1、Designation: A288 91 (Reapproved 2018)A288 18Standard Specification forCarbon and Alloy Steel Forgings for Magnetic RetainingRings for Turbine Generators1This standard is issued under the fixed designation A288; the number immediately following the designation indicates the year oforiginal adoption
2、or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope Scope*1.1 This specification covers quenched and tempered carbon and alloy steel
3、 forgings for magnetic retaining rings for turbinegenerators.1.2 Supplementary requirements of an optional nature are provided. These shall apply only when specified by the purchaser.1.3 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathema
4、ticalconversions to SI units that are provided for information only and are not considered standard.1.4 This international standard was developed in accordance with internationally recognized principles on standardizationestablished in the Decision on Principles for the Development of International
5、Standards, Guides and Recommendations issuedby the World Trade Organization Technical Barriers to Trade (TBT) Committee.2. Referenced Documents2.1 ASTM Standards:2A275/A275M Practice for Magnetic Particle Examination of Steel ForgingsA531/A531M Practice for Ultrasonic Examination of Turbine-Generato
6、r Steel Retaining RingsA788/A788M Specification for Steel Forgings, General Requirements3. Ordering Information3.1 In addition to the ordering information required by Specification A788/A788M, the purchaser shall include with the inquiryand order a detailed drawing, sketch, or written description of
7、 the forging, including the number and location of mechanical testspecimens.4. Manufacture4.1 The melting processes of Specification A788/A788M shall be applicable except that the basic electric furnace process shallbe used if separate refining or remelting is not employed.4.2 Vacuum DegassingFor Cl
8、ass 3 machined forgings over 2Steel 12 in. (63.5 mm) wall thickness, and Classes 4 to 8, themolten steel shall be vacuum treated immediately prior to or during the operation of pouring the ingot in orderdegassed per anymethod listed in Specification A788/A788Mto remove objectionable gases, especiall
9、y hydrogen4.3 DiscardSufficient discard shall be made from each ingot to secure freedom from piping and undue segregation.4.4 Heat Treatment:4.4.1 Heat Treatment for Mechanical PropertiesHeat treatment for properties shall be by quenching and tempering. Forgingsmay be normalized prior to quenching a
10、nd tempering.4.4.2 Tempering TemperatureThe final tempering temperature shall be not less than 1100 F (595 C).4.5 Machining:4.5.1 Preliminary MachiningForgings shall be machined all over prior to quenching and tempering for mechanical properties.1 This specification is under the jurisdiction ofASTM
11、Committee A01 on Steel, Stainless Steel and RelatedAlloys and is the direct responsibility of Subcommittee A01.06on Steel Forgings and Billets.Current edition approved March 1, 2018May 1, 2018. Published March 2018May 2018. Originally approved in 1946. Last previous edition approved in 20132018 asA2
12、88 91(2013).(2018). DOI: 10.1520/A0288-91R18.10.1520/A0288-18.2 For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standardsvolume information, refer to the standards Document Summary page on the ASTM website
13、.This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Becauseit may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior ed
14、itions as appropriate. In all cases only the current versionof the standard as published by ASTM is to be considered the official document.*A Summary of Changes section appears at the end of this standardCopyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-29
15、59. United States14.5.2 Machine to Purchasers Requirements for ShipmentIf required, forgings shall be machined to the dimensions shown onthe purchasers drawingpurchase order prior to shipment.5. Chemical Composition5.1 The steel shall conform to the chemical composition prescribed in Table 1.5.2 Hea
16、t AnalysisThe heat analysis obtained from sampling in accordance with Specification A788/A788M shall comply withTable 1.5.3 Product AnalysisThe purchaser may use the product analysis provision of Table 1 of Specification A788/A788M to obtaina product analysis from a forging representing each heat or
17、 multiple heat.6. Mechanical Properties6.1 Tensile RequirementsThe material shall conform to the requirements for tensile properties prescribed in Table 2.6.2 Notch Toughness RequirementsThe material shall conform to the requirements for notch toughness as prescribed in Table2.7. General Requirement
18、s7.1 Material supplied to this specification shall conform to the requirements of Specification A788/A788M which outlinesadditional ordering information, manufacturing, requirements, testing and retesting methods, and procedures, marking,certification, product analysis variations, and additional sup
19、plementary requirements.7.2 If the requirements of this specification are in conflict with the requirements of Specification A788/A788M, therequirements of this specification shall prevail.8. Sampling8.1 Test LocationTension and notch toughness test specimens shall be taken tangentially from prolong
20、ations on one or bothends of the forging. The direction of the notch of the Charpy bars shall be radial. All test specimens shall be located at midwalland at a distance at least equal to one-half the wall thickness from the end face of the prolongation.8.2 RemovalAll tension and notch toughness test
21、 specimens shall be removed after final heat treatment.9. Number of Tests and Retests9.1 Number of TestsThe number of tension and notch toughness test specimens shall be as prescribed by the purchaser, butin no case shall there be less than one tension and one notch toughness test specimen for each
22、ring.9.2 If any test specimen fails to meet the requirements specified, two adjacent test specimens may be selected for retest withoutreheat-treatment if the failure was not caused by ruptures, cracks, or flakes in the steel. Both of these must meet the requirementsof this specification.9.3 If the r
23、esults of the mechanical tests of any forging do not conform to the requirements specified, the manufacturer mayreaustenitize the forging, but not more than once without approval of the purchaser. Forgings may be retempered without obtainingapproval of the purchaser.10. Test Methods10.1 Nondestructi
24、ve Tests:10.1.1 General RequirementsThe ring shall be free from cracks, seams, laps, shrinkage, and other injurious imperfections.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
25、0.025 0.025 0.025Sulfur, max 0.025 0.020 0.020Silicon 0.150.30 0.150.35 0.150.35Nickel . . . A 1.653.50Chromium . . . 0.701.25 0.701.25Molybdenum . . . 0.15 min 0.20 minVanadium . . . optional 0.070.12A For Class 3 rings with wall thickness over 212 in. (63.5 mm) drawing size, thenickel content shal
26、l be 0.852.0 %.A288 18210.1.2 Magnetic Particle TestMagnetic particle tests of all surfaces shall be made at the manufacturers plant. The procedurefor tests shall be in accordance with Practice A275/A275M. The standards of acceptance shall be by agreement between purchasersand manufacturers.10.1.3 U
27、ltrasonic InspectionAn ultrasonic inspection shall be made at the manufacturers plant on the machined ring inaccordance with Practice A531/A531M. The standards of acceptance shall be by agreement between purchaser and manufacturer.SUMMARY OF CHANGESCommittee A01 has identified the location of the se
28、lected changes to this standard since the last issue(A288-91(2018) that may impact the use of this standard. (Approved May 1, 2018.)(1) Revision to 4.2 changed vacuum degassing reference to Specification A788/A788M.(2) Added optional normalizing in 4.4.1 before quenching and tempering.(3) Changed “p
29、urchasers drawing” to “purchase order” in 4.5.2.ASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this standard are expressly advised that determination of the validity of any such patent rights,
30、 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 committee and must be reviewed every five years andif not revised, either reapproved or withdrawn.Your comments are invited either for revi
31、sion of this standard or for additional standardsand should be addressed to ASTM International Headquarters. Your comments will receive careful consideration at a meeting of theresponsible technical committee, which you may attend. If you feel that your comments have not received a fair hearing you
32、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 Drive, PO Box C700, West Conshohocken, PA 19428-2959,United States. Individual reprints (single or multiple copies) of this standard may be o
33、btained 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.astm.org). Permission rights to photocopy the standard may also be secured from the Copyright Clearance Center, 222Rosewood Drive, Danvers, MA 0
34、1923, Tel: (978) 646-2600; http:/ 2 Tensile and Notch Toughness RequirementsClass TensileStrengthmin, psi(MPa)Yield Strength(0.02 %, offset),min, psi (MPa)Elonga-tion in 2in. or 50mm,min, %Reduc-tion ofArea,min,%CharpyV-notchImpactStrength,RoomTempera-ture min,ft-lbfftlbf(J)1 70 000 (485) 45 000 (31
35、0) 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)A288 183
