1、RecommendedPractices forWelding AusteniticChromium-NickelStainless SteelPiping and TubingANSI/AWS D10.4-86RAn American National StandardKey Words austenitic pipe, chromium-nickel ANSI/AWS D10.4-86pipe, gas metal arc welding, gas tungsten arc welding, An American National Standardrecommended practice
2、, stainless steel pipe, shieldedmetal arc weldingApproved byAmerican National Standards InstituteNovember 12,1986Recommended Practicesfor Welding AusteniticChromium-NickelStainless SteelPiping and TubingSuperseding AWS D10.4-79Prepared byAWS Committee on Piping and TubingIssued, 1986Under the Direct
3、ion ofAWS Technical Activities CommitteeApproved byAWS Board of DirectorsApril 11, 1986AbstractThis document presents a detailed discussion of the metallurgical characteristics and weldability of many grades ofaustenitic stainless steel used in piping and tubing. The delta ferrite content as express
4、ed by ferrite number (FN) isexplained, and its importance in minimizing hot cracking is discussed.A number of Figures and Tables illustrate recommended joint designs and procedures. Appendix A presentsinformation on the welding of high-carbon stainless steel cast pipe fittings.AMERICAN WELDING SOCIE
5、TY550 N.W. LeJeune Road, P.O. Box 351040, Miami, FL 33135Policy Statement on Use of AWS StandardsAll standards of the American Welding Society (codes, specifications, recommended practices, methods, etc.) arevoluntary consensus standards that have been developed in accordance with the rules of the A
6、merican NationalStandards Institute. When AWS standards are either incorporated in or made part of documents that are included infederal or state laws and regulations or the regulations of other governmental bodies, their provisions carry the full legalauthority of the statute. In such cases, any ch
7、anges in those AWS standards must be approved by the governmentalbody having statutory jurisdiction before they can become a part of those laws and regulations. In all cases, thesestandards carry the full legal authority of the contract or other document that invokes AWS standards. Where thiscontrac
8、tual relationship exists, changes in or deviations from requirements of an AWS standard must be by agreementbetween the contracting parties.International Standard Book Number: 0-8171-267-9American Welding Society, 550 N.W. LeJeune Road, P.O. Box 351040, Miami, Florida 33135 1986 by American Welding
9、Society. All rights reservedPrinted in the United States of America5 4 3 2 1Note: By publishing this standard, the American Welding Society does not insure anyone using the information itcontains against liability arising from that. Publication of a standard by the American Welding Society does not
10、carrywith it any right to make, use, or sell any patented items. Each user of the information in this standard should make anindependent investigation of the validity of that information for the particular use and the patent status of any itemreferred to herein.This standard is subject to revision a
11、t any time by the Committee on Piping and Tubing. It must be reviewed every fiveyears and if not revised, it must be either reapproved or withdrawn. Comments (recommendations, additions, ordeletions) and any pertinent data which may be of use in improving this standard are requested and should be ad
12、dressedto AWS Headquarters. Such comments will receive careful considerations by the Committee on Piping and Tubing andthe author of the comment will be informed of the committees response to the comments. Guests are invited to attend allmeetings of the Committee on Piping and Tubing to express thei
13、r comments verbally. Procedures for appeal of anadverse decision concerning all such comments are provided in the Rules of Operation of the Technical ActivitiesCommittee. A copy of these Rules can be obtained from the American Welding Society, 550 N.W. LeJeune Rd., P.O.Box 351040, Miami, Florida 331
14、35.PersonnelAWS Committee on Piping and TubingR. R. Wright, ChairmanR. Giambelluca, 1st Vice ChairmanJ. E. Fisher, 2nd Vice ChairmanE. J. Seel, SecretaryW. L. BallisG. O. CurbowH. W. EbertR. S. GreenR. B. GwinE. A. HarwartG. K. HickoxJ. E. HinkelP. P. Hoh*R. B. KadiyalaA. N. Kugler*R. J. Landrum*J.
15、R. McGuffeyL. A. MaierJ. W. Moeller*M. D. Randall*H. L. SoundersP. C. ShepardE. G. ShifrinG. K. SosninH. A. SosninW. J. SperkoJ. G. TackJ. C. Thompson, Jr. *D. R. Van BurenMoody-Tottrup International, IncorporatedC. F. Braun and CompanySperi AssociatesAmerican Welding SocietyColumbia Gas Distributio
16、n CompaniesConsultantExxon Research and Engineering CompanyNational Certified Pipe Welding BureauMcDermott InternationalConsultantConsultantLincoln Electric CompanyConsultantTechalloy Maryland, IncorporatedConsultantConsultantOak Ridge National LaboratoryBethlehem Welding however, careful adherence
17、tothe procedure requirements will usually produce excel-lent welds in stainless steel piping and tubing.1. Material Compositionsand Specifications1.1 Compositions. Chemical composition ranges andtype numbers for those stainless steels generally availablein wrought piping and tubing are listed in Tab
18、le 1. Theseare American Iron and Steel Institute (AISI) StandardCompositions. Chemical composition ranges and desig-nations for five stainless steels generally available as castpipe are shown in Table 2. These are included becausecast valves and fittings are considered part of a pipingsystem.The wel
19、dability of castings may be somewhat less thanthat of a wrought stainless steel of the same type. This isbecause fully austenitic castings have much larger grainsthan similar wrought material. Consequently, there isless grain boundary area along which to disperse theimpurities. As a result, there ma
20、y be a tendency towardhot cracking when welding some castings. However,proper control of the composition of the casting, toobtain four to ten percent delta ferrite, can prevent hotcracking.1.2 Specifications. Typical American Society for Test-ing and Materials (ASTM) specifications covering pip-ing
21、and tubing in both cast and wrought form (seamlessor welded) are listed in Table 3. ASTM employs the AISItype numbers for designating the austenitic types. How-ever, the ASTM chemical composition requirementsdiffer slightly from the AISI requirements and will varyslightly in different ASTM specifica
22、tions. The composi-tion ranges specified for cast tubular products are identi-cal with those of the American Castings Institute (ACI).Specifications for covered welding electrodes and weld-ing rods and electrodes are provided in Tables 4 and 5.2. Base Metals2.1 Primary Types (304, 305, 309, and 310)
23、. Thesematerials have many applications and are widely usedfor their corrosion and oxidation resistance, high-temperature strength, and low-temperature properties.However, there are a number of welding-related charac-teristics that may affect all of these, as noted below.Types 304 and 305 may become
24、 sensitized by welding,depending on their carbon content and the manner inwhich they are welded, and as a result may requiresolution annealing to restore immunity to intergranularTypesType304304H304L304LN304N305308309309S310310S316316H316L316LN316N317317L321321H347347H348348HTable 1of Chromium-Nicke
25、l Stainless Steel Availablec0.080.04-0.100.030.030.080.120.080.200.080.150.080.080.04-0.100.030.030.080.080.030.080.04-0.100.080.04-0.100.080.04-0.10Mn2.002.002.002.002.002.002.002.002.002.002.002.002.002.002.002.002.002.002.002.002.002.002.002.00Si.00.00.00.00.00.00.00.00.00.50.50.00.00.00.00.001.0
26、0.001.001.001.00.001.001.00Chemical Composition LimitCr18.0-20.018.0-20.018.0-20.018.0-20.018.0-20.017.0-19.019.0-21.022.0-24.022.0-24.024.0-26.024.0-26.016.0-18.016.0-18.016.0-18.016.0-18.016.0-18.018.0-20.018.0-20.017.0-19.017.0-19.017.0-19.017.0-19.017.0-19.017.0-19.0Nib8.0-10.58.0-10.58.0-12.08.
27、0-10.58.0-10.510.5-13.010.0-12.012.0-15.012.0-15.019.0-22.019.0-22.010.0-14.010.0-14.010.0-14.010.0-14.010.0-14.011.0-15.011.0-15.09.0-12.09.0-12.09.0-13.09.0-13.09.0-13.09.0-13.0P0.0450.0450.0450.0450.0450.0450.0450.0450.0450.0450.0450.0450.0450.0450.0450.0450.0450.0450.0450.0450.0450.0450.0450.045
28、, PercentS0.030.030.030.030.030.030.030.030.030.030.030.030.030.030.030.030.030.030.030.030.030.030.030.03in Piping and TubingaOther Elements0.10-0.15 N0.10-0.16 N2.0-3.0 Mo2.0-3.0 Mo2.0-3.0 Mo2.0-3.0 Mo0.10-0.3 N2.0-3.0 Mo0.10-0.16 N3.0-4.0 Mo3.0-4.0 Mo5 X % C min. Ti5 X % C min. Ti10 X % C min. Cb
29、 + Tac10 X % C min. Cb + Ta10 X % C min. Cb + Tac 0.2 Cu10 X % C min. Cb + Tac 0.2 Cua. Single values are maximums.b. For some tubemaking processes, the nickel content of certain austenitic types must be slightly higher than shown.c. Ta is optional.ASTMbDesignationCF3CF8CF8MCF3MCH8CPK20CH20Types ofC
30、omposition19-919-919-10 Mo19-10 Mo25-1225-2025-12Table 2Chromium-Nickel Stainless Steelc0.030.080.080.030.080.200.20Mn1.501.501.501.501.501.501.50p0.040.040.040.040.0400.0400.040CastingsChemical Composition, Percent“1S Si0.04 2.000.04 2.000.04 2.000.04 1.500.040 1.500.040 1.000.040 2.00Cr17.0-21.018
31、.0-21.018.0-21.017.0-21.022.0-26.023.0-27.022.0-26.0Ni8.0-12.08.0-11.09.0-12.09.0-13.012.0-15.019.0-22.012.0-15.0Other Elements2.0-3.0 Mo2.0-3.0 MoNote: Chromium-nickel stainless steel castings with carbon content above 0.20% are covered in the Appendix of this report.a. Single values are maximums.b
32、. American Society for Testing and Materials.Table 3ASTM SpecificationsApplicable to Austenitic Stainless SteelPiping and Tubing ComponentsSpecificationDesignation ProductA213 Seamless ferritic and austenitic alloy steelboiler, superheater, and heat-exchangertubesA249 Welded austenitic steel boiler,
33、 superheater,heat-exchanger, and condenser tubesA269 Seamless and welded austenitic stainless steeltubing for general serviceA270 Seatress and welded austenitic stainless steelsan t ry tubingA271 Seamless austenitic chromium-nickel steelstill tubes for refinery serviceA312 Seamless and welded austen
34、itic stainless steelpipeA351 Austenitic steel castings for valves, flanges,fittings, and other pressure-containingpartsA358 Electric fusion welded austenitic chromium-nickel alloy steel pipe for high-temperatureserviceA376 Seamless austenitic steel pipe for high temper-ature central-station serviceA
35、403 Wrought pipe fittingsA409 Welded large outside diameter light-wallaustenitic chromium-nickel alloy steel pipefor corrosive or high-temperature serviceA430 Austenitic steel forged and bored pipe forhigh-temperature serviceA451 Centrifugal cast austenitic steel pipe for high-temperature serviceA45
36、2 Centrifugal cast austenitic cold wroughtstainless steel pipe for high-temperatureserviceA688 Welded tubesattack when exposed to certain corrosive environments.(See 9.2 for a detailed discussion of this form of corrosiveattack.) However, these steels often are used in the as-welded condition when i
37、t is known that the service condi-tion does not produce intergranular attack.The likelihood of corrosive attack on material sensi-tized by welding is not so great for the higher chromiumgrades such as Types 309 and 310. However, these typescannot be considered totally immune to intergranularattack w
38、hen they are in a sensitized condition.2.2 Chromium-Nickel-Molybdenum Types (316 and317). The addition of molybdenum to the chromium-nickel alloys does not alter their welding characteristicsin any significant way. However, the welds themselvesmay display slightly greater susceptibility to intergran
39、u-lar corrosion in sensitized heat-affected zones than Type304 in nitric acid service. Molybdenum reduces theresistance of stainless steel to corrosion by nitric acid.2.3 Stabilized Types (321 and 347). Titanium, colum-bium and tantalum are carbide stabilizing elements.During the steel making proces
40、s, they combine with car-bon before chromium does. Thus, in subsequent weld-ing, the formation of chromium carbides is minimized.When chromium carbide forms, the adjacent metal isdepleted of chromium, thus reducing the materials cor-rosion resistance.However, during welding, a very narrow zone imme-
41、diately adjacent to the fusion line, in the heat-affectedzone (H AZ) of the weld, is heated to a temperature highenough to dissolve almost all of the titanium, columbiumand tantalum carbides. If the welded joint is subse-quently heated to a temperature in the vicinity of 1200 F(650 C) chromium carbi
42、des will precipitate at the grainboundaries. Thus, the conditions are set up for what isknown as “knife line attack“ in a corrosive environment.Knife line attack can be prevented by reheating thewelded joint to a temperature in the vicinity of 1600F(870 C). At this temperature, titanium, columbium,
43、andtantalum carbides precipitate in preference to chromiumcarbides since their solubility temperature is lower thanthat of chromium carbide. This is called a “stabilizingheat-treatment“ since it does not impair the corrosion resistance of the steel.Type 321 is stabilized with titanium, while Type 34
44、7 isstabilized with columbium and tantalum. Type 321 dis-plays a greater susceptibility to knife line attack thanType 347 because of the lowered solution temperature oftitanium carbide compared with columbium and tanta-lum carbide.2.4 Low Carbon Types (304L, 309S, 310S, and 316L).These types are low
45、 carbon modifications of the corre-sponding or primary grades. In Types 304L and 316L, anextra low carbon content (0.030 percent maximum) min-imizes the precipitation of chromium carbide both dur-ing welding and any sensitizing postweld heat treatment.This in turn preserves the corrosion resistance
46、of theweldment. Similarly, Types 309S and 310S with 0.08percent maximum carbon, reduces the likelihood ofcorrosion in comparison with their higher carboncounterparts.Table 4Electrodes and Welding Rods used in Welding Specific Castand Wrought Austenitic Stainless SteelsBare Welding Rods or Electrodes
47、,Specification AWS A5.9,Gas Tungsten Arc, Gas Metal Arc,and Submerged Arc WeldingER308ER308LER347ER309ER309ER310ER310ER316bER16-8-2ER316bER316LER316ER317LER321ER347ER348a. Castings higher in carbon but otherwise of generally corresponding compositions are available in the heat-resisting grades.These
48、 castings carry the “H“ designation (HF, HH, and HK, for instance). Electrodes best suited for welding these high carbonversions are the standard electrodes recommended for the corresponding but lower carbon corrosion-resistant castings shownabove (see Appendix).b. Joints containing 316, 316L, 317,
49、and 318 weld metal may occasionally display poor corrosion resistance in the “as-welded“condition, particularly where hot oxidizing acids are involved. Corrosion resistance of the weldment, for all grades of Cr-Ni-Mobase metal may be restored by rapid cooling from 1950-2050 F (1065-1120 C).c. Type 321 covered electrodes are not manufactured because titanium is not readily transferred across an electric arc.Type of Stainless SteelWrought304304H305304L3093O9S310310S316316H316L317317L321321H347347H348348HCastaCF-8CF-3CH20CH8CPK-20CF-8MCF-12MCF-3MCF-8CCompositionNominal
