ASTM_A_726_-_05_2010.pdf

Designation:A72605(Reapproved 2010)Standard Specification forCold-Rolled Magnetic Lamination Quality Steel,Semiprocessed Types1This standard is issued under the fixed designation A726;the number immediately following the designation indicates the year oforiginal adoption 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.Scope1.1 This specification covers cold-rolled carbon sheet steelused for magnetic applications.These products,commonlycalled“cold-rolled magnetic lamination steel”(CRML)areusually intended for applications in which the stamped lami-nations or assembled core structures for electrical equipmentare annealed to develop the desired core loss and permeabilitycharacteristics.1.2 By using appropriate lamination annealing practices,theuser can optimize magnetic properties for the various types.1.3 Non-guaranteed core-loss types,usually made to con-trolled chemical compositions,are available but are not cov-ered by this specification.1.4 Higher quality core-loss types are made to controlledchemical compositions and are usually given a critical reduc-tion on a temper-mill to yield specified magnetic propertiesafter a suitable lamination anneal.These products,typicallycalled semiprocessed lamination steel,are classified by theASTM Code Letter D in accordance with Practice A664.1.5 The values stated in customary(cgs-emu and inch-pound)units are to be regarded as standard.The values givenin parentheses are mathematical conversions to SI units whichare provided for information only and are not consideredstandard.2.Referenced Documents2.1 ASTM Standards:2A340 Terminology of Symbols and Definitions Relating toMagnetic TestingA343/A343M Test Method for Alternating-Current Mag-netic Properties of Materials at Power Frequencies UsingWattmeter-Ammeter-Voltmeter Method and 25-cm Ep-stein Test FrameA370 Test Methods and Definitions for Mechanical Testingof Steel ProductsA664 Practice for Identification of Standard Electrical SteelGrades in ASTM SpecificationsA700 Guide for Packaging,Marking,and Loading Methodsfor Steel Products for ShipmentE18 Test Methods for Rockwell Hardness of Metallic Ma-terialsE140 Hardness Conversion Tables for Metals RelationshipAmong Brinell Hardness,Vickers Hardness,RockwellHardness,Superficial Hardness,Knoop Hardness,Sclero-scope Hardness,and Leeb Hardness3.Terminology3.1 Definitions of Terms Specific to This Standard:3.1.1 cold-rolled sheetsheet manufactured from hot-rolleddescaled coils by cold reducing to the desired thickness,generally followed by annealing to recrystallize the grainstructure.In the case of magnetic lamination steels,particularlysemiprocessed lamination steels,temper rolling is used afterannealing to enhance flatness and optimize magnetic propertiesduring the users lamination anneal.3.1.2 magnetic lamination steelsspecialty cold-rolled car-bon sheet steel melted to controlled levels of carbon withadditions of manganese,phosphorus,silicon,and aluminum.Residual elements are generally held as low as possible.Theappropriate chemical composition combined with controlledmill processing results in a carbon sheet steel having mechani-cal properties and magnetic properties(after a quality devel-opment anneal)desired for electrical applications.3.2 Other terms and symbols used in this specification aredefined in Terminology A340.4.Ordering Information4.1 Orders for material under this specification shall includethe following information,as required,to describe the requiredmaterial adequately:4.1.1 ASTM specification number and date of issue.4.1.2 Core-loss type number.1This specification is under the jurisdiction of ASTM Committee A06 onMagnetic Properties and is the direct responsibility of Subcommittee A06.02 onMaterial Specifications.Current edition approved Nov.1,2010.Published December 2010.Originallyapproved in 1976.Last previous edition approved in 2005 as A726 05.DOI:10.1520/A0726-05R10.2For 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 standards Document Summary page onthe ASTM website.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 4.1.3 Finish(indicate typical profilometer range,as re-quired)(see 10.2).4.1.4 Specify not oiled or oiled,as required(see 10.4).4.1.5 Dimensions(nominal thickness and coil width)andtolerances,if not standard(see 9.1).4.1.6 Coil size(must include limitations on inside diameterand maximum weight).4.1.7 Application(scroll slit for hermetic motors,and soforth).4.1.8 Special requirements(indicate hardness range,mag-netic limitations,and so forth).4.1.9 Cast or heat analysis and magnetic test report(requestif required).NOTE1A typical description is as follows:Cold-Rolled Sheet,Magnetic Lamination St