1、Designation: A 426/A 426M 08Standard Specification forCentrifugally Cast Ferritic Alloy Steel Pipe for High-Temperature Service1This standard is issued under the fixed designationA 426/A 426M; the number immediately following the designation indicates the yearof original adoption or, in the case of
2、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.NoteTable 1 was editorially corrected and the year date was changed on Feb. 4, 2008.1. Scope*1.1 This specif
3、ication2covers centrifugally cast alloy steelpipe intended for use in high-temperature, high-pressure ser-vice.1.2 Several grades of ferritic steels are covered. Theircompositions are given in Table 1.1.3 Supplementary Requirements S1 through S12 areprovided. The supplementary requirements provide f
4、or addi-tional tests of an optional nature and when desired shall be sostated in the order (Section 4).1.4 The values stated in either inch-pound units or SI unitsare to be regarded separately as standard. Within the text, theSI units are shown in brackets. The values stated in eachsystem are not ex
5、act equivalents; therefore, each system mustbe used independently of each other. Combining values fromthe two systems may result in nonconformance with thespecification.2. Referenced Documents2.1 ASTM Standards:3A 370 Test Methods and Definitions for Mechanical Testingof Steel ProductsA 609/A 609M P
6、ractice for Castings, Carbon, Low-Alloy,and Martensitic Stainless Steel, Ultrasonic ExaminationThereofA 941 Terminology Relating to Steel, Stainless Steel, Re-lated Alloys, and FerroalloysA 999/A 999M Specification for General Requirements forAlloy and Stainless Steel PipeE94 Guide for Radiographic
7、ExaminationE 165 Test Method for Liquid Penetrant ExaminationE 186 Reference Radiographs for Heavy-Walled (2 to 412-in. 51 to 114-mm) Steel CastingsE 208 Test Method for Conducting Drop-Weight Test toDetermine Nil-Ductility Transition Temperature of FerriticSteelsE 280 Reference Radiographs for Heav
8、y-Walled (412 to12-in. 114 to 305-mm) Steel CastingsE 446 Reference Radiographs for Steel Castings Up to 2 in.51 mm in ThicknessE 709 Guide for Magnetic Particle Testing2.2 ANSI Standard:4B46.1 Surface Texture2.3 ASME Boiler and Pressure Vessel Code:5Section IX Welding Qualifications3. Ordering Info
9、rmation3.1 Orders for material under this specification shall includethe following, as required, to describe the desired materialadequately:3.1.1 Quantity (feet, centimetres, or number of lengths),3.1.2 Name of material (centrifugally cast pipe),3.1.3 Specification number,3.1.4 Grade (Table 1),3.1.5
10、 Size (outside or inside diameter and minimum wallthickness),3.1.6 Length (specific or random) (Section on PermissibleVariations in Length of Specification A 999/A 999M),3.1.7 End finish (Section on Ends of Specification A 999/A 999M),3.1.8 Optional Requirements S1 through S12 and Section14.1,1This
11、specification is under the jurisdiction of ASTM Committee A01 on Steel,Stainless Steel and Related Alloys and is the direct responsibility of SubcommitteeA01.18 on Castings.Current edition approved Feb. 4, 2008. Published February 2008. Originallyapproved in 1958. Last previous edition approved in 2
12、007 as A 426/A 426M - 07.2For ASME Boiler and Pressure Vessel Code applications see related Specifi-cation SA-426 in Section II of that Code.3For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volu
13、me information, refer to the standards Document Summary page onthe ASTM website.4Available from American National Standards Institute (ANSI), 25 W. 43rd St.,4th Floor, New York, NY 10036, http:/www.ansi.org.5Available from American Society of Mechanical Engineers (ASME), ASMEInternational Headquarte
14、rs, Three Park Ave., New York, NY 10016-5990, http:/www.asme.org.1*A Summary of Changes section appears at the end of this standard.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.3.1.9 Test report required (Section on Certified Test
15、Reportof Specification A 999/A 999M),3.1.10 Service temperature if over 1000F 540C (Note 1),and3.1.11 Special requirements or additions to specification.4. General Requirements for Delivery4.1 Material furnished under this specification shall con-form to the applicable requirements of the current ed
16、ition ofSpecification A 999/A 999M unless otherwise provided herein.5. Materials and Manufacture5.1 Heat-TreatmentThe pipe shall be furnished in thenormalized and tempered or liquid-quenched and temperedcondition (Note 1). The temperature for tempering shall not beless than 1250F 675C except for Gra
17、des CP1, CP2, CP11,CP12, and CP15 for which the temperature for tempering shallnot be less than 1100F 595C. Grade CP91 shall benormalized at 1900 1975 F (1040 1080 C) and temperedat 1350 1470 F (730 800 C).5.1.1 Heat treatment shall be performed after the pipe hasbeen allowed to cool below the trans
18、formation range. Defini-tion of heat-treatment terms shall be as given in TerminologyA 941.NOTE 1Except for Grade CP91, it is recommended that the tempera-ture for tempering should be at least 100F 55C above the intendedservice temperature. The purchaser shall advise the manufacturer of theservice t
19、emperature when it is over 1000F 540C.5.2 MachiningThe pipe shall be machined on the innerand outer surfaces to a roughness value no greater than 250 in. 6.35 m arithmetical average deviation (AA) from themean line unless otherwise specified as in ANSI B46.1.6. Chemical Analysis6.1 Heat AnalysisAn a
20、nalysis of each heat shall be madeby the manufacturer to determine the percentages of elementsspecified in Table 1. The analysis shall be made on a testsample taken preferable during the pouring of the heat. Thechemical composition thus determined shall conform to therequirements specified in Table
21、1 (Note 2).NOTE 2The role of alloying elements in the development of GradeTABLE 1 Chemical RequirementsAComposition, %GradeUNSNumberCarbon ManganesePhos-phorus,maxSulfur,maxSilicon Chromium Molybdenum OtherCP1 J12521 0.25max0.30-0.800.040 0.045 0.10-0.50. . . 0.44-0.65 . . .CP2 J11547 0.100.20 0.30-
22、0.610.040 0.045 0.10-0.500.50-0.810.44-0.65 . . .CP5 J42045 0.20max0.30-0.700.040 0.045 0.75max4.00-6.500.45-0.65 . . .CP5b J51545 0.15max0.30-0.600.040 0.045 1.00-2.004.00-6.000.45-0.65 . . .CP9 J82090 0.20max0.30-0.650.040 0.045 0.25-1.008.00-10.000.90-1.20 . . .CP91 J84090 0.080.12 0.300.60 0.030
23、 0.010 0.200.50 8.09.5 0.851.05 nickel, 0.40 max.;columbium,0.0600.10;nitrogen,0.0300.070;vanadium,0.180.25;aluminum, 0.02max.; titanium,0.01 max;zirconium, 0.01max.CP11 J12072 0.050.20 0.30-0.800.040 0.045 0.60max1.00-1.500.44-0.65 . . .CP12 J11562 0.050.15 0.30-0.610.040 0.045 0.50max0.80-1.250.44
24、-0.65 . . .CP15 J11522 0.15max0.30-0.600.040 0.045 0.15-1.65. . . 0.44-0.65 . . .CP21 J31545 0.050.15 0.30-0.600.040 0.045 0.50max2.65-3.350.80-1.06 . . .CP22 J21890 0.050.15 0.30-0.700.040 0.045 0.60max2.00-2.750.90-1.20 . . .CPCA15 J91150 0.15max1.00max0.040 0.040 1.50max11.5-14.00.50 max . . .AWh
25、ere ellipses appear in this table there is no requirement. Editorially corrected.A 426/A 426M 082CP91 has been extensively investigated. V and Nb contribute to precipi-tation strengthening by forming fine and coherent precipitation ofM(C,N)X carbo-nitrides in the ferrite matrix. V also precipitates
26、as VNduring tempering or during creep. Therefore, the addition of strong nitrideforming elements, those with a stronger affinity for nitrogen than Nb andV, as deoxidation agents, interferes with these high-temperature strength-ening mechanisms.66.2 Product AnalysisAproduct analysis may be made bythe
27、 purchaser. The sample for analysis shall be selected so as tobe representative of the pipe being analyzed. The chemicalcomposition thus determined shall conform to the requirementsof Table 1.7. Tensile and Hardness Requirements7.1 Steel used for the castings shall conform to the tensileand hardness
28、 requirements specified in Table 2.8. Permissible Variations in Dimensions8.1 ThicknessThe wall thickness shall not vary over thatspecified by more than18 in. 3 mm. There shall be novariation under the specified wall thickness.9. Number of Tests9.1 One tension and one hardness test shall be made fro
29、meach heat.9.2 If a specimen is machined improperly or if flaws arerevealed by machining or during testing, the specimen may bediscarded and another substituted from the same heat.10. Retests10.1 If the results of the mechanical tests for any heat do notconform to the requirements specified, the cas
30、tings may bereheat-treated and retested, but may not be re-austenitizedmore than twice.11. Test Specimens11.1 Test coupons from which tension test specimens areprepared shall be removed from heat-treated casting prolonga-tions.11.2 When agreed upon between the manufacturer and thepurchaser, test cou
31、pons from which test specimens are pre-pared shall be cast attached to separate blocks from the sameheat as the casting represented. The test blocks shall be heattreated in the same manner as the casting represented.11.3 Tension test specimens shall be machined to the formand dimensions of the stand
32、ard round 2-in. 50-mm gagelength specimens shown in Fig. 6 of Test Methods andDefinitions A 370.12. Hydrostatic Test12.1 Each length of pipe shall be hydrostatically tested inaccordance with Specification A 999/A 999M.12.2 When agreed to between the manufacturer and thepurchaser and so stated in the
33、 order, the hydrostatic test may bedeferred and shall be performed later by the purchaser. Pipefurnished without the hydrostatic test shall include with themandatory marking the letters “NH.” The manufacturer isresponsible for the satisfactory performance of the castingwhen it is tested.12.3 When ce
34、rtification is required by the purchaser and thehydrostatic test has been omitted, the certification shall clearlystate “not hydrostatically tested.” The specification number andmaterial grade shown on the certification shall be followed bythe letters “NH.”13. Visual Inspection13.1 The surface of th
35、e casting shall be free from cracks andhot tears as determined by visual examination. Other surfaceimperfections shall be judged in accordance with visual accep-tance criteria which may be specified in the order.14. Rework and Retreatment14.1 Defects as defined in Section 14 shall be removed andthei
36、r removal verified by visual inspection of the resultantcavities. Defects that are located by inspecting with supple-mentary requirements S6, S7, S8, or S9 shall be removed orreduced to an acceptable size.14.2 If removal of the defect does not infringe upon theminimum wall thickness, the depression
37、may be blendeduniformly into the surrounding surface.14.3 If the cavity resulting from defect removal infringesupon the minimum wall thickness, weld repair is permittedsubject to the purchasers approval. The composition of theweld rod used shall be suitable for the composition of the metalbeing weld
38、ed.14.3.1 Only welders and procedures qualified in accordancewith ASME Boiler and Pressure Vessel Code, Section IX, shallbe used. All repair welds will be inspected to the same qualitystandards used to inspect the casting.14.4 Local or full heat treatment in accordance with tem-pering temperatures s
39、pecified in 5.1 shall follow welding.6Viswanathan, R. and Bakker, W. T., Materials for Ultra Supercritical FossilPower Plants, EPRI, Palo Alto, CA: 2000, TR-114750.TABLE 2 Tensile Properties and Hardness RequirementsTensile strength, min, psi MPa:Grade CP1 65 000 450Grades CP11, CP22 70 000 485Grade
40、s CP5, CP9, CPCA15 90 000 620Grade CP91 85 000 585 to 110 000 760All other grades 60 000 415Yield strength, min, psi MPa:Grade CP1 35 000 240Grades CP11, CP22 40 000 275Grades CP5, CP9 60 000 415Grade CPCA15 65 000 450Grade CP91 60 000 415All other grades 30 000 205Elongation, min, %:AGrade CP1 24Gr
41、ades CP11, CP22 20Grades CP5, CP9, CP91, CPCA15 18All other grades 22Reduction of area, min, %:Grades CP1, CP2, CP11, CP12, CP15,CP21, CP22, CP5, CP5b, CP7, CP935Grade CPCA15 30Grade CP91 45Hardness, max, HB:Grades CP5, CP5b, CP9, CP91, CPCA15 225All other grades 201AElongation in 2 in. 50 mm using
42、a standard round specimen, in either thetransverse or longitudinal direction.A 426/A 426M 08315. Rejection15.1 Each length of pipe received from the manufacturermay be inspected by the purchaser and, if it does not meet therequirements of the specification based on the inspection andtest method as o
43、utlined in the specification, the pipe may berejected and the manufacturer shall be notified. Disposition ofrejected pipe shall be a matter of agreement between themanufacturer and the purchaser.16. Product Marking16.1 Each length of pipe shall be legibly marked with themanufacturers name or brand,
44、the specification number andgrade. In addition, heat numbers or serial numbers that aretraceable to heat numbers shall be marked on each length ofpipe.17. Keywords17.1 alloy steel; centrifugal; ferritic; high-temperature ser-vice; pipe; stainless steel; steel castingsSUPPLEMENTARY REQUIREMENTSSupple
45、mentary requirements shall be applied only when specified by the purchaser. Details of thesupplementary requirements shall be agreed upon between the manufacturer and purchaser. Thespecified tests shall be performed by the manufacturer prior to shipment of the castings.S1. Additional Tension TestsS1
46、.1 Additional tension tests shall be made at a temperatureto be specified by the customer, and the properties to be met area matter of agreement between the purchaser and manufacturer.S2. Flattening TestS2.1 The flattening test shall be made on specimens fromone or both ends of each length of pipe.
47、If the specimen fromany end of any length fails to conform to the requirements ofSpecification A 999/A 999M, that length shall be rejected.S3. PhotomicrographsS3.1 The manufacturer shall furnish one photomicrographat 100 diameters from one specimen of as-finished pipe fromeach heat in each heat-trea
48、tment lot. Such photomicrographsshall be suitable identified as to pipe size, wall thickness, andheat. Such photomicrographs are for information only, to showthe actual metal structure of the pipe as furnished. No photo-micrographs for the individual pieces purchased shall berequired except as speci
49、fied in Section S4.S4. Photomicrographs for Individual PiecesS4.1 The manufacturer shall furnish photomicrographs fromone or both ends of each pipe. All photomicrographs requiredshall be properly identified as to heat number, size, and wallthickness of pipe from which the section was taken. Photomi-crographs shall be further identified to permit association ofeach photomicrograph with the individual length of pipe itrepresents.S5. Metal Structure and Etching TestsS5.1 Etching test
