1、Designation:A804/A804M04(Reapproved 2015)Standard Test Methods forAlternating-Current Magnetic Properties of Materials atPower Frequencies Using Sheet-Type Test Specimens1This standard is issued under the fixed designation A804/A804M;the number immediately following the designation indicates the yea
2、rof 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.Scope1.1 These test methods cover the determination of specificcore lo
3、ss and peak permeability of single layers of sheet-typespecimens tested with normal excitation at a frequency of 50 or60 Hz.NOTE1These test methods have been applied only at the commercialpower frequencies,50 and 60 Hz,but with proper instrumentation andapplication of the principles of testing and c
4、alibration embodied in the testmethods,they are believed to be adaptable to testing at frequenciesranging from 25 to 400 Hz.1.2 These test methods use calibration procedures thatprovide correlation with the 25-cm 250-mm Epstein test.1.3 The range of test magnetic flux densities is governed bythe pro
5、perties of the test specimen and by the availableinstruments and other equipment components.Normally,non-oriented electrical steels can be tested over a range from 8 to 16kG 0.8 to 1.6 T for core loss.For oriented electrical steels,thenormal range extends to 18 kG 1.8 T.Maximum magneticflux densitie
6、s in peak permeability testing are limited princi-pally by heating of the magnetizing winding and tests arelimited normally to a maximum ac magnetic field strength ofabout 150 Oe 12 000 A/m.1.4 These test methods cover two alternative procedures asfollows:Test Method 1Sections 6 12Test Method 2Secti
7、ons 13 191.4.1 Test Method 1 uses a test fixture having(1)twowindings that encircle the test specimen,and(2)a ferromag-netic yoke structure that serves as the flux return path and haslow core loss and low magnetic reluctance.1.4.2 Test Method 2 uses a test fixture having(1)twowindings that encircle
8、the test specimen,(2)a third windinglocated inside the other two windings and immediately adja-cent to one surface of the test specimen,and(3)a ferromag-netic yoke structure which serves as the flux-return path andhas low magnetic reluctance.1.5 The values and equations stated in customary(cgs-emuan
9、d inch-pound)units or SI units are to be regarded separatelyas standard.Within this standard,SI units are shown inbrackets except for the sections concerning calculations wherethere are separate sections for the respective unit systems.Thevalues stated in each system may not be exact equivalents;the
10、refore,each system shall be used independently of the other.Combining values from the two systems may result in noncon-formance with this standard.1.6 This standard does not purport to address all of thesafety concerns,if any,associated with its use.It is theresponsibility of the user of this standa
11、rd to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2.Referenced Documents2.1 ASTM Standards:2A34/A34M Practice for Sampling and Procurement Testingof Magnetic MaterialsA340 Terminology of Symbols and Definitions Relating t
12、oMagnetic 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 FrameA677 Specification for Nonoriented Electrical Steel FullyProcessed TypesA683 Specification for Nonoriented Elect
13、rical Steel,Semi-processed TypesA876 Specification for Flat-Rolled,Grain-Oriented,Silicon-Iron,Electrical Steel,Fully Processed Types3.Terminology3.1 Definitions:1These test methods are under the jurisdiction of ASTM Committee A06 onMagnetic Properties and are the direct responsibility of Subcommitt
14、ee A06.01 onTest Methods.Current edition approved Oct.1,2015.Published October 2015.Originallyapproved in 1982.Last previous edition approved in 2009 as A804/A804M04(2009)1.DOI:10.1520/A0804_A0804M-04R15.2For referenced ASTM standards,visit the ASTM website,www.astm.org,orcontact ASTM Customer Servi
15、ce 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 3.1.1 GeneralThe definitions of terms,symbols,and co
16、n-version factors relating to magnetic testing found in Terminol-ogy A340 are used in these test methods.3.2 Definitions of Terms Specific to This Standard:3.2.1 sheet specimena rectangular specimen comprised ofa single piece of material or paralleled multiple strips ofmaterial arranged in a single layer.4.Significance and Use4.1 Materials EvaluationThese test methods were devel-oped to supplement the testing of Epstein specimens forapplications involving the use of flat,sheared laminationswhere
