1、Designation: A957/A957M 11aStandard Specification forInvestment Castings, Steel and Alloy, CommonRequirements, for General Industrial Use1This standard is issued under the fixed designation A957/A957M; the number immediately following the designation indicates the yearof original adoption or, in the
2、 case of 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 a group of requirements thatare mandatory for castings produ
3、ced by the investment castingprocess to meet the metallurgical requirements of the followingsteel casting specifications issued by ASTM.ASTM Designation Title of SpecificationA27/A27M Steel Castings, Carbon, for General Ap-plicationA148/A148M Steel Castings, High-Strength, for Struc-tural PurposesA2
4、97/A297M Steel Castings, Iron-Chromium and Iron-Chromium-Nickel, Heat-Resistant, forGeneral ApplicationA447/A447M Steel Castings, Chromium-Nickel-Iron Al-loy (25-12 Class), for High-TemperatureServiceA494/A494M Castings, Nickel and Nickel AlloyA560/A560M Castings, Chromium-Nickel AlloyA732/A732M Cas
5、tings, Investment, Carbon and LowAlloy Steel for General Application, andCobalt Alloy for High Strength at ElevatedTemperaturesA743/A743M Castings, Iron-Chromium, Iron-Chromium-Nickel, Corrosion-Resistant, for GeneralApplicationA744/A744M Castings, Iron-Chromium-Nickel, Corro-sion Resistant, for Sev
6、ere ServiceA747/A747M Steel Castings, Stainless, PrecipitationHardeningA890/A890M Castings, Iron-Chromium-Nickel-Molybdenum Corrosion-Resistant, Duplex(Austenitic/Ferritic) for General Applica-tionA915/A915M Steel Castings, Carbon and Alloy, Chemi-cal Requirements Similar to StandardWrought GradesA9
7、58 Steel Castings, Carbon and Alloy, withTensile Requirements, Chemical Require-ments Similar to Standard WroughtGrades1.2 This specification also covers a group of supplementaryrequirements that may be applied to the above specifications asindicated therein. These are provided for use when addition
8、altesting or inspection is desired and apply only when specifiedindividually by the purchaser in the order.1.3 When investment castings are ordered, the requirementsstated in this specification form an integral part of the materialspecification. In cases of conflict, the requirements of thisspecific
9、ation shall take precedence over the individual materialspecification requirements.1.4 The values stated in either SI units or inch-pound unitsare to be regarded separately as standard. The values stated ineach system may not be exact equivalents; therefore, eachsystem shall be used independently of
10、 the other. Combiningvalues from the two systems may result in non-conformancewith the standard.2. Referenced Documents2.1 ASTM Standards:2A27/A27M Specification for Steel Castings, Carbon, forGeneral ApplicationA148/A148M Specification for Steel Castings, HighStrength, for Structural PurposesA297/A
11、297M Specification for Steel Castings, Iron-Chromium and Iron-Chromium-Nickel, Heat Resistant, forGeneral ApplicationA370 Test Methods and Definitions for Mechanical Testingof Steel ProductsA380 Practice for Cleaning, Descaling, and Passivation ofStainless Steel Parts, Equipment, and SystemsA447/A44
12、7M Specification for Steel Castings, Chromium-Nickel-Iron Alloy (25-12 Class), for High-TemperatureServiceA488/A488M Practice for Steel Castings, Welding, Quali-fications of Procedures and PersonnelA494/A494M Specification for Castings, Nickel and NickelAlloyA560/A560M Specification for Castings, Ch
13、romium-NickelAlloyA609/A609M Practice for Castings, Carbon, Low-Alloy,and Martensitic Stainless Steel, Ultrasonic ExaminationThereofA732/A732M Specification for Castings, Investment, Car-bon and Low Alloy Steel for General Application, and1This specification is under the jurisdiction of ASTM Committ
14、ee A01 on Steel,Stainless Steel and Related Alloys and is the direct responsibility of SubcommitteeA01.18 on Castings.Current edition approved Oct. 1, 2011. Published November 2011. Originallyapproved in 1996. Last previous edition approved in 2011 as A957/A957M 11.DOI: 10.1520/A0957_A0957M-11A.2For
15、 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 website.1*A Summary of Changes section appears at the end of this standar
16、d.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.Cobalt Alloy for High Strength at Elevated TemperaturesA743/A743M Specification for Castings, Iron-Chromium,Iron-Chromium-Nickel, Corrosion Resistant, for GeneralApplicationA744/A744M
17、Specification for Castings, Iron-Chromium-Nickel, Corrosion Resistant, for Severe ServiceA747/A747M Specification for Steel Castings, Stainless,Precipitation HardeningA751 Test Methods, Practices, and Terminology for Chemi-cal Analysis of Steel ProductsA800/A800M Practice for Steel Casting, Austenit
18、ic Alloy,Estimating Ferrite Content ThereofA890/A890M Specification for Castings, Iron-Chromium-Nickel-Molybdenum Corrosion-Resistant, Duplex(Austenitic/Ferritic) for General ApplicationA903/A903M Specification for Steel Castings, Surface Ac-ceptance Standards, Magnetic Particle and Liquid Pen-etran
19、t InspectionA915/A915M Specification for Steel Castings, Carbon, andAlloy, Chemical Requirements Similar to StandardWrought GradesA941 Terminology Relating to Steel, Stainless Steel, Re-lated Alloys, and FerroalloysA958 Specification for Steel Castings, Carbon and Alloy,with Tensile Requirements, Ch
20、emical Requirements Simi-lar to Standard Wrought GradesA967 Specification for Chemical Passivation Treatmentsfor Stainless Steel PartsA991/A991M Test Method for Conducting TemperatureUniformity Surveys of Furnaces Used to Heat Treat SteelProductsA997 Practice for Investment Castings, Surface Accepta
21、nceStandards, Visual ExaminationA1067 Specification for Test Coupons for Steel CastingsE29 Practice for Using Significant Digits in Test Data toDetermine Conformance with SpecificationsE94 Guide for Radiographic ExaminationE125 Reference Photographs for Magnetic Particle Indica-tions on Ferrous Cast
22、ingsE165 Practice for Liquid Penetrant Examination for GeneralIndustryE186 Reference Radiographs for Heavy-Walled (2 to 412-in. (50.8 to 114-mm) Steel CastingsE192 Reference Radiographs of Investment Steel Castingsfor Aerospace ApplicationsE280 Reference Radiographs for Heavy-Walled (412 to12-in. (1
23、14 to 305-mm) Steel CastingsE340 Test Method for Macroetching Metals and AlloysE353 Test Methods for Chemical Analysis of Stainless,Heat-Resisting, Maraging, and Other Similar Chromium-Nickel-Iron AlloysE354 Test Methods for Chemical Analysis of High-Temperature, Electrical, Magnetic, and Other Simi
24、lar Iron,Nickel, and Cobalt AlloysE446 Reference Radiographs for Steel Castings Up to 2 in.(50.8 mm) in ThicknessE709 Guide for Magnetic Particle TestingE2660 Digital Reference Images for Investment Steel Cast-ings for Aerospace Applications2.2 SAE Aerospace Recommended Practice:3ARP 1341 Determinin
25、g Decarburization and Carburizationin Finished Parts of Carbon and Low-Alloy Steel3. Terminology3.1 Definitions:3.1.1 The definitions in Test Methods and Definitions A370,Test Methods, Practices, and Terminology A751, and Termi-nology A941 are applicable to this specification and to thoselisted in 1
26、.1.3.2 Definitions of Terms Specific to This Standard:3.2.1 investment casting, na metal casting that is pro-duced in a mold obtained by investing (surrounding) anexpendable pattern with a ceramic slurry that is allowed tosolidify. The expendable pattern may consist of wax, plastic, orother material
27、 and is removed prior to filling the mold withliquid metal.3.2.2 master heat, na quantity of metal processed in asingle furnace or refining vessel at one time in such a manneras to produce the desired composition and properties.3.2.3 sub-heat, na portion of a master heat remeltedwithout additional p
28、rocessing for pouring into castings. Syn-onyms: melt, production heat.4. Materials and Manufacture4.1 Melting ProcessMaster heats shall be made by theelectric furnace process with or without separate refining suchas argon-oxygen-decarburization (AOD), vacuum-oxygen-degassing (VOD), vacuum-induction-
29、melting (VIM), and soforth, unless otherwise specified in the individual specificationor agreed upon between the customer and producer. Masterheats may be used directly for producing castings or convertedinto ingot, bar, shot, or other suitable form, not including gatesand risers from casting produc
30、tion, for later remelting as asub-heat.4.2 Re-Melting ProcessSub-heats shall be produced frommaster heat metal in suitable batch sizes by electric inductionfurnace with or without atmosphere protection such as vacuumor inert gas unless otherwise specified in the individualspecification or agreed upo
31、n between the customer and pro-ducer. Revert (gates, sprues, risers, and rejected castings) shallnot be re-melted except in master heats.4.3 Sampling:4.3.1 If castings are poured directly from one or moremaster heats, then the samples for chemical and other requiredtesting shall also be poured direc
32、tly from each of the masterheats.4.3.2 If castings are poured from a sub-heat, then thesamples for chemical and other required testing shall also bepoured from a sub-heat of that same master heat, but notnecessarily from the same sub-heat as the castings. Thesub-heat used for the test samples shall
33、be produced using thesame practices and additions as used for the castings.3Available from Society of Automotive Engineers (SAE), 400 CommonwealthDr., Warrendale, PA 15096-0001, http:/www.sae.org.A957/A957M 11a24.3.3 Unless otherwise specified by the purchaser, testspecimens may be taken from castin
34、gs or from coupons castintegrally with the castings, in the same molds as the castings,or in separate molds.4.4 Heat Treatment:4.4.1 Castings shall be heat treated in the working zone of afurnace that has been surveyed in accordance with Test MethodA991/A991M.4.4.2 When castings are heat treated at
35、temperatures above2000F (1100C), then the working zone shall have beenestablished by a survey performed at not more than 25F(15C) below nor more than 200F (110C) above the mini-mum heat treatment temperature specified for the grade. If aminimum heat treatment temperature is not specified for thegrad
36、e, then the survey temperature shall be not more than 50F(30C) below nor more than 175F (100C) above the furnaceset point used.4.4.3 The maximum variation in measured temperature asdetermined by the difference between the highest temperatureand the lowest temperature shall be as agreed between thepu
37、rchaser and producer except that during production heattreatment, no portion of the furnace shall be below theminimum specified temperature nor above the maximumspecified temperature for the grade being processed.5. Chemical Composition5.1 Chemical AnalysisChemical analysis of materialscovered by th
38、is specification shall be in accordance with TestMethods, Practices, and Terminology A751.5.2 Heat AnalysisAn analysis of samples obtained inaccordance with 4.3 or Supplementary Requirement S17 asappropriate, shall be made by the manufacturer to determinethe percentages of the elements specified in
39、the individualspecification for the grade being poured. When drillings areused, they shall be taken not less than116 in. 1.6 mm beneaththe surface. The chemical composition thus determined shallconform to the requirements in the individual specification forthe grade being poured.5.3 Product Analysis
40、A product analysis may be made bythe purchaser from material representing each master heat,sub-heat, lot, or casting. The analysis shall be made onrepresentative material. Samples for carbon analysis of carbonand alloy steel shall be taken no closer than116 in. 1.6 mm toa cast surface, except that c
41、astings too thin for this shall beanalyzed on representative material. The chemical compositionthus determined shall meet the requirements specified in theapplicable specification for the grade involved, or shall besubject to rejection by the purchaser, except that the chemicalcomposition determined
42、 for carbon and low alloy steel castingsmay vary from the specified limits by the amounts shown inTable 1. The product analysis tolerances of Table 1 are notapplicable as acceptance criteria for heat analysis by thecasting manufacturer. When comparing product and heatanalysis for other than carbon a
43、nd low alloy steels, thereproducibility Data R2, in Test Methods E353 or E354,asapplicable, shall be taken into consideration.5.4 Unspecified ElementsWhen chemical analysis for el-ements not specified for the grade ordered is desired, Supple-mentary Requirement S13 may be specified.NOTE 1All commerc
44、ial metals contain small amounts of variouselements in addition to those that are specified. It is neither practical nornecessary to specify limits for every unspecified element that might bepresent, despite the fact that the presence of many of these elements isoften routinely determined by the pro
45、ducer.5.5 Grade substitutionGrade substitution is not permitted.Grade substitution occurs when the material being suppliedcontains one or more elements that are not specified for thesupplied material such that the material conforms to therequirements of a different grade.6. Mechanical Requirements6.
46、1 The individual product specifications vary as to whethermechanical tests are required; for this reason, and to determinespecific test requirements, the individual product specificationshould be reviewed. If mechanical testing is required by theproduct specification, sampling shall be in accordance
47、 with 4.3or with Supplementary Requirement S18 as appropriate.6.2 Unless otherwise specified by the purchaser, whenmechanical properties are required by the product specifica-tion, test coupons may be taken from castings, may be castintegrally with the castings, or may be cast in separate molds ofth
48、e same type and material as those used for the castings, inaccordance with Specification A1067, Fig. 1, Fig. 2, Fig. 3, orFig. 4, except when Supplementary Requirement S15 isspecified. The test coupon in Specification A1067, Fig. 4 shallTABLE 1 Product Analysis TolerancesElement Range, %ATolerancesB
49、,COverMaximum or UnderMinimum Limit, %C up to 0.65 0.03 3 %CL+ 0.02above 0.65 0.04Mn up to 1 0.08 3 %MnL+ 0.01above 1 0.09Si up to 0.60 0.22 3 %SiL 0.01above 0.60 0.15P all 0.13 3 %PL+ 0.005S all 0.36 3 %SL+ 0.001Ni up to 2 0.10 3 %NiL+ 0.03above 2 0.25Cr up to 2 0.07 3 %CrL+ 0.04above 2 0.18Mo up to 0.6 0.04 3 %MoL+ 0.03above 0.6 0.06V up to 0.25 0.23 3 %VL+ 0.004above 0.25 0.06W up to 0.10 0.08 3 %WL+ 0.02above 0.10 0.02Cu up to 0.15 0.18 3 %CuL+ 0.02above 0.15 0.05Al up to 0.10 0.08 3 %AlL+ 0.02above 0.10 0.03ATherangedenotesthecompositionlimitsupto
