1、Designation: A995/A995M 121 A995/A995M 12aStandard 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 adop
2、tion 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 NOTETable 3 was editorially corrected in July 2012.1. Scope*1.1 This specification
3、 covers austenitic-ferritic (duplex) stainless steel castings for valves, flanges, fittings, and otherpressure-containing parts.1.2 The duplex stainless steels offer a combination of enhanced mechanical properties and corrosion resistance when properlybalanced in composition and properly heat treate
4、d. Ferrite levels are not specified, but these grades will develop a range ofapproximately 30 to 60 % ferrite with the balance austenite. It is the responsibility of the purchaser to determine which grade shallbe furnished depending on design and service conditions, mechanical properties, and corros
5、ion-resistant characteristics.NOTE 1Because of the possibility of precipitation of embrittling phases, the grades included in this specification are not recommended for serviceat temperatures above 600F 315C.1.3 The values stated in either SI units or inch-pound units are to be regarded separately a
6、s 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 result in non-conformance with the standard.2. Referenced Documents2.1 ASTM Standards:2A488/A488M Practice for Steel Cas
7、tings, Welding, Qualifications of Procedures and PersonnelA703/A703M Specification for Steel Castings, General Requirements, for Pressure-Containing PartsE125 Reference Photographs for Magnetic Particle Indications on Ferrous CastingsE165 Practice for Liquid Penetrant Examination for General Industr
8、yE562 Test Method for Determining Volume Fraction by Systematic 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 consists ofapproximately 30 to 60 % ferrite with th
9、e balance austenite.4. General Conditions for Delivery4.1 Material furnished to this specification shall conform to the applicable requirements of Specification A703/A703M,including the supplementary requirements that are indicated on the purchaser order. Failure to comply with the generalrequiremen
10、ts of Specification A703/A703M constitutes nonconformance with this specification. In case of conflict between therequirements of the specification and Specification A703/A703M, this specification shall prevail.5. Ordering Information5.1 It is the responsibility of the purchaser to specify all requi
11、rements that are necessary for material ordered under thisspecification. Such requirements may included, but are not limited to, the following:1 This specification is under the jurisdiction of ASTM Committee A01 on Steel, Stainless Steel and Related Alloys and is the direct responsibility of Subcomm
12、ittee A01.18on Castings.Current edition approved March 1, 2012Nov. 1, 2012. Published April 2012December 2012. Originally approved in 1998. Last previous edition approved in 20092012as A995/A995M 09.A995/A995M 121. DOI: 10.1520/A0995_A0995M-12.10.1520/A0995_A0995M-12A.2 For referenced ASTM standards
13、, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standardsvolume information, refer to the standards Document Summary page on the ASTM website.This document is not an ASTM standard and is intended only to provide the user of an ASTM
14、 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 versionof the standard as published b
15、y 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 States15.1.1 A description of the casting by pattern number or drawing (dimensi
16、onal tolerances shall be included on the castingdrawing),5.1.2 Quantity (weight and number of castings),5.1.3 Specification designation and date of issue,5.1.4 Grade of steel,5.1.5 Supplementary requirements including acceptance criteria, and5.1.6 Additional requirements.6. Process6.1 The steel shal
17、l be made by the electric furnace process with or without separate refining.7. Heat Treatment7.1 All castings shall be heat treated in accordance with Table 1.8. Chemical Composition8.1 The steel shall conform to the requirements as to chemical composition prescribed in Table 2.9. Tensile Properties
18、9.1 One tension test shall be made from each heat and shall conform to the requirements as to tensile properties prescribed inTable 3.10. Quality10.1 When additional inspection is desired, Supplementary Requirements S5, S6, and S10 may be ordered.11. Repair by Welding11.1 Repairs shall be made using
19、 procedures and welders qualified under Practice A488/A488M.11.2 The composition of the deposited weld metal may be similar to that of the casting or may be suitably alloyed to achievethe desired corrosion resistance and mechanical properties.11.3 Weld repairs shall be subject to the same quality st
20、andards 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 a casting that has leaked on hydrostatic testing or when the depthof the cavity after preparation for repair exceeds 20 % of the actual wall thicknes
21、s, or 1 in. 25 mm, whichever is smaller, or whenthe extent of the cavity exceeds approximately 10 in.2 65 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 repairs is not required unlessSupplementary Re
22、quirement S11 is included in the purchase order.TABLE 1 Heat Treatment RequirementsGrade Heat 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 tim
23、e to heatcasting uniformly to temperature, quench in water or rapid cool byother means.3A Heat 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 castingunifo
24、rmly to temperature and water quench, or the casting may befurnace cooled to 1850F 1010C minimum, 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, f
25、urnace cool to 1910F 1045C minimum,quench in water or rapid cool by other means.6A Heat to 2010F 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 t
26、emperature, furnace cool to 1940F 1060C minimum,quench in water or rapid cool by other means.A995/A995M 12a212.3 Post weld heat treatment shall be in accordance with Table 1.13. Keywords13.1 austenitic-ferritic; duplex stainless steel; pressure-containing; steel castingsSUPPLEMENTARY REQUIREMENTSThe
27、 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 considered suitable for use with thisspecification
28、are given below. Others enumerated in Specification A703/A703M may be used with thisspecification upon agreement between the manufacturer and purchaser.S1. Unspecified ElementsTABLE 2 Chemical RequirementsGrade 1B 2A 3A 4A 5AA 6AA 7ABType 25Cr-5Ni-M0-Cu-N24Cr-10Ni-Mo-N 25Cr-5Ni-Mo-N 22Cr-5Ni-Mo-N 25
29、Cr-7Ni-Mo-N 25Cr-7Ni-Mo-N 27Cr-7Ni-Mo-Cu-NType 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-W-NUNS J93372 J93345 J93371 J92205 J93404 J93380 J93379ACI CD4MCuN CE8MN CD6MN CD3MN CE3MN CD3MWCuN CD3MWNComposition:Carbon, max 0.040 0.080 0.060 0.030
30、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 24.0-26.0 24.0-26.0 26.
31、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 0.15-0.25 0.10-0.30
32、 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 %16 % N $ 45.TABLE 3 Tensile Requirements
33、Grade 1B 2A 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-NType 25Cr-5Ni-Mo-Cu-N24Cr-10Ni-Mo-N25Cr-5Ni-Mo-N22Cr-5Ni-Mo-N25Cr-7Ni-Mo-N25Cr-7Ni-Mo-N27Cr-7Ni-Mo-W-NTensile strength,ksi MPa, min100 690 95 655 95 655 90 620 100 690 100
34、 690 100 690Yield strength(0.2 % offset),ksi MPa, min70 485 65 450 65 450 60 415 75 515 65 450 75 515Elongation in 2 in.50 mm,%, minA16 25 25 25 18 25 20A When ICI test bars are used in tensile testing as provided for in this specification, the gage length to reduced section diameter ratio shall be
35、4:1. Editorially corrected.A995/A995M 12a3S2. Destruction TestsS5. Radiographic InspectionS6. Liquid Penetrant InspectionS8. Charpy Impact TestS10. Examination of Weld PreparationS10.1 Liquid penetrant examination of cavities prepared for welding shall be performed to verify removal of thosedisconti
36、nuities found unacceptable by the inspection method specified for the casting. The method of performing liquid penetrantexamination shall be in accordance the with Practice E165. Unless other degrees of shrinkage or types of discontinuities found inthe cavities are specified, Type II, Internal Shrin
37、kage, of Reference Photographs E125, of Degree 2 in sections up to 2 in. 50 mmthick and of Degree 3 in sections over 2 in. 50 mm thick shall be acceptable.S11. Post Weld Heat TreatmentS11.1 Castings shall be given a post weld solution heat treatment in accordance with Table 1.S12. Prior Approval of
38、Major Weld RepairsOther supplementary requirements considered suitable for use with this specification are:S50. Estimating Ferrite ContentS50.1 Ferrite contents shall be determined by point count (Practice E562), by other quantitative metallographic methods suchas image analysis, by measurement of m
39、agnetic response, or by other methods upon agreement between the manufacturer and thepurchaser. Frequency of testing and location of tests shall be by agreement between the manufacturer and the purchaser.S51. Prior Approval of Weld MaterialS51.1 The purchaser must give approval of all weld filler ma
40、terials 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 09A995/A995M 12) that may impact the use of this standard. (Approved Nov. 1, 2012March1, 2012.).)(1) Added Grade 7A.Corrected
41、PREN formula to %Cr+3.3(%Mo+0.5%W)+16%N45.(2) Corrected “Type” to 27Cr-7Ni-Mo-W-N.(3) Added ACI designation CD3MWN.A995/A995M 12a4ASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this standard a
42、re expressly advised that determination of the validity of any such patent rights, 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
43、 revised, either reapproved or withdrawn. Your comments are invited either for revision 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 y
44、ou may attend. If you feel that your comments have not received a fair hearing you 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,Unite
45、d 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 12a5
