1、Designation: A988/A988M 15aA988/A988M 16Standard Specification forHot Isostatically-Pressed Stainless Steel Flanges, Fittings,Valves, and Parts for High Temperature Service1This standard is issued under the fixed designation A988/A988M; the number immediately following the designation indicates the
2、yearof original adoption 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 hot isostatically-pressed
3、, powder metallurgy, stainless steel piping components for use in pressuresystems. Included are flanges, fittings, valves, and similar parts made to specified dimensions or to dimensional standards, suchas in ASME specification B16.5.1.2 Several grades of martensitic, austenitic, age hardening, and
4、austenitic-ferritic stainless steels are included in thisspecification.1.3 Supplementary requirements are provided for use when additional testing or inspection is desired. These shall apply onlywhen specified individually by the purchaser in the order.1.4 This specification is expressed in both inc
5、h-pound units and in SI units. Unless the order specifies the applicable “M”specification designation (SI units), however, the material shall be furnished to inch-pound units.1.5 The values stated in either inch-pound units or SI units are to be regarded separately as the standard. Within the text,
6、theSI units are shown in brackets. The values stated in each system may not be exact equivalents; therefore, each system shall be usedindependently of the other. Combining values from the two systems may result in non-conformance with the standard.1.6 The following safety hazards caveat pertains onl
7、y to test methods portions 8.1, 8.2, 9.5 9.7, and Section 10 of thisspecification: This standard does not purport to address all of the safety concerns, if any, associated with its use. It is theresponsibility of the user of this standard to establish appropriate safety and health practices and dete
8、rmine the applicability ofregulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2A262 Practices for Detecting Susceptibility to Intergranular Attack in Austenitic Stainless SteelsA275/A275M Practice for Magnetic Particle Examination of Steel ForgingsA745/A745M Practice for Ul
9、trasonic Examination of Austenitic Steel ForgingsA751 Test Methods, Practices, and Terminology for Chemical Analysis of Steel ProductsA923 Test Methods for Detecting Detrimental Intermetallic Phase in Duplex Austenitic/Ferritic Stainless SteelsA961/A961M Specification for Common Requirements for Ste
10、el Flanges, Forged Fittings, Valves, and Parts for PipingApplicationsB311 Test Method for Density of Powder Metallurgy (PM) Materials Containing Less Than Two Percent PorosityE112 Test Methods for Determining Average Grain SizeE165 Practice for Liquid Penetrant Examination for General IndustryE340 P
11、ractice for Macroetching Metals and AlloysE606 Test Method for Strain-Controlled Fatigue TestingG48 Test Methods for Pitting and Crevice Corrosion Resistance of Stainless Steels and RelatedAlloys by Use of Ferric ChlorideSolution1 This specification is under the jurisdiction ofASTM Committee A01 on
12、Steel, Stainless Steel and RelatedAlloys and is the direct responsibility of Subcommittee A01.22onSteel Forgings and Wrought Fittings for Piping Applications and Bolting Materials for Piping and Special Purpose Applications.Current edition approved Dec. 1, 2015May 1, 2016. Published January 2016May
13、2016. Originally approved in 1998. Last previous edition approved in 2015 asA988/A988MA988/A988M 15a.15. DOI: 10.1520/A0988_A0988M-15A.10.1520/A0988_A0988M-16.2 For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at serviceastm.org. For Annual Book of A
14、STM 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 standard an indication of what changes have been made to the previous version. Becauseit may not be technically
15、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 by ASTM is to be considered the official document.*A Summary of Changes section appears at the end of this standar
16、dCopyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States12.2 MSS Standard:SP 25 Standard Marking System for Valves, Fittings, Flanges, and Unions32.3 ASME Specifications and Boiler and Pressure Vessel Codes:B16.5 Dimensional Standards for Ste
17、el Pipe Flanges and Flanged Fittings 42.4 ASME Specification IX Welding Qualifications:SFA-5.4 Specification for Corrosion-Resisting Chromium and Chromium-Nickel Steel Covered Welding Electrodes4SFA-5.9 Specification for Corrosion-Resisting Chromium and Chromium-Nickel Steel Welding Rods and Bare El
18、ectrodes4SFA-5.11 Specification for Nickel and Nickel-Alloy Covered Welding Electrodes4SFA-5.14 Specification for Nickel and Nickel Alloy Bare Welding Electrodes and Rods42.5 AWS Standard:5A5.11 Specification for Nickel and Nickel Alloy Welding Electrodes for Shielded Metal Arc WeldingA5.14 Specific
19、ation for Nickel and Nickel Alloy Bare Welding Electrodes and Rods3. Terminology3.1 Definitions of Terms Specific to This Standard:3.1.1 can, nthe container used to encapsulate the powder during the pressure consolidation process; it is partially or fullyremoved from the final part.3.1.2 compact, nt
20、he consolidated powder from one can. It may be used to make one or more parts.3.1.3 consolidation, nthe bonding of adjacent powder particles in a compact under pressure by heating to a temperature belowthe melting point of the powder.3.1.4 fill stem, nthe part of the compact used to fill the can. It
21、 is not usually integral to the part produced.3.1.5 hot isostatic-pressing, na process for simultaneously heating and forming a compact in which the powder is containedin a sealed formable enclosure usually made from metal and the so-contained powder is subjected to equal pressure from alldirections
22、 at a temperature high enough to permit plastic deformation and consolidation of the powder particles to take place.3.1.6 lot, na number of parts made from a single powder blend following the same manufacturing practice.3.1.7 part, na single item coming from a compact, either prior to or after machi
23、ning.3.1.8 powder blend, na homogeneous mixture of powder from one or more heats of the same grade.3.1.9 rough part, nthe part prior to final machining.4. Ordering Information4.1 It is the responsibility of the purchaser to specify in the purchase order all requirements that are necessary for materi
24、alordered under this specification. Such requirements may include, but are not limited to, the following:4.1.1 Quantity (weight or number of parts),4.1.2 Name of material or UNS number,4.1.3 ASTM designation and year of issue,4.1.4 Dimensions (tolerances and surface finishes should be included),4.1.
25、5 Microstructure examination if required (5.1.4),4.1.6 Inspection (15.1),4.1.7 Whether rough part or finished machined part (8.2.2),4.1.8 Supplementary requirements, if any,4.1.9 Additional requirements (See 7.2 and 17.1), and4.1.10 Requirement, if any, that the manufacturer shall submit drawings fo
26、r approval showing the shape of the rough part beforemachining and the exact location of test specimen material (See 9.3).TABLE 1 Chemical RequirementsComposition, %AUNSDesignation Grade Carbon Manganese Phosphorus Sulfur Silicon Nickel Chromium MolybdenumColumbiumplus Tantalum Tantalum TitaniumMart
27、ensitic Stainless SteelsS41000 13 chromium 0.15 1.00 0.040 0.030 1.00 11.513.5 . . . . . . . . . . . .S41026 13 chromium 0.15 1.00 0.020 0.020 1.00 1.002.00 11.513.5 0.400.60 Other Elements3 Available from Manufacturers Standardization Society of the Valve and Fittings Industry (MSS), 127 Park St.,
28、NE, Vienna, VA 22180-4602, http:/www.mss-.4 Available from American Society of Mechanical Engineers (ASME), ASME International Headquarters, Two Park Ave., New York, NY 10016-5990, http:/www.asme.org.5 Available from American Welding Society (AWS), 8669 NW 36 St., #130, Miami, FL 33166-6672, http:/w
29、ww.aws.org.A988/A988M 162TABLE 1 ContinuedComposition, %AUNSDesignation Grade Carbon Manganese Phosphorus Sulfur Silicon Nickel Chromium MolybdenumColumbiumplus Tantalum Tantalum Titanium0.5 molybdenum Cu 0.50S41500 13 chromium, 4 0.05 0.501.00 0.030 0.030 0.60 3.55.5 11.514.0 0.501.00 . . . . . . .
30、 . .nickelS42390 12 chromium, 1.0 0.180.25 1.00 0.030 0.030 1.00 0.300.80 11.512.5 0.801.20 Other Elementsmolybdenum, N 0.030.08modified V 0.250.35with vanadium Cb 0.080.15Austenitic Stainless SteelsS30400B 18 chromium, 8nickel0.08 2.00 0.045 0.030 1.00 8.011.0 18.020.0 . . . . . . . . . . . .S30403
31、B 18 chromium, 8nickel,low carbon0.035 2.00 0.045 0.030 1.00 8.013.0 18.020.0 . . . . . . . . . . . .S30451C 18 chromium, 8nickel,modified withnitrogen0.08 2.00 0.045 0.030 1.00 8.011.0 18.020.0 . . . . . . . . . . . .S30453 18 chromium, 8nickel,modified withnitrogen0.030 2.00 0.045 0.030 1.00 8.011
32、.0 18.020.0 . . . . . . . . . . . .S31600B 18 chromium, 8nickel,modified withmolybdenum0.08 2.00 0.045 0.030 1.00 10.014.0 16.018.0 2.003.00 . . . . . . . . .S31603B 18 chromium, 8nickel,modified withmolybdenum, lowcarbon0.030 2.00 0.045 0.030 1.00 10.014.0 16.018.0 2.003.00 . . . . . . . . .S31651C
33、 18 chromium, 8nickel,modified withmolybdenum andnitrogen0.08 2.00 0.045 0.030 1.00 10.013.0 16.018.0 2.003.00 . . . . . . . . .S31653C 18 chromium, 8nickel,modified withmolybdenum andnitrogen0.030 2.00 0.045 0.030 1.00 10.013.0 16.018.0 2.003.00 . . . . . . . . .S31700 19 chromium, 13nickel3.5 moly
34、bdenum0.08 2.00 0.045 0.030 1.00 11.015.0 18.0-20.0 3.04.0 . . . . . . . . .S31703 19 chromium, 13nickel,3.5 molybdenum0.030 2.00 0.045 0.030 1.00 11.015.0 18.020.0 3.04.0 . . . . . . . . .S21904 20 chromium, 6nickel, 9manganese0.04 8.010.0 0.045 0.030 1.00 5.57.5 19.021.5 . . . . . . Other Elements
35、N 0.150.40S31254 20 chromium, 18nickel, 6molybdenum, lowcarbon0.020 1.00 0.030 0.010 0.80 17.518.5 19.520.5 6.06.5 . . . Other ElementsCu 0.50-1.00N 0.18-0.22S31725 19 chromium, 15nickel, 4molybdenum0.030 2.00 0.045 0.030 1.00 13.517.5 18.020.0 4.05.0 . . . Other elementsN 0.20S31726 19 chromium, 15
36、nickel, 4molybdenum0.030 2.00 0.045 0.030 1.00 14.517.5 17.020.0 4.05.0 . . . Other ElementsN 0.100.20N08367 22 chromium, 25nickel,6.5 molybdenum,lowcarbon0.030 2.00 0.040 0.030 1.00 23.5025.5020.022.0 6.07.0 Other ElementsN 0.180.25Cu 0.75S32654 25 chromium, 22nickel,7 molybdenum, lowcarbon0.020 2.
37、04.0 0.030 0.005 0.50 21.023.0 24.025.0 7.08.0 Other ElementsN 0.450.55Cu 0.300.60Age-Hardening Stainless SteelsS17400 17 chromium, 4nickel, 3 copper0.07 1.00 0.040 0.030 1.00 3.05.0 15.017.5 . . . 0.150.45 Other ElementsCu 3.05.0Austenitic-Ferritic Stainless SteelsA988/A988M 163TABLE 1 ContinuedCom
38、position, %AUNSDesignation Grade Carbon Manganese Phosphorus Sulfur Silicon Nickel Chromium MolybdenumColumbiumplus Tantalum Tantalum TitaniumS31803 22 chromium, 5.5nickel,modified withnitrogen0.030 2.00 0.030 0.020 1.00 4.56.5 21.023.0 2.53.5 . . . Other ElementsN 0.080.20S32205 22 chromium, 5.5nic
39、kel, modifiedwith high nitrogen0.030 2.00 0.030 0.020 1.00 4.56.5 22.023.0 3.03.5 Other ElementsCu 0.75N 0.14-0.20S32906 29 chromium, 6.5nickel, 2.0molybdenum,modified with highnitrogen0.030 0.801.50 0.030 0.030 0.50 5.87.5 28.030.0 1.502.60 . . . Other ElementsCu 0.80N 0.300.40S32950 26 chromium, 3
40、.5nickel,1.0 molybdenum0.030 2.00 0.035 0.010 0.60 3.55.2 26.029.0 1.002.50 . . . Other ElementsN 0.15-0.35S32750 25 chromium, 7nickel, 4molybdenum,modified withnitrogen0.030 1.20 0.035 0.020 0.80 6.0-8.0 24.026.0 3.0-5.0 . . . Other ElementsN 0.240.32Cu 0.50S39274 25 chromium, 7nickel,modified with
41、nitrogenand tungsten0.030 1.0 0.030 0.020 0.80 6.08.0 24.026.0 2.53.5 . . . Other ElementsN 0.240.32Cu 0.200.80W 1.502.50S32760D 25 chromium, 7nickel, 3.5molybdenum,modified withnitrogen andtungsten0.030 1.00 0.030 0.010 1.00 6.08.0 24.026.0 3.04.0 . . . Other ElementsN 0.200.30Cu 0.501.00W 0.501.00
42、S39277 25 chromium, 7nickel,3.7 molybdenum0.025 0.80 0.025 0.002 0.80 6.58.0 24.026.0 3.04.0 . . . Other ElementsCu 1.202.00W 0.801.20N 0.230.33S32505 27 chromium, 7nickel, 3molybdenum,modified withnitrogen and copper0.030 1.50 0.030 0.020 1.00 4.57.0 24.027.0 2.93.9 . . . Other ElementsCu 1.502.50N
43、 0.250.30A Maximum, unless otherwise specified.B S30400, S30403, S31600, and S31603 shall have a maximum nitrogen content of 0.10 %.C S30451, S31651, S30453, S31653 shall have a nitrogen content of 0.10 to 0.16 %.D % Cr + 3.3 % Mo + 16 % N 40 min.5. Materials and Manufacture5.1 Manufacturing Practic
44、e:5.1.1 Compacts shall be manufactured by placing a single powder blend into a can, evacuating the can, and sealing it. The canmaterial shall be selected to ensure that it has no deleterious effect on the final product. The entire assembly shall be heated andplaced under sufficient pressure for a su
45、fficient period of time to ensure that the final consolidated part meets the densityrequirements of 8.1.1.1. One or more parts shall be machined from a single compact.5.1.2 The powder shall be prealloyed and made by a melting method capable of producing the specified chemical composition,such as but
46、 not limited to, air or vacuum induction melting, followed by gas atomization.5.1.3 When powder from more than one heat of the same grade is used to make a blend, the heats shall be mixed thoroughlyto ensure homogeneity.5.1.4 The compact shall be sectioned and the microstructure examined to check fo
47、r porosity and other internal imperfections.It shall meet the requirements of 8.1.2. The sample shall be taken from the fill stem or from a location in a part as agreed uponby the manufacturer and purchaser.5.1.5 Unless otherwise specified in the purchase order, the manufacturer shall remove the can
48、 material from the surfaces of theconsolidated compacts by chemical or mechanical methods such as by pickling or machining. This removal shall be done beforeor after heat treatment at the option of the manufacturer (See Note 1).NOTE 1Often, it is advantageous to leave the can material in place until
49、 after heat treatment or further thermal processing of the consolidated compact.6. Chemical Composition6.1 The steel, both as a blend and as a part, shall conform to the requirements for chemical composition prescribed in Table 1.Test Methods, Practices, and Terminology of A751 shall apply.A988/A988M 164TABLE 1 Chemical RequirementsComposition, %AUNSDesignation Grade Carbon Manganese Phosphorus Sulfur Silicon Nickel Chromium Molybdenum Copper Ni
