ASTM B887-24
(Test Method)Standard Test Method for Determination of Coercivity (Hcs) of Cemented Carbides
Standard Test Method for Determination of Coercivity (Hcs) of Cemented Carbides
SIGNIFICANCE AND USE
5.1 Measurement of coercivity provides a relative comparison of carbide grain size, binder content, and possibly carbon deficiency for a given graded carbide material or product, and may be employed as a non-destructive measurement indicating deviation from a specified norm.
5.2 This test method allows the non-destructive estimate of average carbide grain size in sintered cemented carbide hardmetals. It is appropriate for a wide range of compositions and tungsten carbide (WC) WC grain sizes, and can be used for acceptance of material or product to specification.
SCOPE
1.1 This test method covers the determination of magnetization coercivity (Hcs) of cemented carbide materials and products using coercive force instrumentation. It is patterned after ISO 3326.
1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.
1.4 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
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This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Designation: B887 − 24
Standard Test Method for
1
Determination of Coercivity (Hcs) of Cemented Carbides
This standard is issued under the fixed designation B887; 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.
1. Scope* 3. Terminology
1.1 This test method covers the determination of magneti- 3.1 Definitions:
zation coercivity (Hcs) of cemented carbide materials and 3.1.1 For definition of terms used in this procedure refer to
products using coercive force instrumentation. It is patterned Terminology A340 and Terminology B243.
after ISO 3326. 3.1.2 dc—direct current.
1.2 The values stated in SI units are to be regarded as
4. Summary of Test Method
standard. No other units of measurement are included in this
4.1 A test sample is positioned in the dc magnetic field of
standard.
the test apparatus and magnetized to technical saturation. The
1.3 This standard does not purport to address all of the
magnetic field polarity is then reversed and the test sample is
safety concerns, if any, associated with its use. It is the
demagnetized by increasing the energy of the reversed mag-
responsibility of the user of this standard to establish appro-
netic field until the test sample reaches zero magnetism. The
priate safety, health, and environmental practices and deter-
coercive force (Hc) is the magnetizing force required to return
mine the applicability of regulatory limitations prior to use.
the saturated magnetic induction to zero.
1.4 This international standard was developed in accor-
dance with internationally recognized principles on standard-
5. Significance and Use
ization established in the Decision on Principles for the
5.1 Measurement of coercivity provides a relative compari-
Development of International Standards, Guides and Recom-
son of carbide grain size, binder content, and possibly carbon
mendations issued by the World Trade Organization Technical
deficiency for a given graded carbide material or product, and
Barriers to Trade (TBT) Committee.
may be employed as a non-destructive measurement indicating
2. Referenced Documents deviation from a specified norm.
2
2.1 ASTM Standards: 5.2 This test method allows the non-destructive estimate of
A340 Terminology of Symbols and Definitions Relating to average carbide grain size in sintered cemented carbide hard-
Magnetic Testing metals. It is appropriate for a wide range of compositions and
B243 Terminology of Powder Metallurgy tungsten carbide (WC) WC grain sizes, and can be used for
E177 Practice for Use of the Terms Precision and Bias in acceptance of material or product to specification.
ASTM Test Methods
6. Interferences
E691 Practice for Conducting an Interlaboratory Study to
Determine the Precision of a Test Method
6.1 Hcs measurement is a non-destructive “bulk” measure-
3
2.2 ISO Standard:
ment that is averaged over the specimen volume. Bi-modal
ISO 3326 Hardmetals - Determination of (the Magnetiza-
grain size distributions will give approximately the same Hc
tion) Coercivity
value as would be obtained from a normal grain size distribu-
tion about the same mean value.
1
6.2 Large test specimens must be sized to fit within the
This test method is under the jurisdiction of ASTM Committee B09 on Metal
Powders and Metal Powder Products and is the direct responsibility of Subcom-
magnetic field coil spacing available for the apparatus em-
mittee B09.06 on Cemented Carbides.
ployed.
Current edition approved Feb. 1, 2024. Published February 2024. Originally
approved in 1998. Last previous edition approved in 2019 as B887 – 12 (2019).
6.3 Small test specimens may be immeasurable if their size
DOI: 10.1520/B0887-24.
prohibits detection by the magnetic field coils for the apparatus
2
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
employed.
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
Standards volume information, refer to the standard’s Document Summary page on
6.4 Specimen shape, that is, symmetry and aspect ratio,
the ASTM website.
3
influence Hc measurement values and repeatability of results.
Available from American National Standards Institute (ANSI), 25 W. 43rd St.,
4th Floor, New York, NY 10036, http://www.ansi.org. Test specimens should be positioned with their long axis in the
*A Summary of Changes section appears at the end of this standard
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United
...
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. 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: B887 − 12 (Reapproved 2019) B887 − 24
Standard Test Method for
1
Determination of Coercivity (Hcs) of Cemented Carbides
This standard is issued under the fixed designation B887; 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.
1. Scope Scope*
1.1 This test method covers the determination of magnetization coercivity (Hcs) of cemented carbide materials and products using
coercive force instrumentation. It is patterned after ISO 3326.
1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility
of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of
regulatory limitations prior to use.
1.4 This international standard was developed in accordance with internationally recognized principles on standardization
established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued
by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
2. Referenced Documents
2
2.1 ASTM Standards:
A340 Terminology of Symbols and Definitions Relating to Magnetic Testing
B243 Terminology of Powder Metallurgy
E177 Practice for Use of the Terms Precision and Bias in ASTM Test Methods
E691 Practice for Conducting an Interlaboratory Study to Determine the Precision of a Test Method
3
2.2 ISO Standard:
ISO 3326 Hardmetals - Determination of (the Magnetization) Coercivity
3. Terminology
3.1 Definitions:
3.1.1 For definition of terms used in this procedure refer to Terminology A340 and Terminology B243.
3.1.2 dc—direct current.
4. Summary of Test Method
4.1 A test sample is positioned in the dc magnetic field of the test apparatus and magnetized to technical saturation. The magnetic
1
This test method is under the jurisdiction of ASTM Committee B09 on Metal Powders and Metal Powder Products and is the direct responsibility of Subcommittee B09.06
on Cemented Carbides.
Current edition approved April 1, 2019Feb. 1, 2024. Published April 2019February 2024. Originally approved in 1998. Last previous edition approved in 20122019 as
B887 – 12.B887 – 12 (2019). DOI: 10.1520/B0887-12R19.10.1520/B0887-24.
2
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
3
Available from American National Standards Institute (ANSI), 25 W. 43rd St., 4th Floor, New York, NY 10036, http://www.ansi.org.
*A Summary of Changes section appears at the end of this standard
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
1
---------------------- Page: 1 ----------------------
B887 − 24
field polarity is then reversed and the test sample is demagnetized by increasing the energy of the reversed magnetic field until the
test sample reaches zero magnetism. The coercive force (Hc) is the magnetizing force required to return the saturated magnetic
induction to zero.
5. Significance and Use
5.1 Measurement of coercivity provides a relative comparison of carbide grain size, binder content, and possibly carbon deficiency
for a given graded carbide material or product, and may be employed as a non-destructive measurement indicating deviation from
a specified norm.
5.2 This test method allows the non-destructive estimate of average carbide grain size in sintered cemented carbide hardmetals.
It is appropriate for a wide range of compositions and tungsten carbide (WC) WC grain sizes, and can be used for acceptance of
material or product to specification.
6. Interferences
6.1 Hcs measurement is a non-destructive “bulk” measurement that is averaged over the specimen volume. Bi-modal grain size
distributions will give approximately the same Hc value as would be obtained from a normal grain size distribution about the same
mean value.
6.2 Large test specimens must be sized to fit within the magnetic field coil spacing available for the apparatus employed.
6.3 Small test specimens may be immeasurable if thei
...
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