1、Designation: A436 84 (Reapproved 2015)Standard Specification forAustenitic Gray Iron Castings1This standard is issued under the fixed designation A436; 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 U.S. Department of Defense.1. Scope1.1 This specification covers austenitic gray iron cast
3、ingsthat are used primarily for their resistance to heat, corrosion,and wear. Austenitic gray iron is characterized by uniformlydistributed graphite flakes, some carbides, and the presence ofsufficient alloy content to produce an austenitic structure.1.2 The values stated in inch-pound units are to
4、be regardedas standard. The values given in parentheses are mathematicalconversions to SI units that are provided for information onlyand are not considered standard.2. Referenced Documents2.1 ASTM Standards:2E30 Test Methods for Chemical Analysis of Steel, Cast Iron,Open-Hearth Iron, and Wrought Ir
5、on (Withdrawn 1995)3E59 Practice for Sampling Steel and Iron for Determinationof Chemical Composition (Withdrawn 1996)3E94 Guide for Radiographic ExaminationE165 Practice for Liquid Penetrant Examination for GeneralIndustryE351 Test Methods for Chemical Analysis of Cast IronAllTypesE433 Reference Ph
6、otographs for Liquid Penetrant Inspec-tionE446 Reference Radiographs for Steel Castings Up to 2 in.(50.8 mm) in Thickness3. Ordering Information3.1 Orders for material to this specification shall include thefollowing information:3.1.1 ASTM designation and date of issue,3.1.2 Type of austenitic gray
7、iron required (see 5.1),3.1.3 Heat treatment required (see 4.2 through 4.5),3.1.4 If repair of castings is permitted (see 4.6),3.1.5 Size and number of test bars required (see 11 through8.4 and 12.1),3.1.6 If special tests are required (see Section 7 and 9.1),3.1.7 If certification is required (see
8、14.1), and3.1.8 If different preparation for delivery requirements areneeded (see 15.1).4. Materials and Manufacture4.1 Melting may be done in any furnace that producescastings meeting the chemical compositions and mechanicalproperties outlined in this specification. These include cupolas,air furnac
9、es, electric furnaces, crucible furnaces, and so forth.4.2 By agreement between the manufacturer and thepurchaser, the castings may be stress relieved by heating to andholding in the temperature range from 1150 to 1200F (620 to650C) for not less than 1 nor more than 2 h/in. of thickness inthe thicke
10、st section. Heating and cooling shall be uniform andshall be not more than 400F (222C)/h for castings less than1 in. in maximum thickness, nor more than 400F/h divided bythe maximum section thickness in inches for thicker castings.During the cooling cycle, castings may be cooled in still airafter th
11、e temperature has dropped to 600F (315C).4.3 If the manufacturer can demonstrate that another treat-ment provides satisfactory stress relief, it may be used byagreement between the manufacturer and the purchaser.4.4 Whenever dimensional changes in high-temperatureservice are a problem, by agreement
12、between the manufacturerand the purchaser, the castings may be stabilized by heating at1600F (870C) for 1 h/in. of section, for a minimum of 1 h.Otherwise, the austenite that is supersaturated with respect tocarbon may reject carbon during service and produce dimen-sional changes.4.5 By agreement be
13、tween the manufacturer and thepurchaser, castings with chilled edges or excessive carbidesmay be annealed at 1750 to 1900F (955 to 1040C) for12 to5 h, followed by uniform cooling, preferably in still air.4.6 Castings shall not be repaired by welding, plugging, orother methods without written permiss
14、ion from the purchaser.1This specification is under the jurisdiction of ASTM Committee A04 on IronCastings and is the direct responsibility of Subcommittee A04.01 on Grey and WhiteIron Castings.Current edition approved Nov. 1, 2015. Published November 2015. Originallyapproved in 1959. Last previous
15、edition approved in 2011 as A43684 (2011). DOI:10.1520/A0436-84R15.2For referenced 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 we
16、bsite.3The last approved version of this historical standard is referenced onwww.astm.org.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States15. Chemical Composition5.1 Many combinations of alloys can be used to obtain anaustenitic gray i
17、ron. This specification includes only the sixtypes defined by the chemical composition limits specified inTable 1.5.2 The chemical analysis for total carbon shall be made onchilled cast pencil-type specimens or from thin wafers approxi-mately132 in. (0.8 mm) thick cut from test coupons. Drillingsare
18、 not reliable because of the probable loss of graphite.5.3 Drillings taken from test coupons, broken testspecimens, or castings shall conform to the requirements forchemical composition as given in Table 1. Sampling shall beconducted in accordance with Practice E59 and chemicalanalysis in accordance
19、 with Test Methods E351 and TestMethods E30. Test Methods E30 should only be used foranalyzing those elements for which specific coverage is notprovided for in Test Methods E351.5.4 Spectrometric techniques may also be used for analysis,but should a dispute arise concerning chemical composition,chem
20、ical analyses determined by Test Methods E351 and TestMethods E30 shall be used for referee analysis.6. Mechanical Properties6.1 Although these irons are not used primarily for theirstrength, the tensile strength and Brinell hardness are indicativeof the correct metallurgical structure. The six type
21、s shallconform to the requirements given in Table 2.7. Magnetic Property Requirements7.1 A convenient shop test for differentiating the varioustypes of austenitic gray iron is based on the fact that a groundface of either the test bars or the castings of Types 1, 2, and 4will not attract a small ste
22、el horseshoe-type magnet, that isnormally attracted to steel. Types 1b,2b, 3, and 5 may beattracted to a magnet. This nonmagnetic test is a convenientqualitative test only for Types 1, 2, and 4 and shall not be usedas a basis for acceptance. In the event that nonmagneticcastings are specified, the m
23、agnetic permeability test shall beused. The specific test conditions and magnetic permeabilitylimits shall be agreed upon between the manufacturer and thepurchaser.NOTE 1Alnico magnets should not be used.8. Test Bars8.1 The separately cast test bars from which tension testspecimens are to be machine
24、d shall be cast to the size andshape shown in Fig. 1. The size of bar cast to represent thecasting shall be at the option of the purchaser. In case no optionis expressed, the manufacturer shall make the choice. The testbars shall be cast in open molds made of suitable core sandwith a minimum of 112
25、in. (38 mm) of sand on all sides andbottom of the12-in. (13-mm) and 1-in. (25-mm) sizes, and 3 in.(76 mm) of sand for the 3-in. test bar.8.2 By agreement between the manufacturer and thepurchaser, the 1-in. (25-mm) keel block shown in Fig. 2 may beused. It shall be an open mold made of suitable core
26、 sand witha minimum of 112 in. (38 mm) of sand on all sides and bottom.8.3 It is recommended that test bars be poured immediatelyafter the castings and from the same ladle of metal. If castingsare to be heat treated, test bars shall be included in the samefurnace load.8.4 By agreement between the ma
27、nufacturer and thepurchaser, tension test specimens may be cut directly fromcentrifugal or other permanent mold castings. The location andorientation of such tension test specimens cut from castingsshall be specified as agreed upon by the manufacturer and thepurchaser.9. Workmanship, Finish, and App
28、earance9.1 The castings shall conform substantially to the dimen-sions on the drawings furnished by the purchaser, or if nodrawing has been provided, to the dimensions predicated bythe pattern supplied by the purchaser. The castings shall be freeof injurious defects. Surfaces of the castings shall b
29、e free ofburnt-on sand and shall be reasonably smooth. In otherrespects, the castings shall conform to whatever points may bespecifically agreed upon between the manufacturer and thepurchaser.10. Tension Test Specimens10.1 The round tension test specimen with 2-in. or 50-mmgage length shown in Fig.
30、3 shall be used, except when the12-in. (13-mm) “Y” block is used or when specimens are cutfrom castings under34-in. (19.0-mm) thickness. In these cases,either of the test specimens shown in Fig. 4 shall be satisfac-tory.11. Number of Test11.1 The number of test bars cast shall be agreed upon bythe m
31、anufacturer and the purchaser.11.2 One tension test shall be made from sections cut fromthe test bars as shown in Fig. 5. If any tension test specimenshows obvious defects, another may be cut from the same testbar or from another test bar representing the same metal.12. Other Tests12.1 Hydrostatic t
32、ests for pressure castings, fracture tests,microstructure standards, radiography standards, and liquidpenetrant inspection may be set up by mutual agreementbetween the manufacturer and the purchaser.12.2 Radiography, when required, shall be in accordancewith Guide E94 and Reference Radiographs E446.
33、12.3 Liquid penetrant inspection, when required, shall be inaccordance with Test Method E165 and Reference PhotographsE433.13. Responsibility for Inspection13.1 Unless otherwise specified in the contract or purchaseorder, the manufacturer is responsible for the performance ofall inspection requireme
34、nts as specified herein. Except asotherwise specified in the contract or order, the manufacturermay use his own or any other facilities suitable for theperformance of the inspection requirements specified herein,unless disapproved by the purchaser. The purchaser reservesA436 84 (2015)2the right to p
35、erform any of the inspections set forth in thespecification where such inspections are deemed necessary toassure supplies and services conform to the prescribed require-ments.14. Waiving of Inspection by Agreement14.1 When agreed upon in writing by the purchaser and thesupplier, a certification shal
36、l be made the basis of acceptance ofthe material. This shall consist of a copy of the manufacturerstest report or a statement by the supplier, accompanied by acopy of the test results, that the material has been sampled,tested, and inspected in accordance with the provisions of thespecification spec
37、ified. Each certification so furnished shall besigned by an authorized agent of the supplier or manufacturer.15. Preparation for Delivery15.1 Unless otherwise specified in the contract or purchaseorder, cleaning, preservation, and packaging of castings shallbe in accordance with the manufacturers co
38、mmercial practice.Packing and marking shall also be adequate to ensure accep-tance and safe delivery by the carrier for the mode oftransportation employed.TABLE 1 Chemical RequirementsElement Composition, %Type 1 Type 1b Type 2 Type 2b Type 3 Type 4 Type 5 Type 6Carbon, total, max 3.00 3.00 3.00 3.0
39、0 2.60 2.60 2.40 3.00Silicon 1.002.80 1.002.80 1.002.80 1.002.80 1.002.00 5.006.00 1.002.00 1.502.50Manganese 0.51.5 0.51.5 0.51.5 0.51.5 0.51.5 0.51.5 0.51.5 0.51.5Nickel 13.5017.50 13.5017.50 18.0022.00 18.0022.00 28.0032.00 29.0032.00 34.0036.00 18.0022.00Copper 5.507.50 5.507.50 0.50 max 0.50 ma
40、x 0.50 max 0.50 max 0.50 max 3.505.50Chromium 1.52.5 2.503.50 1.52.5 3.006.00A2.503.50 4.505.50 0.10 max 1.002.00Sulfur, max 0.12 0.12 0.12 0.12 0.12 0.12 0.12 0.12Molybdenum, max . . . . . . . 1.00AWhere some machining is required, the 3.004.00 % chromium range is recommended.TABLE 2 Mechanical Req
41、uirementsType 1 Type 1b Type 2 Type 2b Type 3 Type 4 Type 5 Type 6Tensile strength, min, ksi (MPa) 25 (172) 30 (207) 25 (172) 30 (207) 25 (172) 25 (172) 20 (138) 25 (172)Brinell hardness (3000 kg) 131 183 149 212 118 174 171 248 118 159 149 212 99 124 124 174Dimensions“Y” Block SizeFor Castings of T
42、hickness Lessthan12 in. (13 mm)For Castings of Thickness12 in.(13 mm) to 112 in. (38 mm)For Castings of Thickness of112 in. (38 mm) and Overin. mm in. mm in. mmA12 13 1 25 3 75B158 40 218 54 5 125C 2 50 3 75 4 100D 4 100 6 150 8 200E 7 175 7 175 7 175approx approx approx approx approx approxNOTE 111
43、6 in. = 1.6 mm;18 in. = 3.2 mm.FIG. 1 “Y” Blocks for Test CouponsA436 84 (2015)316. Keywords16.1 austenitic; gray iron castings; high-nickelMetric Equivalentsin.mm121312511238251NOTE 1The length of the keel block shall be 6 in. (152 mm).FIG. 2 Keel Block for Test CouponsMetric Equivalentsin. mm in.
44、mm0.005 0.13 0.50 12.70.01 2.5 2 50.818 3.2 214 57.238 9.5NOTE 1The gage length and fillets shall be as shown but the ends maybe of any shape to fit the holders of the testing machine in such a way thatthe load shall be axial. The reduced section shall have a gradual taper fromthe ends toward the ce
45、nter, with the ends 0.003 to 0.005 in. (0.08 to 0.13mm) larger in diameter than the center.FIG. 3 Standard Round Tension Test Specimen with 2-in. or50-mm Gage LengthMetric Equivalentsin. mm in. mm0.005 0.13 1.0 25.40.007 0.18 114 31.80.252 6.40 1.4 35.60.357 9.07 134 44.4NOTE 1If desired, the length
46、 of the reduced section may be increasedto accommodate an extensometer.FIG. 4 Examples of Small-Size Specimens Proportional to Stan-dard12-in. (12.7-mm) Round SpecimenA436 84 (2015)4ASTM International takes no position respecting the validity of any patent rights asserted in connection with any item
47、 mentionedin this standard. Users of this standard are expressly advised that determination of the validity of any such patent rights, and the riskof infringement of such rights, are entirely their own responsibility.This standard is subject to revision at any time by the responsible technical commi
48、ttee and must be reviewed every five years andif not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standardsand should be addressed to ASTM International Headquarters. Your comments will receive careful consideration at a me
49、eting of theresponsible technical committee, which you may attend. If you feel that your comments have not received a fair hearing you shouldmake your views known to the ASTM Committee on Standards, at the address shown below.This standard is copyrighted by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,United States. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the aboveaddress or at 610-832-9585 (phone)
