1、Designation: A995/A995M 121Standard Specification forCastings, Austenitic-Ferritic (Duplex) Stainless Steel, forPressure-Containing Parts1This standard is issued under the fixed designation A995/A995M; 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.1NOTETable 3 was editorially corrected in July 2012.1. Scope*1.1 This specification covers austenit
3、ic-ferritic (duplex)stainless steel castings for valves, flanges, fittings, and otherpressure-containing parts.1.2 The duplex stainless steels offer a combination ofenhanced mechanical properties and corrosion resistance whenproperly balanced in composition and properly heat treated.Ferrite levels a
4、re not specified, but these grades will develop arange of approximately 30 to 60 % ferrite with the balanceaustenite. It is the responsibility of the purchaser to determinewhich grade shall be furnished depending on design andservice conditions, mechanical properties, and corrosion-resistant charact
5、eristics.NOTE 1Because of the possibility of precipitation of embrittlingphases, the grades included in this specification are not recommended forservice at temperatures above 600F 315C.1.3 The values stated in either SI units or inch-pound unitsare to be regarded separately as standard. The values
6、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.2. Referenced Documents2.1 ASTM Standards:2A488/A488M Practice for Steel Castings, Welding, Qualifi-c
7、ations of Procedures and PersonnelA703/A703M Specification for Steel Castings, GeneralRequirements, for Pressure-Containing PartsE125 Reference Photographs for Magnetic Particle Indica-tions on Ferrous CastingsE165 Practice for Liquid Penetrant Examination for GeneralIndustryE562 Test Method for Det
8、ermining Volume Fraction bySystematic Manual Point Count3. Terminology3.1 Definitions of Terms Specific to This Standard:3.1.1 duplex stainless steelan iron-chromium-nickel-molybdenum alloy which when properly heat treated consistsof approximately 30 to 60 % ferrite with the balance austenite.4. Gen
9、eral Conditions for Delivery4.1 Material furnished to this specification shall conform tothe applicable requirements of Specification A703/A703M,including the supplementary requirements that are indicated onthe purchaser order. Failure to comply with the generalrequirements of Specification A703/A70
10、3M constitutes non-conformance with this specification. In case of conflict be-tween the requirements of the specification and SpecificationA703/A703M, this specification shall prevail.5. Ordering Information5.1 It is the responsibility of the purchaser to specify allrequirements that are necessary
11、for material ordered under thisspecification. Such requirements may included, but are notlimited to, the following:5.1.1 A description of the casting by pattern number ordrawing (dimensional tolerances shall be included on thecasting drawing),5.1.2 Quantity (weight and number of castings),5.1.3 Spec
12、ification designation and date of issue,5.1.4 Grade of steel,5.1.5 Supplementary requirements including acceptancecriteria, and5.1.6 Additional requirements.6. Process6.1 The steel shall be made by the electric furnace processwith or without separate refining.1This specification is under the jurisdi
13、ction of ASTM Committee A01 on Steel,Stainless Steel and Related Alloys and is the direct responsibility of SubcommitteeA01.18 on Castings.Current edition approved March 1, 2012. Published April 2012. Originallyapproved in 1998. Last previous edition approved in 2009 as A995/A995M 09.DOI: 10.1520/A0
14、995_A0995M-12.2For 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 to the standards Document Summary page onthe ASTM website.*A Summary of Changes section appears at the en
15、d of this standardCopyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States17. Heat Treatment7.1 All castings shall be heat treated in accordance withTable 1.8. Chemical Composition8.1 The steel shall conform to the requirements as tochemical c
16、omposition prescribed in Table 2.9. Tensile Properties9.1 One tension test shall be made from each heat and shallconform to the requirements as to tensile properties prescribedin Table 3.10. Quality10.1 When additional inspection is desired, SupplementaryRequirements S5, S6, and S10 may be ordered.1
17、1. Repair by Welding11.1 Repairs shall be made using procedures and weldersqualified under Practice A488/A488M.11.2 The composition of the deposited weld metal may besimilar to that of the casting or may be suitably alloyed toachieve the desired corrosion resistance and mechanical prop-erties.11.3 W
18、eld repairs shall be subject to the same qualitystandards as used to inspect the castings.12. Post Weld Heat Treatment After Major Weld Repair12.1 Weld repairs shall be considered major in the case of acasting that has leaked on hydrostatic testing or when the depthof the cavity after preparation fo
19、r repair exceeds 20 % of theactual wall thickness, or 1 in. 25 mm, whichever is smaller,or when the extent of the cavity exceeds approximately 10 in.265 cm2. All other weld repairs shall be considered minor.12.2 Castings shall be heat-treated after major weld repairs.Heat treatment after minor weld
20、repairs is not required unlessSupplementary Requirement S11 is included in the purchaseorder.12.3 Post weld heat treatment shall be in accordance withTable 1.13. Keywords13.1 austenitic-ferritic; duplex stainless steel; pressure-containing; steel castingsTABLE 1 Heat Treatment RequirementsGrade Heat
21、 Treatment1B Heat to 1900F 1040C minimum, hold for sufficient time to heatcasting uniformly to temperature, quench in water or rapid cool byother means.2A Heat to 2050F 1120C minimum, hold for sufficient time to heatcasting uniformly to temperature, quench in water or rapid cool byother means.3A Hea
22、t to 1950F 1070C minimum, hold for sufficient time to heatcasting uniformly to temperature, quench in water or rapid cool byother means.4A Heat to 2050F 1120C minimum for sufficient time to heat castinguniformly to temperature and water quench, or the casting may befurnace cooled to 1850F 1010C mini
23、mum, hold for 15 minminimum and then water quench. A rapid cool by other means maybe employed in lieu of water quench.5A Heat to 2050F 1120C minimum, hold for sufficient time to heatcasting to temperature, furnace cool to 1910F 1045C minimum,quench in water or rapid cool by other means.6A Heat to 20
24、10F 1100C minimum, hold for sufficient time to heatcasting uniformly to temperature, quench in water or cool rapidly byother means.7A Heat to 2065F 1130C minimum, hold for sufficient time to heatcasting to temperature, furnace cool to 1940F 1060C minimum,quench in water or rapid cool by other means.
25、A995/A995M 1212SUPPLEMENTARY REQUIREMENTSThe following supplementary requirements shall not apply unless specified in the purchase order. Alist of standardized supplementary requirements for use at the option of the purchaser is included inSpecification A703/A703M. Those which are ordinarily conside
26、red suitable for use with thisspecification are given below. Others enumerated in Specification A703/A703M may be used with thisspecification upon agreement between the manufacturer and purchaser.S1. Unspecified ElementsS2. Destruction TestsS5. Radiographic InspectionS6. Liquid Penetrant InspectionS
27、8. Charpy Impact TestS10. Examination of Weld PreparationS10.1 Liquid penetrant examination of cavities prepared forwelding shall be performed to verify removal of those discon-tinuities found unacceptable by the inspection method specifiedfor the casting. The method of performing liquid penetrantex
28、amination shall be in accordance the with Practice E165.Unless other degrees of shrinkage or types of discontinuitiesfound in the cavities are specified, Type II, Internal Shrinkage,of Reference Photographs E125, of Degree 2 in sections up to2 in. 50 mm thick and of Degree 3 in sections over 2 in. 5
29、0mm thick shall be acceptable.S11. Post Weld Heat TreatmentS11.1 Castings shall be given a post weld solution heattreatment in accordance with Table 1.S12. Prior Approval of Major Weld RepairsOther supplementary requirements considered suitable foruse with this specification are:S50. Estimating Ferr
30、ite ContentTABLE 2 Chemical RequirementsGrade 1B 2A 3A 4A 5AA6AA7ABType 25Cr-5Ni-M0-Cu-N24Cr-10Ni-Mo-N 25Cr-5Ni-Mo-N 22Cr-5Ni-Mo-N 25Cr-7Ni-Mo-N 25Cr-7Ni-Mo-N 27Cr-7Ni-Mo-Cu-NUNS J93372 J93345 J93371 J92205 J93404 J93380 J93379ACI CD4MCuN CE8MN CD6MN CD3MN CE3MN CD3MWCuNComposition:Carbon, max 0.040
31、 0.080 0.060 0.030 0.030 0.030 0.030Manganese, max 1.00 1.00 1.00 1.50 1.50 1.00 1.00-3.00Silicon, max 1.00 1.50 1.00 1.00 1.00 1.00 1.00Phosphorus, max 0.040 0.040 0.040 0.040 0.040 0.030 0.030Sulfur, max 0.040 0.040 0.040 0.020 0.040 0.025 0.020Chromium 24.5-26.5 22.5-25.5 24.0-27.0 21.0-23.5 24.0
32、-26.0 24.0-26.0 26.028.0Nickel 4.7-6.0 8.0-11.0 4.0-6.0 4.5-6.5 6.0-8.0 6.5-8.5 6.08.0Molybdenum 1.70-2.30 3.0-4.5 1.75-2.50 2.5-3.5 4.0-5.0 3.0-4.0 2.03.5Copper 2.7-3.3 . . . . . . 1.00, max . . . 0.50-1.00 1.00 maxTungsten . . . . . . . . . . . . . . . 0.50-1.00 3.04.0Nitrogen 0.10-0.25 0.10-0.30
33、0.15-0.25 0.10-0.30 0.10-0.30 0.20-0.30 0.300.40Boron . . . . . . . . . . . . . . . . . . 0.00100.0100Barium . . . . . . . . . . . . . . . . . . 0.00100.0100Ce + La . . . . . . . . . . . . . . . . . . 0.0050.030A%Cr+3.3%Mo+16%N$ 40.B%Cr+3.3(%Mo+0.5%W)+30%N$ 45.TABLE 3 Tensile RequirementsGrade 1B 2A
34、 3A 4A 5A 6A 7AType 25Cr-5Ni-Mo-Cu-N24Cr-10Ni-Mo-N25Cr-5Ni-Mo-N22Cr-5Ni-Mo-N25Cr-7Ni-Mo-N25Cr-7Ni-Mo-N27Cr-7Ni-Mo-Cu-NTensile strength,ksi MPa, min100 690 95 655 95 655 90 620 100 690 100 690 100 690Yield strength(0.2 % offset),ksi MPa, min70 485 65 450 65 450 60 415 75 515 65 450 75 515Elongation i
35、n 2 in.50 mm,%, minA16 25 25 25 18 25 20AWhen ICI test bars are used in tensile testing as provided for in this specification, the gage length to reduced section diameter ratio shall be 4:1. Editorially corrected.A995/A995M 1213S50.1 Ferrite contents shall be determined by point count(Practice E562)
36、, by other quantitative metallographic methodssuch as image analysis, by measurement of magnetic response,or by other methods upon agreement between the manufacturerand the purchaser. Frequency of testing and location of testsshall be by agreement between the manufacturer and thepurchaser.S51. Prior
37、 Approval of Weld MaterialS51.1 The purchaser must give approval of all weld fillermaterials to be used prior to any weld repairs.SUMMARY OF CHANGESCommittee A01 has identified the location of selected changes to this standard since the last issue(A995/A995M 09) that may impact the use of this stand
38、ard. (Approved March 1, 2012.)(1) Added Grade 7A.ASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this standard are expressly advised that determination of the validity of any such patent rights
39、, and the riskof infringement of such rights, are entirely their own responsibility.This standard is subject to revision at any time by the responsible technical committee and must be reviewed every five years andif not revised, either reapproved or withdrawn. Your comments are invited either for re
40、vision of this standard or for additional standardsand should be addressed to ASTM International Headquarters. Your comments will receive careful consideration at a meeting of theresponsible technical committee, which you may attend. If you feel that your comments have not received a fair hearing yo
41、u shouldmake your views known to the ASTM Committee on Standards, at the address shown below.This standard is copyrighted by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,United States. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the aboveaddress or at 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.org). Permission rights to photocopy the standard may also be secured from the ASTM website (www.astm.org/COPYRIGHT/).A995/A995M 1214
