1、Designation: A 48/A 48M 03Standard Specification forGray Iron Castings1This standard is issued under the fixed designation A 48/A 48M; the number immediately following the designation indicates the yearof original adoption or, in the case of revision, the year of last revision. A number in parenthes
2、es 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. This specification replaces Federal SpecificationQQ-I-652.1. Scope1.1 This specific
3、ation covers gray iron castings intended forgeneral engineering use where tensile strength is a majorconsideration. Castings are classified on the basis of the tensilestrength of the iron in separately cast test bars.1.1.1 This specification subordinates chemical compositionto tensile strength.1.2 C
4、astings produced to this specification are graded on thebasis of minimum tensile strength obtained in special testcoupons designed to standardize cooling rate. The tensilestrength developed in certain casting sections may vary fromtest coupon values (see X1.2).1.3 The values stated in either inch-po
5、und units or SI unitsare to be regarded separately as standard. Within the text, theSI units are shown in brackets. The values stated in eachsystem are not exact equivalents; therefore, each system shallbe used independently of the other. Combining values from thetwo systems may result in nonconform
6、ance with the specifi-cation.2. Referenced Documents2.1 ASTM Standards:A 644 Terminology Relating to Iron CastingsE 8 Test Methods for Tension Testing of Metallic Materials2.2 Military Standard:MIL-STD-129 Marking for Shipment and Storage22.3 Federal Standard:Federal Standard No. 123 Marking for Shi
7、pment (CivilAgencies)23. Terminology3.1 Definitions:3.1.1 Definitions for many terms common to gray ironcastings are found in Terminology A 644.4. Classification4.1 Castings ordered and produced in accordance with thisspecification are classified into a number of grades based on theproperties of sep
8、arately cast test bars (Table 1, Table 2). Eachclass is designated by a number followed by a letter. Thenumber indicates the minimum tensile strength of the sepa-rately cast test bar, and the letter indicates the size of the testbar. Examples of proper designations are as follows:Gray Iron Castings,
9、 ASTM Specification A 48, Class 30B.Gray Iron Castings, ASTM Specification A 48, Class 40C.5. Ordering Information5.1 Orders for material to this specification shall include thefollowing information:5.1.1 ASTM designation number and year of issue,5.1.2 Class of iron required (see 4.1, Table 1, and T
10、able 2),5.1.3 The size of the separately cast test bar (letterclassificationA, B, C, or S) that best represents the thicknessof the controlling section of the casting (see Table 3),5.1.4 The tension test specimen (B or C) to be machinedfrom test bar C (see 13.3, Table 4, and Fig. 1),5.1.5 The tensio
11、n test specimen to be machined from testbar S (see 13.4, Table 4, and Fig. 1),5.1.6 Lot size (see Section 10),5.1.7 Special requirements (see Section 6),5.1.8 Saving tested specimens or unbroken test bars (see15.1), and5.1.9 Special preparation for delivery (see Section 19).6. Special Requirements6.
12、1 When agreed upon in writing between the manufacturerand the purchaser, it may be necessary for the castings to meetspecial requirements as to hardness, chemical composition,microstructure, pressure tightness, radiographic soundness,dimensions, surface finish, and so forth.1This specification is un
13、der the jurisdiction of ASTM Committee A04 on IronCastings and is the direct responsibility of Subcommittee A04.01 on Gray IronCastings.Current edition approved Dec. 1, 2003. Published January 2004. Originallyapproved in 1905. Last previous edition approved in 2000 as A 48 00.2Available from Standar
14、dization Documents Order Desk, Bldg. 4 Section D, 700Robbins Ave., Philadelphia, PA 19111-5094, Attn: NPODS.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.7. Tensile Requirements7.1 Test bars representing castings conforming to this
15、 speci-fication shall meet the requirements for tensile strength asdescribed in Table 1 and Table 2.8. Dimensional Requirements8.1 The castings shall conform to the dimensions or draw-ings furnished by the purchaser, or, if there are no drawings, tothe dimensions predicted by the pattern equipment s
16、upplied bythe purchaser.9. Workmanship and Finish9.1 The surface of the casting shall be free of adhering sand,scale, cracks, and hot tears, as determined by visual examina-tion.9.2 No repairing by plugging or welding of any kind shallbe permitted unless written permission is granted by thepurchaser
17、.10. Sampling10.1 A lot shall consist of one of the following:10.1.1 All the metal poured from a single heating in a batchtype melting furnace.10.1.2 All the metal from two or more batch type meltingfurnaces poured into a single ladle or a single casting.10.1.3 All the metal poured from a continuous
18、 meltingfurnace for a given period of time between changes in charge,processing conditions, or aim-for chemistry or 4 h, whicheveris the shorter period.TABLE 1 Requirements for Tensile Strength of Gray Cast Ironsin Separately Cast Test Bars (Inch-Pound)ClassTensile Strength,min, ksiNominal Test BarD
19、iameter, in.No. 20 A 20 0.8No. 20 B 1.2No. 20 C 2.0No. 20 S Bars SANo. 25 A 25 0.88No. 25 B 1.2No. 25 C 2.0No. 25 S Bars SANo. 30 A 30 0.88No. 30 B 1.2No. 30 C 2.0No. 30 S Bars SANo. 35 A 35 0.88No. 35 B 1.2No. 35 C 2.0No. 35 S Bars SANo. 40 A 40 0.88No. 40 B 1.2No. 40 C 2.0No. 40 S Bars SANo. 45 A
20、45 0.88No. 45 B 1.2No. 45 C 2.0No. 45 S Bars SANo. 50 A 50 0.88No. 50 B 1.2No. 50 C 2.0No. 50 S Bars SANo. 55 A 55 0.88No. 55 B 1.2No. 55 C 2.0No. 55 S Bars SANo. 60 A 60 0.88No. 60 B 1.2No. 60 C 2.0No. 60 S Bars SAAAll dimensions of test bar S shall be as agreed upon between the manufacturerand the
21、 purchaser.TABLE 2 Requirements for Tensile Strength of Gray Cast Ironsin Separately Cast Test Bars (Metric)ClassTensile Strength,min, ksi MPaNominal Test BarDiameter, in. mmNo. 150A 150 20 to 22No. 150B 30No. 150C 50No. 150S Bars SANo. 175A 175 20 to 22No. 175B 30No. 175C 50No. 175S Bars SANo. 200A
22、 200 20 to 22No. 200B 30No. 200C 50No. 200S Bars SANo. 225A 225 20 to 22No. 225B 30No. 225C 50No. 225S Bars SANo. 250A 250 20 to 22No. 250B 30No. 250C 50No. 250S Bars SANo. 275A 275 20 to 22No. 275B 30No. 275C 50No. 275S Bars SANo. 300A 300 20 to 22No. 300B 30No. 300C 50No. 300S Bars SANo. 325A 325
23、20 to 22No. 325B 30No. 325C 50No. 325S Bars SANo. 350A 350 20 to 22No. 350B 30No. 350C 50No. 350S Bars SANo. 375A 375 20 to 22No. 375B 30No. 375C 50No. 375S Bars SANo. 400A 400 20 to 22No. 400B 30No. 400C 50No. 400S Bars SAAAll dimensions of test bar S shall be as agreed upon between the manufacture
24、rand the purchaser.A 48/A 48M 03210.1.3.1 The purchaser may agree to extend the 4-h timeperiod to8hifthemanufacturer can demonstrate sufficientprocess control to warrant such an extension.11. Cast Test Bars11.1 Test bars shall be separate castings poured from thesame lot as the castings they represe
25、nt and shall have dimen-sions as shown in Table 4. Allowance may be made forreasonable pattern draft within the tolerances shown in Table 4.Test bars A, B, and C are all standard test bars in the form ofsimple cylinders. Test bar S is special and is intended for usewhere the standard bars are not sa
26、tisfactory.11.2 The test bars shall be cast in dried, baked, or chemi-cally bonded molds made mainly of an aggregate of siliceoussand with appropriate binders. The average grain size of thesand shall approximate that of the sand in which the castingsare poured. Molds for the test bars shall be appro
27、ximately atroom temperature when poured. More than one test bar may becast in a single mold, but each bar in the mold shall besurrounded by a thickness of sand which is not less than thediameter of the bar. A suitable design for a mold is shown inFig. 2.NOTE 1The intent of these provisions is as fol
28、lows: to prohibit thecasting of test bars in molds of metal, graphite, zircon, light-weightaggregates, or other materials which would significantly affect the tensilestrength of the iron; to prohibit control of tensile strength of the test barsby manipulation of the grain size of the sand; and to pr
29、ohibit the castingof test bars in molds preheated substantially above room temperature.11.3 Test bars that are intended to represent castings that arecooled in the mold to less than 900F 480C, beforeshakeout, shall be cooled in their molds to a temperature lessthan 900F 480C. They then may be cooled
30、 in still air toroom temperature.11.4 Test bars that are intended to represent castings that arehotter than 900F 480C, when shaken out of their molds,shall be cooled as described in 11.3 or (by agreement betweenthe manufacturer and the purchaser) may be shaken out of theirmolds at approximately the
31、same temperature as the castingsthey represent.11.5 When castings are stress-relieved, annealed, or other-wise heat-treated, test bars shall receive the same thermaltreatment and shall be treated adjacent to the castings theyrepresent.12. Number of Tests and Retests12.1 The tension test shall be con
32、ducted in accordance withTest Method E 8.12.2 One tension test shall be performed on each lot andshall conform to the tensile requirements specified.12.3 If the results of a valid test fail to conform to therequirements of this specification, two retests shall be made. Ifeither retest fails to meet
33、the specification requirements, thecastings represented by these test specimens shall be rejected.A valid test is one wherein the specimen has been properlyprepared and appears to be sound and on which the approvedtest procedure has been followed.12.4 If sufficient separately cast test pieces are no
34、t available,the manufacturer shall have the option of removing a testspecimen from a location of representative casting, as agreedupon between the manufacturer and purchaser.12.5 If the first test results indicate that a heat treatment isneeded to meet the test requirements, the entire lot of castin
35、gsand the representative test specimens shall be heat treatedtogether. Testing shall proceed in accordance with 12.1-12.3.12.6 If, after testing, a test specimen shows evidence of adefect, the results of the test may be invalidated and anothermade on a specimen from the same lot.13. Tension Test Spe
36、cimens13.1 For test Bar A, the tension-test specimen A, as shownin Fig. 1, shall be machined concentric with the axis of the testbar.13.2 For test Bar B, the tension test specimen B, as shownin Fig. 1, shall be machined concentric with the axis of the testbar.13.3 For test Bar C, tension test specim
37、ens B or C, as shownin Fig. 1, shall be machined concentric with the axis of the testbar. Unless the size of the tension test specimen to be machinedfrom test bar C is specified in writing by the purchaser, thedecision whether to use tension test specimen B or C shall bemade by the manufacturer of t
38、he castings.13.4 For test bar S, the nature and dimensions of the tensiontest specimen shall be determined by agreement between themanufacturer and purchaser.14. Tension Test14.1 Tension test specimens shall fit the holders of thetesting machine in such a way that the load shall be axial.14.2 The el
39、apsed time from the beginning of loading in thetension test to the instant of fracture shall be not less than 15s for test specimen A and not less than 20 s for specimens B andC.15. Inspection15.1 Unless otherwise specified in the contract or purchaseorder, the manufacturer shall be responsible for
40、carrying out allthe tests and inspections required by this specification, usinghis own or other reliable facilities, and he shall maintaincomplete records of all such tests and inspections. Such recordsshall be available for review by the purchaser.15.1.1 When agreed upon between the manufacturer an
41、dpurchaser, tested specimens or unbroken test bars from thesame lot shall be saved for a period of three months after thedate of the test report.15.2 The purchaser reserves the right to perform any of theinspections set forth in the specification where such inspectionsTABLE 3 Separately Cast Test Ba
42、rs for Use When a SpecificCorrelation Has Not Been Established Between the Test Bar andthe CastingThickness of the Wall of the ControllingSection of the Casting, in. mmTest BarUnder 0.25 under 5 S0.25 to 0.50 5 to 14 A0.51 to 1.00 15 to 25 B1.01 to 2 26 to 50 COver 2 over 50 SA 48/A 48M 033are deeme
43、d necessary to ensure that supplies and servicesconform to the prescribed requirements.16. Rejection and Resubmission16.1 Any castings or lot of castings failing to comply withthe requirements of this specification may, where possible, bereprocessed, retested, and reinspected. If the tests and inspe
44、c-tions on the reprocessed casting(s) show compliance with thisspecification, the castings shall be acceptable; if they do not,they shall be rejected.16.2 If the purchaser should find that a casting or lot ofcastings fails to comply with this specification subsequent toreceipt at his facility, he sh
45、all so notify the manufacturerpromptly and in no case later than six weeks after receipt of theshipment, stating clearly the basis for rejection.17. Certification17.1 When specified by the purchasers order or contract, amanufacturers certification or compliance statement that thecasting or lot of ca
46、stings was made, sampled, tested, andinspected in accordance with this specification, including areport of test results shall be furnished at the time of shipment,and such certification or compliance statement shall be thebasis for acceptance of the casting or lot of castings.17.2 A signature is not
47、 required on the certification or testreport. However, the document shall clearly identify theorganization submitting the certification and the authorizedagent of the manufacturer who certified the test results.Notwithstanding the absence of a signature, the organizationsubmitting the certification
48、is responsible for its content.18. Product Marking18.1 When the size of the casting permits, each casting shallbear the identifying mark of the manufacturer and the part orpattern number at a location shown on the covering drawing or,if not shown on the drawing, at a location at the discretion ofthe
49、 producer.TABLE 4 Diameters and Lengths of Cast Test BarsTest BarAs-Cast Diameter, in. mm Length, in. mmNominal(Mid-Length)Minimum (Bottom) Maximum (Top)Minimum(Specified)Maximum(Recommended)A 0.88 22.4 0.85 21.6 0.96 24.4 5.0 125 6.0 150B 1.20 30.5 1.14 29.0 1.32 33.5 6.0 150 9.0 230C 2.00 50.8 1.90 48.3 2.10 53.3 7.0 175 10.0 255SA. . . . .AAll dimensions of test bar S shall be as agreed upon by the manufacturer and the purchaser.Dimensions, in. mmTension TestSpecimen ATension TestSpecimen BTension TestSpecimen CG
