1、Designation: A990 10aStandard Specification forCastings, Iron-Nickel-Chromium and Nickel Alloys, SpeciallyControlled for Pressure Retaining Parts for CorrosiveService1This standard is issued under the fixed designation A990; the number immediately following the designation indicates the year oforigi
2、nal adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope*1.1 This specification covers iron-nickel-chromium andnickel alloy
3、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 s
4、ervice 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 The values stated in either SI units or inch-pound unitsar
5、e to be regarded separately as standard. The values stated ineach 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.1.3.1 This specification is expressed in both inc
6、h-poundunits and in SI units; however, unless the purchase order orcontract specifies the applicable M specification designation(SI units), the inch-pound units shall apply. Within the text, theSI units are shown in brackets or parentheses.1.4 This standard does not purport to address all of thesafe
7、ty concerns, if any, 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:2A351/A351M Specification for Cas
8、tings, Austenitic, forPressure-Containing PartsA370 Test Methods and Definitions for Mechanical Testingof Steel ProductsA488/A488M Practice for Steel Castings, Welding, Quali-fications of Procedures and PersonnelA494/A494M Specification for Castings, Nickel and NickelAlloyA703/A703M Specification fo
9、r Steel Castings, General Re-quirements, for Pressure-Containing PartsA743/A743M Specification for Castings, Iron-Chromium,Iron-Chromium-Nickel, Corrosion Resistant, for GeneralApplicationA744/A744M Specification for Castings, Iron-Chromium-Nickel, Corrosion Resistant, for Severe ServiceA802/A802M P
10、ractice for Steel Castings, Surface Accep-tance Standards, Visual ExaminationA903/A903M Specification for Steel Castings, Surface Ac-ceptance Standards, Magnetic Particle and Liquid Pen-etrant InspectionA941 Terminology Relating to Steel, Stainless Steel, Re-lated Alloys, and FerroalloysA985/A985M S
11、pecification for Steel Investment CastingsGeneral Requirements, for Pressure-Containing PartsE94 Guide for Radiographic ExaminationE165 Practice for Liquid Penetrant Examination for GeneralIndustryE186 Reference Radiographs for Heavy-Walled (2 to 412-in. (50.8 to 114-mm) Steel CastingsE272 Reference
12、 Radiographs for High-Strength Copper-Base and Nickel-Copper Alloy CastingsE280 Reference Radiographs for Heavy-Walled (412 to12-in. (114 to 305-mm) Steel CastingsE446 Reference Radiographs for Steel Castings Up to 2 in.(50.8 mm) in Thickness2.2 AWS Standards:3AWS A5.4, Specification for Stainless S
13、teel Electrodes forShielded 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.C
14、urrent edition approved Oct. 1, 2010. Published November 2010. Originallyapproved in 1998. Last previous edition approved in 2010 as A990 10. DOI:10.1520/A0990-10A.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Boo
15、k of ASTMStandards volume information, refer 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
16、, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.AWS A5.11/A5.11M, Specification for Nickel and NickelAlloy Welding Electrodes for Shielded MetalArc WeldingAWS A5.14/A5.14M, Specification for Nickel and Nickel-Alloy Bare Welding Electrodes and Rods2.3 ASME/ANSI S
17、tandard:4ASME/ANSI B16.34, Valves-Flanged, Threaded, andWelding End3. Terminology3.1 DefinitionsThe definitions in Test Methods and Defi-nitions A370 and Terminology A941 are applicable to thisspecification.3.2 Definitions of Terms Specific to This Standard:3.2.1 accessible surface, nsurface that ca
18、n be welded onwithout cutting access holes in the casting.3.2.2 refined 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
19、and fabricated items, chips, and turnings.4. General Conditions for Delivery4.1 Other than investment castings, material furnished tothis specification shall conform to the requirements of Speci-fication A703/A703M, including any supplementary require-ments that are indicated in the purchase order.
20、Failure tocomply with the general requirements of Specification A703/A703M constitutes nonconformance with this specification. Incase of conflict between the requirements of this specificationand Specification A703/A703M, this specification shall pre-vail.4.2 Investment Castings Material furnished t
21、o this speci-fication shall conform to the requirements of SpecificationA985/A985M, including any supplementary requirements thatare indicated in the purchase order. Failure to comply with thegeneral requirements of SpecificationA985/A985M constitutesnonconformance with this specification. In case o
22、f conflictbetween the requirements of this specification and Specifica-tion A985/A985M, Specification A985/A985M shall prevail.5. Ordering Information5.1 It is the responsibility of the purchaser to specify allrequirements that are necessary for material ordered to thisspecification. Such requiremen
23、ts may include, but are notlimited to, the following: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
24、 supplied unless otherwise specified.5.1.5 Wetted surfaces (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
25、% Cu alloys,shall be made by one of the two following 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.
26、6.3 Additions of up to 5 % are permitted for compositionaladjustments 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 te
27、nsion test shall be made from each heat. Testresults 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 same4Available from American Society of Mechanical Engineers (ASME), ASMEInternation
28、al Headquarters, Three Park Ave., New York, NY 10016-5990, http:/www.asme.org.TABLE 1 Chemical RequirementsElement, %(max, except where range is given)GradeCW-2M CN3MCu M35-1 CW2MC N2MC 0.020 0.030 0.35 0.020 0.020Mn 1.00 1.50 1.50 1.00 1.00Si 0.80 1.00 1.25 0.45 0.80P 0.030 0.030 0.030 0.015 0.030S
29、 0.015 0.015 0.015 0.015 0.015Mo 15.0-17.5 2.0-3.0 . . . 8.0-10.0 30.0-33.0Fe 2.00 balance 3.5 5.0 3.00Ni balance 27.5-30.5 Balance Balance BalanceCr 15.0-17.5 19.0-22.0 . . . 20.0-23.0 1.00Cu . . . 3.0-3.5 26.0-33.0 0.50 0.20W 1.00 . . . . . . 0.50 0.20V . . . . . . . 0.20 0.20Cb . . . 3.1-4.5 .A99
30、0 10a2procedure as the castings it represents. If the casting grade doesnot require heat treatment, the bar used for the test specimenshall 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 c
31、ast 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 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 furna
32、ce from the same heat ofrefined ingot using the same melting procedure, and shallqualify all of the subsequent heats in that series made in thesame shift.9.3 Procedure:9.3.1 The test plates required under 9.2 shall be processedand tested as follows:9.3.1.1 Prior to welding, the test plate shall be s
33、olution 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 normalcleaning is prohibited.9.3.1.3 Fill the groove
34、in the plate with weld depositaccording to the procedure used in Section 11 and the fillermaterial grade specified in Table 5.TABLE 2 Nondestructive Examination RequirementsMaximum Casting Thickness Class Visual Examination, PracticeA802/A802M MinimumAcceptance LevelRadiographic Examination,Guide E9
35、4Number of CastingsSeverity Level per Table 6Liquid Penetrant Examination, Test Method E165Coverage Minimum Acceptance Levelper SpecificationA903/A903Mless than58 in. (15.9 mm) A Level I 100 % All accessible surfaces Level IB Level II 100 % All accessible wettedsurfacesLevel IIC Level II Initial cas
36、ting 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 IIB Level II 100 % All accessible wettedsurfacesLevel IIIC Level II Initial casting off pattern Weld repairs Level IIID Level II Initial casti
37、ng 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 IVC 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 Le
38、vel II 100 % All accessible surfaces Level IVB Level II 100 % All accessible wettedsurfacesLevel IVC Level III Initial casting off pattern Weld repairs Level 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 acc
39、essible wettedsurfacesLevel VC Level IV Initial casting off pattern Weld repairs Level VD Level IV Initial casting off pattern NA NATABLE 3 Tensile RequirementsGradeCW-2M CN3MCu M35-1 CW2MC N2MTensile strength, min, psi (MPa) 72 00049562 00042565 00045070 00048576 0005250.2 % offset yield strength,
40、min, psi (MPa) 40 00027525 00017025 00017040 00027540 000275Elongation in 2 in. (50 mm), min, %A20.0 35.0 25.0 25.0 20.0AWhen ICI test bars are used in tensile testing as provided for in Specification A985/A985M, the gage length to reduced section diameter ratio shall be 4 to 1.TABLE 4 Heat Treat Re
41、quirementsGrade Heat TreatmentCW-2M Heat to 2225 to 2300F 1220 to 1260C for a minimum 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 temperature/1 in.25 mm of thickness. Quench in water.AM35-1 As-castCW2MC Heat to 2175F 1190C min fo
42、r a min of 2 h at temperature or amin of 1 h/1 in. 25 mm of thickness whichever is greater.Quench in water.AN2M Heat to 2080F 1140C min for a min of 2 h at temperature + 1h/ 1 in. 25 mm of thickness. Quench in water.AAQuench in water or rapid cool by other means as agreed upon by themanufacturer and
43、 purchaser.A990 10a39.3.1.4 For the purposes of the weldability test only, postweld heat treatment of the test plate is prohibited even if partof the procedure. Remove one38-in. (10-mm) min thick bendcoupon longitudinally from the center of the welded plate bymachining, sawing, or abrasive cutting.
44、Make a transverse sidebend test of the welded joint in accordance with PracticeA488/A488M.9.4 Acceptance:9.4.1 On the bent specimen, cracks or other open defectsexceeding18 in. (3.2 mm), measured in any direction on theconvex surface shall be cause for rejection, except that cracksoccurring on and l
45、imited to the corners while testing shall notbe considered.10. Nondestructive Examination10.1 One of four different classes of nondestructive exami-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 requiremen
46、ts for three different NDE meth-ods. Class D will be supplied unless otherwise specified.10.2 Visual ExaminationEach casting shall be examinedvisually in accordance with Practice A802/A802M. Fusiondiscontinuities, expansion discontinuities, and inserts are un-acceptable.All other surface features mu
47、st meet the acceptancecriteria class in Table 2.10.3 Radiographic Examination:10.3.1 The number of castings to be examined radiographi-cally 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
48、 manufacturer and purchaser. Where applicable, the mini-mum coverage shall comply with ASME/ANSI B 16.34.10.3.3 Personnel performing the examination shall be quali-fied in accordance with an acceptable written practice.10.3.4 All castings that are radiographed and found accept-able shall be marked p
49、ermanently 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 normal 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 radiographi
