1、Designation: A957/A957M 12aA957/A957M 13Standard 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 adopti
2、on or, in the 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 that are mandatory for
3、castings produced by the investment castingprocess to meet the metallurgical requirements of the following steel casting specifications issued by ASTM.ASTM Designation Title of SpecificationA27/A27M Steel Castings, Carbon, for General Ap-plicationA128/A128M Steel Castings, Austenitic ManganeseA148/A
4、148M Steel Castings, 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
5、 AlloyA560/A560M 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
6、 Castings, Iron-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 All
7、oy, Chemi-cal Requirements 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 supplementary requirements t
8、hat may be applied to the above specifications asindicated therein. These are provided for use when additional testing or inspection is desired and apply only when specifiedindividually by the purchaser in the order.1.3 When investment castings are ordered, the requirements stated in this specificat
9、ion form an integral part of the materialspecification. In cases of conflict, the requirements of this specification shall take precedence over the individual materialspecification requirements.1 This specification is under the jurisdiction ofASTM Committee A01 on Steel, Stainless Steel and RelatedA
10、lloys and is the direct responsibility of Subcommittee A01.18on Castings.Current edition approved Sept. 1, 2012May 1, 2013. Published October 2012May 2013. Originally approved in 1996. Last previous edition approved in 2012 asA957/A957M 12.A957/A957M 12a. DOI: 10.1520/A0957_A0957M-12A.10.1520/A0957_
11、A0957M-13.This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Becauseit may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult
12、 prior editions as appropriate. In all cases only the current versionof the standard as published by ASTM is to be considered the official document.*A Summary of Changes section appears at the end of this standardCopyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA
13、 19428-2959. United States11.4 The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in eachsystem may not be exact equivalents; therefore, each system shall be used independently of the other. Combining values from thetwo systems may r
14、esult in non-conformance with the standard.2. Referenced Documents2.1 ASTM Standards:2A27/A27M Specification for Steel Castings, Carbon, for General ApplicationA128/A128M Specification for Steel Castings, Austenitic ManganeseA148/A148M Specification for Steel Castings, High Strength, for Structural
15、PurposesA297/A297M Specification for Steel Castings, Iron-Chromium and Iron-Chromium-Nickel, Heat Resistant, for GeneralApplicationA370 Test Methods and Definitions for Mechanical Testing of Steel ProductsA380 Practice for Cleaning, Descaling, and Passivation of Stainless Steel Parts, Equipment, and
16、 SystemsA447/A447M Specification for Steel Castings, Chromium-Nickel-Iron Alloy (25-12 Class), for High-Temperature ServiceA488/A488M Practice for Steel Castings, Welding, Qualifications of Procedures and PersonnelA494/A494M Specification for Castings, Nickel and Nickel AlloyA560/A560M Specification
17、 for Castings, Chromium-Nickel AlloyA609/A609M Practice for Castings, Carbon, Low-Alloy, and Martensitic Stainless Steel, Ultrasonic Examination ThereofA732/A732M Specification for Castings, Investment, Carbon and Low Alloy Steel for General Application, and Cobalt Alloyfor High Strength at Elevated
18、 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, Precipitatio
19、n HardeningA751 Test Methods, Practices, and Terminology for Chemical 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/Fe
20、rritic) for General ApplicationA903/A903M Specification for Steel Castings, Surface Acceptance Standards, Magnetic Particle and Liquid PenetrantInspectionA915/A915M Specification for Steel Castings, Carbon, andAlloy, Chemical Requirements Similar to Standard Wrought GradesA941 Terminology Relating t
21、o Steel, Stainless Steel, Related Alloys, and FerroalloysA958 Specification for Steel Castings, Carbon and Alloy, with Tensile Requirements, Chemical Requirements Similar toStandard Wrought GradesA967 Specification for Chemical Passivation Treatments for Stainless Steel PartsA991/A991M Test Method f
22、or Conducting Temperature Uniformity Surveys of Furnaces Used to Heat Treat Steel ProductsA997 Practice for Investment Castings, Surface Acceptance Standards, Visual ExaminationA1002 Specification for Castings, Nickel-Aluminum Ordered AlloyA1058 Test Methods for Mechanical Testing of Steel ProductsM
23、etricA1067 Specification for Test Coupons for Steel CastingsA1080 Practice for Hot Isostatic Pressing of Steel, Stainless Steel, and Related Alloy CastingsE29 Practice for Using Significant Digits in Test Data to Determine Conformance with SpecificationsE94 Guide for Radiographic ExaminationE125 Ref
24、erence Photographs for Magnetic Particle Indications on Ferrous CastingsE165 Practice for Liquid Penetrant Examination for General IndustryE186 Reference Radiographs for Heavy-Walled (2 to 412-in. (50.8 to 114-mm) Steel CastingsE192 Reference Radiographs of Investment Steel Castings for Aerospace Ap
25、plicationsE280 Reference Radiographs for Heavy-Walled (412 to 12-in. (114 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-IronAlloysE354 Test Methods for Chem
26、ical Analysis of High-Temperature, Electrical, Magnetic, and Other Similar Iron, Nickel, andCobalt 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 Castings for Aerospace
27、Applications2 For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standardsvolume information, refer to the standards Document Summary page on the ASTM website.A957/A957M 1322.2 SAE Aerospace Recommended Pract
28、ice:3ARP 1341 Determining Decarburization and Carburization in 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 t
29、o this specification 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 produced in a mold obtained by investing (surrounding) an expendablepattern with a ceramic slurry that is allowed to solidify. The expendable pattern
30、may consist of wax, plastic, or other material andis removed prior to filling the mold with liquid metal.3.2.2 master heat, na quantity of metal processed in a single furnace or refining vessel at one time in such a manner as toproduce the desired composition and properties.3.2.3 sub-heat, na portio
31、n of a master heat remelted without additional processing for pouring into castings. Synonyms: melt,production heat.4. Materials and Manufacture4.1 Melting ProcessMaster heats shall be made by the electric furnace process with or without separate refining such asargon-oxygen-decarburization (AOD), v
32、acuum-oxygen-degassing (VOD), vacuum-induction-melting (VIM), and so forth, unlessotherwise specified in the individual specification or agreed upon between the customer and producer. Master heats may be useddirectly for producing castings or converted into ingot, bar, shot, or other suitable form,
33、not including gates and risers from castingproduction, for later remelting as a sub-heat.4.2 Re-Melting ProcessSub-heats shall be produced from master heat metal in suitable batch sizes by electric inductionfurnace with or without atmosphere protection such as vacuum or inert gas unless otherwise sp
34、ecified in the individual specificationor agreed upon between the customer and producer. Revert (gates, sprues, risers, and rejected castings) shall not be re-meltedexcept in master heats.4.3 Sampling:4.3.1 If castings are poured directly from one or more master heats, then the samples for chemical
35、and other required testingshall also be poured directly from each of the master heats.4.3.2 If castings are poured from a sub-heat, then the samples for chemical and other required testing shall also be poured froma sub-heat of that same master heat, but not necessarily from the same sub-heat as the
36、 castings. The sub-heat used for the testsamples shall be produced using the same practices and additions as used for the castings.4.3.3 Unless otherwise specified by the purchaser, test specimens may be taken from castings or from coupons cast integrallywith the castings, in the same molds as the c
37、astings, or in separate molds.4.4 Heat Treatment:4.4.1 Castings shall be heat treated in the working zone of a furnace that has been surveyed in accordance with Test MethodA991/A991M.4.4.2 When castings are heat treated at temperatures above 2000F (1100C), then the working zone shall have been estab
38、lishedby a survey performed at not more than 25F (15C) below nor more than 200F (110C) above the minimum heat treatmenttemperature specified for the grade. If a minimum heat treatment temperature is not specified for the grade, then the surveytemperature shall be not more than 50F (30C) below nor mo
39、re than 175F (100C) above the furnace set point used.4.4.3 The maximum variation in measured temperature as determined by the difference between the highest temperature and thelowest temperature shall be as agreed between the purchaser and producer except that during production heat treatment, no po
40、rtionof the furnace shall be below the minimum specified temperature nor above the maximum specified temperature for the grade beingprocessed.5. Chemical Composition5.1 Chemical AnalysisChemical analysis of materials covered by this specification shall be in accordance with Test Methods,Practices, a
41、nd Terminology A751.5.2 Heat AnalysisAn analysis of samples obtained in accordance with 4.3 or Supplementary Requirement S20 as appropriate,shall be made by the manufacturer to determine the percentages of the elements specified in the individual specification for thegrade being poured. When drillin
42、gs are used, they shall be taken not less than 116 in. 1.6 mm beneath the surface. The chemicalcomposition thus determined shall conform to the requirements in the individual specification for the grade being poured.3 Available from Society of Automotive Engineers (SAE), 400 Commonwealth Dr., Warren
43、dale, PA 15096-0001, http:/www.sae.org.A957/A957M 1335.3 Product AnalysisAproduct analysis may be made by the purchaser from material representing each master heat, sub-heat,lot, or casting. The analysis shall be made on representative material. Samples for carbon analysis of carbon and alloy steel
44、shallbe taken no closer than 116 in. 1.6 mm to a cast surface, except that castings too thin for this shall be analyzed on representativematerial. The chemical composition thus determined shall meet the requirements specified in the applicable specification for thegrade involved, or shall be subject
45、 to rejection by the purchaser, except that the chemical composition determined for carbon andlow alloy steel castings may vary from the specified limits by the amounts shown in Table 1. The product analysis tolerances ofTable 1 are not applicable as acceptance criteria for heat analysis by the cast
46、ing manufacturer. When comparing product and heatanalysis for other than carbon and low alloy steels, the reproducibility Data R2, in Test Methods E353 or E354, as applicable, shallbe taken into consideration.5.4 Unspecified ElementsWhen chemical analysis for elements not specified for the grade ord
47、ered is desired, SupplementaryRequirement S13 may be specified.NOTE 1All commercial metals contain small amounts of various elements in addition to those that are specified. It is neither practical nor necessaryto specify limits for every unspecified element that might be present, despite the fact t
48、hat the presence of many of these elements is often routinelydetermined by the producer.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 the supplied material such that the ma
49、terial conforms to the requirementsof a different grade.6. Mechanical Test Requirements6.1 The individual product specifications vary as to whether mechanical tests are required; for this reason, and to determinespecific test requirements, the individual product specification should be reviewed. If mechanical testing is required by the productspecification, sampling shall be in accordance with 4.3 or with Supplementary Requirement S21 as appropriate.6.2 Unless otherwise specified by the purchaser, when mechanical properties are required by the
