1、Designation: A878/A878M 05 (Reapproved 2011)Standard Specification forSteel Wire, Modified Chromium Vanadium Valve SpringQuality1This standard is issued under the fixed designation A878/A878M; the number immediately following the designation indicates the yearof original adoption or, in the case of
2、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 the highest quality of roundmodified chromium vanadium alloy steel va
3、lve spring wire,uniform in quality and temper, intended for the manufacture ofvalve springs and other springs requiring high-fatigue proper-ties when used at moderately elevated temperatures. This wireshall be either in the annealed and cold-drawn or oil-temperedcondition as specified by purchaser.1
4、.2 The values stated in either SI units or inch-pound unitsare to be regarded separately as standard. Within the text, theinch-pound units are shown in brackets. The values stated ineach system are not exact equivalents; therefore, each systemmust be used independent of the other.2. Referenced Docum
5、ents2.1 ASTM Standards:2A370 Test Methods and Definitions 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 ProductsE29 Practice for Using Sig
6、nificant Digits in Test Data toDetermine Conformance with SpecificationsE45 Test Methods for Determining the Inclusion Content ofSteel2.2 Federal Standard:3Fed. Std. No. 123 Marking for Shipment (Civil Agencies)2.3 Military Standard:3MIL-STD-163 Steel Mill Products, Preparation for Ship-ment and Sto
7、rage2.4 AIAG Standard:4AIAG B-5 02.00 Primary Metals Identification Tag Appli-cation Standard3. Ordering Information3.1 Orders for material under this specification shall includethe following information for each ordered item:3.1.1 Quantity (mass),3.1.2 Name of material (modified chromium vanadiumal
8、loy steel valve spring quality wire),3.1.3 Dimensions (Table 1 and Section 8),3.1.4 Condition (Section 6),3.1.5 Packaging (Section 14),3.1.6 Heat analysis report, if requested (5.2),3.1.7 Certification or test report, or both, if specified (Sec-tion 13), and3.1.8 ASTM designation and year of issue.N
9、OTE 1A typical ordering description is as follows: 20 000-kgoil-tempered modified chromium vanadium alloy steel valve springquality wire, size 6.00 mm in 150-kg coils toASTM _ dated _ , or forinch-pound, 40 000-lb oil-tempered modified chromium vanadium alloysteel valve spring quality wire, size 0.2
10、50 in. in 350-lb coils to ASTM _dated _ .4. Materials and Manufacture4.1 The steel may be made by any commercially acceptedsteel making process. The steel shall be continuously cast.4.2 The finished wire shall be free from detrimental pipeand undue segregation.5. Chemical Composition5.1 The steel sh
11、all conform to the requirements for chemicalcomposition specified in Table 2.5.2 Heat AnalysisEach heat of steel shall be analyzed bythe manufacturer to determine the percentage of elementsprescribed in Table 2. This analysis shall be made from a testspecimen preferably taken during the pouring of t
12、he heat.When requested, this shall be reported to the purchaser andshall conform to the requirements of Table 2.1This specification is under the jurisdiction of ASTM Committee A01 on Steel,Stainless Steel and Related Alloys and is the direct responsibility of SubcommitteeA01.03 on Steel Rod and Wire
13、.Current edition approved Nov. 1, 2011. Published November 2011. Originallyapproved in 1987. Last previous edition approved in 2005 as A878/A878M 05.DOI: 10.1520/A0878_A0878M-05R11.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.or
14、g. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.3Available from Standardization Documents Order Desk, DODSSP, Bldg. 4,Section D, 700 Robbins Ave., Philadelphia, PA 19111-50984Available from Automotive Industry Action Group (AIAG
15、), 26200 Lahser Rd.,Suite 200, Southfield, MI 48034.1*A Summary 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.5.3 Product AnalysisAn analysis may be made by thepurchaser from fi
16、nished wire representing each heat of steel.The average of all the separate determinations made shall bewithin the limits specified in the analysis column. Individualdeterminations may vary to the extent shown in the productanalysis tolerance column, except that the several determina-tions of a sing
17、le element in any one heat shall not vary bothabove and below the specified range.5.4 For referee purposes, Test Methods, Practices, andTerminology A751 shall be used.6. Mechanical Properties6.1 Annealed and Cold DrawnWhen purchased in theannealed and cold-drawn condition, the wire shall have beengi
18、ven a sufficient amount of cold working to meet the purchas-ers coiling requirements and shall be in a suitable condition torespond properly to heat treatment. In special cases thehardness, if desired, shall be stated in the purchase order.6.2 Oil TemperedWhen purchased in the oil-temperedcondition,
19、 the tensile strength and % R.A. shall conform to therequirements prescribed in Table 3.6.2.1 Number of TestsOne test specimen shall be taken foreach five coils, or fraction thereof, in a lot. Each heat in a givenlot shall be tested.6.2.2 Location of TestsTest specimens shall be taken fromeither end
20、 of the coil.6.2.3 Test MethodThe tension test shall be made inaccordance with Test Methods and Definitions A370.6.3 Wrap Test:6.3.1 Oil-tempered or cold-drawn wire 4.00 mm 0.162 in.and smaller in diameter shall wind on itself as an arbor withoutbreakage. Larger diameter wire up to and including 8.0
21、0 mm0.312 in. in diameter shall wrap without breakage on amandrel twice the wire diameter. The wrap test is not appli-cable to wire over 8.00 mm 0.312 in. in diameter.6.3.2 Number of TestsOne test specimen shall be taken foreach five coils, or fraction thereof, in a lot. Each heat in a givenlot shal
22、l be tested.6.3.3 Location of TestsTest specimens shall be taken fromeither end of the coil.6.3.4 Test MethodThe wrap test shall be made in accor-dance with Test Methods and Definitions A370.6.4 Special Surface InspectionWhen specified, the entirelength of every coil shall be inspected for surface i
23、mperfectionswith a magnetic or eddy current defect analyzer, or both, orequivalent. The defect depth of this surface inspection shall beagreed upon between the manufacturer and the purchaser. Alldetected defects shall be properly marked so the purchaser hasthe ability to identify and discard that le
24、ngth of wire.7. Metallurgical Requirements7.1 Surface Condition:7.1.1 The surface of the wire as received shall be free ofimperfections such as pits, die marks, scratches, seams, andother defects tending to impair the fatigue value of the springs.7.1.2 Number of TestsOne test specimen shall be taken
25、from each end of every coil.7.1.3 Test MethodThe surface shall be examined afteretching in a solution of equal parts of hydrochloric acid andwater that has been heated to approximately 80C for up to 2min in order to remove the oxide scale layer from the wiresurface. Test ends shall be examined using
26、 103 magnification.TABLE 1 Permissible Variations in Wire DiameterASI UnitsDiameter, mmPermissibleVariations,6mmPermissibleOut-of Round,mm0.5 to 2.0, incl 0.02 0.02Over 2.0 to 4.0, incl 0.03 0.03Over 4.0 to 9.5, incl 0.04 0.04Inch-Pound UnitsDiameter, in.PermissibleVariations,6in.PermissibleOut-of R
27、ound,in.0.020 to 0.075, incl 0.0008 0.0008Over 0.075 to 0.148, incl 0.001 0.001Over 0.148 to 0.375, incl 0.0015 0.0015AFor purposes of determining conformance with this specification, all specifiedlimits are absolute as defined in Recommended Practice E29.TABLE 2 Chemical RequirementsAnalysis, % Pro
28、duct AnalysisTolerance, %Carbon 0.600.75 60.02Manganese 0.500.90 60.03Phosphorus 0.025 max +0.005Sulfur 0.025 max +0.005Silicon 0.150.30 60.02Chromium 0.350.60 60.05Vanadium 0.100.25 60.01TABLE 3 Tensile RequirementsASI UnitsDiameter, mm MPa, min MPa, max Min % R.A.B0.5 2000 2170 b1.0 1930 2100 b1.5
29、 1830 2000 b2.0 1760 1900 453.0 1660 1800 453.75 1620 1760 404.5 1590 1730 405.0 1550 1690 405.7 1520 1660 406.3 1480 1620 407.9 1450 1590 409.5 1410 1550 40Inch-Pound UnitsDiameter, in. ksi, min ksi, max Min % R.A.B0.020 290 315 b0.040 280 305 b0.060 265 290 b0.080 255 275 450.120 240 260 450.148 2
30、35 255 400.177 230 250 400.200 225 245 400.225 220 240 400.250 215 235 400.312 210 230 400.375 205 225 40ATensile strength valves for intermediate diameters may be interpolated.Bb is not applicable to wire diameters under .080 in. (2.0 mm).A878/A878M 05 (2011)27.2 Decarburization:7.2.1 Transverse se
31、ctions of the wire properly mounted,polished, and etched shall show no completely decarburized(carbon-free) areas when examined at a magnification of 100diameters. Partial decarburization shall not exceed a depth of0.025 mm 0.001 in. on wire 5.00 mm 0.192 in. and smaller,or 0.038 mm 0.0015 in. on la
32、rger than 5.00 mm 0.192 in.7.2.2 To reveal the decarburization more accurately inuntempered wire, the specimen shall be hardened and temperedbefore microscopic examination. Prior to hardening, the speci-men shall be filed flat on one side enough to reduce thediameter at least 20 %. The subsequent mo
33、unted specimenshall show the flattened section, as well as the original wireedge. Any decarburization on this flattened section shallnecessitate a new specimen for examination.7.2.3 Number of TestsOne test specimen shall be taken foreach five coils, or fraction thereof, in a lot.7.2.4 Location of Te
34、stsTest specimens may be taken fromeither end of the coil.7.3 Inclusion Content:7.3.1 The inclusion content of the wire or wire rod in theworst case shall not exceed the limits shown in Table 4 asdescribed in Test Methods E45, Plate I-r, Method D, except thatalternate methodologies are acceptable up
35、on agreement be-tween purchaser and supplier provided minimum requirementsare not lower than those of Test Methods E45, Method D.7.3.1.1 If any coil exceeds the limits listed in Table 4, allcoils in the lot will be inspected. Each coil that fails to meet therequirements will be rejected.7.3.2 Number
36、 of TestsOne test specimen shall be taken foreach 10 coils, or fraction thereof, in the lot.7.3.3 Location of TestsTest specimens may be taken fromeither end of the coil.7.3.4 Test MethodA longitudinal section approximately12.7 mm 0.5 in. long shall be ground to the centerline andproperly mounted an
37、d polished. Examination shall be made inaccordance with Test Methods E45.7.3.5 Upon agreement by the purchaser and supplier, theinclusion requirements may be waived.8. Dimensions and Permissible Variations8.1 The permissible variations in the diameter of the wireshall be as specified in Table 1.8.2
38、Number of TestsOne test specimen shall be taken fromeach end of every coil.9. Workmanship, Finish, and Appearance9.1 Annealed and Cold DrawnThe wire shall not bekinked or improperly cast. To test for cast, a few convolutionsof wire shall be cut loose from the coil and placed on a flatsurface. The wi
39、re shall lie substantially flat on itself and notspring up nor show a wavy condition.9.2 Oil TemperedThe wire shall be uniform in quality andtemper and shall not be wavy or crooked.9.3 Each coil shall be one continuous length of wireproperly coiled and firmly tied.9.4 No welds are permitted in the f
40、inished product and anywelds made during processing must be removed.10. Retests10.1 If any test specimen exhibits obvious defects it may bediscarded and another specimen substituted.11. Inspection11.1 Unless otherwise specified in the contract or purchaseorder, the manufacturer is responsible for th
41、e performance ofall inspection and test requirements specified in this specifica-tion. Except as otherwise specified in the contract or purchaseorder, the manufacturer may use his own or any other suitablefacilities for the performance of the inspection and testrequirements unless disapproved by the
42、 purchaser at the timethe order is placed. The purchaser shall have the right toperform any of the inspections and tests set forth in thisspecification when such inspections and tests are deemednecessary to assure that the material conforms to prescribedrequirements.12. Rejection and Rehearing12.1 U
43、nless otherwise specified, any rejection based on testsmade in accordance with these specifications shall be reportedto the manufacturer as soon as possible so that an investigationmay be initiated.12.2 The material must be adequately protected and cor-rectly identified in order that the manufacture
44、r may make aproper investigation.13. Certification13.1 When specified in the purchase order or contract, amanufacturers or suppliers certification shall be furnished tothe purchaser that the material was manufactured, sampled,tested, and inspected in accordance with this specification andhas been fo
45、und to meet the requirements. When specified in thepurchase order or contract, a report of the test results shall befurnished.13.2 The certification shall include the specification num-ber, year date of issue, and revision letter, if any.TABLE 4 Maximum Inclusion ContentNOTE 1The surface zone is fro
46、m the wire surface to13 radius deep. The core is the balance.Zone Inclusion TypeABCDThin Heavy Thin Heavy Thin Heavy Thin HeavySurface111111Core 2 1 2 1 2 1 2 1A878/A878M 05 (2011)314. Packaging, Marking, and Loading for Shipment14.1 The coil mass, dimensions, and the method of packag-ing shall be a
47、greed upon between the manufacturer andpurchaser.14.2 The size of the wire, purchasers order number, ASTMspecification number, heat number, and name or mark of themanufacturer shall be marked on a tag securely attached toeach coil of wire.14.3 Unless otherwise specified in the purchasers order,packa
48、ging, marking, and loading for shipments shall be inaccordance with those procedures recommended by PracticesA700.14.4 For Government ProcurementPackaging, packing,and marking of material for military procurement shall be inaccordance with the requirements of MIL-STD-163, Level A,Level C, or commerc
49、ial as specified in the contract or purchaseorder. Marking for shipment of material for civil agencies shallbe in accordance with Fed. Std. No. 123.14.5 Bar CodingIn addition to the previously-stated iden-tification requirements, bar coding is acceptable as a supple-mentary identification method. Bar coding should be consistentwith AIAG Standard 02.00, Primary Metals Identification TagApplication. The bar code may be applied to a substantiallyaffixed tag.15. Keywords15.1 alloy; modified chromium vanadium; valve spri
