1、Designation: A470/A470M 05 (Reapproved 2010)Standard Specification forVacuum-Treated Carbon and Alloy Steel Forgings forTurbine Rotors and Shafts1This standard is issued under the fixed designation A470/A470M; the number immediately following the designation indicates the yearof original adoption or
2、, 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.This standard has been approved for use by agencies of the Department of Defense.1. Scope1.
3、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 ineach system may not be exact equivalents; therefore, eachsystem shall be
4、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 theresponsibility of the user of this standard to establish appro-priat
5、e safety and health practices and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2A275/A275M Practice for Magnetic Particle Examinationof Steel ForgingsA293 Specification for Steel Forgings, Carbon and Alloy,for Turbine Generator Rotors
6、and Shafts3A370 Test Methods and Definitions for Mechanical Testingof Steel ProductsA418/A418M Practice for Ultrasonic Examination of Tur-bine and Generator Steel Rotor ForgingsA472/A472M Specification for Heat Stability of SteamTurbine Shafts and Rotor ForgingsA788/A788M Specification for Steel For
7、gings, General Re-quirementsE139 Test Methods for Conducting Creep, Creep-Rupture,and Stress-Rupture Tests of Metallic Materials3. Ordering Information and General Requirements3.1 Material supplied to this specification shall conform tothe requirements of Specification A788/A788M, which out-lines ad
8、ditional ordering information, manufacturing methodsand procedures, marking, certification, production analysisvariations, and additional supplementary requirements.3.2 In addition to the ordering information required bySpecification A788/A788M, the purchaser shall include withthe inquiry and order,
9、 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, supplementaryrequirements, and purchase options desired.3.3 Forging DrawingEach forging shall be manufacturedin accordance with a drawing furnished
10、by the purchasershowing the dimensions of the forging and bore hole, if any,and the location of mechanical test specimens.3.4 Supplementary RequirementsSupplementary require-ments are provided. These requirements shall apply only whenspecified in the purchase order.3.5 If the requirements of this sp
11、ecification are in conflictwith the requirements of Specification A788/A788M, therequirements of this specification shall prevail.4. Manufacture4.1 Melting Process: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
12、consumable electrode-electroslag or vacuum-arcremelting processes are included in Supplementary Require-ment S7.4.2 Vacuum TreatmentThe vacuum degassing require-ments of Specification A788/A788M are mandatory.1This specification is under the jurisdiction of ASTM Committee A01 on Steel,Stainless Stee
13、l and Related Alloys and is the direct responsibility of SubcommitteeA01.06 on Steel Forgings and Billets.Current edition approved April 1, 2010. Published May 2010. Originallyapproved in 1962. Last previous edition approved in 2005 as A470/A470M 05e1.DOI: 10.1520/A0470_A0470M-05E01.2For referenced
14、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. The last approved version of this historical standard is referenc
15、edon www.astm.org.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.4.3 DiscardSufficient discard shall be taken from eachingot to secure freedom from pipe and harmful segregation inthe finished forging.4.4 Forging ProcessThe forging s
16、hall 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 axial center of the ingot.4.5 Heat Treatment:4.5.1 The heat treatment for mechanica
17、l 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 air blast at the manufacturers option. Fastercooling rates for Grades A, B, D, and E
18、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 transformation temperature range. At the manufac-turers option, this operation may be
19、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 firstnormalizing temperature described in 4.5.1.1. This treatmentshall be performed
20、 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, asecond tempering operation shall be performed prior to theoperations described in 4.6.2
21、 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 temperaturelimits in 4.5.1.4. However, with the prior approval of thepurchaser, the second temperi
22、ng 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 temperingoperation. Mechanical property tests after the first temper areoptional with the man
23、ufacturer.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 temperature, but not less than1025F 550C.4.5.1.5 With the prior approval of the purchase
24、r, 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 final tempering temperature, or higher,additional tension tests must be obtained (6.1
25、.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 properties, all surfaces of the forging shall be roughmachined prior to stress reli
26、ef 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 thepurchaser, or indicated on the purchasers drawing, to removeobjectionable center conditions
27、 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).4.6.4 Machining to Purchasers Requirements forShipmentThe forging as shipped shall conform to the finish
28、and dimension requirements specified on the purchasersdrawing or order.TABLE 1 Chemical RequirementsAGrade 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
29、0.012 0.025Sulfur 0.012 0.012 0.015 0.015 0.025SiliconBBB,CB BNickel 3.203.70 3.203.70 3.254.00 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
30、 0.015 0.015EquivalentSpecification A293Grade Designation (replaced bySpecification A470). . . 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
31、 material that is subsequently VAR Processed.DSupplementary Requirement, see S1.ETo be reported 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 A293.A470/A470M 05 (2010)25. Chemical Composition5.1 Th
32、e 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 andproduct analysis tolerances shall conform to SpecificationA788/A788M.6. Mechanic
33、al 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 Final acceptance tests shall be made after heat treat-ment of the forging for
34、 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 reportedto the purchaser. The purchaser may require check tests aftercompletion of
35、 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 A370. Tensionspecimens shall be the standard 0.5-in. diameter by 2-in. gagelength or 12.5- by 50.0-mm type as shown in Test
36、Methodsand Definitions A370.6.1.5 The yield strength prescribed in Table 2 shall bedetermined by the offset method of Test Methods and Defini-tions A370.6.2 Impact Test:6.2.1 The steel shall conform to the requirements for notchtoughness (both transition temperature and room temperatureimpact values
37、) 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 Methods and Definitions A370. The notchdirection of the Charpy specimens shall be ta
38、ngential.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 cooling rates, presence of non-metallics,and orientation of the test samples are some of
39、 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 the tensile requirements ofTable 2.7.2 The finish on each forging shall conform to t
40、he 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 request ultrasonic, magnetic par-ticle, dye penetrant, etch, or other accepted no
41、ndestructiveexamination necessary to evaluate imperfections and ensurecompliance with this requirement.8.2 Ultrasonic Examination:8.2.1 An ultrasonic examination shall be made on themachined forging at the manufacturers plant. This examina-tion shall be made in accordance with Test Method A418/A418M
42、 to demonstrate freedom from rejectable internal indi-cations.TABLE 2 Tensile and Notch Toughness RequirementsGrade A Grade B Grade C Grade D Grade EClass 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 65
43、5min, 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 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, %:Lon
44、gitudinalprolongation22 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 40Radial 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,mi
45、n, ftlbf J28 38 25 34 20 27 50 68 45 61 40 54 6 8 12 16A470/A470M 05 (2010)38.2.2 The ultrasonic examination shall be made from allavailable surfaces prior to removal of test specimens thatwould interfere with complete testing of the forging.8.2.3 Forgings with recordable ultrasonic indications shal
46、lbe 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 conventional or mutuallyacceptable examination procedures whether the forging
47、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 the bore.8.3.2 If objectionable conditions are encountered during theint
48、ernal 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 Test9.1 Each Grade D and E forging shall be subjected to a heatstability
49、test at the manufacturers plant in accordance with thelatest issue of Test Method A472/A472M to determine thestability or freedom from tendency to distort during high-temperature operating 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 manufacturer and the purchaser,the stress relief may be performed
