ASTM A901-12
(Specification)Standard Specification for Amorphous Magnetic Core Alloys, Semi-Processed Types
Standard Specification for Amorphous Magnetic Core Alloys, Semi-Processed Types
ABSTRACT
This specification covers the general requirements to which flat-cast, amorphous, semi-processed, iron-base magnetic core alloys must conform. These alloys shall be produced by a rapid-quenching, direct-casting process, resulting in metals with noncrystalline structure. The metallic alloys shall be made to meet specified maximum core-loss values and shall be intended primarily for commercial power frequency applications in magnetic devices. Desirable core-loss and permeability characteristics shall be developed by further heat treatment in a magnetic field. Amorphous magnetic core alloys shall be composed principally of iron with small amounts of alloying elements such as boron and silicon. Other chemical elements shall be in residual amounts or can be added to improve fabrication or the physical or magnetic properties. The material shall conform to the required physical and mechanical properties such as density, ductility, thermal expansion, thermal conductivity, volume resistivity, lamination factor, surface, edge, and pinholes. The alloy shall also conform to the magnetic property requirements such as DC induction, DC coercive field strength, DC residual induction, core loss, and specific exciting power.
SCOPE
1.1 This specification covers the general requirements to which flat-cast, amorphous, semi-processed, iron-base magnetic core alloys must conform.
1.2 These alloys are produced by a rapid-quenching, direct-casting process, resulting in metals with noncrystalline (amorphous) structure. The metallic alloys are made to meet specified maximum core-loss values and are intended primarily for commercial power frequency (50- and 60-Hz) applications in magnetic devices. Desirable core-loss and permeability characteristics are developed by further heat treatment in a magnetic field by the user. The heat treatment typically consists of heating the material to a temperature of 320 to 420°C in a dry, inert atmosphere for 5 to 10 min, although soak times of up to 2 h may be used for large transformer cores. A magnetic field may be required during annealing as designated by the producer. Exact optimum annealing conditions depend on the processing of the material and the size and shape of the device.
1.3 Some of these alloys are sensitive to mechanical stress. Care must be exercised in minimizing any stresses on the material in its final application, otherwise, its magnetic properties will be significantly impaired.
1.4 This specification is developed to aid in the purchase of transformer grade amorphous strip. It provides the chemical, physical, and magnetic parameters and procedures for quality control tests.
1.5 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.
Note 1—For more information on procedures associated with this specification, refer to the following: Practices A34/A34M, A664, A700, and B490; Test Methods A370 and A773/A773M.
1.6 This standard does not purport to address the safety concerns associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.
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Designation:A901 −12
Standard Specification for
1
Amorphous Magnetic Core Alloys, Semi-Processed Types
This standard is issued under the fixed designation A901; the number immediately following the designation indicates the year of
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.
NOTE 1—For more information on procedures associated with this
1. Scope
specification, refer to the following: Practices A34/A34M, A664, A700,
1.1 This specification covers the general requirements to
and B490; Test Methods A370 and A773/A773M.
which flat-cast, amorphous, semi-processed, iron-base mag-
1.6 This standard does not purport to address the safety
netic core alloys must conform.
concerns associated with its use. It is the responsibility of the
1.2 These alloys are produced by a rapid-quenching, direct-
user of this standard to establish appropriate safety and health
casting process, resulting in metals with noncrystalline (amor-
practices and determine the applicability of regulatory limita-
phous) structure. The metallic alloys are made to meet speci-
tions prior to use.
fied maximum core-loss values and are intended primarily for
commercial power frequency (50- and 60-Hz) applications in
2. Referenced Documents
magnetic devices. Desirable core-loss and permeability char-
3
2.1 ASTM Standards:
acteristics are developed by further heat treatment in a mag-
2
netic field by the user. The heat treatment typically consists of A34/A34M Practice for Sampling and Procurement Testing
of Magnetic Materials
heating the material to a temperature of 320 to 420°C in a dry,
inert atmosphere for 5 to 10 min, although soak times of up to A340 Terminology of Symbols and Definitions Relating to
2 h may be used for large transformer cores. A magnetic field Magnetic Testing
may be required during annealing as designated by the pro- A370 Test Methods and Definitions for Mechanical Testing
ducer. Exact optimum annealing conditions depend on the of Steel Products
processing of the material and the size and shape of the device.
A664 Practice for Identification of Standard Electrical Steel
Grades in ASTM Specifications
1.3 Some of these alloys are sensitive to mechanical stress.
A700 Practices for Packaging, Marking, and Loading Meth-
Care must be exercised in minimizing any stresses on the
ods for Steel Products for Shipment
material in its final application, otherwise, its magnetic prop-
A712 Test Method for Electrical Resistivity of Soft Mag-
erties will be significantly impaired.
netic Alloys
1.4 This specification is developed to aid in the purchase of
A773/A773M Test Method for dc Magnetic Properties of
transformer grade amorphous strip. It provides the chemical,
Materials Using Ring and Permeameter Procedures with
physical, and magnetic parameters and procedures for quality
dc Electronic Hysteresigraphs
control tests.
A900/A900M Test Method for Lamination Factor of Amor-
1.5 The values stated in customary (cgs-emu and inch-
phous Magnetic Strip
pound) units are to be regarded as standard. The values given
B490 Practice for Micrometer Bend Test for Ductility of
in parentheses are mathematical conversions to SI units which
Electrodeposits
are provided for information only and are not considered
C693 Test Method for Density of Glass by Buoyancy
standard.
D3455 Test Methods for Compatibility of Construction Ma-
terial with Electrical Insulating Oil of Petroleum Origin
1
This specification is under the jurisdiction of ASTM Committee A06 on
3. Terminology
Magnetic Properties and is the direct responsibility of Subcommittee A06.02 on
Material Specifications.
3.1 The terms and symbols used in this specification are
Current edition approved Feb. 15, 2012. Published March 2012. Originally
defined in Terminology A340.
approved in 1990. Last previous edition approved in 2008 as A901–03(2008). DOI:
10.1520/A0901-12.
2
The process of heat treatment in a magnetic field is covered by a patent held by
General Electric Co. Interested parties are invited to submit information regarding
3
the identification of acceptable alternatives to this patented item to the Committee For referenced ASTM standards, visit the ASTM website, www.astm.org, or
on Standards, ASTM International Headquarters. Your comments will receive contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
1
careful consideration at a meeting of the responsible technical committee, which Standards volume information, refer to the standard’s Document Summary page on
you may attend. the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
1
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This document is not anASTM standard and is intended only to provide the user of anASTM standard an indication of what changes have been made to the previous version. Because
it 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 version
of the standard as published by ASTM is to be considered the official document.
Designation:A901–03 (Reapproved 2008) Designation: A901 – 12
Standard Specification for
1
Amorphous Magnetic Core Alloys, Semi-Processed Types
This standard is issued under the fixed designation A901; 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.
1. Scope
1.1 This specification covers the general requirements to which flat-cast, amorphous, semi-processed, iron-base magnetic core
alloys must conform.
1.2 Thesealloysareproducedbyarapid-quenching,direct-castingprocess,resultinginmetalswithnoncrystalline(amorphous)
structure. The metallic alloys are made to meet specified maximum core-loss values and are intended primarily for commercial
power frequency (50- and 60-Hz) applications in magnetic devices. Desirable core-loss and permeability characteristics are
2
developed by further heat treatment in a magnetic field by the purchaser.user. The heat treatment typically consists of heating the
materialtoatemperatureof320to420°Cinadry,inertatmospherefor5to10min,althoughsoaktimesofupto2hmaybeused
for large transformer cores. A magnetic field may be required during annealing as designated by the producer. Exact optimum
annealing conditions depend on the processing of the material and the size and shape of the device.
1.3 Some of these alloys are sensitive to mechanical stress. Care must be exercised in minimizing any stresses on the material
in its final application, otherwise, its magnetic properties will be impaired significantly. significantly impaired.
1.4 This specification is developed to aid in the purchase of transformer grade amorphous strip. It provides the chemical,
physical, and magnetic parameters and procedures for quality control tests.
1.5 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.
NOTE 1—For more information on procedures associated with this specification, refer to the following: PracticesA34/A34M,A664,A700, and B490;
Test Methods A370 and A773/A773M.
1.6 This standard does not purport to address the safety concerns associated with its use. It is the responsibility of the user of
this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior
to use.
2. Referenced Documents
3
2.1 ASTM Standards:
A34/A34M Practice for Sampling and Procurement Testing of Magnetic Materials
A340 Terminology of Symbols and Definitions Relating to Magnetic Testing
A370 Test Methods and Definitions for Mechanical Testing of Steel Products
A664 Practice for Identification of Standard Electrical Steel Grades in ASTM Specifications
A700 Practices for Packaging, Marking, and Loading Methods for Steel Products for Shipment
A712 Test Method for Electrical Resistivity of Soft Magnetic Alloys
A773/A773M TestMethodfordcMagneticPropertiesofMaterialsUsingRingandPermeameterProcedureswithdcElectronic
Hysteresigraphs
A900/A900M Test Method for Lamination Factor of Amorphous Magnetic Strip
B490 Practice for Micrometer Bend Test for Ductility of Electrodeposits
C693 Test Method for Density of Glass by Buoyancy
1
This specification is under the jurisdiction of ASTM Committee A06 on Magnetic Properties and is the direct responsibility of Subcommittee A06.02 on Material
Specifications.
Current edition approved Nov. 1, 2008. Published December 2008. Originally approved in 1990. Last previous edition approved in 2003 as A901–03. DOI:
10.1520/A0901-03R08.
Current edition approved Feb. 15, 2012. Published March 2012. Originally approved in 1990. Last previous edition approved in 2008 as A901–03(2008). DOI:
10.1520/A0901-12.
2
The process of heat treatment in a magnetic field is covered by a patent held by General Electric Co. Interested parties are invited to submit information regarding the
identification of acceptable alternatives to this patented item to the Committee on Standards, ASTM International Headquarters. Your comments will receive careful
consideration at a meeting of the responsible technical committee, which you may attend.
3
ForreferencedASTMstandards,visittheASTMwebsite,www.astm.org,orcontactASTMCustomerServiceatservice@astm.org.ForAnnualBookofASTMStandards
volume information, refer to the standard’s Document
...
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