwire specimen containing the welded section shall be not less than 96 % of the specified minimum stress at 1 % extension.TABLE 1 Chemical RequirementsElement Composition, %Carbon 0.50 to 1.00Man
24、ganese 0.40 to 1.30Manganese 0.30 to 1.30Phosphorus, max 0.035Sulfur, max 0.045Silicon 0.15 to 0.60Silicon 0.15 to 1.20B957/B957M 16211.4 A welded section shall not be required to meet the stress at 1 % extension, and wrap tests.12. Density and Resistivity12.1 For the purpose of calculating mass per
25、 unit length, cross sections, and so forth, the density of galvanized steel wire at 20Cshall be taken as 0.281 lb/in.3 7780 kg/m3.12.2 A maximum resistivity of galvanized steel wire is not guaranteed, but a typical value of 0.19157 mm2/m may be usedfor calculating purposes. For conversion to other u
26、nits of conductivity or resistivity, refer to Test Method B193.13. Dimensions and Permissible Variations13.1 The specified diameter of the zinc-coated wire from Section 4 shall be expressed in decimal fractions of an inch to fourdecimal places, or in millimeters to two decimal places.TABLE 2 Grade 4
27、 Extra-High-Strength Tensile RequirementsSpecifiedDiameter, in.Stress at 1%Extension,min, kpsiUltimate TensileStrength,min, kpsiElongationin 10 in.,min %0.0500 to 0.0899, incl 225 265 3.00.0900 to 0.1199, incl 220 260 3.00.1200 to 0.1399, incl 215 255 3.50.1400 to 0.1900, incl 210 250 3.5TABLE 3 Gra
28、de 4 Extra-High-Strength Tensile RequirementsMetricSpecifiedDiameter,mmStress at1% Extension,min, MPaUltimate TensileStrength,min, MPaElongationin 250 mm,min %1.27 to 2.28, incl 1550 1825 3.02.29 to 3.04, incl 1515 1790 3.03.05 to 3.55, incl 1480 1760 3.53.56 to 4.82, incl 1450 1725 3.5TABLE 4 Grade
29、 5 Ultra-High-Strength Tensile RequirementsSpecifiedDiameter,in.Stress at1% Extension,min, kpsiUltimateTensileStrength,min, kpsiElongationin 10 in.min %0.0500 to 0.0899, incl 230 285 3.00.0900 to 0.1199, incl 225 275 3.00.1200 to 0.1399, incl 220 270 3.50.1400 to 0.1900, incl 215 265 3.5TABLE 5 Grad
30、e 5 Ultra-High-Strength Tensile RequirementsMetricSpecifiedDiameter,mmStressat 1%Extension,min, MPaUltimateTensile Strength,min, MPaElongationin 250 mm,min %1.27 to 2.28, incl 1580 1965 3.02.29 to 3.04, incl 1550 1900 3.03.05 to 3.55, incl 1515 1860 3.53.56 to 4.82, incl 1480 1825 3.5TABLE 6 Initial
31、 Settings for Determining Stress at 1% ExtensionSpecifiedDiameter,in.Initial Stress,kpsiInitial Settingof Extensometer,in./in.0.0500 to 0.0899, incl 18 0.0005 (0.05 % extension)0.0900 to 0.1199, incl 36 0.0010 (0.10 % extension)0.1200 to 0.1900, incl 54 0.0015 (0.15 % extension)B957/B957M 16313.2 To
32、 determine the applicable tolerance range from Table 12 or Table 13, round the specified diameter to the nearest 0.001in. 0.01 mm, in accordance with the rounding method of Practice E29.13.3 Measure the largest and smallest diameter taken at the same cross section rounded to the nearest 0.001 in. 0.
33、01 mm inaccordance with the rounding method of Practice E29. Calculate the average of the two measurements. The calculated value shallnot differ from the specified diameter by more than the applicable tolerance range shown in Table 12 or Table 13.TABLE 7 Initial Settings for Determining Stress at 1%
34、 ExtensionMetricSpecifiedDiameter,mmInitial Stress,MPaInitial Settingof Extensometer,mm/mm1.27 to 2.28, incl 124 0.0005 (0.05 % extension)2.29 to 3.04, incl 248 0.0010 (0.10 % extension)3.05 to 4.82, incl 372 0.0015 (0.15 % extension)TABLE 8 Zinc CoatingSpecified Diameterof Coated Wire,in.Area Densi
35、tyof Zinc Coating, min of UncoatedWire Surface,oz/ft20.0500 to 0.0599, incl 0.600.0600 to 0.0749, incl 0.650.0750 to 0.0899, incl 0.700.0900 to 0.1039, incl 0.750.1040 to 0.1199, incl 0.800.1200 to 0.1399, incl 0.850.1400 to 0.1799, incl 0.900.1800 to 0.1900, incl 1.00TABLE 9 Zinc Coating MetricSpec
36、ified Diameterof Coated Wire,mmArea Densityof Zinc Coating, min ofUncoated Wire Surface,g/m21.27 to 1.52, incl 1831.53 to 1.90, incl 1981.91 to 2.28, incl 2142.29 to 2.64, incl 2292.65 to 3.04, incl 2443.05 to 3.55, incl 2593.56 to 4.57, incl 2744.58 to 4.82, incl 305TABLE 10 Mandrel Size for Adhere
37、nce TestNOTE 1Loosening or detachment during the adhesion test ofsuperficial, small particles of zinc formed by mechanical polishing of thesurface of the zinc-coated wire shall not be considered cause for rejection.Specified WireDiameter,in.Ratio of Mandrel Diameterto Wire Diameter0.0500 to 0.1399,
38、incl 40.1400 to 0.1900, incl 5TABLE 11 Mandrel Size for Adherence Test MetricNOTE 1Loosening or detachment during the adhesion test ofsuperficial, small particles of zinc formed by mechanical polishing of thesurface of the zinc-coated wire shall not be considered cause for rejection.SpecifiedWire Di
39、ameter,mmRatio of Mandrel Diameterto Wire Diameter1.27 to 3.55, incl 43.56 to 4.82, incl 5B957/B957M 16414. Workmanship, Finish, and Appearance14.1 The zinc coating shall be reasonably smooth, continuous, of reasonably uniform thickness, and free of imperfections notconsistent with good commercial p
40、ractice.15. Number of Tests and Retests15.1 One test specimen shall be taken from each 5000 lb 2500 kg or fraction thereof in the inspection lot.15.2 Each specimen shall be tested for compliance with Sections 7, 8, 10, and 13. At least half of the specimens shall be testedfor compliance with Section
41、 9.15.3 Should one or more of the test specimens fail any of the tests specified, the nonconforming coil or coils may be removedand the balance of the lot subjected to retests. For retest purposes, two additional coils for each 5000 lbs 2500 kg in the lot shallbe sampled and tested for the property
42、in which the original sample failed to comply.15.4 Should any of the retest specimens fail to meet the properties specified, the lot represented by the test specimens shall berejected.15.5 Instead of rejecting the entire lot as provided in Paragraph 15.4, the producer may test specimens from every c
43、oil in thelot for the property in which failure occurred and reject only the nonconforming coils.16. Inspection16.1 Unless otherwise specified in the contract or purchase order, the manufacturer shall be responsible for the performance ofall inspection and test requirements specified.16.2 All inspec
44、tions and tests shall be made at the place of manufacture unless otherwise especially agreed upon between themanufacturer and the purchaser at the time of the purchase.16.3 The manufacturer shall afford the inspector representing the purchaser all reasonable manufacturers facilities to satisfyhim th
45、at the material is being furnished in accordance with this specification.TABLE 12 Permissible Variations in Diameter of Zinc-CoatedSteel WireNOTE 1It is recognized that the surface of zinc coatings, particularlythose produced by the hot-dip method of coating, are not perfectly smoothand devoid of ir
46、regularities. If the tolerances shown in the table are rigidlyapplied to such irregularities that are inherent to the product, unjustifiedrejections of wire that would actually be satisfactory for use could occur.It is intended that these tolerances be used in gaging the wires where thereis a minimu
47、m of such diameter irregularities due to galvanizing.Specified Diameter,in.Permissible Variation, in.Plus Minus0.0500 to 0.0749, incl 0.0015 0.0010.0750 to 0.1199, incl 0.002 0.0020.1200 to 0.1399, incl 0.003 0.0020.1400 to 0.1900, incl 0.004 0.003TABLE 13 Permissible Variations in Diameter of Zinc-
48、CoatedSteel Wire MetricNOTE 1It is recognized that the surface of zinc coatings, particularlythose produced by the hot-dip method of coating, are not perfectly smoothand devoid of irregularities. If the tolerances shown in the table are rigidlyapplied to such irregularities that are inherent to the
49、product, unjustifiedrejections of wire that would actually be satisfactory for use could occur.It is intended that these tolerances be used in gaging the wires where thereis a minimum of such diameter irregularities due to galvanizing.Specified Diameter,mmPermissible Variation, mmPlus Minus1.27 to 2.28, incl 0.038 0.0252.29 to 3.04, incl 0.051 0.0513.05 to 3.55, incl 0.076 0.0513.56 to 4.82, incl 0.102 0.076B957/B957M 16517. Rejection and Rehearing17.1 Material that fails to conform to the requirements of this specification shall be
