1、Designation: A 990 08Standard Specification forCastings, Iron-Nickel-Chromium and Nickel Alloys, SpeciallyControlled for Pressure Retaining Parts for CorrosiveService1This standard is issued under the fixed designation A 990; the number immediately following the designation indicates the year oforig
2、inal adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.1. Scope*1.1 This specification covers iron-nickel-chromium andnickel allo
3、y castings specially processed with restricted meltpractices, weldability testing, and nondestructive examination(NDE) requirements.1.2 A number of grades of iron-nickel-chromium and nickelalloy castings are included in this specification. Since thesegrades possess varying degrees of suitability for
4、 service incorrosive environments, it is the responsibility of the purchaserto determine which grade shall be furnished. Selection willdepend on design and service conditions, mechanical proper-ties, and corrosion-resistant characteristics.1.3 This specification is expressed in both inch-pound units
5、and in SI units; however, unless the purchase order or contractspecifies the applicable M specification designation (SI units),the inch-pound units shall apply. The values stated in eitherinch-pound units or SI units are to be regarded separately asstandard. Within the text, the SI units are shown i
6、n brackets.The values stated in each system may not be exact equivalents;therefore, each system shall be used independently of the other.Combining values from the two systems may result in noncon-formance with the standard.1.4 This standard does not purport to address all of thesafety concerns, if a
7、ny, associated with its use. It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2A 351/A 351M Specification for Castings, Austenit
8、ic, forPressure-Containing PartsA 370 Test Methods and Definitions for Mechanical Testingof Steel ProductsA 488/A 488M Practice for Steel Castings, Welding, Quali-fications of Procedures and PersonnelA 494/A 494M Specification for Castings, Nickel andNickel AlloyA 703/A 703M Specification for Steel
9、Castings, GeneralRequirements, for Pressure-Containing PartsA 743/A 743M Specification for Castings, Iron-Chromium,Iron-Chromium-Nickel, Corrosion Resistant, for GeneralApplicationA 744/A 744M Specification for Castings, Iron-Chromium-Nickel, Corrosion Resistant, for Severe ServiceA 802/A 802M Pract
10、ice for Steel Castings, Surface Accep-tance Standards, Visual ExaminationA 903/A 903M Specification for Steel Castings, SurfaceAcceptance Standards, Magnetic Particle and Liquid Pen-etrant InspectionA 941 Terminology Relating to Steel, Stainless Steel, Re-lated Alloys, and FerroalloysA 985/A 985M Sp
11、ecification for Steel Investment CastingsGeneral Requirements, for Pressure-Containing PartsE94 Guide for Radiographic ExaminationE 165 Test Method for Liquid Penetrant ExaminationE 186 Reference Radiographs for Heavy-Walled (2 to 412-in. 51 to 114-mm) Steel CastingsE 272 Reference Radiographs for H
12、igh-Strength Copper-Base and Nickel-Copper Alloy CastingsE 280 Reference Radiographs for Heavy-Walled (412 to12-in. 114 to 305-mm) Steel CastingsE 446 Reference Radiographs for Steel Castings Up to 2 in.51 mm in Thickness2.2 AWS Standards:3AWS A5.4, Specification for Stainless Steel Electrodes forSh
13、ielded Metal Arc WeldingAWS A5.9, Specification for Bare Stainless Steel WeldingElectrodes and Rods1This specification is under the jurisdiction of ASTM Committee A01 on Steel,Stainless Steel and Related Alloys and is the direct responsibility of SubcommitteeA01.18 on Castings.Current edition approv
14、ed March 1, 2008. Published March 2008. Originallyapproved in 1998. Last previous edition approved in 2006 as A 990 06.2For 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
15、to the standards Document Summary page onthe ASTM website.3Available from American Welding Society (AWS), 550 NW LeJeune Rd.,Miami, FL 33126, http:/www.aws.org.1*A Summary of Changes section appears at the end of this standard.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Co
16、nshohocken, PA 19428-2959, United States.AWS A5.11, Specification for Nickel and Nickel AlloyElectrodes for Shielded Metal Arc WeldingAWSA5.14, Specification for Nickel and NickelAlloy BareWelding Electrodes and Rods2.3 ASME/ANSI Standard:4ASME/ANSI B16.34, Valves-Flanged, Threaded, andWelding End3.
17、 Terminology3.1 DefinitionsThe definitions in Test Methods and Defi-nitions A 370 and Terminology A 941 are applicable to thisspecification.3.2 Definitions of Terms Specific to This Standard:3.2.1 accessible surface, nsurface that can be welded onwithout cutting access holes in the casting.3.2.2 ref
18、ined ingot, nmetal processed by argon-oxygen-decarburization (AOD) or vacuum-oxygen-decarburization(VOD) and cast to a size and shape suitable for remelting.3.2.3 revert, ngates, risers, and castings. Also includesscrapped machinery and fabricated items, chips, and turnings.4. General Conditions for
19、 Delivery4.1 Other than investment castings, material furnished tothis specification shall conform to the requirements of Speci-fication A 703/A 703M, including any supplementary require-ments that are indicated in the purchase order. Failure tocomply with the general requirements of Specification A
20、 703/A 703M constitutes nonconformance with this specification. Incase of conflict between the requirements of this specificationand Specification A 703/A 703M, this specification shall pre-vail.4.2 Investment Castings Material furnished to this speci-fication shall conform to the requirements of Sp
21、ecificationA 985/A 985M, including any supplementary requirementsthat are indicated in the purchase order. Failure to comply withthe general requirements of Specification A 985/A 985M con-stitutes nonconformance with this specification. In case ofconflict between the requirements of this specificati
22、on andSpecification A 985/A 985M, Specification A 985/A 985Mshall prevail.5. Ordering Information5.1 It is the responsibility of the purchaser to specify allrequirements that are necessary for material ordered to thisspecification. Such requirements may include, but are notlimited to, the following:
23、5.1.1 Quantity.5.1.2 Grade designation (Table 1).5.1.3 Description of the casting by pattern number ordrawing. Dimensional tolerances should be included on thecasting drawing.5.1.4 Nondestructive inspection class required (Table 2).Class D will be supplied unless otherwise specified.5.1.5 Wetted sur
24、faces (Table 2).5.2 The purchaser shall specify any supplementary require-ments desired, including standards of acceptance, required todescribe adequately the desired material.6. Process and Manufacture6.1 Alloys, except for nickel base, 25 to 35 % Cu alloys,shall be made by one of the two following
25、 processes:6.1.1 Electric arc or induction furnace melting followed byAOD or VOD refining, or6.1.2 Electric induction furnace melting of refined ingot.6.2 Nickel base alloys with 25 to 35 % Cu shall be made by6.1.1 or 6.1.2 or by electric furnace.6.3 Additions of up to 5 % are permitted for composit
26、ionaladjustments and deoxidation.6.4 Revert shall not be used.7. Chemical Composition7.1 These alloys shall conform to the chemical compositionrequirements prescribed in Table 1. An analysis of every heatis required.8. Tensile Properties8.1 One tension test shall be made from each heat. Testresults
27、shall conform to the tensile requirements specified inTable 3. The bar shall be solution heat treated per therequirements of Table 4 in production furnaces to the sameprocedure as the castings it represents. If the casting grade doesnot require heat treatment, the bar used for the test specimenshall
28、 not be heat treated.9. Weldability Qualification9.1 Each heat shall be qualified by weldability testing.9.2 Sampling:9.2.1 The weldability test plate shall be cast in accordancewith Fig. 1.9.2.2 For heats produced under 6.1.1, at least one weldabil-ity test plate shall be cast from each heat.9.2.3
29、For heats produced under 6.1.2, at least one weldabil-ity test plate shall be cast from the first heat in an uninterruptedseries of heats, made in the same furnace from the same heat ofrefined ingot using the same melting procedure, and shallqualify all of the subsequent heats in that series made in
30、 thesame shift.9.3 Procedure:9.3.1 The test plates required under 9.2 shall be processedand tested as follows:4Available from American Society of Mechanical Engineers (ASME), ASMEInternational Headquarters, Three Park Ave., New York, NY 10016-5990, http:/www.asme.org.TABLE 1 Chemical RequirementsEle
31、ment, %(max, except where range is given)GradeCW-2M CN3MCu M35-1C 0.020 0.030 0.35Mn 1.00 1.50 1.50Si 0.80 1.00 1.25P 0.030 0.030 0.030S 0.015 0.015 0.015Mo 15.0-17.5 2.0-3.0 . . .Fe 2.00 balance 3.5Ni balance 27.5-30.5 BalanceCr 15.0-17.5 19.0-22.0 . . .Cu . . . 3.0-3.5 26.0-33.0W 1.00 . .A9900829.
32、3.1.1 Prior to welding, the test plate shall be solution heattreated according to the requirements of Table 4 in productionfurnaces to the same procedure as the castings it represents.9.3.1.2 All forms of cold working, mechanical deformation,hammering, or peening, in excess of that required for norm
33、alcleaning is prohibited.9.3.1.3 Fill the groove in the plate with weld depositaccording to the procedure used in Section 11 and the fillermaterial grade specified in Table 5.9.3.1.4 For the purposes of the weldability test only, postweld heat treatment of the test plate is prohibited even if partof
34、 the procedure. Remove one38-in. (10-mm) min thick bendcoupon longitudinally from the center of the welded plate bymachining, sawing, or abrasive cutting. Make a transverse sidebend test of the welded joint in accordance with PracticeA 488/A 488M.9.4 Acceptance:9.4.1 On the bent specimen, cracks or
35、other open defectsexceeding18 in. (3.2 mm), measured in any direction on theconvex surface shall be cause for rejection, except that cracksoccurring on and limited to the corners while testing shall notbe considered.10. Nondestructive Examination10.1 One of four different classes of nondestructive e
36、xami-nation shall be imposed on castings ordered to this specifica-tion. Classes A, B, C, and D are defined in Table 2. Each classimposes specific requirements for three different NDE meth-ods. Class D will be supplied unless otherwise specified.10.2 Visual ExaminationEach casting shall be examinedv
37、isually in accordance with Practice A 802/A 802M. Fusiondiscontinuities, expansion discontinuities, and inserts are un-acceptable.All other surface features must meet the acceptancecriteria class in Table 2.10.3 Radiographic Examination:10.3.1 The number of castings to be examined radiographi-cally
38、and the acceptance criteria shall be in accordance with thespecified class in Table 2 and Table 6.10.3.2 The extent of coverage shall be agreed upon betweenthe manufacturer and purchaser. Where applicable, the mini-mum coverage shall comply with ASME/ANSI B 16.34.TABLE 2 Nondestructive Examination R
39、equirementsMaximum Casting Thickness Class Visual Examination, PracticeA 802/A 802M MinimumAcceptance LevelRadiographic Examination,Guide E94Number of CastingsSeverity Level per Table 6Liquid Penetrant Examination, Test Method E 165Coverage Minimum Acceptance Levelper SpecificationA 903/A 903Mless t
40、han58 in. (15.9 mm) A Level I 100 % All accessible surfaces Level IB Level II 100 % All accessible wettedsurfacesLevel IIC Level II Initial casting off pattern Weld repairs Level IID Level II Initial casting off pattern NA NA58 to 1 in. (15.9 to 25.4 mm) A Level I 100 % All accessible surfaces Level
41、 IIB Level II 100 % All accessible wettedsurfacesLevel IIIC Level II Initial casting off pattern Weld repairs Level IIID Level II Initial casting off pattern NA NAOver 1 to 2 in. (25.4 to 50.8 mm) A Level I 100 % All accessible surfaces Level IIIB Level II 100 % All accessible wettedsurfacesLevel IV
42、C Level II Initial casting off pattern Weld repairs Level IVD Level II Initial casting off pattern NA NAOver 2 to 412 in. (50.8 to 114 mm) A Level II 100 % All accessible surfaces Level IVB Level II 100 % All accessible wettedsurfacesLevel IVC Level III Initial casting off pattern Weld repairs Level
43、 VD Level III Initial casting off pattern NA NAOver 412 in. (114 mm) A Level III 100 % All accessible surfaces Level VB Level III 100 % All accessible wettedsurfacesLevel VC Level IV Initial casting off pattern Weld repairs Level VD Level IV Initial casting off pattern NA NATABLE 3 Tensile Requireme
44、ntsGradeCW-2M CN3MCu M35-1Tensile strength, min, psi (MPa) 72 000(495)62 000(425)65 000(450)0.2 % offset yield strength, min, psi (MPa) 40 000(275)25 000(170)25 000(170)Elongation in 2 in. (50 mm), min, %A20.0 35.0 25.0AWhen ICI test bars are used in tensile testing as provided for in SpecificationA
45、 985/A 985M, the gage length to reduced section diameter ratio shall be 4 to 1.TABLE 4 Heat Treat RequirementsGrade Heat TreatmentCW-2M Heat to 2250 6 25F (1232 6 14C) for a min of 1 h attemperature/1 in. (25 mm) of thickness. Quench in water.ACN3MCu Heat to 2050F (1120C) min for a min of 1 h at tem
46、perature/1 in.(25 mm) of thickness. Quench in water.AM35-1 As-castAQuench in water or rapid cool by other means as agreed upon by themanufacturer and purchaser.A99008310.3.3 Personnel performing the examination shall be quali-fied in accordance with an acceptable written practice.10.3.4 All castings
47、 that are radiographed and found accept-able shall be marked permanently RT.10.3.5 For Classes C and D, if a rejectable indication isfound, that first casting shall be scrapped or repaired and thesecond casting radiographed. If the second casting passes, thenno additional radiography beyond the norm
48、al amount is re-quired. If that second casting fails, all remaining castings shallbe radiographed in only the rejectable areas found on the firstand second castings. After changes are made to the gating orrisering of a pattern, and the subsequent castings produce norejectable radiographic indication
49、s, then no additional radiog-raphy beyond the sampling rate agreed upon by the purchaserand the producer shall be required.10.4 Liquid Penetrant Examination:10.4.1 All Class A, B, and C castings shall be liquidpenetrant (LP) tested in accordance with Table 2 after the finalspecified heat treatment.10.4.2 Personnel performing the examination shall be quali-fied in accordance with an acceptable written practice.10.4.3 When welding is performed after the liquid penetrantexamination, the repair weld and at least14 in. (6 mm) of thesurrounding material shall be
