ASTM A596/A596M-95(2009)e1
(Test Method)Standard Test Method for Direct-Current Magnetic Properties of Materials Using the Ballistic Method and Ring Specimens
Standard Test Method for Direct-Current Magnetic Properties of Materials Using the Ballistic Method and Ring Specimens
SIGNIFICANCE AND USE
Test methods using suitable ring-type specimens are the preferred methods of determining the basic magnetic properties of a material caused by the absence of demagnetizing effects and are well suited for specification acceptance, service evaluation, and research and development.
Provided the test specimen is representative of the bulk material as is usually the case for thin strip and wire, this test is also suitable for design purposes.
When the test specimen is not necessarily representative of the bulk material such as a ring machined from a large forging or casting, the results of this test method may not be an accurate indicator of the magnetic properties of the bulk material. In such instances, the test results when viewed in context of past performance history will be useful for judging the suitability of the current material for the intended application.
SCOPE
1.1 This test method covers dc ballistic testing for the determination of basic magnetic properties of materials in the form of ring, toroidal, link, double-lapped Epstein cores, or other standard shapes which may be cut, stamped, machined, or ground from cast, compacted, sintered, forged, or rolled materials. It includes tests for normal induction and hysteresis taken under conditions of 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 very low magnetic field strength up to 200 or more Oe [15.9 or more kA/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 Testing under this test method is inherently more accurate than other methods. When specified dimensional or shape requirements are observed, the measurements are a good approximation to absolute properties. Test accuracy available is primarily limited by the accuracy of instrumentation. In most cases, equivalent results may be obtained using Test Method A773/A773M or the 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 to the direction of crystallographic orientation without interference 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 official definitions see Terminology A340. Note that the term flux density used in this document is synonymous with the term magnetic induction.
1.7 Warning—Mercury has been designated by EPA and many state agencies as a hazardous material that can cause central nervous system, kidney, and liver damage. Mercury, or its vapor, may be hazardous to health and corrosive to materials. Caution should be taken when handling mercury and mercury-containing products. See the applicable product Material Safety Data Sheet (MSDS) for details and EPA’s website (http://www.epa.gov/mercury/faq.htm) for additional information. Users should be aware that selling mercury or mercury-containing products, or both, in your state may be prohibited by state law.
1.8 The values 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 separate sections for the respective unit systems. The values stated in each system are not exact equivalents; therefore, each system shall be 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 use. It is the responsibility of the ...
General Information
Relations
Standards Content (Sample)
NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
´1
Designation: A596/A596M − 95(Reapproved 2009)
Standard Test Method for
Direct-Current Magnetic Properties of Materials Using the
Ballistic Method and Ring Specimens
This standard is issued under the fixed designationA596/A596M; the number immediately following the designation indicates the year
of original adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.
A superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
´ NOTE—Updated IEC information editorially in November 2009.
1. Scope 1.7 Warning—Mercury has been designated by EPA and
many state agencies as a hazardous material that can cause
1.1 This test method covers dc ballistic testing for the
central nervous system, kidney, and liver damage. Mercury, or
determination of basic magnetic properties of materials in the
its vapor, may be hazardous to health and corrosive to
form of ring, toroidal, link, double-lapped Epstein cores, or
materials.Cautionshouldbetakenwhenhandlingmercuryand
other standard shapes which may be cut, stamped, machined,
mercury-containing products. See the applicable product Ma-
or ground from cast, compacted, sintered, forged, or rolled
terial Safety Data Sheet (MSDS) for details and EPA’s website
materials. It includes tests for normal induction and hysteresis
(http://www.epa.gov/mercury/faq.htm)foradditionalinforma-
taken under conditions of steep wavefront reversals of the
tion. Users should be aware that selling mercury or mercury-
direct-current magnetic field strength.
containingproducts,orboth,inyourstatemaybeprohibitedby
1.2 This test method shall be used in conjunction with
state law.
Practice A34/A34M.
1.8 The values stated in either customary (cgs-emu and
1.3 Thistestmethodissuitableforatestingrangefromvery
inch-pound) units or SI units are to be regarded separately as
lowmagneticfieldstrengthupto200ormoreOe[15.9ormore
standard. Within this test method, the SI units are shown in
kA/m]. The lower limit is determined by integrator sensitivity
brackets except for the sections concerning calculations where
and the upper limit by heat generation in the magnetizing
there are separate sections for the respective unit systems. The
winding. Special techniques and short duration testing may
values stated in each system are not exact equivalents;
extend the upper limit of magnetic field strength.
therefore,eachsystemshallbeusedindependentlyoftheother.
1.4 Testing under this test method is inherently more accu- Combiningvaluesfromthetwosystemsmayresultinnoncon-
rate than other methods. When specified dimensional or shape formance with this method.
requirements are observed, the measurements are a good
1.9 This standard does not purport to address all of the
approximationtoabsoluteproperties.Testaccuracyavailableis
safety concerns, if any, associated with its use. It is the
primarily limited by the accuracy of instrumentation. In most
responsibility of the user of this standard to establish appro-
cases, equivalent results may be obtained using Test Method
priate safety and health practices and determine the applica-
A773/A773M or the test methods of IEC Publication 60404-4.
bility of regulatory limitations prior to use.
1.5 This test method permits a choice of test specimen to
2. Referenced Documents
permit measurement of properties in any desired direction
relative to the direction of crystallographic orientation without
2.1 ASTM Standards:
interference from external yoke systems.
A34/A34MPractice for Sampling and Procurement Testing
of Magnetic Materials
1.6 Thesymbolsandabbreviateddefinitionsusedinthistest
A340Terminology of Symbols and Definitions Relating to
method appear in Fig. 1 and Sections 5, 6, 9, and 10. For the
Magnetic Testing
official definitions see Terminology A340. Note that the term
A341/A341MTest Method for Direct Current Magnetic
fluxdensityusedinthisdocumentissynonymouswiththeterm
Properties of Materials Using D-C Permeameters and the
magnetic induction.
Ballistic Test Methods
This test method is under the jurisdiction of ASTM Committee A06 on
MagneticPropertiesandisthedirectresponsibilityofSubcommitteeA06.01onTest
Methods. For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Current edition approved Nov. 1, 2009. Published January 2010. Originally contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
approved in 1969. Last previous edition approved in 2004 as A596/ Standards volume information, refer to the standard’s Document Summary page on
´1
A596M–95(2004) . DOI: 10.1520/A0596_A0596M-95R09E01. the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
´1
A596/A596M − 95 (2009)
context of past performance history will be useful for judging
the suitability of the current material for the intended applica-
tion.
4. Interferences
4.1 This test method has several important requirements.
Unless adequate inside diameter to outside diameter ratios are
maintained in the test specimens, the magnetic field strength
will be excessively nonuniform throughout the test specimen
andthemeasuredparameterscannotberepresentedasmaterial
properties.
4.2 The basic quality of materials having directionally
sensitivepropertiescannotbetestedsatisfactorilywithringsor
laminations. With them it is necessary to use Epstein speci-
mens cut with their lengths in the direction of specific interest
NOTE 1—
or to use long link-shaped or spirally wound toroidal core test
A —Multirange ammeter, main-magnetizing current circuit
specimens whose long dimensions are similarly located. The
A —Multirange ammeter, hysteresis-current circuit
acceptableminimumwidthofstripusedinsuchtestspecimens
N —Magnetizing (primary) winding
is also sensitive to the material under test. At present, it is
N —Flux-sensing (secondary) winding
F—Electronic integrator believed that the grain-oriented silicon steels should have a
R —Main current control rheostat
1 strip width of at least 3 cm [30 mm].
R —Hysteresis current control rheostat
4.3 Unlessringspecimensarelargeindiameter,itisdifficult
S —Reversing switch
S —Shunting switch for hysteresis current control rheostat toprovideasufficientnumberofprimaryturnsneededtoreach
FIG. 1 Basic Circuit Using Ring-Type Cores
the highest magnetic field strength. In general, magnetic
materials tend to have nonuniform properties throughout the
body of the test specimen; for this reason, uniformly distrib-
A343/A343MTest Method for Alternating-Current Mag-
uted test windings and uniform specimen cross-sectional area
netic Properties of Materials at Power Frequencies Using
are highly desirable to suppress nonuniform behavior to a
Wattmeter-Ammeter-Voltmeter Method and 25-cm Ep-
tolerable degree.
stein Test Frame
A773/A773MTest Method for dc Magnetic Properties of
5. Apparatus
Materials Using Ring and Permeameter Procedures with
dc Electronic Hysteresigraphs
5.1 The apparatus shall consist of as many of the compo-
2.2 IEC Standard:
nents described in 5.2-5.10 as are required to perform the
Publication 60404-4Ed. 2.2, Magnetic Materials—Part 4:
desired test. The basic circuit is shown in Fig. 1.
Methods of Measurement of the D-C Magnetic Properties
5.2 Balance and Scales:
of Magnetically Soft Materials, IEC, 2008
5.2.1 The balance used to weigh the test specimen shall be
capable of weighing to an accuracy of better than 0.1%.
3. Significance and Use
5.2.2 The micrometer, caliper, or other length-measuring
3.1 Test methods using suitable ring-type specimens are
device used in the determination of magnetic path length and
the preferred methods of determining the basic magnetic
cross-sectional area shall be capable of measuring to an
properties of a material caused by the absence of demagnetiz-
accuracy of better than 0.1%.
ing effects and are well suited for specification acceptance,
5.3 dc Power Supply—The preferred source of dc current is
service evaluation, and research and development.
a high quality linear power supply of either unipolar or bipolar
3.2 Provided the test specimen is representative of the bulk
operation. The power supply must exhibit high stability and
material as is usually the case for thin strip and wire, this test
very low ripple to achieve the most accurate results. Program-
is also suitable for design purposes.
mable bipolar operational amplifier power supplies have
3.3 Whenthetestspecimenisnotnecessarilyrepresentative
proven to be very satisfactory for this type of testing. Other
of the bulk material such as a ring machined from a large
stable sources of dc current such as storage batteries are
forgingorcasting,theresultsofthistestmethodmaynotbean
permitted.
accurate indicator of the magnetic properties of the bulk
5.4 Main-Current-Control Rheostat R —When nonpro-
material. In such instances, the test results when viewed in
grammable sources of dc current such as storage batteries are
used, rheostats must be used to control the current. These
Available fromAmerican National Standards Institute (ANSI), 25 W. 43rd St.,
rheostatsmusthavesufficientpowerratingandheat-dissipating
4th Floor, New York, NY 10036.
capabilitytohandlethelargesttestcurrentwithoutundesirable
Lloyd, M. G., “Errors in Magnetic Testing with Ring Specimens,’’ Technical
changes in resistance and, therefore, magnetizing current
News Bulletin, National Institute for Standards andTechnology,Vol 5, 1909, p. 435
(S108). during conduct of the test.
´1
A596/A596M − 95 (2009)
5.5 Hysteresis-Current-Control Rheostat R —The 6. Test Specimen
hysteresis-current-control rheostat, when required, must have
6.1 When the test specimen represents a test lot of material,
the same power rating and resistance as the main-current-
its selection shall conform to the requirements of Practice
control rheostat.
A34/A34M or of an individual specification.
5.6 Main-Current Ammeter A —Measurement of the mag- 6.2 To qualify as a test specimen suitable for evaluation of
netizing current can be accomplished with either a dc ammeter material properties the effective ratio of mean diameter to
radialwidthshallbenotlessthan10to1(oraninsidediameter
oracombinationofaprecisionshuntresistoranddcvoltmeter.
to outside diameter ratio not less than 0.82). When the test
The meters and shunt resistor, if used, must have an accuracy
specimen has smaller ratios than the above requirements, the
of at least 0.25%. To improve test accuracy multirange digital
testresultsshouldnotberepresentedasmaterialpropertiesbut
ammeters or voltmeters are preferred. Autoranging capability
should be called core properties because of nonuniform flux
is desirable for convenience but is not essential for this test
distribution.
method.Ifanalogmetersareused,therangesmustbesuchthat
all test readings are made in the upper two thirds of the scale. 6.3 When link, oval-shaped, or rectangular test specimen
forms are used, the requirements of 6.2 apply to the end or
5.7 Hysteresis-CurrentAmmeter,A —Thehysteresis-current
corner sections where flux crowding occurs. When straight-
measuring system shall conform to the requirements in 5.6.In
sided test specimens are very long relative to the length of the
general, a separate measuring system is not required since the
corner or end sections, they are suitable for basic material
main current ammeter ( A ) can also be used to measure the
properties evaluation with relatively unoriented materials pro-
hysteresis current.
vided the uncertainty in determination of true-path (effective)
length is less than 5% of the total path length. When this
5.8 Reversing Switch, S —Because of the low resistance
uncertainty in path length (shortest or longest relative to the
nature of the magnetizing circuit, it is imperative that high
mean-path length) exceeds 5%, the test values should be
quality switches be used. Changes in switch resistance upon
reported as core properties and not basic material properties.
reversal will cause deviation from the cyclically magnetized
6.4 The test specimen may be constructed of solid, lami-
condition which, if excessive, will impair test accuracy and
nated, or strip materials and in any of the shapes described in
precision. Experience has shown that mercury switches are the
1.1.
best suited for this application. Knife blade switches or
mechanical or electrically operated contractors can also be
6.5 Test specimen cores made from strip may be laminated,
used provided the requirement for uniform and equal contact machined, spirally wound, or Epstein specimens (the method
resistance can be maintained. Because of the presence of
of selection for Epstein specimens is described inTest Method
leakagecurrentsintheopencondition,solidstaterelaysarenot A343/A343M, Annex A3). When the material is to be tested
permitted. The difficulties inherent in the use of main current half transverse and half longitudinal, the material shall be cut
into Epstein strips or square laminations of adequate dimen-
reversing switches can be minimized by use of linear power
sional ratio.
supplies capable of accepting a remote programming signal.
Such power supplies are permitted provided that the magne-
6.6 Test specimens used for basic material evaluation shall
tizingcurrentisequal(towithin0.1%)ineitherpolaritywhen
be cut, machined, ground, slit, or otherwise formed to have a
normal induction testing is conducted, current reversals can be
cross section that remains sufficiently uniform that its nonuni-
conductedwithnoovershootoroscillationandthemagnetizing formity will not materially affect the accuracy of establishing
current is truly zero for the zero current programming signal. andmeasuringfluxdensity, B,ormagneticfieldstrength, H,in
the test specimen.
5.9 Hysteresis Switch, S (When Required)—This switch
6.7 When required for material properties development, the
should conform to requirements in 5.8.
test specimen shall have received a stress relief or other heat
5.10 Integrator, F—Because of their superior accuracy,
treatment after preparation. This heat treatment is subject to
stability, and ease of operation, electronic charge integrators
agreementbetweenmanufacturerandpurchaser,manufacturers
are the preferred means of measuring magnetic flux. Integra-
recommendation,ortherecommendedheattreatmentprovided
tors using either operational amplifier and capacitor feedback by the appropriate ASTM standard for the material. The heat
(analog integrator) or pulse counting are permitted. The accu- treatment used shall be reported with the magnetic test results.
racy of the integrator must be better than 1% full scale. If
7. Calibration of Integrator
analog display meters are use
...
Questions, Comments and Discussion
Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.