1、Designation: A 470/A 470M 05e1Standard Specification forVacuum-Treated Carbon and Alloy Steel Forgings forTurbine Rotors and Shafts1This standard is issued under the fixed designationA 470/A 470M; the number immediately following the designation indicates the yearof original adoption or, in the case
2、 of revision, the year of last revision. A number in parentheses indicates the year of last reapproval.A superscript epsilon (e) indicates an editorial change since the last revision or reapproval.This standard has been approved for use by agencies of the Department of Defense.e1NOTEStep-cooling tem
3、peratures in S4.1.2 editorially corrected in September 2006.1. Scope*1.1 This specification covers vacuum-treated carbon andalloy steel forgings for turbine rotors and shafts.1.2 The values stated in either SI units or inch-pound unitsare to be regarded separately as standard. The values stated inea
4、ch system may not be exact equivalents; therefore, eachsystem shall be used independently of the other. Combiningvalues from the two systems may result in non-conformancewith the standard.1.3 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is
5、theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2A 275/A 275M Test Method for Magnetic Particle Exami-nation of Steel ForgingsA 293 S
6、pecification for Steel Forgings, Carbon and Alloy,for Turbine Generator Rotors and Shafts3A 370 Test Methods and Definitions for Mechanical Testingof Steel ProductsA 418 Test Method for Ultrasonic Examination of Turbineand Generator Steel Rotor ForgingsA 472 Test Method for Heat Stability of Steam T
7、urbineShafts and Rotor ForgingsA 751 Test Methods, Practices and Terminology for Chemi-cal Analysis of Steel ProductsA 788 Specification for Steel Forgings, General Require-mentsE 139 Test Methods for Conducting Creep, Creep-Rupture,and Stress-Rupture Tests of Metallic Materials3. Ordering Informati
8、on and General Requirements3.1 Material supplied to this specification shall conform tothe requirements of Specification A 788, which outlines addi-tional ordering information, manufacturing methods and pro-cedures, marking, certification, production analysis variations,and additional supplementary
9、requirements.3.2 In addition to the ordering information required bySpecification A 788, the purchaser shall include with theinquiry and order, the grade and class of steel, alternativemaximum for silicon content (see Table 1), the choice of yieldstrength offset (0.2 or 0.02 %), and any tests, suppl
10、ementaryrequirements, and purchase options desired.3.3 Forging DrawingEach forging shall be manufacturedin accordance with a drawing furnished by the purchasershowing the dimensions of the forging and bore hole, if any,and the location of mechanical test specimens.3.4 Supplementary RequirementsSuppl
11、ementary require-ments are provided. These requirements shall apply only whenspecified in the purchase order.3.5 If the requirements of this specification are in conflictwith the requirements of Specification A 788, the requirementsof this specification shall prevail.4. Manufacture4.1 Melting Proces
12、s:4.1.1 The steel shall be made by the basic electric-furnaceprocess.4.1.2 Provisions for subsequent secondary melting of thesteel by the consumable electrode-electroslag or vacuum-arcremelting processes are included in Supplementary Require-ment S7.1This specification is under the jurisdiction of A
13、STM Committee A01 on Steel,Stainless Steel, and Related Alloys and is the direct responsibility of SubcommitteeA01.06 on Steel Forgings and Billets.Current edition approved Sept. 1, 2005. Published September 2005. Originallyapproved in 1962. Last previous edition approved in 2003 as A 470 03.2For re
14、ferenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.3Withdrawn.1*A Summary of Changes section appears at the end of this
15、 standard.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.4.2 Vacuum TreatmentThe vacuum degassing require-ments of Specification A 788 are mandatory.4.3 DiscardSufficient discard shall be taken from eachingot to secure freedom from p
16、ipe and harmful segregation inthe finished forging.4.4 Forging ProcessThe forging shall receive its hotmechanical work under a press of ample power to adequatelywork the metal throughout the maximum section of theforging. It is important to maintain the axial center of theforging in common with the
17、axial center of the ingot.4.5 Heat Treatment:4.5.1 The heat treatment for mechanical properties shallconsist of double-normalizing and tempering for Grades A, B,D, and E and normalizing, quenching, and tempering for GradeC. In normalizing treatments, the forging may be cooled in stillair or in an ai
18、r blast at the manufacturers option. Fastercooling rates for Grades A, B, D, and E may be used ifauthorized by the purchaser. These rates are obtained by liquidquenching, or by the addition of water sprays of fog to the airblast.4.5.1.1 The first normalizing treatment shall be from wellabove the tra
19、nsformation temperature range. At the manufac-turers option, this operation may be performed as a part of thepreliminary treatment of the forging before preliminary ma-chining (see 4.6.1).4.5.1.2 The second normalizing or quenching treatmentshall be from above the transformation range but below the
20、firstnormalizing temperature described in 4.5.1.1. This treatmentshall be performed after preliminary machining (see 4.6.1).4.5.1.3 The final tempering temperature for Grades A, B, C,and E shall be not less than 1075F 580C and for Grade Dnot less than 1200F 650C. With prior purchaser approval, aseco
21、nd tempering operation shall be performed prior to theoperations described in 4.6.2 and 4.6.3 to complete the heattreatment cycle. This second temper will be in place of thestress relief specified in 4.5.1.4 and 4.5.1.5 and the tempera-tures applied to the second temper will meet the temperaturelimi
22、ts in 4.5.1.4. However, with the prior approval of thepurchaser, the second tempering temperature may be equal, orslightly exceed, the first tempering temperature as a means ofadjusting final strength or toughness. The required tests formechanical properties shall be made after the second temperingo
23、peration. Mechanical property tests after the first temper areoptional with the manufacturer.4.5.1.4 After heat treatment and subsequent rough machin-ing and axial boring (see 4.6.2 and 4.6.3), the forging shall bestress-relieved at a temperature not more than 100F 55Cbelow the final tempering tempe
24、rature, but not less than1025F 550C.4.5.1.5 With the prior approval of the purchaser, the stress-relief temperature may approach, equal, or slightly exceed thefinal tempering temperature as a means of adjusting finalstrength or toughness. If the stress-relief temperature is within25F (14C) of the fi
25、nal tempering temperature, or higher,additional tension tests must be obtained (6.1.3).4.6 Machining:4.6.1 Preliminary Rough MachiningAll exterior surfacesof the forging shall be machined prior to heat treatment formechanical properties.4.6.2 Second Rough MachiningAfter heat treatment formechanical
26、properties, all surfaces of the forging shall be roughmachined prior to stress relief and the stability test.4.6.3 Axial Bore:4.6.3.1 Forgings shall be bored to permissible bore size andtolerance when required by the purchasers drawing.4.6.3.2 Forgings may be bored to limits agreed to by thepurchase
27、r, or indicated on the purchasers drawing, to removeobjectionable center conditions revealed by ultrasonic exami-nation.4.6.3.3 Unless otherwise specified by the purchaser, themanufacturer may bore the forging at any time prior to stressrelief (see Supplementary Requirement S2).TABLE 1 Chemical Requ
28、irementsAGrade A Grade B Grade C Grade D Grade ENi-Mo-V Ni-Mo-V Ni-Cr-Mo-V Cr-Mo-V Ni-Mo-VCarbon 0.220.30 0.220.30 0.28 0.250.35 0.30Manganese 0.200.60 0.200.60 0.200.60 1.00 0.70Phosphorus 0.012 0.012 0.012 0.012 0.025Sulfur 0.012 0.012 0.015 0.015 0.025SiliconBBB,CB BNickel 3.203.70 3.203.70 3.254
29、.00 0.75 2.00 min.Chromium 0.75 0.75 1.252.00 1.051.50 0.75MolybdenumD0.400.60 0.400.60 0.250.60 1.001.50 0.25 minVanadium 0.040.12 0.040.12 0.050.15 0.200.30 0.030.12AntimonyEEE E EAluminumF0.015 0.015 0.015 0.015 0.015EquivalentSpecification A 293Grade Designation (replaced bySpecification A 470).
30、 . . Classes 2 and 3G.AMaximum or range, unless otherwise indicated.B0.10 % max, unless an alternative value, not in excess of 0.30 %, is specified in the purchase order.C0.15 to 0.30 % silicon is permitted for material that is subsequently VAR Processed.DSupplementary Requirement, see S1.ETo be rep
31、orted for information only on all Grades.FTotal of soluble and insoluble.GPhosphorus of 0.035 max and sulfur of 0.035 max were specified for Specification A 293.A 470/A 470M 05e124.6.4 Machining to Purchasers Requirements forShipmentThe forging as shipped shall conform to the finishand dimension req
32、uirements specified on the purchasersdrawing or order.5. Chemical Composition5.1 The steel shall conform to the requirements for chemicalcomposition prescribed in Table 1.5.2 Chemical Analysis:5.2.1 Product AnalysisThe manufacturer shall make aproduct analysis from each forging. The sample location
33、andproduct analysis tolerances shall conform to SpecificationA 788.6. Mechanical Properties6.1 Tension Test:6.1.1 The steel shall conform to the tensile requirements ofTable 2.6.1.2 The number and location of tension test specimensshall be as specified on the drawing furnished by the purchaser.6.1.3
34、 Final acceptance tests shall be made after heat treat-ment of the forging for mechanical properties prior to stressrelief, unless the stress relief temperature is within 25F 14Cof the tempering temperature, or higher, in which case checktests shall be made after the stress relief treatment and repo
35、rtedto the purchaser. The purchaser may require check tests aftercompletion of all heating cycles, including stress relief and theheat stability tests.6.1.4 Testing shall be performed in accordance with thelatest revision of Test Methods and Definitions A 370. Tensionspecimens shall be the standard
36、0.5-in. diameter by 2-in. gagelength or 12.5- by 50.0-mm type as shown in Test Methodsand Definitions A 370.6.1.5 The yield strength prescribed in Table 2 shall bedetermined by the offset method of Test Methods and Defini-tions A 370.6.2 Impact Test:6.2.1 The steel shall conform to the requirements
37、for notchtoughness (both transition temperature and room temperatureimpact values) prescribed in Table 2.6.2.2 The impact specimens shall be machined from radialbars taken from the main body of the forging, as shown in thepurchasers drawing. The specimens shall be Charpy V-notch,as shown in Test Met
38、hods and Definitions A 370. The notchdirection of the Charpy specimens shall be tangential.6.3 The properties at the axial bore region may not neces-sarily be the same as those determined at the surface radial oraxial prolongation regions. Slight variations in chemical ho-mogeneity, different coolin
39、g rates, presence of non-metallics,and orientation of the test samples are some of the factors thatcan contribute to the difference. If axial bore properties arerequired, they can be obtained through Supplementary Re-quirement S2.7. Dimensions, Tolerances, and Finish7.1 The steel shall conform to th
40、e tensile requirements ofTable 2.7.2 The finish on each forging shall conform to the finishspecified on the purchasers drawing or order.8. Nondestructive Tests8.1 General Requirements:8.1.1 The forgings shall be free of cracks, seams, laps,shrinkage, and similar imperfections.8.1.2 The purchaser may
41、 request ultrasonic, magnetic par-ticle, dye penetrant, etch, or other accepted nondestructiveexamination necessary to evaluate imperfections and ensurecompliance with this requirement.8.2 Ultrasonic Examination:TABLE 2 Tensile and Notch Toughness RequirementsGrade A Grade B Grade C Grade D Grade EC
42、lass 2 Class 3 Class 4 Class 5 Class 6 Class 7 Class 8 Class 9Tensile strength, 80 550 90 620 105 725 90 to 110 105 to 125 120 to 135 105 to 125 95 655min, ksi MPa 620760 725860 825930 725860Yield strength, 55 380 70 485 85 585 70 485 85 585 95 655 85 585 70 485min, ksi MPa0.2 % offset 60 415 75 520
43、 90 620 75 520 90 620 100 690 90 620 75 5200.02 % offset 55 380 70 485 85 585 70 485 85 585 95 655 85 585 70 485Elongation in 2 in.or 50 mm,min, %:Longitudinalprolongation22 20 17 20 18 18 17 20Radial body 20 17 16 18 17 17 14 15Reduction of area,min, %:Longitudinalprolongation50 48 45 52 52 52 43 4
44、0Radial body 50 45 40 50 50 50 38 35Transition tem-peratureFATT50max,F C100 38 110 43 140 60 10 12 20 7 30 1 250 121 175 80Room tempera-ture impact,min, ftlbf J28 38 25 34 20 27 50 68 45 61 40 54 6 8 12 16A 470/A 470M 05e138.2.1 An ultrasonic examination shall be made on themachined forging at the m
45、anufacturers plant. This examina-tion shall be made in accordance with Test Method A 418 todemonstrate freedom from rejectable internal indications.8.2.2 The ultrasonic examination shall be made from allavailable surfaces prior to removal of test specimens thatwould interfere with complete testing o
46、f the forging.8.2.3 Forgings with recordable ultrasonic indications shallbe referred to the purchaser for evaluation based on the nature,frequency, and location of indications, both stationary andtraveling. If the ultrasonic indications are considered objection-able, it shall be determined by conven
47、tional or mutuallyacceptable examination procedures whether the forging will berejected.8.3 Internal Examination:8.3.1 Axial bore, when specified for internal visual exami-nation, shall be in accordance with the drawing furnished bythe purchaser. The drawing shall specify the nominal dimen-sions of
48、the bore.8.3.2 If objectionable conditions are encountered during theinternal examination of the bore, the manufacturer shall notifythe purchaser of the location and nature of the condition.Further action shall be taken only after mutual agreementbetween the manufacturer and purchaser.9. Stability T
49、est9.1 Each Grade D and E forging shall be subjected to a heatstability test at the manufacturers plant in accordance with thelatest issue of Test Method A 472 to determine the stability orfreedom from tendency to distort during high-temperatureoperating conditions.9.2 The stability test shall be conducted after the forging hasbeen stress relieved in accordance with 4.5.1.4.NOTE 1If agreed upon between the
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