1、Designation: A988/A988M 15A988/A988M 15aStandard 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 March 1, 2015Dec. 1, 2015. Published April 2015Janu
13、ary 2016. Originally approved in 1998. Last previous edition approved in 20132015 asA988/A988M13.15. DOI: 10.1520/A0988_A0988M-15.10.1520/A0988_A0988M-15A.2 For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at serviceastm.org. For Annual Book of ASTM
14、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 poss
15、ible 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 standardCop
16、yright 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 Steel P
17、ipe 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 Electr
18、odes4SFA-5.11 Specification for Nickel and Nickel-Alloy Covered Welding Electrodes43. 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.
19、3.1.2 compact, nthe 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
20、 fill the can. It 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 f
21、rom alldirections 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
22、to or after machining.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 nec
23、essary for materialordered 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
24、be included),4.1.5 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 s
25、ubmit drawings for 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 Tant
26、alum TitaniumMartensitic 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 Elements0.5 molybdenum Cu 0.50S41500 13 chromium, 4 0.05 0.501.00 0.030 0.030 0.60 3.55.5 11.514.0 0.5
27、01.00 . . . . . . . . .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 0.080.153 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.A988/A988M 15a2TABLE 1 ContinuedComposition, %AUNSDesignation Grade Carbon Manganese Phosphorus Su
29、lfur Silicon Nickel Chromium MolybdenumColumbiumplus Tantalum Tantalum TitaniumAustenitic Stainless SteelsS30400B 18 chromium, 8nickel0.08 2.00 0.045 0.030 1.00 8.011.0 18.020.0 . . . . . . . . . . . .S30403B 18 chromium, 8nickel,low carbon0.035 2.00 0.045 0.030 1.00 8.013.0 18.020.0 . . . . . . . .
30、 . . . .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 8.011.0 18.020.0 . . . . . . . . . . . .S31600B 18 chromium, 8nickel,modified withmolybdenum0.08 2
31、.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 18 chromium, 8nickel,modified withmolybdenum andnitrogen0.08 2.00 0.045 0.030 1.00 10.013.0
32、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 molybdenum0.08 2.00 0.045 0.030 1.00 11.015.0 18.0-20.0 3.04.0 . . . . . . . . .S31703 19 chromiu
33、m, 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 ElementsN 0.150.40S31254 20 chromium, 18nickel, 6molybdenum, lowcarbon0.020 1.00 0.030 0.010 0.80 17.
34、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, 15nickel, 4molybdenum0.030 2.00 0.045 0.030 1.00 14.517.5 17.020.0 4.05.0 . . . Other ElementsN
35、 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 2.04.0 0.030 0.005 0.50 21.023.0 24.025.0 7.08.0 Other ElementsN 0.450.55Cu 0.300.60Age-Hardeni
36、ng 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 SteelsS31803 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 0.0
37、80.20S32205 22 chromium, 5.5nickel, 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 0.14-0.20A988/A988M 15a3TABLE 1 ContinuedComposition, %AUNSDesignation Grade Carbon Manganese Phosphorus Sulfur Silicon Nickel Chromium MolybdenumColumbiumplus Tant
38、alum Tantalum TitaniumS32906 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, 3.5nickel,1.0 molybdenum0.030 2.00 0.035 0.010 0.60 3.55.2 26.029.0 1.002.50 . . . Other Elem
39、entsN 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 withnitrogenand tungsten0.030 1.0 0.030 0.020 0.80 6.08.0 24.026.0 2.53.5 . . . Other ElementsN
40、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 0.501.00S39277 25 chromium, 7nickel,3.7 molybdenum0.025 0.80 0.025 0.002 0.80 6.58.0 24.026.0 3.04.0
41、 . . . 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 0.250.30A Maximum, unless otherwise specified.B S30400, S30403, S31600, and S31603 shall ha
42、ve 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 Practice:5.1.1 Compacts shall be manufactured by placing a single powder blend into a can, evacuati
43、ng 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 sufficient period of time to ensure that the final consolidated part meets the densityrequirem
44、ents 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 not limited to, air or vacuum induction melting, followed by gas atomization.5.1.3 When pow
45、der 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 for porosity and other internal imperfections.It shall meet the requirements of 8.1.2. The sam
46、ple 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 material from the surfaces of theconsolidated compacts by chemical or mechanical methods su
47、ch 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 after heat treatment or further thermal processing of the consolidated compact.6. Chemical
48、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.6.1.1 A representative sample of each blend of powder shall be analyzed by the manufacturer to determ
49、ine the percentage ofelements prescribed in Table 1. The blend shall conform to the chemical composition requirements prescribed in Table 1.6.1.2 When required by the purchaser, the chemical composition of a sample from one part from each lot of parts shall bedetermined by the manufacturer. The composition of the sample shall conform to the chemical requirements prescribed in Table1.A988/A988M 15a46.2 Addition of lead, selenium, or other unspecifi
