ASTM A840/A840M-00(2006)
(Specification)Standard Specification for Fully Processed Magnetic Lamination Steel (Withdrawn 2011)
Standard Specification for Fully Processed Magnetic Lamination Steel (Withdrawn 2011)
ABSTRACT
This specification covers standard requirements for flat-rolled carbon steel used in the fully processed condition in magnetic lamination applications. Steels supplied to this specification normally do not require further heat treatment by the user. There are no chemical requirements for these lamination steels. Instead the steels shall be produced to specified maximum core-loss values. Steels produced to this specification are available in thicknesses of 0.0185 in. (0.47 mm) and 0.025 in. (0.64 mm). For each thickness there are two core-loss types. The core loss is determined using the Epstein test method at a frequency of 60 Hz and a maximum flux density of 15 kG. In addition to the magnetic property requirements, dimensional tolerances, lamination factors and mechanical hardnesses are specified.
SCOPE
1.1 This specification covers cold-rolled carbon steel coils or strip used in the fully processed condition in magnetic lamination applications.
1.2 This steel is produced to specified maximum core-loss values and is intended primarily for commercial power frequency (50- and 60-Hz) applications in magnetic devices. Desirable core-loss and permeability characteristics are developed during mill processing, so further heat treatment by the purchaser is not necessary for most uses.
1.3 Fully processed magnetic lamination steels are flat-rolled low carbon iron alloys having 1 % maximum silicon and 0.4 % maximum aluminum.
1.4 The values stated in customary (cgs-emu and inch-pound) units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units which are provided for information only and are not considered standard.
WITHDRAWN RATIONALE
This specification covers cold-rolled carbon steel coils or strip used in the fully processed condition in magnetic lamination applications.
Formerly under the jurisdiction of Committee A06 on Magnetic Properties, this specification was withdrawn in May 2011. This standard is being withdrawn with no replacement because of a lack of commercial/technical interest.
General Information
Relations
Standards Content (Sample)
NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Please contact ASTM International (www.astm.org) for the latest information.
Designation: A 840/A 840M – 00 (Reapproved 2006)
Standard Specification for
Fully Processed Magnetic Lamination Steel
ThisstandardisissuedunderthefixeddesignationA840/A840M;thenumberimmediatelyfollowingthedesignationindicatestheyear
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 (ϵ) indicates an editorial change since the last revision or reapproval.
1. Scope 3. Terminology
1.1 This specification covers cold-rolled carbon steel coils 3.1 The terms and symbols used in this specification are
or strip used in the fully processed condition in magnetic defined in Terminology A340A340.
lamination applications.
4. Classification
1.2 This steel is produced to specified maximum core-loss
values and is intended primarily for commercial power fre- 4.1 The fully processed magnetic lamination steel types
described by this specification are as shown in Table 1.
quency (50- and 60-Hz) applications in magnetic devices.
Desirable core-loss and permeability characteristics are devel-
5. Ordering Information
oped during mill processing, so further heat treatment by the
5.1 Ordersformaterialunderthisspecificationshallinclude
purchaser is not necessary for most uses.
as much of the following information as necessary to describe
1.3 Fully processed magnetic lamination steels are flat-
the desired material adequately:
rolledlowcarbonironalloyshaving1%maximumsiliconand
5.1.1 ASTM specification number.
0.4% maximum aluminum.
5.1.2 Name of material (fully processed magnetic lamina-
1.4
tion steel).
2. Referenced Documents
5.1.3 ASTM core-loss type number.
2.1 ASTM Standards: 5.1.4 Thickness, width and length (if in cut lengths instead
of coils).
A34/A34M Practice for Sampling and Procurement Testing
of Magnetic Materials 5.1.5 Total weight of ordered item.
5.1.6 Limitations in coil size or lift weights.
A340 Terminology of Symbols and Definitions Relating to
Magnetic Testing 5.1.7 End Use—The purchaser shall disclose as much
A343/A343M Test Method for Alternating-Current Mag- pertinent information as possible about the intended applica-
tion to enable the supplier to provide material characteristics
netic Properties of Materials at Power Frequencies Using
Wattmeter-Ammeter-VoltmeterMethodand25-cmEpstein most suitable for specific fabricating practices.
5.1.8 Special requirements or exceptions to the provisions
Test Frame
A664 PracticeforIdentificationofStandardElectricalSteel of this specification.
Grades in ASTM Specifications
6. Manufacture
A700 PracticesforPackaging,Marking,andLoadingMeth-
6.1 Melting Practice:
ods for Steel Products for Shipment
6.1.1 These fully processed magnetic lamination steels may
A719/A719M Test Method for Lamination Factor of Mag-
be made by basic oxygen, electric furnace, or other steelmak-
netic Materials
ing practices.
6.1.2 Thesesteelstypicallycontainlessthan0.03%carbon.
This specification is under the jurisdiction of ASTM Committee A06 on
6.1.3 The addition of silicon, aluminum, manganese, and
Magnetic Properties and is the direct responsibility of Subcommittee A06.02 on
phosphorus may be used to enhance punchability and improve
Material Specifications.
magnetic properties by increasing electrical resistivity. The
Current edition approved Jan. 1, 2006. Published January 2006. Originally
approved in 1985. Last previous edition approved in 2000 as A840/A840M–00.
alloy additions are usually restricted such that the density of
For referenced ASTM standards, visit the ASTM website, www.astm.org, or 3 3
these steels is maintained above 7.825 g/cm (7825 kg/m ).
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
6.1.4 Residual elements such as copper, nickel, chromium,
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. molybdenum, and tin should be held as low as practicable.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Please contact ASTM International (www.astm.org) for the latest information.
A 840/A 840M – 00 (2006)
A B C
TABLE 1 Core-Loss Types and Maximum Core-Loss Values at 15 kG (1.5 T) and 60 Hz for As-Sheared Epstein Specimens
Strip Thickness, Maximum Core Loss
Typical Relative Peak
A
ASTM Core-Loss Type
Permeability
in. (mm) W/lb (W/kg)
47C550 0.0185 (0.47) 5.50 (12.13) 1150
47C600 6.00 (13.23) 1300
64C700 0.025 (0.64) 7.00 (15.43) 1250
64C750 7.50 (16.53) 1400
A
See Practice A 664A664.
B
Maximum core losses at 15 kG (1.5 T) and 50 Hz are 0.79 times maximum core loss at 60 Hz.
C
One half of the strips cut parallel to and one half of the strips cut perpendicular to the rolling direction.
6.1.5 The producer is not required to report chemical 9. Dimensions and Permissible Variations
composition of each lot except where a clear need for such
9.1 Thickness—Specified thickness should be one of the
information has been shown. In such cases, the analyses to be
common thicknesses as follows:
reported shall be negotiated between the manufacturer and the
Thickness, in. (mm)
purchaser.
6.2 Typical Processing:
0.0185 (0.47)
0.025 (0.64)
6.2.1 Processing sequence for fully processed magnetic
lamination steel comprises hot rolling, pickling, cold rolling,
9.2 Thickness Variations—The average thickness of the
and annealing.
material supplied shall be as close as possible to the ordered
6.2.2 Themillannealingoperationistypicallynondecarbur-
thickness. Measurements made with a contacting micrometer
izing or partially decarburizing, resulting in a finished product
atpointsnocloserthan ⁄8in.(10mm)fromtheedgeofasheet
that can be prone to magnetic aging depending on the carbon
or coil of specified width shall not differ from the specified
content.
thickness by more than the value (which include taper) shown
6.2.3 Unless otherwise specified, these steels are supplied
in Table 2.
with a smooth surface finish in the as-annealed condition. The
requiredsurfacetextureisimpartedfromtherollsurfacetothe 9.3 Taper—The rolling of flat rolled coils inherently pro-
steel surface during cold rolling.
duces an edge which is thinner than the rest of the coil width.
6.3 When changes in the manufacture of the material are
This characteristic is termed tapered edge or feather or gamma
believed to exert possible significant effects upon the user’s
and occurs primarily within 1 or 2 in. (25 or 50 mm) from the
fabricating practices and upon the magnetic performance to be
as-rollededgeofthematerial.Thethicknessvariationinvolved
obtained in the specified end use, the manufacturer shall notify
inedgetapersometimesisthemajorportionofthetotaloverall
the purchaser before shipment is made to provide opportunity
thickness variation permitted in 9.2. It may be expected that in
to evaluate the effects.
the case of edge slit coils, the following limits on the
differencesinthicknessmeasuredwithinthefirst2in.(50mm)
7. Magnetic Properties
or less from either edge of the ordered width will apply:
7.1 Core losses are guaranteed and shall conform to the
Ordered Thickness, Maximum Taper,
limits given in Table 1. in. (mm) in. (mm)
7.2 Permeabilitydependsonalloycompositionandprocess-
0.0185 0.47 0.0012 0.030
ing. Relative peak permeability is a dimensionless quantity
0.025 0.64 0.0014 0.036
which is the same in all unit systems. Typical relative peak
More restricted taper tolerances or tolerances on mill edge
permeability values are found in Table 1.
coils shall be negotiated between the manufacturer and the
7.3 Note that fully processed electrical steels do not nor-
purchaser.
mally need a user anneal. Therefore, care must be taken to
minimize fabrication strain, as magnetic properties can be
9.4 Width Tolerances—Maximum deviations from the or-
adversely affected. Examples of such strain are roller leveling
dered width shall be as shown in Table 3.
and improper slitting practices.
8. Mechanical Requirements
TABLE 2 Thickness Tolerances, Cold-Rolled Sheet, Fully
Processed Magnetic Lamination Steel for Specified Width 2 to 60
8.1 Lamination Factor
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