1、Designation: A 288 91 (Reapproved 2008)Standard Specification forCarbon and Alloy Steel Forgings for Magnetic RetainingRings for Turbine Generators1This standard is issued under the fixed designation A 288; the number immediately following the designation indicates the year oforiginal adoption or, i
2、n the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.1. Scope1.1 This specification covers quenched and tempered carbonand alloy steel forgings fo
3、r magnetic retaining rings for turbinegenerators.1.2 Supplementary requirements of an optional nature areprovided. These shall apply only when specified by thepurchaser.1.3 The values stated in inch-pound units are to be regardedas standard. The values given in parentheses are mathematicalconversion
4、s to SI units that are provided for information onlyand are not considered standard.2. Referenced Documents2.1 ASTM Standards:2A 275/A 275M Practice for Magnetic Particle Examinationof Steel ForgingsA 531/A 531M Practice for Ultrasonic Examination ofTurbine-Generator Steel Retaining RingsA 788/A 788
5、M Specification for Steel Forgings, GeneralRequirements3. Ordering Information3.1 In addition to the ordering information required bySpecification A 788/A 788M, the purchaser shall include withthe inquiry and order a detailed drawing, sketch, or writtendescription of the forging, including the numbe
6、r and locationof mechanical test specimens.4. Manufacture4.1 The melting processes of Specification A 788/A 788Mshall be applicable except that the basic electric furnaceprocess shall be used if separate refining or remelting is notemployed.4.2 Vacuum DegassingFor Class 3 machined forgingsover 212 i
7、n. (63.5 mm) wall thickness, and Classes 4 to 8, themolten steel shall be vacuum treated immediately prior to orduring the operation of pouring the ingot in order to removeobjectionable gases, especially hydrogen.4.3 DiscardSufficient discard shall be made from eachingot to secure freedom from pipin
8、g and undue segregation.4.4 Heat Treatment:4.4.1 Heat Treatment for Mechanical PropertiesHeattreatment for properties shall be by quenching and tempering.4.4.2 Tempering TemperatureThe final tempering tem-perature shall be not less than 1100F (595C).4.5 Machining:4.5.1 Preliminary MachiningForgings
9、shall be machinedall over prior to quenching and tempering for mechanicalproperties.4.5.2 Machine to Purchasers Requirements forShipmentIf required, forgings shall be machined to thedimensions shown on the purchasers drawing prior to ship-ment.5. Chemical Composition5.1 The steel shall conform to th
10、e chemical compositionprescribed in Table 1.5.2 Heat AnalysisThe heat analysis obtained from sam-pling in accordance with Specification A 788/A 788M shallcomply with Table 1.5.3 Product AnalysisThe purchaser may use the productanalysis provision of Table 1 of SpecificationA 788/A 788M toobtain a pro
11、duct analysis from a forging representing each heator multiple heat.1This specification is under the jurisdiction of ASTM 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 March 1, 2
12、008. Published April 2008. Originallyapproved in 1946. Last previous edition approved in 2003 as A 288 91(2003).2For referenced 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
13、standards Document Summary page onthe ASTM website.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.6. Mechanical Properties6.1 Tensile RequirementsThe material shall conform tothe requirements for tensile properties prescribed in Tab
14、le 2.6.2 Notch Toughness RequirementsThe material shallconform to the requirements for notch toughness as prescribedin Table 2.7. General Requirements7.1 Material supplied to this specification shall conform tothe requirements of Specification A 788/A 788M which out-lines additional ordering informa
15、tion, manufacturing, require-ments, testing and retesting methods, and procedures, marking,certification, product analysis variations, and additional supple-mentary requirements.7.2 If the requirements of this specification are in conflictwith the requirements of Specification A 788/A 788M, therequi
16、rements of this specification shall prevail.8. Sampling8.1 Test LocationTension and notch toughness test speci-mens shall be taken tangentially from prolongations on one orboth ends of the forging. The direction of the notch of theCharpy bars shall be radial. All test specimens shall be locatedat mi
17、dwall and at a distance at least equal to one-half the wallthickness from the end face of the prolongation.8.2 RemovalAll tension and notch toughness test speci-mens shall be removed after final heat treatment.9. Number of Tests and Retests9.1 Number of TestsThe number of tension and notchtoughness
18、test specimens shall be as prescribed by the pur-chaser, but in no case shall there be less than one tension andone notch toughness test specimen for each ring.9.2 If any test specimen fails to meet the requirementsspecified, two adjacent test specimens may be selected forretest without reheat-treat
19、ment if the failure was not caused byruptures, cracks, or flakes in the steel. Both of these must meetthe requirements of this specification.9.3 If the results of the mechanical tests of any forging donot conform to the requirements specified, the manufacturermay reaustenitize the forging, but not m
20、ore than once withoutapproval of the purchaser. Forgings may be retempered withoutobtaining approval of the purchaser.10. Test Methods10.1 Nondestructive Tests:10.1.1 General RequirementsThe ring shall be free fromcracks, seams, laps, shrinkage, and other injurious imperfec-tions.10.1.2 Magnetic Par
21、ticle TestMagnetic particle tests ofall surfaces shall be made at the manufacturers plant. Theprocedure for tests shall be in accordance with PracticeA 275/A 275M. The standards of acceptance shall be byagreement between purchasers and manufacturers.10.1.3 Ultrasonic InspectionAn ultrasonic inspecti
22、onshall be made at the manufacturers plant on the machined ringin accordance with Practice A 531/A 531M. The standards ofacceptance shall be by agreement between purchaser andmanufacturer.ASTM International takes no position respecting the validity of any patent rights asserted in connection with an
23、y item mentionedin this standard. Users of this standard are expressly advised that determination of the validity of any such patent rights, and the riskof infringement of such rights, are entirely their own responsibility.This standard is subject to revision at any time by the responsible technical
24、 committee and must be reviewed every five years andif not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standardsand should be addressed to ASTM International Headquarters. Your comments will receive careful consideration a
25、t a meeting of theresponsible technical committee, which you may attend. If you feel that your comments have not received a fair hearing you shouldmake your views known to the ASTM Committee on Standards, at the address shown below.This standard is copyrighted by ASTM International, 100 Barr Harbor
26、Drive, PO Box C700, West Conshohocken, PA 19428-2959,United States. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the aboveaddress or at 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.ast
27、m.org).TABLE 1 Chemical RequirementsClass 1, % Classes 2and 3, %Classes 4, 5, 6, 7,and 8, %Carbon, max 0.50 max 0.45 max 0.45Manganese 0.601.00 0.601.00 1.00 maxPhosphorus, max 0.025 0.025 0.025Sulfur, max 0.025 0.020 0.020Silicon 0.150.30 0.150.35 0.150.35Nickel . . .A1.653.50Chromium . . . 0.701.2
28、5 0.701.25Molybdenum . . . 0.15 min 0.20 minVanadium . . . optional 0.070.12AFor Class 3 rings with wall thickness over 212 in. (63.5 mm) drawing size, thenickel content shall be 0.852.0 %.TABLE 2 Tensile and Notch Toughness RequirementsClass TensileStrengthmin, psi(MPa)Yield Strength(0.02 %, offset
29、),min, psi (MPa)Elonga-tionin2in.or50mm,min, %Reduc-tion ofArea,min,%CharpyV-notchImpactStrength,RoomTempera-ture min,ft-lbf (J)1 70 000 (485) 45 000 (310) 18 40 15 (20)2 90 000 (620) 65 000 (450) 20 50 25 (34)3 110 000 (760) 80 000 (550) 18 50 20 (27)4 120 000 (825) 95 000 (655) 18 45 35 (47)5 130 000 (895) 110 000 (760) 16 40 30 (41)6 140 000 (965) 125 000 (860) 14 40 30 (41)7 150 000 (1035) 135 000 (930) 13 35 25 (34)8 165 000 (1140) 150 000 (1035) 12 35 25 (34)A 288 91 (2008)2
