1、Designation:A719/A719M14Standard Test Method forLamination Factor of Magnetic Materials1This standard is issued under the fixed designation A719/A719M;the number immediately following the designation indicates the yearof original adoption or,in the case of revision,the year of last revision.A number
2、 in parentheses indicates the year of last reapproval.A superscript epsilon()indicates an editorial change since the last revision or reapproval.1.Scope1.1 This test method covers measurement of the laminationfactor(Note 1)of a specimen composed of strips cut frommagnetic material.NOTE1Lamination fa
3、ctor is also termed space factor or stackingfactor.1.2 This test method shall be used in conjunction withPractice A34/A34M.1.3 The values and equations stated in customary(cgs-emuand inch-pound)or SI units are to be regarded separately asstandard.Within this test method,SI units are shown inbrackets
4、.The values stated in each system may not be exactequivalents;therefore each system shall be used independentlyof the other.Combining values from the two systems mayresult in nonconformance with this test method.1.4 This standard does not purport to address the safetyconcerns associated with its use
5、.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:2A34/A34M Practice for Sampling and Procurement Testingof Magnetic Materials3.Sum
6、mary of Test Method3.1 The laminated test specimen is subjected to pressure ina compression device and the resulting volume is then deter-mined from the measured specimen height,width,and length.An equivalent solid volume is calculated from the specimenmass and the true density of the specimen mater
7、ial.The ratio ofthe calculated(equivalent solid)volume to the measuredvolume is the lamination factor.4.Significance and Use4.1 Lamination factor,S,indicates the deficiency of effec-tive steel volume which is due to the presence of oxides,roughness,insulating coatings,and other conditions affectingt
8、he steel surface.4.2 The term Lamination Factor,S,pertains strictly to thedetermination of the proportion of material as defined byprecise sampling and procedures of this test method.Alterna-tive usage of the term Lamination Factor has evolved toinclude sampling and procedures outside of the context
9、 of thistest method.Consideration of alternative sampling and proce-dures should not be included within the scope of this testmethod.5.Apparatus5.1 Testing MachineA compression testing machine orother compression device capable of exerting the specifiedpressure.5.2 Metal PlatesTwo flat,smooth,rigid
10、metal plates withsquare edges and ends are required.They shall be of sufficientstiffness to distribute the pressure uniformly over the surface ofthe sample.Each plate shall be 8.46 in.215 mm long andhave a minimum width of 1.97 in.50 mm so that the area ofstrips under pressure when testing 1.18-in.3
11、0-mm widespecimens will be 10 in.26450 mm2.5.2.1 Extensions can be added to the plates to allow the useof micrometers or outside calipers instead of inside calipers fordetermining plate separation.Precautions must be taken toensure that,within the limits of accuracy of the measurements,no significan
12、t deflection of these extensions result from the testpressure.5.3 Length-Measuring ToolsCalipers or other devices ofadequate accuracy for measurement of plate separation.6.Sampling6.1 Test strips shall be selected as representative of thesurface condition.Core loss test specimens(Epstein testspecime
13、ns)are normally used for this purpose.6.2 In routine testing,where the core loss specimens are toosmall to conform to the minimum number of strips requirement1This test method is under the jurisdiction of ASTM Committee A06 onMagnetic Properties and is the direct responsibility of Subcommittee A06.0
14、1 on TestMethods.Current edition approved May 1,2014.Published May 2014.Originallyapproved in 1975.Last previous edition approved in 2007 as A719/A719M-02(2007).DOI:10.1520/A0719_A0719M-14.2For referenced ASTM standards,visit the ASTM website,www.astm.org,orcontact ASTM Customer Service at serviceas
15、tm.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 of Table 1,sufficient specimens may be combined to provide anadequa
16、te test specimen.The combined specimens must be ofthe same thickness and material,have similar surfaces,and berepresentative of the surface condition of the test lot.6.3 When a referee test becomes necessary,the test speci-men must be composed of strips taken from one lot of steel.Itmust be representative of the surface condition,thickness,andother variables.The shearing burrs should be removed and thestrips wiped free of loose particles.7.Test Specimen7.1 The number of strips in the test specim
