1、Designation:A1048/A1048M06(Reapproved 2011)Standard Specification forPressure Vessel Forgings,Alloy Steel,Higher StrengthChromium-Molybdenum-Tungsten for Elevated TemperatureService1This standard is issued under the fixed designation A1048/A1048M;the number immediately following the designation indi
2、cates theyear of original adoption or,in the case of revision,the year of last revision.A number in parentheses indicates the year of lastreapproval.A superscript epsilon()indicates an editorial change since the last revision or reapproval.1.Scope1.1 This specification covers chromium-molybdenum-tun
3、gsten alloy steel forgings intended primarily for use inboilers and pressure vessels for elevated temperature service.1.1.1 Elevated temperatures are temperatures in the rangewhere creep and stress rupture properties are important for thealloy steels in this specification.1.2 Supplementary requireme
4、nts are provided both in thisspecification and in the General Requirements SpecificationA788/A788M for use when additional testing or inspection isdesired.These shall apply only when specified individually bythe purchaser in the purchase order or contract.1.3 Unless the order specifies the applicabl
5、e“M”specifica-tion designation,the forgings shall be supplied to the inch-pound units.1.4 The values stated in either inch-pound or SI(metric)units are to be regarded separately as standard.Within the textand tables,the SI units are shown in brackets.The values statedin each system may not be exact
6、equivalents;therefore,eachsystem shall be used independently of the other.Combiningvalues from the two systems may result in nonconformancewith the specification.2.Referenced Documents2.1 ASTM Standards:2A275/A275M Practice for Magnetic Particle Examination ofSteel ForgingsA388/A388M Practice for Ul
7、trasonic Examination of SteelForgingsA788/A788M Specification for Steel Forgings,General Re-quirementsA966/A966M Practice for Magnetic Particle Examination ofSteel Forgings Using Alternating Current3.Ordering Information and General Requirements3.1 In addition to the ordering information required by
8、Specification A788/A788M,the purchaser should include withthe inquiry and order the following information:3.1.1 A drawing,sketch,or written description of therequired forging and the manner of providing test material(seeSection 6).3.1.2 Desired supplementary requirements including thosefrom Specific
9、ation A788/A788M.3.1.3 Requirements for alternate ultrasonic examinationprocedure(see 7.1.2).3.1.4 At the purchasers option Test Method A966/A966Mshall be used for the magnetic particle examination.3.2 Forgings supplied to this specification shall conform tothe requirements of Specification A788/A78
10、8M which,inaddition to ordering information,includes manufacturing re-quirements,testing and retesting methods and procedures,marking,certification,product analysis variations and addi-tional supplementary requirements.3.3 If the requirements of this specification are in conflictwith those of Specif
11、ication A788/A788M,the requirements ofthis specification shall prevail.4.Materials and Manufacture4.1 The steel melting procedures of Specification A788/A788M shall apply except that the open hearth process shallnot be used,and that the molten steel shall be vacuum degassedprior to or during teeming
12、 of the ingot to remove objectionablegasses,notably hydrogen.4.2 Heat Treatment:4.2.1 After being permitted to transform following comple-tion of forging the material may be given an intermediate heattreatment such as normalizing and tempering or a subcriticalanneal prior to preliminary machining to
13、 the required heattreatment contour.The purchaser may specify supplementaryrequirement S1 to have the forgings rough machined before thefinal heat treatment.1This specification is under the jurisdiction of ASTM Committee A01 on Steel,Stainless Steel and Related Alloys and is the direct responsibilit
14、y of SubcommitteeA01.06 on Steel Forgings and Billets.Current edition approved Oct.1,2011.Published January 2012.Originallyapproved in 2006.Last previous edition approved in 2006 as A1048/A1048M 06.DOI:10.1520/A1048_A1048M-06R11.2For referenced ASTM standards,visit the ASTM website,www.astm.org,orco
15、ntact ASTM Customer Service at serviceastm.org.For Annual Book of ASTMStandards volume information,refer to the standards Document Summary page onthe ASTM website.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 4.2.2 Heat treatment applie
16、d either after rough machining ordirectly after cooling from forging shall consist of normalizingand tempering as follows:Normalize from 1950 to 2050F 1065 to 1120CTemper at 1290 to 1400F 700 to 760C4.2.3 Multiple normalize or temper cycles,or both,may beapplied providing the final stages comply with the temperaturesshown in 4.2.2.5.Chemical Composition5.1 Heat AnalysisThe heat analysis obtained fromsamples taken in accordance with Specification A788/A788Mshall comply with Table 1.5.2 The manufa
