1、Designation: A159 83 (Reapproved 2011)Standard Specification forAutomotive Gray Iron Castings1This standard is issued under the fixed designation A159; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A nu
2、mber 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. This specification replaces Federal specificationAA-I-653A.1. Scope
3、1.1 This specification applies to gray iron castings, cast insand molds, used in the products of the automobile, truck,tractor, and allied industries.1.2 The values stated in inch-pound units are to be regardedas standard. No other units of measurement are included in thisstandard.2. Referenced Docu
4、ments2.1 The following documents of the issue in effect on thedate of material procurement form a part of this specification tothe extent referenced herein:2.2 ASTM Standards:2A247 Test Method for Evaluating the Microstructure ofGraphite in Iron CastingsE10 Test Method for Brinell Hardness of Metall
5、ic Materials2.3 Military Standard:MIL-STD-129 Marking for Shipment and Storage32.4 Federal Standard:Fed. Std. No. 123 Marking for Shipment (Civil Agencies)33. Grades3.1 The specified grades, hardness ranges, and metallurgicaldescription are shown in Table 1 and Table 2 and in Section 9.4. Ordering I
6、nformation4.1 Orders for materials under this specification shall in-clude the following information:4.1.1 ASTM designation,4.1.2 Grade designation of gray iron required (3.1),4.1.3 If special heat treatment is required (see Section 6),4.1.4 If special microstructure requirements are needed (seeSect
7、ion 7),4.1.5 Surface where hardness test is to be performed (see9.4),4.1.6 Depth and surface hardness of case required (see 9.6),4.1.7 Inspection lot and sampling plan required (see Section10),4.1.8 If additional requirements are needed (see 11.3), and4.1.9 Whether special packaging and marking is r
8、equired(see Section 12).5. Hardness5.1 The foundry shall exercise the necessary controls andinspection techniques to ensure compliance with the specifiedhardness range, Brinell hardness shall be determined in accor-dance with Test Method E10, after sufficient material has beenremoved from the castin
9、g surface to ensure representativehardness readings. The 10-mm ball and 3000-kg load shall beused unless otherwise agreed upon. The area or areas on thecasting where hardness is to be checked shall be established byagreement between supplier and purchaser and shall be shownon the drawing.6. Heat Tre
10、atment6.1 Unless otherwise specified, castings of Grades G1800and G2500 may be annealed in order to meet the desiredhardness range.1This specification is under the jurisdiction of ASTM Committee A04 on IronCastings and is the direct responsibility of SubcommitteeA04.01 on Grey and WhiteIron Castings
11、.Current edition approved March 1, 2011. Published September 2011. Originallyapproved in 1935. Last previous edition approved in 2006 as A159 83 (2006).DOI: 10.1520/A0159-83R11.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. F
12、or 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 19111-5098, http:/www.dodssp.daps.mil.TABLE 1 Grades of Gray IronGra
13、de Casting Hardness Range DescriptionG1800 HB 187 max4.4 BID min or as agreedAferritic-pearliticG2500 HB 170-2294.64.0 BID or as agreedApearlitic-ferriticG3000 HB 187-2414.43.9 BID or as agreedApearliticG3500 HB 207-2554.23.8 BID or as agreedApearliticG4000 HB 217-2694.13.7 BID or as agreedApearliti
14、cABrinell impression diameter (BID) is the diameter in millimetres of the impres-sion of a 10 mm ball at 3000-kg load.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.6.2 Appropriate heat treatment for removal of residualstresses, or
15、to improve machinability or wear resistance may bespecified by agreement between supplier and purchaser.7. Microstructure7.1 The microstructure shall consist of flake graphite in amatrix of ferrite or pearlite or mixtures thereof.7.2 As graphite size and shape somewhat affect hardness-strength ratio
16、 and other properties, the type size and distribu-tion of the graphite flakes at a designated location on thecasting may be specified by agreement between supplier andpurchaser in accordance with Method A247.7.3 Unless otherwise specified, the matrix microstructure ofcastings covered by this specifi
17、cation shall be substantially freeof primary cementite. Castings in Grades G1800 and G2500may have a matrix of ferrite or pearlite or both. Grades G3000,G3500, and G4000 shall be substantially pearlite in matrixstructure.8. Heavy-Duty Brake Drums and Clutch Plates8.1 These castings are considered as
18、 special cases and arecovered in Table 2.9. Alloy Gray Iron Automotive Camshafts9.1 These castings are considered as special cases.9.2 Grade DesignationG4000d.9.3 ChemistryAlloy gray iron camshafts shall containalloys within the following range or as agreed upon betweensupplier and purchaser.Chromiu
19、m 0.851.25 %Molybdenum 0.400.60 %Nickel as agreed9.4 Casting HardnessHB 241-321 determined on a bear-ing surface as agreed by supplier and purchaser.9.5 MicrostructureExtending 45 on both sides of thecenterline of the cam nose and to a minimum depth of 1/8 in.(3.2 mm), the surface shall consist of p
20、rimary carbides (ofacicular or cellular form or a mixture thereof) and graphite ina fine pearlitic matrix. The graphite shall be Type VII A and Edistribution, 4 to 7 flake size in accordance with Method A247.The amount of primary carbides and location at which thestructure is checked shall be a matt
21、er of agreement between thesupplier and the purchaser.9.6 Selective HardeningThe cam areas of camshaft cast-ing are usually selectively hardened by flame or inductionhardening by the supplier. The depth and surface hardness ofthe hardened case shall be as agreed upon between supplier andpurchaser.10
22、. Quality Assurance Provisions10.1 Responsibility for InspectionUnless otherwise speci-fied in the contract or purchase order, the producer is respon-sible for the performance of all inspection and tests require-ments specified in this specification. Except as otherwisespecified in the contract or p
23、urchase order, the producer mayuse his own or any other suitable facilities for the performanceof the inspection and test requirements specified herein, unlessdisapproved by the purchaser. The purchaser shall have theright to perform any of the inspection and tests set for in thisspecification where
24、 such inspections are deemed necessary toassure that material conform to prescribed requirements.10.2 LotFor the purpose of inspection, lot and samplingplans shall be agreed upon between the purchaser and theproducer.11. General11.1 Castings furnished to this specification shall be repre-sentative o
25、f good foundry practice and shall conform todimensions and tolerances specified on the casting drawing.11.2 Minor imperfections usually not associated with thestructural function may occur in castings. These are oftenrepairable but repairs shall be made only where allowed by thepurchaser and only by
26、 approved methods.11.3 Additional casting requirements may be agreed uponby purchaser and supplier. These should appear as productspecifications on the casting or part drawing.12. Preparation for Delivery12.1 Unless otherwise specified in the contract or purchaseorder, castings shall be cleaned, pre
27、served, and packaged inaccordance with suppliers standard commercial practice.12.2 Government ProcurementWhen specified for Gov-ernment procurement, castings shall be marked for shipment inaccordance with MIL-STD-129 for military procurement andFed. Std. No. 123 for civil agency procurement.TABLE 2
28、Brake Drums and Clutch Plates for Special ServiceGrade Carbon min, %ACasting HardnessMicrostructureGraphite MatrixG2500a 3.40 HB 170-2294.64.0 BID or as agreedType VII, size 24BA distributionlamellar pearliteferrite if present not to exceed 15%G3500b 3.40CHB 207-2554.23.8 BID or as agreedType VII, s
29、ize 35BA distributionlamellar pearliteferrite or carbide if present not to exceed 5%G3500c 3.50CHB 207-2554.23.8 BID or as agreedType VII, size 35BA distributionlamellar pearliteferrite or carbide, if present not to exceed 5%AThe chemical analysis for total carbon shall be made on chilled pencil-typ
30、e specimens or from thin wafers approximately 1/32 in. (0.8 mm) thick cut from test coupons.Drillings are not reliable because of the probable loss of graphite.BSee Method A247.CGrades G 3500b and G 3500c normally require alloying to obtain the specified hardness at the high carbon levels specified.
31、A159 83 (2011)2APPENDIX(Nonmandatory Information)X1. GRAY IRONX1.1 DefinitionX1.1.1 gray irona cast iron in which the graphite ispresent as flakes instead of temper carbon nodules as inmalleable iron or small spherulites as in ductile iron.X1.2 Chemical CompositionX1.2.1 The ranges in composition ge
32、nerally employed inproducing the various grades of most automotive gray ironcastings are shown in Table X1.1. The composition ranges forsuch special applications as heavy duty brake drums and clutchplates and camshafts are shown in Table X1.2 and Table X1.3,respectively. The contents of certain elem
33、ents for these appli-cations are critical in terms of service requirements and theranges are specified in the standard.X1.2.2 The specific composition range for a given grademay vary according to the prevailing or governing section ofthe castings being produced.X1.2.3 Alloying elements such as chrom
34、ium, copper,nickel, tin, molybdenum, or other elements may be employedto meet the specified hardness or microstructural requirementsor to provide the properties needed for particular serviceconditions.X1.3 MicrostructureX1.3.1 The microstructure of the various grades of gray ironare generally a mixt
35、ure of flake graphite in a matrix of ferrite,pearlite, or tempered pearlite. The relative amounts of each ofthese constituents depends on the analysis of the iron, castingdesign, and foundry techniques as they affect solidification andsubsequent cooling rate and heat treatments if any.X1.3.2 The dis
36、tribution and size of graphite flakes like thematrix structure of gray iron depends greatly on the solidifi-cation rate and cooling rate of the casting. If a section solidifiesvery rapidly an appreciable amount of carbide causing amottled fracture or chilled corners can be present. If a sectioncools
37、 slowly, as in a massive heavy-section casting, an appre-ciable amount of ferrite may be present. In like manner, lightsections will contain small graphite flakes while graphite willform in much larger flakes if the same iron is poured into aheavy casting.X1.3.3 For these reasons the strength and ha
38、rdness of grayiron are greatly influenced by the rate of cooling during andafter solidification, the design and nature of the mold and thecasting, and by other factors such as inoculation practice inaddition to the composition of the iron.X1.3.4 Alloying with nickel, chromium, molybdenum, tin,copper
39、 or other alloys usually promotes a more stable pearliticstructure and is often done to obtain increased hardness,strength, and wear resistance especially in heavy sectionssubjected to severe service.X1.3.5 Alloying is sometimes used to obtain structurescontaining a controlled percentage of carbides
40、 as in camshaftor valve lifter castings.X1.3.6 Primary carbides or pearlite or both, can be decom-posed by appropriate heat treatment. Gray irons of suitableTABLE X1.1 Typical Base Compositions, %Grade Carbon Silicon Manganese Sulfur, max Phosphorus, max Approximate CarbonEquivalentG1800 3.403.70 2.
41、302.80 0.500.80 0.15 0.25 4.254.5G2500 3.203.50 2.002.40 0.600.90 0.15 0.20 4.04.25G3000 3.103.40 1.902.30 0.600.90 0.15 0.15 3.94.15G3500 3.003.30 1.802.20 0.600.90 0.15 0.12 3.73.9G4000 3.003.30 1.802.10 0.701.00 0.15 0.10 3.73.9(usually alloyed)TABLE X1.2 Usual Composition of Brake Drums and Clut
42、chPlates for Special ServiceChemical Compo-sition, %GradeG2500aGradeG3500bGradeG3500cCarbon, total (mandatory) 3.40 min 3.40 min 3.50 minSilicon (as required) 1.602.10 1.301.80 1.301.80Manganese (as required) 0.600.90 0.600.90 0.600.90Sulfur, max 0.12 0.12 0.12Phosphorus, max 0.15 0.15 0.15Alloys as
43、 required as required as requiredTABLE X1.3 Usual Chemical Composition of Alloy Gray IronAutomotive CamshaftsGrade G4000d, %Total carbon 3.103.60Silicon 1.952.40Manganese 0.600.90Phosphorus 0.10 maxSulfur 0.15 maxChromium 0.851.25Molybdenum 0.400.60Nickel 0.200.45 optionalCopper residualA159 83 (201
44、1)3composition and structure can be hardened by liquid quenchingor by flame or induction selective hardening.X1.4 Mechanical PropertiesX1.4.1 The mechanical properties listed in Table X1.4 canbe used for design purposes. However, the suitability of aparticular grade for an intended application is be
45、st determinedby laboratory or service tests. Typical mechanical propertiesfor such specialized applications as heavy-duty brake drumsand clutch plates are shown in Table X1.5.X1.5 Application of Gray Iron in Automotive Castings(see Table X1.6)X1.5.1 The graphite flakes in gray iron give this metal m
46、anydesirable properties. These include excellent machinability,high thermal conductivity, vibration dampening properties, andresistance to wear or scuffing. Due to its low freezing tempera-ture for a ferrous alloy, high fluidity, and low shrinkageproperties it is more readily cast in complex shapes
47、than otherferrous metals.X1.5.2 Gray iron castings of the lower-strength GradesG1800 and G2500 are characterized by excellent machinabil-ity, high damping capacity, low modulus of elasticity, andcomparative ease of manufacture. When higher strength isobtained by a reduction in the carbon or carbon e
48、quivalent,castings are more difficult to machine, have lower dampingcapacity, higher modulus of elasticity, and may be moredifficult to manufacture.X1.6 Special Applications of Gray IronX1.6.1 Heavy-Duty Brake Drums and Clutch PlatesAutomotive brake drums and clutch plates for heavy-dutyservice are
49、considered as special cases. Typical chemicalanalyses and mechanical properties are listed in Table X1.2 andTable X1.5. Heavy-duty irons for such service require highcarbon contents for resistance to thermal shock and to mini-mize heat checking. To maintain strength levels specified forGrades G3500b and G3500c normally requires alloying due totheir high carbon contents.X1.6.2 MicrostructureSee Table 2 for microstructure requirements.X1.6.3 Suggested UsageFollowing are suggested grades for brake drums and clutchplates accordin
copyright@ 2008-2019 麦多课文库(www.mydoc123.com)网站版权所有
备案/许可证编号:苏ICP备17064731号-1