1、Designation: A774/A774M 14Standard Specification forAs-Welded Wrought Austenitic Stainless Steel Fittings forGeneral Corrosive Service at Low and ModerateTemperatures1This standard is issued under the fixed designation A774/A774M; the number immediately following the designation indicates the yearof
2、 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 five grades of as-welded,wrough
3、t austenitic stainless steel fittings for low-pressurepiping and intended for low and moderate temperatures andgeneral corrosive service. Users should note that certaincorrosive conditions may restrict the use of one or more grades.For applications requiring a product that requires heat treat-ment o
4、r full pressure rating, refer to Specification A403/A403M. The term “fittings” applies to butt and socket weldingparts such as 45 and 90 elbows, tees, reducers, wyes, laterals,crosses, and stub ends.1.2 This specification covers as-welded fittings 3 through 48in. 75 through 1225 mm in outside diamet
5、er and in nominalwall thicknesses 0.062 through 0.500 in. 1.6 through 12.7mm. Table 1 and Table 2 list the common diameters andnominal thicknesses of fittings in this specification.1.3 This specification does not apply to cast fittings. Castaustenitic steel fittings are covered by Specification A351
6、/A351M.1.4 Optional supplementary requirements are provided forfittings where a greater degree of examination is desired. Thesesupplementary requirements call for additional tests. Whendesired, one or more of these may be specified in the order.1.5 This specification is expressed in both inch-pound
7、unitsand in SI units. However, unless the order specifies theapplicable “M” specification designation (SI units), the mate-rial shall be furnished to inch-pound units.1.6 The values stated in either SI units or inch-pound unitsare to be regarded separately as standard. Within the text, theSI units a
8、re shown in brackets. The values stated in eachsystem may not be exact equivalents; therefore, each systemshall be used independently of the other. Combining valuesfrom the two systems may result in non-conformance with thestandard.2. Referenced Documents2.1 In addition to those reference documents
9、listed inSpecification A960/A960M, the following list of standardsapply to this specification:2.2 ASTM Standards:2A240/A240M Specification for Chromium and Chromium-Nickel Stainless Steel Plate, Sheet, and Strip for PressureVessels and for General ApplicationsA351/A351M Specification for Castings, A
10、ustenitic, forPressure-Containing PartsA403/A403M Specification for WroughtAustenitic StainlessSteel Piping FittingsA960/A960M Specification for Common Requirements forWrought Steel Piping FittingsE527 Practice for Numbering Metals and Alloys in theUnified Numbering System (UNS)2.3 ASME Standard:Sec
11、tion IX ASME Boiler and Pressure Vessel Code32.4 MSS Standard:SP 43 Wrought Stainless Steel Butt Welding Fittings42.5 AWS Standards:A5.4 Corrosion-Resisting Chromium and Chromium-NickelSteel Covered Welding Electrodes5A5.9 Corrosion-Resisting Chromium and Chromium-NickelSteel Welding Rods and Bare E
12、lectrodes51This specification is under the jurisdiction of ASTM Committee A01 on Steel,Stainless Steel and Related Alloys and is the direct responsibility of SubcommitteeA01.22 on Steel Forgings and Wrought Fittings for Piping Applications and BoltingMaterials for Piping and Special Purpose Applicat
13、ions.Current edition approved Oct. 1, 2014. Published October 2014. Originallyapproved in 1980. Last previous edition approved in 2013 as A774/A774M 13.DOI: 10.1520/A0774_A0774M-14.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.or
14、g. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.3Available from American Society of Mechanical Engineers (ASME), ASMEInternational Headquarters, Two Park Ave., New York, NY 10016-5990, http:/www.asme.org.4Available from Manufact
15、urers Standardization Society of the Valve and FittingsIndustry (MSS), 127 Park St., NE, Vienna, VA 22180-4602, http:/www.mss-.5Available from American Welding Society (AWS), 550 NW LeJeune Rd.,Miami, FL 33126, http:/www.aws.org.*A Summary of Changes section appears at the end of this standardCopyri
16、ght ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States12.6 SAE Standard:J1086 Unified Numbering System for Metals and Alloys63. Ordering Information3.1 See Specification A960/A960M and the following:3.1.1 Dimensions (outside diameter and specified
17、 wallthickness, see Table 1 and Table 2),3.1.2 Grade (Table 3), and3.1.3 End use, if known.4. General Requirements4.1 Product furnished to this specification shall conform tothe requirements of Specification A960/A960M, including anysupplementary requirements that are indicated in the purchaseorder.
18、 Failure to comply with the requirements of SpecificationA960/A960M constitutes non-conformance with this specifi-cation. In case of a conflict between the requirements of thisspecification and Specification A960/A960M, this specificationshall prevail.5. Manufacture5.1 The fittings shall be made fro
19、m flat-rolled steel, such asin Specification A240/A240M. The flat rolled steel shall be inthe solution annealed condition unless other heat treat condi-tions are agreed upon by the manufacturer and the purchaser.The fittings shall be formed by a hot or cold process, andwelded by a shielded welding p
20、rocess with or without theaddition of filler metal.5.2 Fittings shall be furnished clean and free of scale.5.3 Welding:5.3.1 The joints shall be full penetration double-welded orsingle-welded butt joints employing fusion-welding processeswith or without the addition of filler metal as defined underD
21、efinitions, ASME Boiler and Pressure Vessel Code, SectionIX. This specification makes no provision for any difference inweld quality requirements regardless of the weld joint-typeemployed (single or double) in making the weld. Weldingprocedures and welding operators shall be qualified in accor-dance
22、 with ASME Boiler and Pressure Vessel Code, SectionIX.5.3.2 For fittings employing multiple passes, the root-passmay be made without the addition of filler metal.5.3.3 The alloy content (chromium, nickel, molybdenum,columbium, and tantalum) of the deposited weld metal shallconform to that required o
23、f the base metal or for equivalentweld metal as given in the AWS filler metal specification A5.4or A5.9, except that, when welding on Types 304L base metal,the deposited weld metal shall correspond, respectively, toAWS Types E308L (ER308L) and, when welding on Type 321base metal, the weld metal shal
24、l correspond to AWS TypesE347 (ER347 or ER321).6Available from Society of Automotive Engineers (SAE), 400 CommonwealthDr., Warrendale, PA 15096-0001, http:/www.sae.org.TABLE 1 Common Tubular Fittings Sizes, Outside DiameterAin. mm in. mm3 76 1234 325312 90 14 3554 100 16 405412 115 18 4606 150 20 51
25、0658 170 24 6108 205 30 760858 220 36 91510 255 40 10151034 275 42 107012 305 48 1220AOther sizes may be furnished provided they comply with all other requirementsof this specification.TABLE 2 Common Tubular Fittings Nominal ThicknessesAin. or gauge in. mm16 gauge 0.062 1.614 gauge 0.078 2.012 gauge
26、 0.109 2.811 gauge 0.125 3.210 gauge 0.140 3.68 gauge 0.172 4.4316 in. 0.187 4.814 in. 0.250 6.4516 in. 0.312 8.038 in. 0.375 9.512 in. 0.500 12.5AOther thicknesses may be furnished provided they comply with all otherrequirements of this specification.TABLE 3 Chemical RequirementsNOTE 1Where an elli
27、psis (.) appears in this table, there is no requirement.Composition, %Grade UNSDesigna-tionACarbon,maxBMan-ganese,maxPhos-phorus,maxSulfur,maxSilicon,maxChromium Nickel Molybdenum Tita-niumColum-bium plusTantalumNitro-gen,maxTP 304L S30403 0.030 2.00 0.045 0.030 1.00 18.020.0 8.012.0 . . . . . . . .
28、 . 0.10TP 316L S31603 0.030 2.00 0.045 0.030 1.00 16.018.0 10.014.0 2.003.00 . . . . . . 0.10TP 317L S31703 0.030 2.00 0.045 0.030 1.00 18.020.0 11.015.0 3.04.0 . . . . . . 0.10TP 321 S32100 0.08 2.00 0.045 0.030 1.00 17.019.0 9.012.0 . . .C. .TP 347 S34700 0.08 2.00 0.045 0.030 1.00 17.019.0 9.012.
29、0 . . . . . .D.ANew designation established in accordance with Practice E527 and SAE J1086.BThe carbon analysis shall be reported to the nearest 0.01 % except for the low carbon (0.030) types, that shall be reported to the nearest 0.001 %.CTi = 5X(C+N) 0.70.DThe columbium plus tantalum content shall
30、 be not less than ten times the carbon content and not more than 1.10 %.A774/A774M 1426. Chemical Composition6.1 The steel shall conform to requirements of chemicalcomposition for the respective material prescribed in Table 3.6.2 The purchaser may make a product analysis on productsmade to this spec
31、ification in accordance with SpecificationA960/A960M.6.3 The steel shall not contain any unspecified elements forthe ordered grade to the extent that it conforms to therequirements of another grade for which that element is aspecified element having a required minimum content.6.4 Mill certificates o
32、f analysis of each heat of steel shall befurnished on request.7. Mechanical Properties7.1 The material used in making these fittings shall conformto the test requirements listed in Table 4 for the specified grade.Mechanical tests made on the sheet or plate by the manufac-turer shall qualify the shee
33、t or plate material.7.2 Mechanical properties of fittings made to this specifica-tion are not verified unless specific tests and limits have beenagreed upon between the purchaser and manufacturer.8. Heat Treatment8.1 Heat treatment is not required (see 16.1).9. Permissible Variations in Nominal Dime
34、nsions9.1 Refer to MSS SP 43 for tolerances for fittings coveredby this specification. For fittings not covered in MSS SP 43(wyes and laterals) acceptance limits must be agreed uponbetween the purchaser and manufacturer.10. Hydrostatic Tests10.1 Hydrostatic testing of the fittings is not required by
35、 thisspecification.11. Surface Finish, Appearance, and CorrosionProtection11.1 The requirements of Specification A960/A960M apply.11.2 When the removal of a surface discontinuity reducesthe wall thickness below 8712 % of the specified nominal wallthickness at any point, the fitting shall be subject
36、to rejection orto repair as provided in Section 14.12. Inspection12.1 The manufacturer shall afford the purchasers inspectorall reasonable facilities necessary to satisfy him that thematerial is being furnished in accordance with the specifica-tion. Mill inspection by the purchaser shall not interfe
37、reunnecessarily with the manufacturers operations. All tests andinspections shall be made at the place of manufacture, unlessotherwise agreed to.12.2 Other tests, when required by agreement, shall be madefrom material of the lots covered in the order.NOTE 1A lot shall consist of all fittings of the
38、same type, size, andwall thickness, manufactured from one heat of material and using one lotnumber of electrode or one heat of weld wire.13. Repair of Defects13.1 Injurious defects that are deeper than the minimumspecified in Section 12 may be repaired with the approval ofthe purchaser. Such defects
39、 shall be entirely removed by eitherchipping, machining, or grinding before welding. Reweldingshall be in accordance with 5.3 of this specification.14. Rejection and Rehearing14.1 Material that fails to conform to the requirements ofthis specification may be rejected. Rejection should be reportedto
40、the producer or supplier promptly and in writing. In case ofdissatisfaction with the results of the test, the producer orsupplier may make claim for rehearing.14.2 Fittings that develop defects in shop working orapplication operations may be rejected. Upon rejection themanufacturer shall be notified
41、 in writing.15. Certification15.1 Test reports are required for all fittings covered by thisspecification. Each test report shall meet the requirements forcertification in Specification A960/A960M as well as includethe following information specific to this specification:TABLE 4 Mechanical Test Requ
42、irementsTypeAUNSDesignationTensileStrengthYieldStrengthElongation in2in.50 mm,min, %Hardness, maxBksi MPa ksi MPa Brinell RockwellB304L S30403 70-95 485-65525 170 40.0 183 88316L S31603 70-95 485-65525 170 40.0 217 95317L S31703 75-100 515-69030 205 35.0 217 95321 S32100 75-100 515-69030 205 40.0 21
43、7 95347 S34700 75-100 515-69030 205 40.0 202 92AUnless otherwise indicated, a grade designation originally assigned by the American Iron and Steel Institute (AISI).BEither Brinell or Rockwell B Hardness is permissible.A774/A774M 14315.1.1 Chemical analysis results, Section 6 (Table 3), re-ported res
44、ults shall be to the same number of significant figuresas the limits specified in Table 3 for that element.15.1.2 Tensile property results, Section 7 (Table 2) reportyield strength and tensile strength in ksi MPa and elongationin percent, and15.1.3 Any supplementary testing required by the purchaseo
45、rder.16. Product Marking16.1 In addition to marking requirements of SpecificationA960/A960M, the additional marking of the letters “HT-O” toindicate that there has been no heat treating after welding orforming is required.17. Packaging17.1 The manufacturer shall box, crate, or package in securelifts
46、 or bundles to ensure safe delivery. If specified, the endsshall be protected with wooden or plastic plugs. Specialpackaging requiring extra operations other than those abovemust be specified by the purchaser.18. Keywords18.1 austenitic stainless steel; corrosive service applica-tions; pipe fittings
47、-steel; piping applications; stainless steelfittings; temperature service applications-lowSUPPLEMENTARY REQUIREMENTSSupplementary requirements shall not be considered unless specified in the order, in which event,any or all of the supplementary tests specified in Specification A960/A960M shall be ma
48、de at the placeof manufacture, unless otherwise agreed upon. The tests specified shall be witnessed by thepurchasers inspector before shipment of material if so specified in the order.SUMMARY OF CHANGESCommittee A01 has identified the location of selected changes to this specification since the last
49、 issue,A774/A774M 13, that may impact the use of this specification. (Approved October 1, 2014)(1) Revised Section 11 to clarify requirements for surfacefinish, appearance, and corrosion protection.Committee A01 has identified the location of selected changes to this specification since the last issue,A774/A774M 09, that may impact the use of this specification. (Approved October 1, 2013)(1) Revised Sections 15 and 16 on certification and marking.ASTM
