1、Designation: A957/A957M 12aStandard 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-plicationA128/A128M Steel Castings, Austenitic ManganeseA148/A148M Steel Cast
4、ings, High-Strength, for Struc-tural PurposesA297/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/A560
5、M Castings, Chromium-Nickel AlloyA732/A732M Castings, 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
6、-Chromium-Nickel, Corro-sion Resistant, for Severe 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 R
7、equirements Similar to StandardWrought GradesA958 Steel Castings, Carbon and Alloy, withTensile Requirements, Chemical Require-ments Similar to Standard WroughtGradesA1002 Castings, Nickel-Aluminum Ordered Alloy1.2 This specification also covers a group of supplementaryrequirements that may be appli
8、ed to the above specifications asindicated therein. These are provided for use when additionaltesting 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 integr
9、al part of the materialspecification. In cases of conflict, the requirements of thisspecification 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 inea
10、ch system may not be exact equivalents; therefore, eachsystem shall be used independently of 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 Applica
11、tionA128/A128M Specification for Steel Castings, AusteniticManganeseA148/A148M Specification for Steel Castings, HighStrength, for Structural PurposesA297/A297M Specification for Steel Castings, Iron-Chromium and Iron-Chromium-Nickel, Heat Resistant,for General ApplicationA370 Test Methods and Defin
12、itions for Mechanical Testingof Steel ProductsA380 Practice for Cleaning, Descaling, and Passivation ofStainless Steel Parts, Equipment, and SystemsA447/A447M Specification for Steel Castings, Chromium-Nickel-Iron Alloy (25-12 Class), for High-TemperatureServiceA488/A488M Practice for Steel Castings
13、, Welding, Qualifi-cations of Procedures and PersonnelA494/A494M Specification for Castings, Nickel and NickelAlloyA560/A560M Specification for Castings, Chromium-NickelAlloy1This specification is under the jurisdiction of ASTM Committee A01 on Steel,Stainless Steel and Related Alloys and is the dir
14、ect responsibility of SubcommitteeA01.18 on Castings.Current edition approved Sept. 1, 2012. Published October 2012. Originallyapproved in 1996. Last previous edition approved in 2012 as A957/A957M 12.DOI: 10.1520/A0957_A0957M-12A.2For referenced ASTM standards, visit the ASTM website, www.astm.org,
15、 orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.*A Summary of Changes section appears at the end of this standardCopyright ASTM International, 100 Barr Harbor Drive, PO Box C700,
16、 West Conshohocken, PA 19428-2959. United States1A609/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, andCobalt Alloy for High Strength
17、 at Elevated TemperaturesA743/A743M Specification for Castings, Iron-Chromium,Iron-Chromium-Nickel, Corrosion Resistant, for GeneralApplicationA744/A744M Specification for Castings, Iron-Chromium-Nickel, Corrosion Resistant, for Severe ServiceA747/A747M Specification for Steel Castings, Stainless,Pr
18、ecipitation HardeningA751 Test Methods, Practices, and Terminology for Chemi-cal Analysis of Steel ProductsA800/A800M Practice for Steel Casting, Austenitic Alloy,Estimating Ferrite Content ThereofA890/A890M Specification for Castings, Iron-Chromium-Nickel-Molybdenum Corrosion-Resistant, Duplex(Aust
19、enitic/Ferritic) for General ApplicationA903/A903M Specification for Steel Castings, Surface Ac-ceptance Standards, Magnetic Particle and Liquid Pen-etrant InspectionA915/A915M Specification for Steel Castings, Carbon, andAlloy, Chemical Requirements Similar to StandardWrought GradesA941 Terminology
20、 Relating to Steel, Stainless Steel, RelatedAlloys, and FerroalloysA958 Specification for Steel Castings, Carbon and Alloy,with Tensile Requirements, Chemical Requirements Simi-lar to Standard Wrought GradesA967 Specification for Chemical Passivation Treatments forStainless Steel PartsA991/A991M Tes
21、t Method for Conducting TemperatureUniformity Surveys of Furnaces Used to Heat Treat SteelProductsA997 Practice for Investment Castings, Surface AcceptanceStandards, Visual ExaminationA1002 Specification for Castings, Nickel-Aluminum Or-dered AlloyA1058 Test Methods for Mechanical Testing of SteelPr
22、oductsMetricA1067 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 CastingsE165 Practice fo
23、r 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 to 12-in. (114 to 305-mm) Steel
24、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 Similar Iron,Nickel, and
25、 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 Determining Decarburization an
26、d 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, TerminologyA941, and Test Methods A1058 are applicable to this specifi-cation and to those listed in 1
27、.1.3.2 Definitions of Terms Specific to This Standard:3.2.1 investment casting, na metal casting that is producedin a mold obtained by investing (surrounding) an expendablepattern with a ceramic slurry that is allowed to solidify. Theexpendable pattern may consist of wax, plastic, or othermaterial a
28、nd is removed prior to filling the mold with liquidmetal.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 pro
29、cessing 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-me
30、lting (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 producti
31、on, 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 upon
32、between the customer and pro-ducer. Revert (gates, sprues, risers, and rejected castings) shallnot be re-melted except in master heats.4.3 Sampling:3Available from Society of Automotive Engineers (SAE), 400 CommonwealthDr., Warrendale, PA 15096-0001, http:/www.sae.org.A957/A957M 12a24.3.1 If casting
33、s are poured directly from one or moremaster heats, then the samples for chemical and other requiredtesting shall also be poured directly 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-
34、heat of that same master heat, but notnecessarily from the same sub-heat as the castings. Thesub-heat used for the test samples shall be produced using thesame practices and additions as used for the castings.4.3.3 Unless otherwise specified by the purchaser, testspecimens may be taken from castings
35、 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 te
36、mperatures 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 thegrade,
37、 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 thepurc
38、haser 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 this
39、 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 S20 asappropriate, shall be made by the manufacturer to determinethe percentages of the elements specified in th
40、e 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 AnalysisA
41、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 cas
42、tings 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 f
43、or 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 and
44、 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 commercia
45、l 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 produ
46、cer.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 Test Requirement
47、s6.1 The individual product specifications vary as to whethermechanical tests are required; for this reason, and to determineTABLE 1 Product Analysis TolerancesElement Range, %ATolerancesB,COverMaximum or UnderMinimum Limit, %C upto0.65 0.03%CL+ 0.02above 0.65 0.04Mn upto1 0.08%MnL+ 0.01above 1 0.09
48、Si upto0.60 0.22%SiL 0.01above 0.60 0.15P all 0.13%PL+ 0.005S all 0.36%SL+ 0.001Ni upto2 0.10%NiL+ 0.03above 2 0.25Cr upto2 0.07%CrL+ 0.04above 2 0.18Mo upto0.6 0.04%MoL+ 0.03above 0.6 0.06V upto0.25 0.23%VL+ 0.004above 0.25 0.06W upto0.10 0.08%WL+ 0.02above 0.10 0.02Cu upto0.15 0.18%CuL+ 0.02above
49、0.15 0.05Al up to 0.10 0.08 % AlL+ 0.02above 0.10 0.03AThe range denotes the composition limits up to which tolerances are computedby the equation, and above which the tolerances are given by a constant.BThe subscript L for the elements in each equation indicates that the limits of theelement specified by the applicable specification are to be inserted into theequation to calculate the tolerance for the upper limit and the lower limit (ifapplicable), respectively. Examples of computing tolerances are presented infootnote C.CTo illustrat
