1、Designation: B476 01 (Reapproved 2012)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 Department of Defense.1. Scope1.1 This speci
3、fication 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 mate
4、rials 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 regardeda
5、s 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 of t
6、his standard to become familiarwith all hazards including those identified in the appropriateMaterial Safety Data Sheet (MSDS) for this product/materialas provided by the manufacturer, to establish appropriatesafety and health practices, and determine the applicability ofregulatory limitations prior
7、 to use.2. Referenced DocumentsThe following documents of the issue in effect, on the dateof material purchase, form a part of this specification to theextent referenced herein:2.1 ASTM Standards:2B63 Test Method for Resistivity of Metallically ConductingResistance and Contact MaterialsB772 Guide fo
8、r 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 Conformance with Specifications
9、E55 Practice for Sampling Wrought Nonferrous Metals andAlloys for Determination of Chemical CompositionE112 Test Methods for Determining Average Grain SizeE384 Test Method for Knoop and Vickers Hardness ofMaterials3. Terminology3.1 Definition:3.1.1 lot, nthe quantity of material of the same type, si
10、ze,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 specification.4.1.1.1 If a revision
11、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 form,4.1.4 Dimensions of t
12、he 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),4.1.8 Special requirements (if any), and4.1.9 Certification (Section 14).4.2 Specify the following, if required:4.2.1 Certificate of complianc
13、e of physical and chemicalrequirement.4.2.2 Test DataSpecify tests and analyses to be performedand reported.4.2.3 Special packaging, if required.1This specification is under the jurisdiction of ASTM Committee B02 onNonferrous Metals and Alloys and is the direct responsibility of SubcommitteeB02.05 o
14、n Precious Metals and Electrical Contact Materials.Current edition approved May 1, 2012. Published May 2012. Originallyapproved in 1968. Last previous edition approved in 2006 as B476 01 (2006).DOI: 10.1520/B0476-01R12.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact A
15、STM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.5. Materials and Manufactur
16、e5.1 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 cold working operations. it shall be finished
17、, 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 requirements prescribed in this specifi-cation, any
18、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 upon between theproducer and user at the time o
19、f 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 measurement,should be established between prod
20、ucer 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 to the diameter ofwire and rod shall be as pr
21、escribed 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 width standard tolerance for slit products s
22、hall 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, orother forms should be negotiated between the manufacturerand the purchaser. The following suggestion
23、is to be used forguidance only when the manufacturer and the purchaserdiscuss flatness requirements. It is not a requirement of thisspecification, unless agreed upon and made part of the pur-chase order or request for quotation. The flatness of a flat formshall be that the maximum deviation from the
24、 flat surface shallbe less than 1 % of the measurement distance specified for theproduct, such as diameter for circles, length or width of blanks,or any specific measurement length; that is, maximum of 0.20in. (5.08 mm) deviation in any 20 in. (508 mm) length in anydirection.7. Workmanship7.1 Surfac
25、es 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 SamplingThe portion size and selection of piecessh
26、all be 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 physical tests, a test specimenshall be taken
27、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 method orextraneous flaws, it may be discar
28、ded 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 been performed. Theresults of this retest sh
29、all 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 limit, this test shallbe repeated on each of
30、 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.10. Test Methods10.1 The properties enumerated in the
31、applicable productspecification shall be 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 Sup
32、erficial), or a combination ofthese mechanical 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.TABLE 1 Round Wire and Rod Diameter ToleranceDiameter, in. (mm) Toleran
33、ce, 6, 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 (1.02 to 4.75), incl 0.0005 (0.013)Over 0.187 to 0.250 (4.75
34、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 (2012)211. Significance of Numerical Limits11.1 For purpose of determining compliance with the speci-fied limits for requirements of the properties listed in
35、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)Vicker (specify load)Rockwell (all scales
36、, specify which)Rockwell superficial (all scales,specify which)nearest unit on the last righthand place of figure ofspecified limitResistivity VcmTensile strength psi (MPa) nearest 1000 psi (nearest 10MPa)Yield Strength psi (MPa) nearest 1000 psi (nearest10 MPa)ElongationBelow 5 % percent nearest mu
37、ltiple 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 reasonable facilities to satisfy him that thema
38、terial 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 13 for surface defects. Allmaterial shall be visually free from structural defects
39、, cracks,seams, porosity, inclusions, segregation, and other defectsdescribed in 7.1.12.2.1.1 If during 13 visual inspection an area of injuriousdefects is suspected, further inspection at 103 to 203 magni-fication is recommended to try to ascertain if the area inquestion is definitely defective as
40、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 103 to 203magnification can be performed
41、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 503 magnification to determine if it meets therequirements listed in
42、 7.1 and in 12.2.1. In no case shall anydefect exceed 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 specified.12.2.4 Spectrographic or
43、 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 purchasershall maintain test data and sa
44、mples 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 samples representing each lot haveb
45、een manufactured, tested, and inspected in accordance withthis specification and the requirements have been met. Whenspecified in the purchase order or contract, a report of the testresults shall be furnished.15. Packaging and Package Marking15.1 The material shall be separated by size, composition,
46、and temper, and prepared for shipment in such a manner as toensure acceptance by common carrier for transportation and toafford protection from the normal hazards of transportation.15.2 Each shipping unit shall be legibly marked with thepurchase order number, metal or alloy designation, temper,size,
47、 shape, gross and net weight, and name of supplier. Thespecification number shall be shown when specified.TABLE 2 Round Rod Straightness and Length ToleranceLength, ft (m)Straightness TolerancesApplicable to any longitudinal edgeMaximum Curvature (Depth of Arc; in. (mm)Length TolerancesApplicable on
48、ly to full length piecesLength Tolerances in. (mm)Under 2 (0.6) 0.031 (0.78) 60.125 (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. 60.125 (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. 60.375 (9.52)10 (3.0
49、) and over 0.50 (12.7) in any 10-ft (3.0-m) portion of the total length. 60.500 (12.7)TABLE 3 Strip and Sheet Thickness Tolerance for Widths to 8.00in. (203 mm) InclusiveThickness, in (mm)ThicknessTolerance, 6, 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.
