GB/T 21944.3-2022Special products of silicon carbide—Kiln furniture of reaction bonded silicon carbide—Part 3: Rollers (English PDF)

Foreword

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

This document is part 3 of GB/T 21944 "Reaction Sintered Silicon Carbide Kiln Furniture for Special Silicon Carbide Products". GB/T 21944 has the following sections were published.

--- Part 1: Square beams;

--- Part 2: Special-shaped beams;

--- Part 3: Roller bars;

--- Part 4: Burner cover.

This document replaces GB/T 21944.3-2008 "Reaction Sintered Silicon Carbide Kiln Furniture for Special Silicon Carbide Products - Part 3: Roller Bar", and compared with GB/T 21944.3-2008, in addition to structural adjustment and editorial changes, the main technical changes are as follows:

a) Modified normative references (see Chapter 2, Chapter 2 of the 2008 edition);

b) Changed the product code, shape diagram and dimensions (see 4.1, 3.1 of the 2008 edition);

c) Changed the product mark (see 4.2, 3.2 of the 2008 edition);

d) The requirements for chemical composition have been changed (see 5.1, 4.1 of the 2008 edition);

e) Added requirements for cracks (see 5.3.2);

f) Changed the requirements for some dimensional deviations (see 5.4, 4.3 of the 2008 edition);

g) Changed the requirements for safe load (see 5.6, 4.6 of the 2008 edition);

h) Changed the detection method of chemical composition (see 6.1, 5.1 of the 2008 edition);

i) Changed the detection method of bulk density and apparent porosity in physical properties (see 6.2.1, 5.2.1 of the 2008 edition);

j) Changed the detection method of surface pits (see 6.3.1, 5.5 of the 2008 edition);

k) Added a straightness detection method (see 6.5);

l) The detection method of the safe load has been changed (see Appendix A, Appendix A of the 2008 edition).

Introduction

Reaction sintered silicon carbide kiln furniture is currently mainly divided into four categories: square beam, special-shaped beam, roller bar and burner sleeve due to different uses and application fields.

There are big differences in the classification, performance and technical requirements of these four types of products. In order to scientifically and rationally analyze the technology of reaction sintered silicon carbide kiln furniture the technical content is standardized and coordinated. GB/T 21944 "Silicon Carbide Special Products Reaction Sintered Silicon Carbide Kiln Furniture" is planned to consist of four parts. constitute.

--- Part 1: Square beams. The purpose is to establish the technical specifications for reaction sintered silicon carbide kiln furniture such as square beams.

--- Part 2: Special-shaped beams. The purpose is to establish the technical specification for reaction sintered silicon carbide kiln furniture such as special-shaped beams.

--- Part 3: Roller bar. The purpose is to establish the technical specification for reaction sintered silicon carbide kiln furniture such as rollers.

--- Part 4: Burner cover. The purpose is to establish the technical specification for the reaction sintered silicon carbide kiln furniture such as burner sleeves.

1 Scope

This document specifies the product classification, technical requirements, test methods, inspection rules, packaging, marking, transportation and store.

This document applies to reaction sintered silicon carbide rolls with a temperature not higher than 1350°C.

2 Normative references

The contents of the following documents constitute essential provisions of this document through normative references in the text. Among them, dated citations documents, only the version corresponding to that date applies to this document; for undated references, the latest edition (including all amendments) applies to this document.

GB/T 6569 Test method for bending strength of fine ceramics

GB/T 10325 Sampling inspection rules for acceptance of shaped refractory products

GB/T 14390 Test method for high temperature bending strength of fine ceramics

GB/T 16546 General provisions for packaging, marking, transportation, storage and quality certificates of shaped refractory materials

GB/T 16555 Chemical Analysis Method of Carbon, Silicon Carbide and Nitride Refractories

GB/T 25995 Test method for density and apparent porosity of fine ceramics

3 Terms and Definitions

There are no terms and definitions that need to be defined in this document.

4 Product categories