ASTM A220 A220M-1999(2004) Standard Specification for Pearlitic Malleable Iron.pdf

1、Designation: A 220/A 220M 99 (Reapproved 2004)Standard Specification forPearlitic Malleable Iron1This standard is issued under the fixed designation A 220/A 220M; the number immediately following the designation indicates the yearof original adoption or, in the case of revision, the year of last rev

2、ision. A number in parentheses indicates the year of last reapproval.A superscript epsilon (e) 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 specification covers pearlitic malleabl

3、e iron cast-ings for general engineering usage at temperatures from normalambient to approximately 750F 400C.1.1.1 For continuous service at temperatures up to 1200F650C design factors should be incorporated to compensatefor possible property changes, as demonstrated by Marshalland Sommer2and by Pea

4、rson.31.2 Without knowledge of casting geometry and processdetails, no quantitative relationship can be stated between theproperties of the iron in the various locations of a casting andthose of a test bar cast from the same iron.1.3 The values stated in either inch-pound units or SI unitsare to be

5、regarded separately as standard. Within the test, the SIunits are shown in brackets. The values stated in each systemare not exact equivalents; therefore, each system shall be usedindependently of the other. Combining values from the twosystems may result in nonconformance with the specification.2.

6、Referenced Documents2.1 ASTM Standards:4A 220M Specification for Pearlitic Malleable Iron (Metric)5A 247 Test Method for Evaluating the Microstructure ofGraphite in Iron CastingsA 644 Terminology Relating to Iron CastingsE 8 Test Methods for Tension Testing of Metallic MaterialsE 10 Test Method for

7、Brinell Hardness of Metallic Materi-alsE 18 Test Methods for Rockwell Hardness and RockwellSuperficial Hardness of Metallic MaterialsE 140 Hardness Conversion Tables for Metals RelationshipAmong Brinell Hardness, Vickers Hardness, RockwellHardness, Superficial Hardness, Knoop Hardness, andScleroscop

8、e Hardness2.2 Military Standard:6MIL-STD-129 Marking for Shipment and Storage2.3 Federal Standard:6Fed. Std. No. 123 Marking for Shipment (Civil Agencies)3. Terminology3.1 Definitions:3.1.1 Definitions for many terms common to iron castingsare found in Terminology A 644.4. Classification4.1 Iron pro

9、duced for castings ordered under this specifica-tion is classified in a number of grades as shown in Table 1 andis qualified by tests on separately cast test bars. Separately casttest bars shall be poured from the same lot of iron as thecastings they represent and shall be heat treated with thosecas

10、tings.5. Ordering Information5.1 The purchase order for castings ordered under thisspecification shall state the specification designation, the yearin which the specification was issued, and the grade of pearliticmalleable iron to be supplied.5.2 Any options or special additions to the basic require

11、-ments of this specification shall be clearly and fully stipulated.6. Chemical Composition6.1 The chemical composition of the iron shall be such as toproduce the mechanical properties required by this specifica-tion.1This specification is under the jurisdiction of ASTM Committee A04 on IronCastings

12、and is the direct responsibility of Subcommittee A04.02 on Malleable andDuctile Iron Castings.Current edition approved Oct. 1, 2004. Published October 2004. Originallyapproved in 1968. Last previous edition approved in 1999 as A 220/A 220M 99.2Marshall, L. C., and Sommer, G. F., “Stress-Rupture Prop

13、erties of MalleableIron at Elevated Temperatures,” Proceedings, American Society of Testing andMaterials, Vol 58, pp. 752773.3Pearson, D. A., “Stress-Rupture and Elongation Properties of Malleable Iron atElevated Temperatures,” Transactions, 70th Castings Congress and Exposition, May9, 1966.4For ref

14、erenced ASTM standards, visit 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.5Withdrawn.6Available from Standardization Documents Order Desk, DODS

15、SP, Bldg. 4,Section D, 700 Robbins Ave., Philadelphia, PA 19111-50981Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.7. Mechanical Requirements7.1 Factors influencing the properties of castings and theirrelationship to those of test s

16、pecimens and separate testcastings are discussed in Appendix X1.7.2 Tensile Test:7.2.1 Tensile Test Specimens:7.2.1.1 The tensile test specimens shall be cast to the formand dimensions shown in Fig. 1 or Fig. 2 using the same kindof molding material used for the production castings.7.2.1.2 All test

17、specimens shall be suitably identified withthe designation of the pour period.7.2.1.3 All test specimens shall be heat treated in the sameproduction furnace and for the same cycles as the castings theyrepresent.7.2.2 Tensile Test Method:7.2.2.1 The tensile test is usually performed on unmachinedspec

18、imens. However, for referee work the specimen may bemachined from the standard cast bar to the dimensions shownin Fig. 3.7.2.2.2 Gage LengthThe gage length of the standardtensile specimen shall be 2.00 6 0.01 in. 50.0 6 0.3 mm.7.2.2.3 Cross-Sectional AreaThe diameter used to com-pute the cross-secti

19、onal area shall be the average between thelargest and smallest diameter in that section of the 2-in.50-mm gage length having the smallest diameter and shall bemeasured to the nearest 0.001 in. 0.02 mm. No cast barhaving a mean diameter less than1932 in. 15 mm shall beaccepted for test.7.2.2.4 Speed

20、of TestingAfter reaching a stress equivalentto approximately half of the anticipated yield stress, the speedof the moving head of the testing machine shall not exceed0.50 in./mm 12.5 mm/min through the breaking load.7.2.2.5 Yield StrengthYield strength may be determinedby any of the approved techniq

21、ues described in Test MethodsE 8. In referee work it shall be determined at an offset of 0.2 %from the stress-strain curve. Yield strength shall be reported tothe nearest 100 psi megapascal.7.2.2.6 Tensile StrengthThe tensile strength shall be themaximum load carried by the specimen during the test

22、dividedby the original cross-sectional area of the gage length, as foundin accordance with 7.2.2.3. It shall be reported to the nearest100 psi megapascal.7.2.2.7 ElongationThe increase in gage length after frac-ture of a tensile specimen, measured to the nearest 0.01 in.0.25 mm expressed as a percen

23、tage of the original gagelength. It shall be reported to the nearest 0.5 %.7.2.3 Number of Tests and Retests:7.2.3.1 At least three tensile test specimens shall be castfrom a representative ladle of iron from each 4-h pour periodduring which the purchasers castings were poured.TABLE 1 Tensile Test R

24、equirementsInch-Pound GradesEnglishGradeTensile Strength,minYield Strength, min Elongation, mnpsi psi 2 in., %40010 60 000 40 000 1045008 65 000 45 000 845006 65 000 45 000 650005 70 000 50 000 560004 80 000 60 000 470003 85 000 70 000 380002 95 000 80 000 290001 105 000 90 000 1Metric GradesMetricG

25、radeTensile Strength,minYield Strength, min Elongation, minMPa MPa 50 mm, %280M10 400 280 10310M8 450 310 8310M6 450 310 6340M5 480 340 5410M4 550 410 4480M3 590 480 3550M2 650 550 2620M1 720 620 1FIG. 1 Unmachined Tension Test SpecimenNOTE 1Modification may be made in the dimensions indicated above

26、for those details of the specimen outside of the gage length as required bytesting procedure and equipment.FIG. 2 Alternative Unmachined Tension Test SpecimenNOTE 1The gage length and filets shall be as shown, but the ends maybe of any shape to fit the holders of the testing machine in such a way th

27、atthe load shall be axial. The reduced section shall have a gradual taper fromthe ends toward the center, with the ends 0.003 to 0.005 in. 0.08 to 0.13mm larger in diameter than the center.FIG. 3 Machined Tension Test SpecimenA 220/A 220M 99 (2004)27.2.3.2 Only one test specimen need be tested to qu

28、alifyeach pour period and heat treatment batch provided therequirements of this specification are met by that test specimen.7.2.3.3 If after testing, a specimen shows evidence of adefect, another tensile test may be made on a companionspecimen. Also, a retest shall be permitted whenever fractureoccu

29、rs outside the central 50 % of the gage length.7.2.3.4 If the result of a valid test fails to conform to therequirements of this specification, two retests shall be made. Ifeither of the retests fails to meet specification, the castingsrepresented by these test specimens shall be rejected. A validte

30、st is one wherein the test specimen has been properlyprepared and appears to be sound and on which the approvedtest procedure has been followed.7.2.3.5 If the first test results indicate that a reheat treatmentis needed to meet the test requirements, the entire lot ofcastings and the representative

31、test specimens shall be reheattreated together. Testing shall then be repeated in accordancewith 7.2.3.1-7.2.3.4.7.2.4 The results of all tests, including retests, shall beposted in permanent records, that shall state any abnormalitiesobserved during the test and in the fractured ends. Such recordss

32、hall be kept for at least one year after production of thecastings and shall be available for examination by the pur-chaser or by an authorized representative.7.2.5 Tensile test results, obtained in accordance with thissection, must conform to the requirements of Table 1.7.2.6 When agreed upon betwe

33、en the manufacturer and thepurchaser, tested specimens or unbroken test bars, or both,shall be saved by the manufacturer for a period of three monthsafter the date of the test report.7.3 Hardness Test:7.3.1 If the purchase agreement requires hardness testing,the acceptable hardness range shall be st

34、ated and a locationshall be clearly shown on the covering drawing(s).7.3.2 Hardness Test Method:7.3.2.1 The Brinell method of hardness testing in accor-dance with Test Method E 10, shall be employed wheneverpossible.7.3.2.2 For castings of such size or shape that do not permitBrinell testing with th

35、e standard 3000-kgf load, the 500-kgfload may be employed; the hardness number being reported asHB 10/500/15. In very unusual cases where it is impossible touse the Brinell method, the Rockwell test may be substituted,using Test Methods E 18 with an appropriate Rockwell scale.Conversions of hardness

36、 values from one method to anotheraccording to Tables E 140, that does not specifically cover castirons, are approximate only and are generally inadvisable.7.3.2.3 Sufficient material shall be removed from the castsurface to ensure that the measured hardness is representative.7.3.3 Sampling procedur

37、es and the frequency of hardnesstesting shall be fully detailed on the purchase agreement.Otherwise hardness tests shall be performed at the discretion ofthe producer.7.3.4 Castings failing to conform to the required hardnessrange may be reheat treated and retested. If after reheat treatingthey stil

38、l fail the hardness requirements, they shall be rejected.7.3.5 Typical hardness ranges for the various grades ofpearlitic malleable iron are listed in Table 2.8. Microstructure Requirements8.1 The microstructure of the pearlitic malleable iron shallconsist of temper carbon nodules uniformly distribu

39、ted in amatrix of ferrite, pearlite, and tempered transformation prod-ucts of austenite.8.2 When agreed upon between the purchaser and theproducer, the maximum decarburization at any as-cast surfaceafter heat treatment may be stipulated in writing as measuredby visual depletion of combined carbon af

40、ter polishing, etchingin nital, and viewing at 1003.8.3 If the castings are to be subsequently hardened, theselected grade designation should be preceded by the letter L.Such castings shall contain sufficient combined carbon in thematrix to respond satisfactorily to any of the common harden-ing proc

41、esses properly applied. A minimum hardness of 197HB is recommended. Free ferrite shall be as low as isconsistent with other properties.8.4 In referee work, the metallographic practice recom-mended in Test Method A 247 shall be followed.9. Soundness Requirements9.1 All castings on visual examination,

42、 shall be sound andfree from obvious shrinkage and porosity.9.2 If the purchaser requires soundness tests to be per-formed, it shall be so stated in the purchase agreement and themethod and soundness requirements shall be detailed.10. Dimensional Requirements10.1 The castings shall conform to the di

43、mensions given ondrawings furnished by the purchaser, or to the dimensionsestablished by the patterns supplied by the purchaser.10.1.1 Variations of solid casting dimensions as shown inTable 3 will be permitted unless otherwise agreed uponbetween the purchaser and the producer.11. Workmanship, Finis

44、h and Appearance11.1 The surface of the castings shall be clean, free fromsand, and have a workmanlike finish.11.2 No repairing by plugging or welding of any kind shallbe permitted unless written permission is granted by thepurchaser.12. Identification Marking12.1 When the size of the casting permit

45、s, each casting shallbear the identifying mark of the manufacturer and the part orTABLE 2 Typical Hardness RangesAInch-Pound GradeMetric GradeTypical Hardness,HBTypical IndentationDiameters, mm40010 280M10 149197 4.34.945008 310M8 156197 4.34.845006 310M6 156207 4.24.850005 340M5 179229 4.04.560004

46、410M4 197241 3.94.370003 480M3 217269 3.74.180002 550M2 241285 3.63.990001 620M1 269321 3.43.7AHardness test in accordance with Test Method E 10 using a 0.39-in. 10-mmball and 6600lbf 3000-kgf load.A 220/A 220M 99 (2004)3pattern number at a location shown on the covering drawingand, if not shown on

47、the drawing, at such a location at thediscretion of the producer that the identification will notinterfere with subsequent processing and service of the casting.13. Responsibility for Inspection13.1 Unless otherwise specified in the contract or purchaseorder, the manufacturer shall be responsible fo

48、r carrying out allthe tests and inspections required by this specification, usinghis own or other reliable facilities. The manufacturer shallmaintain complete records of all such tests and inspections.Such records shall be available for review by the purchaser.13.2 The manufacturer shall afford the

49、purchasers inspectorall reasonable facilities necessary to satisfy that the material isbeing produced and furnished in accordance with the appli-cable specification. Foundry inspection by the purchaser shallnot interfere unnecessarily with the manufacturers operations.13.3 The purchaser reserves the right to perform any of thetests and inspections set forth in this specification where suchtests and inspections are deemed necessary to assure thatcompliance with this specification is being met.14. Rejection