1、Designation: A719/A719M 02 (Reapproved 2007)A719/A719M 14Standard 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
2、, 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 This test method covers measurement of the lamination factor (Note 1) of a specimen composed of strips c
3、ut from magneticmaterial.NOTE 1Lamination factor is also termed space factor or stacking factor.1.2 This test method shall be used in conjunction with Practice A34/A34M.1.3 The values and equations stated in customary (cgs-emu and inch-pound) or SI units are to be regarded separately asstandard. Wit
4、hin this test method, SI units are shown in brackets. The values stated in each system may not be exact equivalents;therefore each system shall be used independently of the other. Combining values from the two systems may result innonconformance with this test method.1.4 This standard does not purpo
5、rt to address the safety concerns associated with its use. It is the responsibility of the user ofthis standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations priorto use.2. Referenced Documents2.1 ASTM Standards:2A34/A34M Practice for
6、Sampling and Procurement Testing of Magnetic Materials3. Summary of Test Method3.1 The laminated test specimen is subjected to pressure in a compression device and the resulting volume is then determinedfrom the measured specimen height, width, and length. An equivalent solid volume is calculated fr
7、om the specimen mass and thetrue density of the specimen material. The ratio of the calculated (equivalent solid) volume to the measured volume is thelamination factor.4. Significance and Use4.1 Lamination factor, S, indicates the deficiency of effective steel volume which is due to the presence of
8、oxides, roughness,insulating coatings, and other conditions affecting the steel surface.4.2 The term Lamination Factor, S, pertains strictly to the determination of the proportion of material as defined by precisesampling and procedures of this test method.Alternative usage of the term Lamination Fa
9、ctor has evolved to include sampling andprocedures outside of the context of this test method. Consideration of alternative sampling and procedures should not be includedwithin the scope of this test method.5. Apparatus5.1 Testing MachineA compression testing machine or other compression device capa
10、ble of exerting the specified pressure.5.2 Metal PlatesTwo flat, smooth, rigid metal plates with square edges and ends are required. They shall be of sufficientstiffness to distribute the pressure uniformly over the surface of the sample. Each plate shall be 8.46 in. 215 mm long and havea minimum wi
11、dth of 1.97 in. 50 mm so that the area of strips under pressure when testing 1.18-in. 30-mm wide specimens willbe 10 in.2 6450 mm2.1 This test method is under the jurisdiction of ASTM Committee A06 on Magnetic Properties and is the direct responsibility of Subcommittee A06.01 on Test Methods.Current
12、 edition approved Nov. 1, 2007May 1, 2014. Published January 2008May 2014. Originally approved in 1975. Last previous edition approved in 20022007 asA719/A719M-02. -02 (2007). DOI: 10.1520/A0719_A0719M-02R07.10.1520/A0719_A0719M-14.2 For referencedASTM standards, visit theASTM website, www.astm.org,
13、 or contactASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standardsvolume information, refer to the standards Document Summary page on the ASTM website.This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes
14、have been made to the previous version. Becauseit may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current versionof the standard as published by ASTM is to be considered the official
15、document.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States15.2.1 Extensions can be added to the plates to allow the use of micrometers or outside calipers instead of inside calipers fordetermining plate separation. Precautions must be t
16、aken to ensure that, within the limits of accuracy of the measurements, nosignificant deflection of these extensions result from the test pressure.5.3 Length-Measuring ToolsCalipers or other devices of adequate accuracy for measurement of plate separation.6. Sampling6.1 Test strips shall be selected
17、 as representative of the surface condition. Core loss test specimens (Epstein test specimens) arenormally used for this purpose.6.2 In routine testing, where the core loss specimens are too small to conform to the minimum number of strips requirementof Table 1, sufficient specimens may be combined
18、to provide an adequate test specimen. The combined specimens must be of thesame thickness and material, have similar surfaces, and be representative of the surface condition of the test lot.6.3 When a referee test becomes necessary, the test specimen must be composed of strips taken from one lot of
19、steel. It mustbe representative of the surface condition, thickness, and other variables. The shearing burrs should be removed and the stripswiped free of loose particles.7. Test Specimen7.1 The number of strips in the test specimens shall consist of the be equal to or greater than the minimum numbe
20、r of stripsprescribed in Table 1.7.2 Each strip shall have a minimum length of 9.84 in. 250 mm and a width of 1.18 in. 30 mm. See Practice A34/A34M.7.3 Length and width dimensions should be known to at least 0.25 % and preferably to 0.1 %.TABLE 1 Number of Strips in Lamination Factor Test Specimensa
21、lign=“left“ colwidth=“1.16in“align=“center“colwidth=“0.67in“ElectricalSheetGage NumberAThickness Number ofStrips perTest Specimenin. mm16 0.0625 1.59 2417 0.0560 1.42 2418 0.0500 1.27 3019 0.0453 1.15 3020 0.0375 0.95 4021 0.0340 0.86 4022 0.0310 0.79 5023 0.0280 0.71 5024 0.0250 0.64 6025 0.0220 0.
22、55 6026 0.0185 0.47 8027 0.0170 0.43 8028 0.0155 0.39 8029 0.0140 0.35 10030 0.0125 0.32 10031 0.0100 0.25 100TABLE 1 Minimum Number of Strips in Lamination Factor TestSpecimensThickness Minimum Number ofStrips per TestSpecimenin. mm0.031 or greater 0.79 or greater 120.0280 0.71 120.0250 0.64 120.02
23、20 0.55 120.0185 0.47 160.0140 0.35 200.0120 0.30 240.0110 0.27 240.0100 0.25 280.0090 0.23 280.0080 0.20 320.0070 0.18 360.0060 0.15 440.0050 0.13 520.0040 0.10 64A NoteFor the sake of convenience for the users of this test method, theelectrical sheet gage numbers are listed for the nominal thickne
24、ss values listedabove.A719/A719M 1428. Procedure8.1 Determine the mass of the test specimen by weighing.8.2 Stack the strips evenly and place them symmetrically between the two flat plates in the compression testing machine.8.3 Apply pressure so it is distributed uniformly across the test specimen.8
25、.4 The recommended standard minimum test pressure shall be 50 psi 345 kPa. Other pressures, depending on the application,may be agreed upon between the seller and the purchaser.8.5 If more than one test pressure is used, apply the pressures in ascending order.8.6 Calculate the average separation of
26、the backing plates, or stack height, at the required pressure from measurements of theplates separation.8.6.1 When using a compression testing machine make four measurements of the separation, one at each corner of the backingplates.8.6.2 When using a compression device designed specifically for det
27、ermining this factor only two measurements, taken on thelongitudinal axis of the strips at each end of the plates, are required.9. Calculation9.1 Customary Units:9.1.1 Calculate the percentage lamination factor as follows:S 5m/2.54 wl h!#3100 (1)where:S = lamination factor, %;m = mass of test specim
28、en, g;w = width of test specimen, cm;l = length of test specimen, cm; = density of the specimen material;g/cm3, (see Practice A34/A34M); andh = measured average separation of the plate facesor stack height, in.9.2 SI Units:9.2.1 Calculate the percentage lamination factor as follows:S 5m/wlh!#3100 (2
29、)S 5m/wlh!#3108 (2)where:S = lamination factor, %;m = mass of test specimen, g;w = width of specimen, mm;l = length of specimen, mm; = density of specimen material, kg/m3; andh = measured stack height, mm.10. Precision and Bias10.1 PrecisionThe precision of the procedure in this test method for meas
30、uring the lamination factor of magnetic materialsis being has not been determined.10.2 BiasSince there is no accepted reference material for determining the bias for the procedure in this test method formeasuring lamination factor, bias has not been determined.A719/A719M 14311. Keywords11.1 laminati
31、on factor; space factor; stacking factorASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this standard are expressly advised that determination of the validity of any such patent rights, and the
32、 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 andif not revised, either reapproved or withdrawn.Your comments are invited either for revision of
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34、ke your views known to the ASTM Committee on Standards, at the address shown below.This standard is copyrighted by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,United States. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the aboveaddress or at 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.org). Permission rights to photocopy the standard may also be secured from the ASTM website (www.astm.org/COPYRIGHT/).A719/A719M 144
