1、Designation: B476 01 (Reapproved 2017)Standard Specification forGeneral Requirements for Wrought Precious Metal ElectricalContact Materials1This standard is issued under the fixed designation B476; the number immediately following the designation indicates the year oforiginal adoption or, in the cas
2、e of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.This standard has been approved for use by agencies of the U.S. Department of Defense.1. Scope1.1 This
3、specification covers general requirements commonto wrought precious metal electrical contact alloy products inthe form of sheet, strip, wire, and rod. Unless otherwisespecified in the purchase order or in an individual specification,these general requirements shall apply to wrought electricalcontact
4、 materials where indicated in the applicable productspecifications issued by ASTM.1.2 In case of conflict, the requirements on the purchaseorder, the individual specification, and this general specifica-tion shall prevail in the sequence named.1.3 The values stated in inch-pound units are to be rega
5、rdedas standard. The values given in parentheses are mathematicalconversions to SI units that are provided for information onlyand are not considered standard.1.4 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user
6、 of this standard to become familiarwith all hazards including those identified in the appropriateSafety Data Sheet (SDS) for this product/material as providedby the manufacturer, to establish appropriate safety and healthpractices, and determine the applicability of regulatory limi-tations prior to
7、 use.1.5 This international standard was developed in accor-dance with internationally recognized principles on standard-ization established in the Decision on Principles for theDevelopment of International Standards, Guides and Recom-mendations issued by the World Trade Organization TechnicalBarrie
8、rs to Trade (TBT) Committee.2. Referenced Documents2.1 The following documents of the issue in effect, on thedate of material purchase, form a part of this specification tothe extent referenced herein:2.2 ASTM Standards:2B63 Test Method for Resistivity of Metallically ConductingResistance and Contac
9、t MaterialsB772 Guide for Specifying the Chemical Compositions forElectrical Contact Materials (Arcing and Nonarcing)E3 Guide for Preparation of Metallographic SpecimensE8 Test Methods for Tension Testing of Metallic MaterialsE29 Practice for Using Significant Digits in Test Data toDetermine Conform
10、ance with SpecificationsE55 Practice for Sampling Wrought Nonferrous Metals andAlloys for Determination of Chemical CompositionE112 Test Methods for Determining Average Grain SizeE384 Test Method for Microindentation Hardness of Mate-rials3. Terminology3.1 Definitions:3.1.1 lot, nthe quantity of mat
11、erial of the same type, size,and finish produced at one time from the same cast or heat, andheat treated in the same heat-treatment cycle.4. Ordering Information4.1 Orders for material to this specification shall include thefollowing information:4.1.1 Designation and revision date of this specificat
12、ion.4.1.1.1 If a revision date is not designated, the latest revisionshould be used.4.1.2 Designation and revision date of the applicable prod-uct specification.4.1.2.1 If a revision date is not designated, the latest revisionof the product specification should be used.4.1.3 Description of material
13、form,4.1.4 Dimensions of the material,4.1.5 Total quantity of each size,4.1.6 Temper of the material (annealed, cold worked, etc.),4.1.7 Temper test (hardness or tensile) (Section 10),1This specification is under the jurisdiction of ASTM Committee B02 onNonferrous Metals and Alloys and is the direct
14、 responsibility of SubcommitteeB02.05 on Precious Metals and Electrical Contact Materials.Current edition approved April 1, 2017. Published April 2017. Originallyapproved in 1968. Last previous edition approved in 2012 as B476 01 (2012).DOI: 10.1520/B0476-01R17.2For referenced ASTM standards, visit
15、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.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959.
16、 United StatesThis international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for theDevelopment of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Bar
17、riers to Trade (TBT) Committee.14.1.8 Special requirements (if any), and4.1.9 Certification (Section 14).4.2 Specify the following, if required:4.2.1 Certificate of compliance of physical and chemicalrequirement.4.2.2 Test DataSpecify tests and analyses to be performedand reported.4.2.3 Special pack
18、aging, if required.5. Materials and Manufacture5.1 The raw material shall be of such quality and purity thatthe finished product shall have the properties and characteris-tics prescribed in the applicable product specification issued byASTM.5.2 The product shall be produced by a combination of hotor
19、 cold working operations. it shall be finished, unless other-wise specified, by such cold working, annealing, or heattreatment as may be necessary to meet the specified properties.6. Dimensions and Permissible Variations6.1 GeneralFor the purpose of determining conformancewith the dimensional requir
20、ements prescribed in thisspecification, any measured value outside the specified limitingvalues for any dimension may be cause for rejection.6.2 Tolerance tables to cover all forms of products canbecome quite voluminous. For this reason, it is recommendedthat tolerances be established and agreed upo
21、n between theproducer and user at the time of placing an order or an inquiryfor quotation of price and delivery. Refer to Section 16(Supplementary Requirements). Details of form and tolerancesfor products not covered by this specification, such as, thetypes of materials listed below, and means of me
22、asurement,should be established between producer and user.6.2.1 Sawed products,6.2.2 Square sheared products,6.2.3 Flat wire, thickness, width and edge radius tolerances,6.2.4 Edge rolled flat wire, thickness, width and cornerradius tolerances.6.3 Wire and Rod:6.3.1 The standard tolerances applied t
23、o the diameter ofwire and rod shall be as prescribed in Table 1.6.3.2 The rod straightness and length tolerance shall bethose prescribed in Table 2.6.4 Strip and SheetSupplied in the form of coils, flatlengths or on spools.6.4.1 The thickness tolerances shall be those prescribed inTable 3.6.4.2 The
24、width standard tolerance for slit products shall bethose prescribed in Table 4.6.4.3 The straightness (camber or edgewise curvature) tol-erance for slit strip is prescribed in Table 4 also.6.5 FlatnessThe flatness of blanks, shims, circles, or otherforms should be negotiated between the manufacturer
25、 and thepurchaser. The following suggestion is to be used for guidanceonly when the manufacturer and the purchaser discuss flatnessrequirements. It is not a requirement of this specification,unless agreed upon and made part of the purchase order orrequest for quotation. The flatness of a flat form s
26、hall be thatthe maximum deviation from the flat surface shall be less than1 % of the measurement distance specified for the product,such as diameter for circles, length or width of blanks, or anyspecific measurement length; that is, maximum of 0.20 in.(5.08 mm) deviation in any 20 in. (508 mm) lengt
27、h in anydirection.7. Workmanship7.1 Surfaces of all material furnished to this specificationshall be smooth, clean, and free from scratches, stains, roughspots, slivers, laps, scale, pits, and any other injurious defectswithin limits consistent with the best possible practice.8. Sampling8.1 Sampling
28、The portion size and selection of pieces shallbe as follows:8.1.1 Chemical AnalysisSamples for chemical analysisshall be taken and prepared in accordance with Practice E55.The minimum weight of the composite sample that is to bedivided into three equal parts shall be 6 g.8.1.2 Physical TestsFor phys
29、ical tests, a test specimenshall be taken from each of four randomly selected individualunits of finished product from a lot. If the lot consists of lessthan four units, a piece shall be taken from each individual unit.9. Number of Tests and Retests9.1 If any specimen tested shows a defective test m
30、ethod orextraneous flaws, it may be discarded and another specimensubstituted.9.2 If the chemical analysis fails to conform to the specifiedlimits, analysis shall be made on a new composite sample,prepared from samples selected in accordance with PracticeE55 or 8.1.2 after the physical tests have be
31、en performed. Theresults of this retest shall comply with the specified require-ments.9.3 The required physical tests shall be performed on 2 of 4of the pieces selected in accordance with 8.1.2.9.3.1 If one of the two tests made to determine any of thephysical properties fails to meet a specified li
32、mit, this test shallbe repeated on each of the two remaining pieces selected inaccordance with 8.1.2 and the results of both of these tests shallcomply with the specified requirements.9.4 In the case of micro hardness, the number of readingsshall not be less than 5 on each test specimen.TABLE 1 Roun
33、d Wire and Rod Diameter ToleranceDiameter, in. (mm) Tolerance, , in. (mm)Up to 0.010 (0.25), incl 0.0001 (0.002)Over 0.010 to 0.020 (0.25 to 0.51), incl 0.0002 (0.005)Over 0.020 to 0.030 (0.51 to 0.76), incl 0.0003 (0.008)Over 0.030 to 0.040 (0.76 to 1.02), incl 0.0004 (0.010)Over 0.040 to 0.187 (1.
34、02 to 4.75), incl 0.0005 (0.013)Over 0.187 to 0.250 (4.75 to 6.35), incl 0.001 (0.03)Over 0.250 to 0.375 (6.35 to 9.52), incl 0.0015 (0.04)Over 0.375 to 0.750 (9.52 to 19.0), incl 0.002 (0.05)B476 01 (2017)210. Test Methods10.1 The properties enumerated in the applicable productspecification shall b
35、e determined in accordance with thefollowing: Test Methods B63 and E384, Methods E3, E8, andE112, and Practice E55.10.2 The contract or order may specify ultimate tensilestrength, elongation, microhardness (Knoop or Vickers), hard-ness (Rockwell or Rockwell Superficial), or a combination ofthese mec
36、hanical properties as temper criterion. If the contractor order does not specify a temper criterion, then the criterionfor temper designation will be ultimate tensile strength andelongation.11. Significance of Numerical Limits11.1 For purpose of determining compliance with the speci-fied limits for
37、requirements of the properties listed in thefollowing table, an observed value or a calculated value shallbe rounded as indicated in accordance with Practice E29.Property UnitRounded Unitfor Observed orCalculated ValueChemical composition percentHardnessKnoop (100-g load unless other-wise specified)
38、Vicker (specify load)Rockwell (all scales, specify which)Rockwell superficial (all scales,specify which)nearest unit on the last righthand place of figure ofspecified limitResistivity cmTensile strength psi (MPa) nearest 1000 psi (nearest 10MPa)Yield Strength psi (MPa) nearest 1000 psi (nearest10 MP
39、a)ElongationBelow 5 % percent nearest multiple of 0.5 %5 % and over percent nearest 1 %Grain sizeUp to 0.055 mm incl. mm nearest multiple of 0.005mmOver 0.055 to 0.160, mm, incl. mm nearest 0.01 mm12. Inspection12.1 The manufacturer shall afford the inspector represent-ing the purchaser, all reasona
40、ble facilities to satisfy him that thematerial is being furnished in accordance with this specifica-tion.12.2 The manufacturer shall perform or have performed atleast these minimum tests to ensure conformance to thisspecification:12.2.1 Visual inspection at 1 for surface defects. Allmaterial shall b
41、e visually free from structural defects, cracks,seams, porosity, inclusions, segregation, and other defectsdescribed in 7.1.12.2.1.1 If during 1 visual inspection an area of injuriousdefects is suspected, further inspection at 10 to 20 magni-fication is recommended to try to ascertain if the area in
42、question is definitely defective as described in 7.1 and 12.2.1.12.2.1.2 Although not required by the manufacturer, thepurchaser may inspect the four randomly selected individualunits chosen for physical tests in 8.1.2 for surface defects priorto performing the physical tests. An inspection at 10 to
43、 20magnification can be performed to look for defects described in7.1 and 12.2.1.12.2.1.3 If during visual inspection an injurious defect issuspected, a sample containing the defect may be mounted andsuitably polished and etched. The sample may then be exam-ined at 50 magnification to determine if i
44、t meets the require-ments listed in 7.1 and in 12.2.1. In no case shall any defectexceed 0.0005 in. (0.01 mm) in depth.12.2.2 Hardness test or tension test can be applied, but notboth unless specified by user.12.2.3 Dimensional inspections shall be made as required toensure conformance to tolerances
45、 specified.12.2.4 Spectrographic or chemical analysis when requiredby order13. Rejection13.1 Material that fails to conform to this specification willbe rejected, and the manufacturer shall be notified within 30days after receipt of the material.13.2 In the event of rejection, manufacturer and purch
46、asershall maintain test data and samples for not less than 6 weeksfrom the date of the test reports to resolve any disputed testresults.14. Certification14.1 When specified in the purchase order or contract, themanufacturers or suppliers certification shall be furnished tothe purchaser stating that
47、samples representing each lot havebeen manufactured, tested, and inspected in accordance withTABLE 2 Round Rod Straightness and Length ToleranceLength, ft (m)Straightness TolerancesApplicable to any longitudinal edgeMaximum Curvature (Depth of Arc; in. (mm)Length TolerancesApplicable only to full le
48、ngth piecesLength Tolerances in. (mm)Under 2 (0.6) 0.031 (0.78) 0.125 (3.18)2 (0.6) and under 5 (1.5) 0.031 (0.78) in any 2-ft (0.6-m) portion of the total length. 0.125 (3.18)5 (1.5) and under 10 (3.0) 0.125 (3.18) in any 5-ft (1.5-m) portion of the total length. 0.375 (9.52)10 (3.0) and over 0.50
49、(12.7) in any 10-ft (3.0-m) portion of the total length. 0.500 (12.7)TABLE 3 Strip and Sheet Thickness Tolerance for Widths to 8.00in. (203 mm) InclusiveThickness, in (mm)ThicknessTolerance, , in. (mm)Up to 0.004 (0.10), incl 0.0003 (0.008)Over 0.004 to 0.006 (0.10 to 0.15), incl 0.0004 (0.010)Over 0.006 to 0.009 (0.15 to 0.23), incl 0.0006 (0.015)Over 0.009 to 0.013 (0.23 to 0.33), incl 0.0008 (0.020)Over 0.013 to 0.017 (0.33 to 0.43), incl 0.0010 (0.025)Over 0.017 to 0.021 (0.43 to 0.53), incl 0.0013 (0.033)Over 0.021 to 0.026 (0.53 to 0.66), incl 0.0015
