ASTM_A_638_-_A_638M_-_10.pdf

Designation:A638/A638M10Standard Specification forPrecipitation Hardening Iron Base Superalloy Bars,Forgings,and Forging Stock for High-Temperature Service1This standard is issued under the fixed designation A638/A638M;the number immediately following the designation indicates the yearof original adoption or,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.1.Scope*1.1 This specification2covers hot-finished or cold-finishedprecipitation hardening iron base superalloy bars,forgings,andforging stock for high-temperature service.The mechanicalproperties of these alloys are developed by suitable solutiontreating and precipitation hardening treatments.1.2 Two grades of iron base alloy are covered.Selection willdepend upon design,service conditions,mechanical properties,and elevated temperature characteristics.1.3 The values stated in either inch-pound units or SI(metric)units are to be regarded separately as standards;withinthe text and tables,the SI units are shown in brackets.Thevalues stated in each system are not exact equivalents;there-fore,each system must be used independent of the other.Combining values from the two systems may result in noncon-formance with the specification.1.4 Unless the order specifies an“M”designation,thematerial shall be furnished to inch-pound units.2.Referenced Documents2.1 ASTM Standards:3A484/A484M Specification for General Requirements forStainless Steel Bars,Billets,and ForgingsA751 Test Methods,Practices,and Terminology for Chemi-cal Analysis of Steel ProductsE30 Test Methods for ChemicalAnalysis of Steel,Cast Iron,Open-Hearth Iron,and Wrought Iron(Withdrawn 1995)4E527 Practice for Numbering Metals and Alloys in theUnified Numbering System(UNS)3.Ordering Information3.1 It is the responsibility of the purchaser to specify allrequirements that are necessary for material ordered under thisspecification.Such requirements may include,but are notlimited to,the following:3.1.1 Quantity(weight or number of pieces),3.1.2 Name of material(precipitation hardening iron basesuperalloy),3.1.3 Form(bars,forgings,and forging stock),3.1.4 Dimensions(in the case of rough or finished forgingsthe order shall be accompanied by a print or drawing orotherwise adequately described as to the shape and dimension),3.1.5 Grade designation(Table 1),3.1.6 Condition(Section 5),3.1.7 Finish(Section 3),3.1.8 Mechanical requirements(Section 8),3.1.9 ASTM designation,and3.1.10 Special requirements.4.General Requirements4.1 In addition to the requirements of this specification,allrequirements of the current edition of Specification A484/A484M shall apply.Failure to comply with the generalrequirements of Specification A484/A484M constitutes non-conformance with this specification.5.Condition5.1 The product forms covered in this specification may befurnished in one of the following conditions:5.1.1 Hot-finished,5.1.2 Solution treated(Grade 660 onlyType 1 or Type 2solution treatment as specified),5.1.3 Solution and precipitation treated(Grade 660 onlyType 1 or Type 2 solution treatment as specified),or5.1.4 Other as specified.6.Heat Treatment6.1 Samples cut from bars,forgings,or a sample forgedfrom the forging stock shall conform to the mechanicalproperties of Table 1 and Table 2 when heat treated asprescribed in Table 3.1This specification is under the jurisdiction of ASTM Committee A01 on Steel,Stainless Steel and Related Alloys and is the direct responsibility of SubcommitteeA01.17 on Flat-Rolled and Wrought Stainless Steel.Current edition approved April 1,2010.Published April 2010.Originallyapproved in 1970.Last previous edition approved in 2004 as A638/A638M 00(2004).DOI:10.1520/A0638_A0638M-10.2For ASME Boiler and Pressure Vessel Code applications see related Specifi-cation SA-638 in Section II of that Code.3For 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 standards Document Summary page onthe ASTM website.4The last approved version of this historical standard is referenced onwww.astm.org.*A Summary of Changes section appears at the end of this standardCopyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1Copyright by ASTM Intl(all rights reserved);6.2 When a sample cut from the forging stock and heattreated as prescribed in Table 2 conforms to the properties inTables 3 and 4,it shall be accepted as equivalent to a forgedcoupon.7.Chemical Composition7.1 The steel shall conform to the requirements for chemicalcomposition specified in Table 4.7.2 Methods and practices relating to chemical analysisrequired by this specification shall be in accordance with TestMethods,Practices,and Terminology A751,except that forremelt material,product analysis tolerances may be used todeterm