GB/T 20168-2017 English PDF (GB/T20168-2017)

GB/T 20168-2017: Rapidly quenched neodymium iron boron permanent magnetic powder
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GB/T 20168-2017
GB
NATIONAL STANDARD OF THE
PEOPLE’S REPUBLIC OF CHINA
ICS 77.120.99
H 65
Replacing GB/T 20168-2006
Rapidly-quenched Neodymium Iron Boron Permanent
Magnetic Powder
ISSUED ON: OCTOBER 14, 2017
IMPLEMENTED ON: MAY 1, 2018
Issued by: General Administration of Quality Supervision, Inspection and
Quarantine of the People’s Republic of China;
Standardization Administration of the People’s Republic of China.
Table of Contents
Foreword ... 3
1 Scope ... 5
2 Normative References ... 5
3 Terms and Definitions ... 6
4 Classification and Designations ... 6
5 Requirements ... 7
6 Test Methods ... 9
7 Inspection Rules ... 9
8 Marking, Packaging, Transportation, Storage and Quality Certificate ... 10
Appendix A (informative) Preparation Process and Chemical Composition Ratio of
Rapidly-quenched Neodymium Iron Boron Permanent Magnetic Powder ... 12
Appendix B (informative) Comparison of Principal Magnetic Properties of Rapidly-
quenched Neodymium Iron Boron Permanent Magnetic Powder between the
International System of Units and the Electromagnetic System of Units ... 13
Appendix C (informative) Additional Magnetic Properties and Other Physical and
Chemical Properties of Rapidly-quenched Neodymium Iron Boron Permanent
Magnetic Powder ... 15
Appendix D (informative) Test Method for the Principal Magnetic Properties of
Isotropic Rapidly-quenched Neodymium Iron Boron Permanent Magnetic Powder
Using a Vibrating Sample Magnetometer ... 17
Appendix E (normative) Principal Magnetic Properties of Corresponding Magnet Test
Samples of Rapidly-quenched Neodymium Iron Boron Permanent Magnetic Powder
... 18
Foreword
This Standard was drafted in accordance with the rules provided in GB/T 1.1-2009.
This Standard serves as a replacement of GB/T 20168-2006 Rapidly-quenched Neodymium Iron
Boron Permanent Magnetic Powder.
In comparison with GB/T 20168-2006, apart from editorial modifications, the main technical
differences are as follows:
---The normative reference GB/T 5158.4 is added (see Chapter 2);
---The requirements for additional magnetic properties are added (see 5.4);
---The expression method for designations is modified from the previous numerical type
to the character type composed of letters and numbers (see 4.2, 4.3 and Table 1);
---Some designations of Category-L and Category-H are added, and some designations of
Category-M are deleted (see Table 1);
---The property parameters of some designations of Category-M are modified (see Table
1);
---The order of appendices is adjusted in accordance with the citation order of the main
text (see appendices);
---Informative Appendix B is added (see Appendix B);
---The saturation trend charts of typical designations of magnetic powers of Category-L,
Category-M and Category-H are added (see Appendix C).
This Standard was proposed by and shall be under the jurisdiction of National Technical
Committee 229 on Rare Earth of Standardization Administration of China. (SAC/TC 229).
The drafting organizations of this Standard: Beijing Zhong Ke San Huan Hi-tech Co., Ltd.;
Shanghai San Huan Magnetics Co., Ltd.; The Eighth Research Institute of Nuclear Industry;
Jiangxi Jiang Tungsten Rare Metal New Materials Co., Ltd.; Grirem Advanced Materials Co.,
Ltd.; Shenyang New Oak Magnetic Materials Co., Ltd.; Dongyang Yinhai Magnetic Industry
Co., Ltd.; Ningbo Yunsheng Co., Ltd.; Chengdu Galaxy Magnets Co., Ltd.; Central Iron and Steel
Research Institute; Ganzhou Qiandong Rare Earth Group Co., Ltd.; Anhui Earth Panda New
Materials Co., Ltd.
The main drafters of this Standard: Rao Xiaolei, Cai Daoyan, Qin Guochao, Chen Weiqiang,
Xiang Yousheng, Chen Gang, Xia Xiufu, Yao Nanhong, Wen Bin, Guo Xiaoyan, Chen Xin, Yu
Dunbo, Li Kuoshe, Gao Liqun, Peng Zhengguo, Li Wei, Zhu Minggang, He Jinzhou, Shen
Guodi, Huang Xiulian, Li Yong, Lou Yonghui, Luo Xianping.
Rapidly-quenched Neodymium Iron Boron Permanent
Magnetic Powder
1 Scope
This Standard specifies the requirements, test methods, inspection rules, marking, packaging,
transportation, storage and quality certificate of rapidly-quenched neodymium iron boron
permanent magnetic powder.
This Standard is applicable to isotropic neodymium iron boron permanent magnetic powder
produced by single-rolling or atomized rapid quenching process. Specifically speaking, single-
rolled rapidly-quenched neodymium iron boron permanent magnetic powder is used to
manufacture bonded magnets through processes, such as: molding, injection molding, extrusion
molding and calendaring molding, etc.; atomized rapidly-quenched neodymium iron boron
permanent magnetic powder is used to manufacture bonded magnets through processes, such
as: injection molding and extrusion molding, etc.
2 Normative References
The contents of the following documents constitute indispensable clauses of this document
through the normative references in the text. In terms of references with a specified date, only
versions with a specified date are applicable to this document. In terms of references without a
specified date, the latest version (including all the modifications) is applicable to this document.
GB/T 1479.1 Metallic Powders - Determination of Apparent Density - Part 1: Funnel Method
GB/T 1480 Metallic Powders - Determination of Particle Size by Dry Sieving
GB/T 3217 Methods of Test of the Magnetic Properties of Permanent Magnetic (magnetically
hard) Materials
GB/T 5158.4 Metallic Powders - Determination of Oxygen Content by Reduction Methods -
Part 4: Total Oxygen by Reduction-extraction
GB/T 8170 Rules of Rounding off for Numerical Values and Expression and Judgement of
Limiting Values
GB/T 9637 Electrotechnical Terminology - Magnetic Materials and Components
GB/T 15676 Terms for Rare Earths
GB/T 17803 Designation System for Rare Earth Products
XB/T 617.7 Chemical Analysis Methods for Neodymium Iron Boron Alloy - Part 7:
Determination of Oxygen and Nitrogen Contents - Impulse-infrared and Impulse-thermal
Conductance Absorption Method
3 Terms and Definitions
The terms and definitions established in GB/T 9637 and GB/T 15676, and the following are
applicable to this document. For ease of use, some terms and definitions in GB/T 9637 and
GB/T 15676 are repeated below.
3.1 principal magnetic properties
Include the residual magnetic induction intensity (Br), intrinsic coercive force (HcJ), magnetic
induction intensity coercive force (HcB) and maximum magnetic energy product [(BH)max] of
permanent magnetic materials.
3.2 additional magnetic properties
Include the residual magnetic induction intensity temperature coefficient [(Br)], intrinsic
coercive force temperature coefficient [(HcJ)], Curie temperature (Tc), magnetization
saturation trend of residual magnetic induction intensity and intrinsic coercive force of
permanent magnetic materials.
3.3 rapid quenching magnetic powder
Rapidly solidifying magnetic powder produced through the rapid quenching process, with a
microcrystalline structure.
Please refer to Appendix A for the preparation process and chemical composition ratio of
rapidly-quenched neodymium iron boron permanent magnetic powder.
4 Classification and Designations
4.1 Classification
In accordance with the intrinsic coercive force, rapidly-quenched neodymium iron boron
permanent magnetic powder is classified into three categories of products: low coercive force
L, medium coercive force M and high coercive force H.
4.2 Designations
In accordance with the maximum magnetic energy product, each category of products is divided
into several designations. The expression method for the designations shall comply with the
provisions of GB/T 17803.
4.3 Designation Expression Method
The product shall be clean and free of visible rust spots and inclusions.
5.4 Additional Magnetic Properties and Other Physical and Chemical Properties
The additional magnetic properties and other physical and chemical properties of the product
are shown in Appendix C. If the demand-side has special requirements, the supply-side and the
demand-side may negotiate separately.
6 Test Methods
6.1 Principal magnetic properties
6.1.1 The principal magnetic properties of the product are tested using a vibrating sample
magnetometer that satisfies the accuracy requirements. Please refer to Appendix D for the test
method.
6.1.2 Upon agreement between the supply-side and the demand-side, the magnetic powder may
also be made into magnets for testing. The requirements for magnetic test samples are: the
bonder mass fraction is 2.5%, the density () is 6.00 g/cm3  0.05 g/cm3, the size is 10 mm 
10 mm; the test method shall comply with the provisions of GB/T 3217; the numerical rounding
of the magnetic properties test results shall be carried out in accordance with the provisions of
GB/T 8170. The principal magnetic property values of the test samples with corresponding
magnet designations of the magnetic power are shown in Appendix E.
6.2 Particle Size
The test method for the particle size of the product shall comply with the provisions of GB/T
1480.
6.3 Appearance Quality
The appearance quality of the product is visually inspected using a 10 magnifying glass.
7 Inspection Rules
7.1 Inspection and Acceptance
7.1.1 The product shall be inspected by the supply-side’s quality and technical supervision
department to ensure that the product quality complies with the provisions of this Standard. In
addition, a quality certificate shall be filled out.
7.1.2 The demand-side may inspect the received products in accordance with the provisions of
this Standard. If the inspection results are inconsistent with the provisions of this Standard, the
demand-side shall submit in writing to the supply-side within 1 month from the date of receipt
of the products, and the supply-side and the demand-side shall negotiate and resolve this
problem. If no quality objection is raised for more than 1 month, then, it will be deemed that
Appendix D
(informative)
Test Method for the Principal Magnetic Properties of Isotropic Rapidly-quenched
Neodymium Iron Boron Permanent Magnetic Powder Using a Vibrating Sample
Magnetometer
D.1 Sample Preparation Method and Test Procedures
D.1.1 Use an electronic balance with an accuracy of 0.1 mg to weigh the mass of the specimen
tube (mtube) of the magnetic powder to be tested.
D.1.2 Put an appropriate amount of magnetic powder into the specimen tube and compact it. It
is required that the surface shall be flattened. Then, weigh them together. Measure the sum of
the mass of the magnetic powder and the mass of the specimen tube (mtube + powder). In accordance
with the mass of the specimen tube (mtube), and the sum of the mass of the magnetic powder and
the mass of the specimen tube (mtube + powder), calculate the mass of the magnetic powder (mpowder).
D.1.3 Drop 502 glue into the specimen tube containing the magnetic powder, so as to solidify
the magnetic powder. Then, put the specimen tube into the sample pressing machine and press
the sealing copper sheet into the end face of the specimen tube in parallel, so as to prevent the
magnetic powder from rotating with the magnetic field during measurement.
D.1.4 After the magnetic powder is dried and solidified, put the specimen tube into the
magnetizer and magnetize it along the axial direction with a pulse magnetic field of 0H  4.5
T.
D.1.5 Place the specimen tube on the vibrating sample magnetometer measurement bracket.
The magnetization direction is consistent with the direction of the measuring magnetic field.
Enter the type of specimen, and the mass of the magnetic powder (mpowder), the density of the
magnetic powder () and the demagnetization factor (N) for the demagnetization curve
measurement.
D.2 Determination of Demagnetization Factor N
In accordance with the diameter (D) and length (L) of the sample, determine the
demagnetization factor (N).
GB/T 20168-2017
GB
NATIONAL STANDARD OF THE
PEOPLE’S REPUBLIC OF CHINA
ICS 77.120.99
H 65
Replacing GB/T 20168-2006
Rapidly-quenched Neodymium Iron Boron Permanent
Magnetic Powder
ISSUED ON: OCTOBER 14, 2017
IMPLEMENTED ON: MAY 1, 2018
Issued by: General Administration of Quality Supervision, Inspection and
Quarantine of the People’s Republic of China;
Standardization Administration of the People’s Republic of China.
Table of Contents
Foreword ... 3
1 Scope ... 5
2 Normative References ... 5
3 Terms and Definitions ... 6
4 Classification and Designations ... 6
5 Requirements ... 7
6 Test Methods ... 9
7 Inspection Rules ... 9
8 Marking, Packaging, Transportation, Storage and Quality Certificate ... 10
Appendix A (informative) Preparation Process and Chemical Composition Ratio of
Rapidly-quenched Neodymium Iron Boron Permanent Magnetic Powder ... 12
Appendix B (informative) Comparison of Principal Magnetic Properties of Rapidly-
quenched Neodymium Iron Boron Permanent Magnetic Powder between the
International System of Units and the Electromagnetic System of Units ... 13
Appendix C (informative) Additional Magnetic Properties and Other Physical and
Chemical Properties of Rapidly-quenched Neodymium Iron Boron Permanent
Magnetic Powder ... 15
Appendix D (informative) Test Method for the Principal Magnetic Properties of
Isotropic Rapidly-quenched Neodymium Iron Boron Permanent Magnetic Powder
Using a Vibrating Sample Magnetometer ... 17
Appendix E (normative) Principal Magnetic Properties of Corresponding Magnet Test
Samples of Rapidly-quenched Neodymium Iron Boron Permanent Magnetic Powder
... 18
Foreword
This Standard was drafted in accordance with the rules provided in GB/T 1.1-2009.
This Standard serves as a replacement of GB/T 20168-2006 Rapidly-quenched Neodymium Iron
Boron Permanent Magnetic Powder.
In comparison with GB/T 20168-2006, apart from editorial modifications, the main technical
differences are as follows:
---The normative reference GB/T 5158.4 is added (see Chapter 2);