1、Designation:A 840/A 840M 00(Reapproved 2006)Standard Specification forFully Processed Magnetic Lamination Steel1This standard is issued under the fixed designationA840/A840M;the number immediately following the designation indicates the yearof original adoption or,in the case of revision,the year of
2、 last revision.A number in parentheses indicates the year of last reapproval.A superscript epsilon(e)indicates an editorial change since the last revision or reapproval.1.Scope1.1 This specification covers cold-rolled carbon steel coilsor strip used in the fully processed condition in magneticlamina
3、tion applications.1.2 This steel is produced to specified maximum core-lossvalues and is intended primarily for commercial power fre-quency(50-and 60-Hz)applications in magnetic devices.Desirable core-loss and permeability characteristics are devel-oped during mill processing,so further heat treatme
4、nt by thepurchaser is not necessary for most uses.1.3 Fully processed magnetic lamination steels are flat-rolled low carbon iron alloys having 1%maximum silicon and0.4%maximum aluminum.1.4 The values stated in inch-pound units are to be regardedas standard.The values given in parentheses are mathema
5、ticalconversions to SI units that are provided for information onlyand are not considered standard.2.Referenced Documents2.1 ASTM Standards:2A 34/A 34M Practice for Sampling and Procurement Test-ing of Magnetic MaterialsA 340 Terminology of Symbols and Definitions Relating toMagnetic TestingA 343/A
6、343M Test Method for Alternating-Current Mag-netic Properties of Materials at Power Frequencies UsingWattmeter-Ammeter-Voltmeter Method and 25-cm EpsteinTest FrameA 664 Practice for Identification of Standard ElectricalSteel Grades in ASTM SpecificationsA 700 Practices for Packaging,Marking,and Load
7、ingMethods for Steel Products for ShipmentA 719/A 719M Test Method for Lamination Factor of Mag-netic Materials3.Terminology3.1 The terms and symbols used in this specification aredefined in Terminology A 340.4.Classification4.1 The fully processed magnetic lamination steel typesdescribed by this sp
8、ecification are as shown in Table 1.5.Ordering Information5.1 Orders for material under this specification shall includeas much of the following information as necessary to describethe desired material adequately:5.1.1 ASTM specification number.5.1.2 Name of material(fully processed magnetic lamina-
9、tion steel).5.1.3 ASTM core-loss type number.5.1.4 Thickness,width and length(if in cut lengths insteadof coils).5.1.5 Total weight of ordered item.5.1.6 Limitations in coil size or lift weights.5.1.7 End UseThe purchaser shall disclose as muchpertinent information as possible about the intended app
10、lica-tion to enable the supplier to provide material characteristicsmost suitable for specific fabricating practices.5.1.8 Special requirements or exceptions to the provisionsof this specification.6.Manufacture6.1 Melting Practice:6.1.1 These fully processed magnetic lamination steels maybe made by
11、basic oxygen,electric furnace,or other steelmak-ing practices.6.1.2 These steels typically contain less than 0.03%carbon.6.1.3 The addition of silicon,aluminum,manganese,andphosphorus may be used to enhance punchability and improvemagnetic properties by increasing electrical resistivity.Thealloy add
12、itions are usually restricted such that the density ofthese steels is maintained above 7.825 g/cm3(7825 kg/m3).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 a
13、pproved Jan.1,2006.Published January 2006.Originallyapproved in 1985.Last previous edition approved in 2000 as A 840/A 840M 00.2For referenced ASTM standards,visit the ASTM website,www.astm.org,orcontact ASTM Customer Service at serviceastm.org.For Annual Book of ASTMStandards volume information,ref
14、er to the standards Document Summary page onthe ASTM website.1Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959,United States.6.1.4 Residual elements such as copper,nickel,chromium,molybdenum,and tin should be held as low as practicable.6.1.5 The producer
15、 is not required to report chemicalcomposition of each lot except where a clear need for suchinformation has been shown.In such cases,the analyses to bereported shall be negotiated between the manufacturer and thepurchaser.6.2 Typical Processing:6.2.1 Processing sequence for fully processed magnetic
16、lamination steel comprises hot rolling,pickling,cold rolling,and annealing.6.2.2 The mill annealing operation is typically nondecarbur-izing or partially decarburizing,resulting in a finished productthat can be prone to magnetic aging depending on the carboncontent.6.2.3 Unless otherwise specified,these steels are suppliedwith a smooth surface finish in the as-annealed condition.Therequired surface texture is imparted from the roll surface to thesteel surface during cold rolling.6.3 When changes
