1、Designation: A957/A957M 18aStandard 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 Low-Alloy Steel for General Application, andCobalt Alloy for High Strength at ElevatedTemperaturesA743/A743M Castings, Iron-Chromium, Iron-Chromium-Nickel, Corrosion-Resistant, for GeneralApplicationA744/A744M Castings, Iro
6、n-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
7、Requirements Similar to StandardWrought GradesA958/A958M 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 b
8、e applied 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 a
9、n integral 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 sta
10、ted ineach system may not be exact equivalents; therefore, eachsystem shall be used independently of the other. Combiningvalues from the two systems may result in nonconformancewith the standard.1.5 This international standard was developed in accor-dance with internationally recognized principles o
11、n standard-ization established in the Decision on Principles for theDevelopment of International Standards, Guides and Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trade (TBT) Committee.2. Referenced Documents2.1 ASTM Standards:2A27/A27M Specification for Steel Castin
12、gs, Carbon, forGeneral ApplicationA128/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 Applicat
13、ionA370 Test Methods and Definitions for Mechanical Testingof Steel ProductsA380/A380MA447/A447M Specification for Steel Castings, Chromium-Nickel-Iron Alloy (25-12 Class), for High-TemperatureService1This specification is under the jurisdiction of ASTM Committee A01 on Steel,Stainless Steel and Rel
14、ated Alloys and is the direct responsibility of SubcommitteeA01.18 on Castings.Current edition approved Sept. 1, 2018. Published September 2018. Originallyapproved in 1996. Last previous edition approved in 2018 as A957/A957M 18.DOI: 10.1520/A0957_A0957M-18A.2For referenced ASTM standards, visit the
15、 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.*A Summary of Changes section appears at the end of this standardCopyright ASTM International, 100 Bar
16、r Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United StatesThis international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for theDevelopment of International Standards, Guides and Recomm
17、endations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.1A488/A488M Practice for Steel Castings, Welding, Qualifi-cations of Procedures and PersonnelA494/A494M Specification for Castings, Nickel and NickelAlloyA560/A560M Specification for Castings, Chromium-Nicke
18、lAlloyA609/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 at Elevated TemperaturesA743/A743M Specifi
19、cation 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,Precipitation HardeningA751 Test Methods, Pra
20、ctices, 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(Austenitic/Ferritic) for General ApplicationA90
21、3/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 Relating to Steel, Stainless Steel, Relate
22、dAlloys, and FerroalloysA958/A958M Specification for Steel Castings, Carbon andAlloy, with Tensile Requirements, Chemical Require-ments Similar to Standard Wrought GradesA967/A967M Specification for Chemical Passivation Treat-ments for Stainless Steel PartsA991/A991M Test Method for Conducting Tempe
23、ratureUniformity 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 SteelProductsMetricA1067/A1067M Spec
24、ification for Test Coupons for SteelCastingsA1080 Practice for Hot Isostatic Pressing of Steel, StainlessSteel, and Related Alloy CastingsE29 Practice for Using Significant Digits in Test Data toDetermine Conformance with SpecificationsE94/E94M Guide for Radiographic Examination Using In-dustrial Ra
25、diographic FilmE125 Reference Photographs for Magnetic Particle Indica-tions on Ferrous CastingsE165/E165M Practice for Liquid Penetrant Examination forGeneral IndustryE186 Reference Radiographs for Heavy-Walled (2 to 412 in.(50.8 to 114 mm) Steel CastingsE192 Reference Radiographs of Investment Ste
26、el Castingsfor Aerospace ApplicationsE280 Reference Radiographs for Heavy-Walled (412 to 12in. (114 to 305 mm) Steel CastingsE340 Practice for Macroetching Metals and AlloysE353 Test Methods for Chemical Analysis of Stainless,Heat-Resisting, Maraging, and Other Similar Chromium-Nickel-Iron AlloysE35
27、4 Test Methods for Chemical Analysis of High-Temperature, Electrical, Magnetic, and Other Similar 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 C
28、ast-ings for Aerospace Applications2.2 SAE Aerospace Recommended Practice:3ARP 1341 Determining 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 Termin
29、ology A751, TerminologyA941, and Test Methods A1058 are applicable to this specifi-cation and to those listed in 1.1.3.2 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
30、 ceramic slurry that is allowed to solidify. Theexpendable pattern may consist of wax, plastic, or othermaterial and 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
31、 the desired composition and properties.3.2.3 sub-heat, na portion of a master heat remeltedwithout additional processing for pouring into castings.Synonymsmelt, production heat.4. Materials and Manufacture4.1 When the purchaser imposes the requirements of thisspecification, the manufacturer is resp
32、onsible for compliancewith the specification requirements during the production andprocessing of the casting by themselves and any of theirsubcontractors.4.2 Melting ProcessMaster heats shall be made by theelectric furnace process, with or without separate refining suchas argon-oxygen-decarburizatio
33、n (AOD), vacuum-oxygen-degassing (VOD), vacuum-induction-melting (VIM), and so3Available from Society of Automotive Engineers (SAE), 400 CommonwealthDr., Warrendale, PA 15096-0001, http:/www.sae.org.A957/A957M 18a2forth, unless otherwise specified in the individual specificationor agreed upon betwee
34、n 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 production, for later remelting as asub-heat.4.3 Re-Melting ProcessSub-heats shall be produced frommaster heat me
35、tal 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 between the customer and pro-ducer. Revert (gates, sprues, risers, and rejected castings) shallnot be r
36、e-melted except in master heats.4.4 Sampling:4.4.1 If castings 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.4.4.2 If castings are poured from a sub-heat, then thesamples for chemic
37、al 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 be produced using thesame melting practices and additions as used to produce thecastings.4.4.3 Unless oth
38、erwise specified by the purchaser, testspecimens may be taken from castings or from coupons castintegrally with the castings, in the same molds as the castings,or in separate molds.4.5 Heat Treatment:4.5.1 Castings shall be heat treated in the working zone of afurnace that has been surveyed in accor
39、dance with Test MethodA991/A991M.4.5.2 When castings are heat treated at temperatures above2000 F 1100 C, then the working zone shall have beenestablished by a survey performed at not more than 25 F15 C below nor more than 200 F 110 C above theminimum heat treatment temperature specified for the gra
40、de. Ifa minimum heat treatment temperature is not specified for thegrade, then the survey temperature shall be not more than 50 F30 C below nor more than 175 F 100 C above thefurnace set point used.4.5.3 The maximum variation in measured temperature, asdetermined by the difference between the highes
41、t temperatureand the lowest temperature, shall be as agreed between thepurchaser 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 Co
42、mposition5.1 Chemical AnalysisChemical analysis of materialscovered by this specification shall be in accordance with TestMethods, Practices, and Terminology A751.5.2 Heat AnalysisAn analysis of samples obtained inaccordance with 4.4 or Supplementary Requirement S20, asappropriate, shall be made by
43、the manufacturer to determinethe percentages of the elements specified in the individualspecification for the grade being poured. When drillings areused, they shall be taken not less than116 in. 2 mm beneaththe surface. The chemical composition thus determined shallconform to the requirements in the
44、 individual specification forthe grade being poured.5.3 Product AnalysisA 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 sha
45、ll be taken no closer than116 in. 2 mm toa cast surface, except that castings 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 reje
46、ction by the purchaser, except that the chemicalcomposition determined for carbon and low-alloy steel andstainless steel castings may vary from the specified limits bythe amounts shown in Table 1 and Table 2, respectively. Theproduct analysis tolerances of Table 1 are not applicable asacceptance cri
47、teria for heat analysis by the casting manufac-turer. When comparing product and heat analysis for other thancarbon and low-alloy steels, and stainless steels, the reproduc-ibility data R2 in Test Methods E353 or E354, as applicable,shall be taken into consideration.TABLE 1 Product Analysis Toleranc
48、es Carbon and Low-AlloySteelsElement 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 0.09Si 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%Cr
49、L+ 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 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 subscriptLfor the elements in each equation indicates that the limits of theelement specified by the applicable specification are to be inserted into theeq
