1、Designation: A596/A596M 95 (Reapproved 2009)1A596/A596M 14Standard Test Method forDirect-Current Magnetic Properties of Materials Using theBallistic Method and Ring Specimens1This standard is issued under the fixed designation A596/A596M; the number immediately following the designation indicates th
2、e yearof 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 NOTEUpdated IEC information editorially in November 2009.1.
3、Scope1.1 This test method covers dc ballistic testing for the determination of basic magnetic properties of materials in the form ofring, toroidal, link, double-lapped Epstein cores, or other standard shapes which may be cut, stamped, machined, or ground fromcast, compacted, sintered, forged, or rol
4、led materials. It includes tests for normal induction and hysteresis taken under conditionsof steep wavefront reversals of the direct-current magnetic field strength.1.2 This test method shall be used in conjunction with Practice A34/A34M.1.3 This test method is suitable for a testing range from ver
5、y low magnetic field strength up to 200 or more Oe 15.9 or morekA/m. The lower limit is determined by integrator sensitivity and the upper limit by heat generation in the magnetizing winding.Special techniques and short duration testing may extend the upper limit of magnetic field strength.1.4 Testi
6、ng under this test method is inherently more accurate than other methods. When specified dimensional or shaperequirements are observed, the measurements are a good approximation to absolute properties. Test accuracy available is primarilylimited by the accuracy of instrumentation. In most cases, equ
7、ivalent results may be obtained using Test Method A773/A773M orthe test methods of IEC Publication 60404-4.1.5 This test method permits a choice of test specimen to permit measurement of properties in any desired direction relative tothe direction of crystallographic orientation without interference
8、 from external yoke systems.1.6 The symbols and abbreviated definitions used in this test method appear in Fig. 1 and Sections 5, 6, 9, and 10. For the officialdefinitions see Terminology A340. Note that the term flux density used in this document is synonymous with the term magneticinduction.1.7 Wa
9、rningMercury has been designated by EPA and many state agencies as a hazardous material that can cause centralnervous system, kidney, and liver damage. Mercury, or its vapor, may be hazardous to health and corrosive to materials. Cautionshould be taken when handling mercury and mercury-containing pr
10、oducts. See the applicable product Material Safety Data Sheet(MSDS) for details and EPAs website (http:/www.epa.gov/mercury/faq.htm ) for additional information. Users should be awarethat selling mercury or mercury-containing products, or both, in your state may be prohibited by state law.1.8 The va
11、lues stated in either customary (cgs-emu and inch-pound) units or SI units are to be regarded separately as standard.Within this test method, the SI units are shown in brackets except for the sections concerning calculations where there are separatesections for the respective unit systems. The value
12、s stated in each system are not exact equivalents; therefore, each system shallbe used independently of the other. Combining values from the two systems may result in nonconformance with this method.1.9 This standard does not purport to address all of the safety concerns, if any, associated with its
13、 use. It is the responsibilityof the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatorylimitations prior to use.2. Referenced Documents2.1 ASTM Standards:2A34/A34M Practice for Sampling and Procurement Testing of Magnetic Material
14、s1 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 edition approved Nov. 1, 2009May 1, 2014. Published January 2010June 2014. Originally approved in 1969. Last previous edition app
15、roved in 20042009 asA596/A596M95(2004)A596/A596M95(2009)1. DOI: 10.1520/A0596_A0596M-95R09E01. 10.1520/A0596_A0596M-14.2 For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standardsvolume information, refer t
16、o 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 have been made to the previous version. Becauseit may not be technically possible to adequately depict all change
17、s 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 document.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. Unit
18、ed States1A340 Terminology of Symbols and Definitions Relating to Magnetic TestingA341/A341M Test Method for Direct Current Magnetic Properties of Materials Using D-C Permeameters and the Ballistic TestMethodsA343/A343M Test Method for Alternating-Current Magnetic Properties of Materials at Power Fr
19、equencies Using Wattmeter-Ammeter-Voltmeter Method and 25-cm Epstein Test FrameA773/A773M Test Method for dc Magnetic Properties of Materials Using Ring and Permeameter Procedures with dc ElectronicHysteresigraphs2.2 IEC Standard:3Publication 60404-4 Ed. 2.2, Magnetic MaterialsPart 4: Methods of Mea
20、surement of the D-C Magnetic Properties ofMagnetically Soft Materials, IEC, 20083. Significance and Use3.1 Test methods using suitable ring-type specimens4 are the preferred methods of determining the basic magnetic propertiesof a material caused by the absence of demagnetizing effects and are well
21、suited for specification acceptance, service evaluation,and research and development.3.2 Provided the test specimen is representative of the bulk material as is usually the case for thin strip and wire, this test isalso suitable for design purposes.3.3 When the test specimen is not necessarily repre
22、sentative of the bulk material such as a ring machined from a large forgingor casting, the results of this test method may not be an accurate indicator of the magnetic properties of the bulk material. In suchinstances, the test results when viewed in context of past performance history will be usefu
23、l for judging the suitability of the currentmaterial for the intended application.4. Interferences4.1 This test method has several important requirements. Unless adequate inside diameter to outside diameter ratios aremaintained in the test specimens, the magnetic field strength will be excessively n
24、onuniform throughout the test specimen and themeasured parameters cannot be represented as material properties.3 Available from American National Standards Institute (ANSI), 25 W. 43rd St., 4th Floor, New York, NY 10036.4 Lloyd, M. G., “Errors in Magnetic Testing with Ring Specimens,Specimens,” Tech
25、nical News Bulletin, National Institute for Standards and Technology, Vol 5, 1909,p. 435 (S108).NOTE 1A1Multirange ammeter, main-magnetizing current circuitA2Multirange ammeter, hysteresis-current circuitN1Magnetizing (primary) windingN2Flux-sensing (secondary) windingFElectronic integratorR1Main cu
26、rrent control rheostatR2Hysteresis current control rheostatS1Reversing switchS2Shunting switch for hysteresis current control rheostatFIG. 1 Basic Circuit Using Ring-Type CoresA596/A596M 1424.2 The basic quality of materials having directionally sensitive properties cannot be tested satisfactorily w
27、ith rings orlaminations. With them it is necessary to use Epstein specimens cut with their lengths in the direction of specific interest or to uselong link-shaped or spirally wound toroidal core test specimens whose long dimensions are similarly located. The acceptableminimum width of strip used in
28、such test specimens is also sensitive to the material under test. At present, it is believed that thegrain-oriented silicon steels should have a strip width of at least 3 cm 30 mm.4.3 Unless ring specimens are large in diameter, it is difficult to provide a sufficient number of primary turns needed
29、to reachthe highest magnetic field strength. In general, magnetic materials tend to have nonuniform properties throughout the body of thetest specimen; for this reason, uniformly distributed test windings and uniform specimen cross-sectional area are highly desirableto suppress nonuniform behavior t
30、o a tolerable degree.5. Apparatus5.1 The apparatus shall consist of as many of the components described in 5.2 5.10 as are required to perform the desired test.The basic circuit is shown in Fig. 1.5.2 Balance and Scales:5.2.1 The balance used to weigh the test specimen shall be capable of weighing t
31、o an accuracy of better than 0.1 %.60.1 % ofthe specimen mass.5.2.2 The micrometer, caliper, or other length-measuring device used in the determination of magnetic path length andcross-sectional area shall be capable of measuring to an accuracy of better than 0.1 %. 60.1 % of the measured values.5.3
32、 dc Power SupplyThe preferred source of dc current is a high quality linear power supply of either unipolar or bipolaroperation. The power supply must exhibit high stability and very low ripple to achieve the most accurate results. Programmablebipolar operational amplifier power supplies have proven
33、 to be very satisfactory for this type of testing. Other stable sources ofdc current such as storage batteries are permitted.5.4 Main-Current-Control Rheostat R1When nonprogrammable sources of dc current such as storage batteries are used,rheostats must be used to control the current. These rheostat
34、s must have sufficient power rating and heat-dissipating capability tohandle the largest test current without undesirable changes in resistance and, therefore, magnetizing current during conduct of thetest.5.5 Hysteresis-Current-Control Rheostat R2The hysteresis-current-control rheostat, when requir
35、ed, must have the same powerrating and resistance as the main-current-control rheostat.5.6 Main-Current Ammeter A1Measurement of the magnetizing current can be accomplished with either a dc ammeter or acombination of a precision shunt resistor and dc voltmeter. The meters and shunt resistor, if used
36、, must have an accuracy of at least0.25 %. To improve test accuracy multirange digital ammeters or voltmeters are preferred. Autoranging capability is desirable forconvenience but is not essential for this test method. If analog meters are used, the ranges must be such that all test readings aremade
37、 in the upper two thirds of the scale.5.7 Hysteresis-Current Ammeter, A2The hysteresis-current measuring system shall conform to the requirements in 5.6. Ingeneral, a separate measuring system is not required since the main current ammeter (A1) can also be used to measure the hysteresiscurrent.5.8 R
38、eversing Switch, S1Because of the low resistance nature of the magnetizing circuit, it is imperative that high qualityswitches be used. Changes in switch resistance upon reversal will cause deviation from the cyclically magnetized condition which,if excessive, will impair test accuracy and precision
39、. Experience has shown that mercury switches are the best suited for thisapplication. Knife blade switches or mechanical or electrically operated contractorscontactors can also be used provided therequirement for uniform and equal contact resistance can be maintained. Because of the presence of leak
40、age currents in the opencondition, solid state relays are not permitted. The difficulties inherent in the use of main current reversing switches can beminimized by use of linear power supplies capable of accepting a remote programming signal. Such power supplies are permittedprovided that the magnet
41、izing current is equal (to within 0.1 %) in either polarity when normal induction testing is conducted,current reversals can be conducted with no overshoot or oscillation and the magnetizing current is truly zero for the zero currentprogramming signal.5.9 Hysteresis Switch, S2 (When Required)This sw
42、itch should conform to requirements in 5.8.5.10 Integrator, FBecause of their superior accuracy, stability, and ease of operation, electronic charge integrators are thepreferred means of measuring magnetic flux. Integrators using either operational amplifier and capacitor feedback (analogintegrator)
43、 or pulse counting are permitted. The accuracy of the integrator must be better than 1 % full scale. If analog displaymeters are used to read the value of flux, the measurement should be made on the upper two thirds of the scale.Analog integratorsmust have drift adjust circuitry and the drift should
44、 not exceed 100 Maxwell-turns 106 Wb-turns per minute on the most sensitiverange. It is also desirable that the integrator have appropriate scaling circuitry to permit direct reading of either flux () or fluxdensity (B). Ballistic galvanometers or moving coil fluxmeters are allowed provided the 1 %
45、full-scale accuracy requirement is met.A596/A596M 1436. Test Specimen6.1 When the test specimen represents a test lot of material, its selection shall conform to the requirements of PracticeA34/A34M or of an individual specification.6.2 To qualify as a test specimen suitable for evaluation of materi
46、al properties the effective ratio of mean diameter to radialwidth shall be not less than 10 to 1 (or an inside diameter to outside diameter ratio not less than 0.82). When the test specimenhas smaller ratios than the above requirements, the test results should not be represented as material properti
47、es but should be calledcore properties because of nonuniform flux distribution.6.3 When link, oval-shaped, or rectangular test specimen forms are used, the requirements of 6.2 apply to the end or cornersections where flux crowding occurs. When straight-sided test specimens are very long relative to
48、the length of the corner or endsections, they are suitable for basic material properties evaluation with relatively unoriented materials provided the uncertainty indetermination of true-path (effective) length is less than 5 % of the total path length. When this uncertainty in path length (shortesto
49、r longest relative to the mean-path length) exceeds 5 %, the test values should be reported as core properties and not basic materialproperties.6.4 The test specimen may be constructed of solid, laminated, or strip materials and in any of the shapes described in 1.1.6.5 Test specimen cores made from strip may be laminated, machined, spirally wound, or Epstein specimens (the method ofselection for Epstein specimens is described in Test Method A343/A343M, Annex A3). When the material is to be tested halftransverse and half longitudinal, the ma
