ASTM_A_901_-_12.pdf

Designation:A90112Standard Specification forAmorphous Magnetic Core Alloys,Semi-Processed Types1This standard is issued under the fixed designation A901;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 the general requirements towhich flat-cast,amorphous,semi-processed,iron-base mag-netic core alloys must conform.1.2 These alloys are produced by a rapid-quenching,direct-casting process,resulting in metals with noncrystalline(amor-phous)structure.The metallic alloys are made to meet speci-fied maximum core-loss values and are intended primarily forcommercial power frequency(50-and 60-Hz)applications inmagnetic devices.Desirable core-loss and permeability char-acteristics are developed by further heat treatment in a mag-netic field by the user.2The heat treatment typically consists ofheating the material to a temperature of 320 to 420C in a dry,inert atmosphere for 5 to 10 min,although soak times of up to2 h may be used for large transformer cores.A magnetic fieldmay be required during annealing as designated by the pro-ducer.Exact optimum annealing conditions depend on theprocessing of the material and the size and shape of the device.1.3 Some of these alloys are sensitive to mechanical stress.Care must be exercised in minimizing any stresses on thematerial in its final application,otherwise,its magnetic prop-erties will be significantly impaired.1.4 This specification is developed to aid in the purchase oftransformer grade amorphous strip.It provides the chemical,physical,and magnetic parameters and procedures for qualitycontrol tests.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.NOTE1For more information on procedures associated with thisspecification,refer to the following:Practices A34/A34M,A664,A700,and B490;Test Methods A370 and A773/A773M.1.6 This standard does not purport to address the safetyconcerns associated with its use.It is the responsibility of theuser of this standard to establish appropriate safety and healthpractices and determine the applicability of regulatory limita-tions prior to use.2.Referenced Documents2.1 ASTM Standards:3A34/A34M Practice for Sampling and Procurement Testingof Magnetic MaterialsA340 Terminology of Symbols and Definitions Relating toMagnetic TestingA370 Test Methods and Definitions for Mechanical Testingof Steel ProductsA664 Practice for Identification of Standard Electrical SteelGrades in ASTM SpecificationsA700 Practices for Packaging,Marking,and Loading Meth-ods for Steel Products for ShipmentA712 Test Method for Electrical Resistivity of Soft Mag-netic AlloysA773/A773M Test Method for dc Magnetic Properties ofMaterials Using Ring and Permeameter Procedures withdc Electronic HysteresigraphsA900/A900M Test Method for Lamination Factor of Amor-phous Magnetic StripB490 Practice for Micrometer Bend Test for Ductility ofElectrodepositsC693 Test Method for Density of Glass by BuoyancyD3455 Test Methods for Compatibility of Construction Ma-terial with Electrical Insulating Oil of Petroleum Origin3.Terminology3.1 The terms and symbols used in this specification aredefined in Terminology A340.1This 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 Feb.15,2012.Published March 2012.Originallyapproved in 1990.Last previous edition approved in 2008 as A90103(2008).DOI:10.1520/A0901-12.2The process of heat treatment in a magnetic field is covered by a patent held byGeneral Electric Co.Interested parties are invited to submit information regardingthe identification of acceptable alternatives to this patented item to the Committeeon Standards,ASTM International Headquarters.Your comments will receivecareful consideration at a meeting of the responsible technical committee,1whichyou may attend.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.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 4.Dimensions4.1 WidthTolerances on nominal as-cast strip width shallbe 60.65%of the specified purchase width.4.2 ThicknessThe nominal thickness shall be 0.001 in.(0.025 mm)as measured by a 0.25-in.(6.35-mm)diameteranvil micrometer.The nominal thickness may vary 60.0002in.(60.005 mm),but the maximum thickness variation acrossthe width shall be within 61