Foreword

This document was drafted in accordance with the provisions of GB/T 1.1-2020 "Standardization Work Guidelines Part 1: Structure and Drafting Rules of Standardization Documents".

This document replaces GB/T 2480-2008 "General Abrasive Silicon Carbide". Compared with GB/T 2480-2008, apart from structural adjustments and editorial changes, the main technical changes are as follows:

1. The scope of application has been changed (see Chapter 1, Chapter 1 of the 2008 edition).
2. The trademark designation has been changed (see Chapter 4, Chapter 3 in the 2008 edition).
3. The chemical composition indicators have been changed (see 5.1, 4.1 in the 2008 edition).
4. The density metric has been changed (see 5.3, 4.2 in the 2008 edition).
5. The magnetic content index has been changed (see 5.5, 4.5 in the 2008 edition).
6. The content on J-series abrasive micro powder has been added (see 5.1, 5.3, and Table 3);
7. Requirements for marking, transportation, and storage have been added (see Chapter 8).

Please note that some content in this document may involve patents. The issuing organization of this document assumes no responsibility for identifying patents.

This document was proposed by the China Machinery Industry Federation.

This document is under the jurisdiction of the National Technical Committee on Standardization of Abrasives and Grinding Tools (SAC/TC139).

This document was drafted by: Baige Abrasives Co., Ltd., Zigong Fengrui New Materials Co., Ltd., Shandong Guanhua New Materials Co., Ltd., Pingdingshan Yicheng New Materials Co., Ltd., and China National Machinery Industry International Cooperation Co., Ltd.

The main drafters of this document are: Chen Deguang, Chang Yanli, Wu Meng, Wang Xueqiang, Lü Chunchang, Xia Xuefeng, Li Hang, and Su Yan.

The previous versions of the document replaced by this document are: GB 2480-1981, GB 2480-1983, GB/T 2480-1996, and GB/T 2480-2008.

1. Scope

This document specifies the grades, technical requirements, test methods, inspection rules, packaging, marking, transportation, and storage of silicon carbide abrasives.

This document applies to silicon carbide abrasives used in the manufacture of bonded abrasives, coated abrasives, and for free grinding, polishing, and cutting.

2 Normative references

The contents of the following documents, through normative references within the text, constitute essential provisions of this document. For dated references, only the edition cited applies; for undated references, the latest edition of the referenced document (including any amendments) applies.

• GB/T 2481 (all parts) - Determination and marking of abrasive grain size composition for bonded abrasives
• GB/T 3045 Chemical Analysis Methods for Common Abrasive Silicon Carbide
• GB/T 4676 Sampling Method for Common Abrasives
• GB/T 9258 (all parts) Abrasive particle size analysis for coated abrasives
• JB/T 6569 Packaging for General Abrasives
• JB/T 6570 Method for Determination of Magnetic Material Content in Common Abrasives
• JB/T 11433 Determination of density of common abrasives

3. Terms and Definitions

This document does not contain any terms or definitions that need to be defined.

4 Brand

The designations for silicon carbide abrasives are as follows:

• The grade of black silicon carbide for ceramic bonded abrasives, coated abrasives, and free grinding, polishing, and cutting is C;
• The grade of green silicon carbide for ceramic bonded abrasives, coated abrasives, and free grinding, polishing, and cutting is GC;
• The grade of black silicon carbide for organically bonded abrasives is CB;
• The grade of green silicon carbide for organically bonded abrasives is GC-B.

5 Technical Requirements

5.1 Chemical composition

The chemical composition of each brand of product shall conform to the provisions of Table 1.

5.2 Particle size distribution

The particle size distribution of abrasives used for bonded abrasives and for free grinding, polishing, and cutting shall comply with the provisions of GB/T 2481 (all parts).

The abrasive grain size distribution for coated abrasives shall comply with the provisions of GB/T 9258 (all parts).

5.3 Density

For F220 (P220) and coarse-grained grades: the density of black silicon carbide should not be less than 3.15 g/cm³, and the density of green silicon carbide should not be less than 3.20 g/cm³.

For F230 (J240, P240) and finer particle sizes: the density of black silicon carbide should not be less than 3.13 g/cm³, and the density of green silicon carbide should not be less than 3.18 g/cm³.

5.4 Ferroalloy particle content

For F30 (P36) and all other coarser particle sizes, zero ferroalloy particles that do not pass through a 355μm sieve are considered; for F36~F90 (P40~P100), zero ferroalloy particles that do not pass through the bottom sieve during particle size inspection are considered; for F100~F220 (P120~P220), zero ferroalloy particles that do not pass through the second bottom sieve during particle size inspection are considered.

5.5 Magnetic content

The magnetic content of each product brand should comply with the requirements in Table 2.

6. Test Methods

• 6.1 The chemical composition shall be tested in accordance with the provisions of GB/T 3045.
• 6.2 The grit size distribution of abrasives for bonded abrasives and for free grinding, polishing and cutting shall be tested in accordance with the provisions of GB/T 2481 (all parts); the grit size distribution of abrasives for coated abrasives shall be tested in accordance with the provisions of GB/T 9258 (all parts).
• 6.3 The density shall be tested in accordance with the provisions of JB/T 11433.
• 6.4 The content of ferroalloy particles and magnetic materials shall be tested in accordance with the provisions of JB/T 6570.

7 Inspection Rules

Inspection rules content...