1、Designation: A957/A957M 11a A957/A957M 12Standard 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 adopt
2、ion 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-plicationA148/A148M Steel Castings, High-Strength, for Struc-
4、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/A560M Castings, Chromium-Nickel All
5、oyA732/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-Chromium-Nickel, Corro-sion Re
6、sistant, 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 Requirements Similar to Standard
7、Wrought GradesA958 Steel Castings, Carbon and Alloy, withTensile Requirements, Chemical Require-ments Similar to Standard WroughtGrades1.2 This specification also covers a group of supplementary requirements that may be applied to the above specifications asindicated therein. These are provided for
8、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 specification form an integral part of the materialspecification. In cases of conflict, the requireme
9、nts of this specification shall take precedence over the individual materialspecification requirements.1.4 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
10、 used independently of the other. Combining values from thetwo systems may result in non-conformance with the standard.1 This specification is under the jurisdiction of ASTM Committee A01 on Steel, Stainless Steel and Related Alloys and is the direct responsibility of Subcommittee A01.18on Castings.
11、Current edition approved Oct. 1, 2011May 1, 2012. Published November 2011August 2012. Originally approved in 1996. Last previous edition approved in 2011 asA957/A957M 11.A957/A957M 11a. DOI: 10.1520/A0957_A0957M-11A.10.1520/A0957_A0957M-12.This document is not an ASTM standard and is intended only t
12、o 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 prior editions as appropriate. In all cases only the current versiono
13、f 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 19428-2959. United States12. Referenced Documents2.1 ASTM Standards:2
14、A27/A27M Specification for Steel Castings, Carbon, for General ApplicationA148/A148M Specification for Steel Castings, High Strength, for Structural PurposesA297/A297M Specification for Steel Castings, Iron-Chromium and Iron-Chromium-Nickel, Heat Resistant, for GeneralApplicationA370 Test Methods an
15、d Definitions for Mechanical Testing of Steel ProductsA380 Practice for Cleaning, Descaling, and Passivation of Stainless Steel Parts, Equipment, and SystemsA447/A447M Specification for Steel Castings, Chromium-Nickel-Iron Alloy (25-12 Class), for High-Temperature ServiceA488/A488M Practice for Stee
16、l Castings, Welding, Qualifications of Procedures and PersonnelA494/A494M Specification for Castings, Nickel and Nickel AlloyA560/A560M Specification for Castings, Chromium-Nickel AlloyA609/A609M Practice for Castings, Carbon, Low-Alloy, and Martensitic Stainless Steel, Ultrasonic Examination Thereo
17、fA732/A732M Specification for Castings, Investment, Carbon and Low Alloy Steel for General Application, and Cobalt Alloyfor High Strength at Elevated TemperaturesA743/A743M Specification for Castings, Iron-Chromium, Iron-Chromium-Nickel, Corrosion Resistant, for General ApplicationA744/A744M Specifi
18、cation for Castings, Iron-Chromium-Nickel, Corrosion Resistant, for Severe ServiceA747/A747M Specification for Steel Castings, Stainless, Precipitation HardeningA751 Test Methods, Practices, and Terminology for Chemical Analysis of Steel ProductsA800/A800M Practice for Steel Casting, Austenitic Allo
19、y, 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 Acceptance Standards, Magnetic Particle and Liquid PenetrantInspec
20、tionA915/A915M Specification for Steel Castings, Carbon, and Alloy, Chemical Requirements Similar to Standard Wrought GradesA941 Terminology Relating to Steel, Stainless Steel, Related Alloys, and FerroalloysA958 Specification for Steel Castings, Carbon and Alloy, with Tensile Requirements, Chemical
21、 Requirements Similar toStandard Wrought GradesA967 Specification for Chemical Passivation Treatments for Stainless Steel PartsA991/A991M Test Method for Conducting Temperature Uniformity Surveys of Furnaces Used to Heat Treat Steel ProductsA997 Practice for Investment Castings, Surface Acceptance S
22、tandards, Visual ExaminationA1058 Test Methods for Mechanical Testing of Steel ProductsMetricA1067 Specification for Test Coupons for Steel CastingsE29 Practice for Using Significant Digits in Test Data to Determine Conformance with SpecificationsE94 Guide for Radiographic ExaminationE125 Reference
23、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 Applicati
24、onsE280 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 Chemical An
25、alysis 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 Applica
26、tions2.2 SAE Aerospace Recommended Practice:3ARP 1341 Determining Decarburization and Carburization in Finished Parts of Carbon and Low-Alloy Steel3. Terminology3.1 Definitions:2 For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at serviceastm.org.
27、 For Annual Book of ASTM Standardsvolume information, refer to the standards Document Summary page on the ASTM website.3 Available from Society of Automotive Engineers (SAE), 400 Commonwealth Dr., Warrendale, PA 15096-0001, http:/www.sae.org.A957/A957M 1223.1.1 The definitions in Test Methods and De
28、finitions A370, Test Methods, Practices, and Terminology A751, and TerminologyA941, and Test Methods A1058 are applicable to 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
29、 by investing (surrounding) an expendablepattern with a ceramic slurry that is allowed to solidify. The expendable pattern 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
30、 refining vessel at one time in such a manner as toproduce the desired composition and properties.3.2.3 sub-heat, na portion of a master heat remelted without additional processing for pouring into castings. Synonyms: melt,production heat.4. Materials and Manufacture4.1 Melting ProcessMaster heats s
31、hall be made by the electric furnace process with or without separate refining such asargon-oxygen-decarburization (AOD), vacuum-oxygen-degassing (VOD), vacuum-induction-melting (VIM), and so forth, unlessotherwise specified in the individual specification or agreed upon between the customer and pro
32、ducer. Master heats may be useddirectly for producing castings or converted into ingot, bar, shot, or other suitable form, 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 bat
33、ch sizes by electric inductionfurnace with or without atmosphere protection such as vacuum or inert gas unless otherwise specified in the individual specificationor agreed upon between the customer and producer. Revert (gates, sprues, risers, and rejected castings) shall not be re-meltedexcept in ma
34、ster heats.4.3 Sampling:4.3.1 If castings are poured directly from one or more master heats, then the samples for chemical 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 requi
35、red testing shall also be poured froma sub-heat of that same master heat, but not necessarily from the same sub-heat as the 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 purcha
36、ser, test specimens may be taken from castings or from coupons cast integrallywith 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 a furnace that has been surveyed in accordance with Test MethodA991/
37、A991M.4.4.2 When castings are heat treated at temperatures above 2000F (1100C), then the working zone shall have been establishedby 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 tre
38、atment temperature is not specified for the grade, then the surveytemperature shall be not more than 50F (30C) below nor more 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 thel
39、owest temperature shall be as agreed between the purchaser and producer except that during production heat treatment, no portionof the furnace shall be below the minimum specified temperature nor above the maximum specified temperature for the grade beingprocessed.5. Chemical Composition5.1 Chemical
40、 AnalysisChemical analysis of materials covered by this specification shall be in accordance with Test Methods,Practices, and Terminology A751.5.2 Heat AnalysisAn analysis of samples obtained in accordance with 4.3 or Supplementary Requirement S17 as appropriate,shall be made by the manufacturer to
41、determine the percentages of the elements specified in the individual specification for thegrade being poured. When drillings 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 sp
42、ecification for the grade being poured.5.3 Product AnalysisA product 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 shallbe taken
43、 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 to rejection
44、 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 ofA957/A957M 123Table 1 are not applicable as acceptance criteria for heat analysis by the cas
45、ting 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 or
46、dered 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
47、that 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 m
48、aterial 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
49、 mechanical testing is required by the productspecification, sampling shall be in accordance with 4.3 or with Supplementary Requirement S18 as appropriate.6.2 Unless otherwise specified by the purchaser, when mechanical properties are required by the product specification, testcoupons may be taken from castings, may be cast integrally with the castings, or may be cast in separate molds of the same typeand material as those used for the castings, in accordance with Specification A1067, Fig. 1, Fig. 2, Fig. 3, or Fig. 4, except whenSupplementary
