1、Designation: A 901 03 (Reapproved 2008)Standard Specification forAmorphous Magnetic Core Alloys, Semi-Processed Types1This standard is issued under the fixed designation A 901; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the ye
2、ar 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-n
3、etic core alloys must conform.1.2 These alloys are produced by a rapid-quenching, direct-casting process, resulting in metals with noncrystalline struc-ture. The metallic alloys are made to meet specified maximumcore-loss values and are intended primarily for commercialpower frequency (50- and 60-Hz
4、) applications in magneticdevices. Desirable core-loss and permeability characteristicsare developed by further heat treatment in a magnetic field bythe purchaser.2The heat treatment typically consists of heatingthe material to a temperature of 320 to 420C in a dry, inertatmosphere for 5 to 10 min,
5、although soak times of up to 2 hmay be used for large transformer cores. A magnetic field maybe required during annealing as designated by the producer.Exact optimum annealing conditions depend on the processingof the material and the size and shape of the device.1.3 Some of these alloys are sensiti
6、ve to mechanical stress.Care must be exercised in minimizing any stresses on thematerial in its final application, otherwise, its magnetic prop-erties will be impaired significantly.1.4 This specification is developed to aid in the purchase oftransformer grade amorphous strip. It provides the chemic
7、al,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 co
8、nsideredstandard.NOTE 1For more information on procedures associated with thisspecification, refer to the following: PracticesA 34/A 34M,A 664,A 700,and B 490; Test Methods A 370 and A 773/A 773M.1.6 This standard does not purport to address the safetyconcerns associated with its use. It is the resp
9、onsibility 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:3A 34/A 34M Practice for Sampling and Procurement Test-ing of Magnetic MaterialsA 340 Terminolo
10、gy of Symbols and Definitions Relating toMagnetic TestingA 370 Test Methods and Definitions for Mechanical Testingof Steel ProductsA 664 Practice for Identification of Standard ElectricalSteel Grades in ASTM SpecificationsA 700 Practices for Packaging, Marking, and LoadingMethods for Steel Products
11、for ShipmentA 712 Test Method for Electrical Resistivity of Soft Mag-netic AlloysA 773/A 773M Test Method for dc Magnetic Properties ofMaterials Using Ring and Permeameter Procedures withdc Electronic HysteresigraphsA 900/A 900M Test Method for Lamination Factor ofAmorphous Magnetic StripB 490 Pract
12、ice for Micrometer Bend Test for Ductility ofElectrodepositsC 693 Test Method for Density of Glass by BuoyancyD 3455 Test Methods for Compatibility of ConstructionMaterial with Electrical Insulating Oil of Petroleum Origin3. Terminology3.1 The terms and symbols used in this specification aredefined
13、in Terminology A 340.1This 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, 2008. Published December 2008. Originallyapproved in 1990. Last previous e
14、dition approved in 2003 as A 901 03.2The 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, AS
15、TM 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 ASTMSta
16、ndards volume information, refer 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.4. Dimensions4.1 WidthTolerances on nominal as-cast strip shall be+0.004, 0.020 in. (+0.1 mm,
17、0.5 mm) from specifiedpurchase 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 610 % of the m
18、ean thickness, or asagreed upon between the purchaser and the producer.5. Material Requirements5.1 Amorphous magnetic core alloys are composed princi-pally of iron with small amounts of alloying elements such asboron and silicon. Other chemical elements are in residualamounts or can be added to impr
19、ove fabrication or the physicalor magnetic properties. The producer shall provide, on request,a statement of the nominal chemistry being supplied. Thenominal composition for one particular alloy, in weight per-cent, is: iron 92, silicon 5, and boron 3.6. Sampling6.1 A continuously cast strip in one
20、coil without breaks willconstitute one test lot. In practice, this may represent quantitiesup to 2200 lb (1000 kg), depending on the width of the strip.6.2 Test samples normally shall be taken from both ends ofthe continuous strip of each test lot. Other sample frequenciesmay be used as agreed upon
21、by the producer and the purchaser.6.3 For small coils, less than 100 lb (45 kg), and for coilscontaining splices, the test lot shall be as agreed upon betweenthe producer and the purchaser.7. Physical and Mechanical Property Requirements7.1 DensityThe density shall be provided by the producerto a pr
22、ecision of 60.05 g/cm3(650 kg/m3) as measured by TestMethod C 693.7.2 DuctilityStrip bend ductility, with free solidificationsurface facing inward, shall be such that a minimum 1-mlength of ribbon may be passed 180 around a 0.125-in.(3-mm) polished steel rod without cracking or fracture.7.3 Thermal
23、ExpansionThe nominal coefficient of ther-mal expansion shall be reported for the temperature range 40 to400C.7.4 Thermal ConductivityThe nominal value measuredacross the width shall be reported for temperatures of 25, 100,and 400C. The defined thermal conductivity of the materialshall not differ fro
24、m the reported value by more than 620 %.7.5 Volume ResistivityThe nominal volume resistivityshall be reported as measured by Test Method A 712.7.6 Lamination FactorThe minimum lamination factor ofuncoated material shall be 77 % as measured in accordancewith Test Method A 900/A 900M. The lamination f
25、actor forcoated material shall be as agreed between the producer and thepurchaser.7.7 SurfaceThe strip surface and edges shall have nowrinkles, dimples, cracks, folds, flakes, or other injuriousimperfections that would make the material unsuitable for thefabrication of transformer cores.7.8 EdgeThe
26、strip edge shall have no slivers with amaximum dimension exceeding 0.004 in. (0.1 mm).7.9 CamberThe strip edge shall show no excessive lateralcurvature (camber). Maximum deviation from a straight line ofan 8-ft (2.4-m) strip edge shall not exceed 0.1 in. (2.5 mm).7.10 PinholesThe strip shall have no
27、 pinholes exceeding0.08 in. (2.0 mm). Maximum hole frequency, visible against alight source, shall not be more than 1 per 3 in.2(19.4 3 104m2).8. Magnetic Property Requirements8.1 Test ProcedureThe magnetic quality of each batch ofmaterial (as defined in 6.1) shall be determined by obtainingtest sam
28、ples from both ends of a batch (or lot). These samplesshall be annealed in a dry, inert atmosphere with an appliedmagnetic field of at least 10 Oe (800 A/m) using the time andtemperature sequence recommended by the producer. Thesamples may be either in toroidal or flat strip form as agreedupon betwe
29、en the producer and the purchaser.8.2 Amorphous magnetic core alloys are purchased tospecified maximum core loss requirements. The purchasershall make clear to the producer the limiting values of core lossrequired for the ordered material. For the nominal compositiongiven in 5.1, the guaranteed maxi
30、mum core loss is shown inTable 1.8.3 Depending upon the desired end use, other magneticproperties such as specific exciting power, saturation induction,residual induction, and coercive field strength may need to bespecified. The purchaser is responsible for specifying the limitson magnetic propertie
31、s. The purchaser shall also state whetherand what specific tests are required. The guaranteed magneticproperties for the nominal composition given in 5.1 are shownin Table 1.9. Product Uniformity Verification9.1 Since it is assumed that the process will give “essen-tially identical properties to all
32、 parts of a coil,” and that testsamples are taken at only both ends of a coil, it remains for theproducer to verify the uniformity of this product. At regulartime intervals, the producer shall perform appropriate tests atTABLE 1 Magnetic Property Requirements for the Nominal Composition of Fe92B3Si5
33、TestTemperature,CMinimum DC Induction, Hm= 10 Oe (800 A/m)Maximum DC CoerciveField Strength (Hc)Hm=1Oe (80 A/m)Minimum DC ResidualInduction (Br)Hm=1Oe (80 A/m)Maximum 60 Hz Core Loss(Pc(B:f) 14.0 kG (1.40 T)Maximum 60 Hz SpecificExciting Power (Pz(B:f)14.0 kG (1.40 T)25 15.4 kG (1.54 T) 40 mOe (3.2
34、A/m) 12.0 kG (1.20 T) 0.114 W/lb (0.251 W/kg) 0.50 VA/lb (1.1 VA/kg)85 14.7 kG (1.47 T) 100 14.5 kG (1.45 T) A 901 03 (2008)2regular (length) intervals to verify the uniformity of magneticand mechanical properties throughout the length of a coil.9.2 Verification of uniformity test results as obtaine
35、d in 9.1shall be made available to the purchaser when requested.10. Packaging and Marking10.1 The strip shall be free from rust, fingerprints, andgrease. No continuous indication of oxide shall be visible alongthe surface or edges of the strip.10.2 SpoolThe inside diameter of the spool hub shall be9
36、.0 6 0.1 in. (229 6 3 mm). The outside diameter of the stripwound on this spool shall be at least 30 in. (762 mm) and shallnot exceed 35 in. (890 mm).10.3 There shall be no more than three breaks in the stripper spool. At any break, the strip ends shall be sheared square,butted, and joined with tape
37、 which shall extend substantiallyacross the width of the strip, but not beyond the strip edges.10.3.1 The tape shall have the following characteristics:tape thickness no greater than the strip thickness; tape basematerial and adhesive capable of withstanding the normalcore-annealing cycle without si
38、gnificant detriment to tape andstrip; tape tensile strength and adhesive shear strength suffi-cient to withstand normal core-processing tension and accel-eration; and tape base material and adhesive compatible withtransformer oil when tested in accordance with Test MethodsD 3455.10.4 The strip shall
39、 be manufactured and wound on thespool in a manner such that, when the strip is removed from thespool, the edge of the strip will be perpendicular to the axis ofthe spool with no tendency to curve to one side.10.5 The strip shall be packed to prevent physical damageduring shipment. The packaging tec
40、hniques used shall permitweather-protected storage at the purchasers site for a period ofsix months without degradation of the material.10.6 The amorphous metal will be placed on a pallet withthe spool axis perpendicular to the pallet allowing handling byfork truck. Unpacking will involve only strap
41、 cutting and nonail withdrawal.10.7 MarkingTo provide traceability, each spool shall bemarked, in an agreed manner, with reference number allowingidentification of the material cast.11. Testing11.1 Test ReportsThe producer shall furnish certified testreports assuring compliance with the requirements
42、 of thisspecification.11.2 RejectionAfter establishment of a mutually accept-able sampling and test procedure, the purchaser may, at hisoption, sample test incoming material for any characteristicdefined by this specification and accept or reject material basedupon these sample tests.12. Keywords12.
43、1 amorphous; coercive field strength; core loss; induc-tion; residual induction; specific exciting powerAPPENDIX(Nonmandatory Information)X1. TYPICAL PHYSICAL PROPERTIESX1.1 Typical physical properties for the composition givenin 5.1 are listed in Table X1.1. The data provided are forinformation onl
44、y and are not requirements in this specification.TABLE X1.1 Typical Physical PropertiesNOTE 1Impurities, particularly carbon, play a major role in the agingof electrical steels, the principal cause for which are interstitial migrationand grain boundary precipitation. Accelerated (200 days at 543K) a
45、ndlong-term (14 years at 400K) aging studies have shown that the agingcharacteristics of metallic glasses (that is, amorphous magnetic corealloys) are not adversely influenced by the presence of carbon in the alloychemistry. The likely reason for this is that amorphous alloys do notcontain either cr
46、ystals or grain boundaries. See Ramanan, V.R.V., et al.,Journal of Applied Physics, Vol 73, No. 10, May 15, 1993, p. 5366.Density 7.20 6 0.05 g/cm3(7200 6 50 kg/m3)Thermal expansion 6 m/mKThermal conductivity 0.0140.024 cal/(scmC) (6 to 10W/(mK)Volume resistivity 120 Vcm (1.20 3 106Vm)Crystallizatio
47、n temperatureA550CCurie temperatureA420CADetermined by differential scanning calorimetry (DSC) at a heating rate of20C/min.A 901 03 (2008)3ASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this s
48、tandard are expressly advised that determination of the validity of any such patent rights, and the riskof infringement of such rights, are entirely their own responsibility.This standard is subject to revision at any time by the responsible technical committee and must be reviewed every five years
49、andif not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standardsand should be addressed to ASTM International Headquarters. Your comments will receive careful consideration at a meeting of theresponsible technical committee, which you may attend. If you feel that your comments have not received a fair hearing you shouldmake your views known to the ASTM Committee on Standards, at the address shown below.This standard is copyrighted by ASTM In
