ASTM C863-00(2022)

Standard Test Method for Evaluating Oxidation Resistance of Silicon Carbide Refractories at Elevated Temperatures

SIGNIFICANCE AND USE
3.1 The oxidation of silicon carbide refractories at elevated temperatures is an important consideration in the application of these refractories. The product of oxidation is amorphous silica or cristobalite, depending upon the temperature at which oxidation takes place. This oxide formation is associated with expansion and degradation of strength. The quantity of water vapor in the atmosphere greatly affects the rate of oxidation.  
3.2 The test, which creates and measures the expansion, is suitable for guidance in product development and relative comparison in application work where oxidation potential is of concern. The variability of the test is such that it is not recommended for use as a referee test.
SCOPE
1.1 This test method covers the evaluation of the oxidation resistance of silicon carbide refractories at elevated temperatures in an atmosphere of steam. The steam is used to accelerate the test. Oxidation resistance is the ability of the silicon carbide (SiC) in the refractory to resist conversion to silicon dioxide (SiO2) and its attendant crystalline growth.  
1.2 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.  
1.3 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.

General Information

• Status: Published
• Publication Date: 31-Oct-2022
• ICS: 81.080 - Refractories
• Technical Committee: C08 - Refractories
• Drafting Committee: C08.04 - Chemical Behaviors

Relations

• Refers: ASTM C830-00(2011) - Standard Test Methods for Apparent Porosity, Liquid Absorption, Apparent Specific Gravity, and Bulk Density of Refractory Shapes by Vacuum Pressure
• Effective Date: 01-Jul-2011
• Refers: ASTM C914-09 - Standard Test Method for Bulk Density and Volume of Solid Refractories by Wax Immersion
• Effective Date: 01-Mar-2009
• Refers: ASTM C830-00(2006) - Standard Test Methods for Apparent Porosity, Liquid Absorption, Apparent Specific Gravity, and Bulk Density of Refractory Shapes by Vacuum Pressure
• Effective Date: 01-Jun-2006
• Refers: ASTM C20-00(2005) - Standard Test Methods for Apparent Porosity, Water Absorption, Apparent Specific Gravity, and Bulk Density of Burned Refractory Brick and Shapes by Boiling Water
• Effective Date: 01-Dec-2005
• Refers: ASTM C914-95(2004) - Standard Test Method for Bulk Density and Volume of Solid Refractories by Wax Immersion
• Effective Date: 01-Sep-2004
• Refers: ASTM C20-00 - Standard Test Methods for Apparent Porosity, Water Absorption, Apparent Specific Gravity, and Bulk Density of Burned Refractory Brick and Shapes by Boiling Water
• Effective Date: 10-Apr-2000
• Refers: ASTM C830-00 - Standard Test Methods for Apparent Porosity, Liquid Absorption, Apparent Specific Gravity, and Bulk Density of Refractory Shapes by Vacuum Pressure
• Effective Date: 10-Apr-2000
• Refers: ASTM C914-95(1999) - Standard Test Method for Bulk Density and Volume of Solid Refractories by Wax Immersion
• Effective Date: 01-Jan-1999

Overview

ASTM C863-00(2022), titled "Standard Test Method for Evaluating Oxidation Resistance of Silicon Carbide Refractories at Elevated Temperatures," provides a methodology for assessing the oxidation resistance of silicon carbide (SiC) refractory products. The standard is developed by ASTM International and is crucial for understanding the long-term performance of SiC refractories in high-temperature environments where oxidation can cause degradation. This standard ensures international alignment by following principles established by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

Key Topics

Oxidation Resistance in Silicon Carbide Refractories

• Purpose: Evaluates the ability of SiC refractories to resist oxidation - the conversion to silicon dioxide (SiO₂), which leads to amorphous silica or cristobalite formation depending on the temperature.
• Test Conditions: The method uses elevated temperatures (typically between 800°C and 1200°C) and introduces steam to simulate oxidizing environments, accelerating oxidation processes in the material.
• Impact of Oxidation: Oxidation is associated with expansion and loss of strength in SiC refractories; the amount of water vapor in the surrounding atmosphere significantly accelerates the rate of oxidation.
• Measurement Parameters: The test mainly quantifies percent volume change due to oxidation, along with supplementary evaluation of weight, bulk density, and dimensional changes.
• Test Reliability: Suitable for product development and comparative studies, but not intended as a referee test due to test variability.

Applications

Industrial Relevance and Practical Uses
ASTM C863 is highly relevant for industries using silicon carbide refractories in harsh, oxidizing, high-temperature environments such as:

• Steel, Non-ferrous Metals, and Glass Manufacturing: Evaluating SiC bricks and monolithics in furnaces, reactors, and kilns to ensure durability and service life.
• Chemical Processing: Assessing linings for vessels and reactors where steam and oxidizing conditions are prevalent.
• Product Development: Helps producers compare oxidation resistance across refractory compositions and optimize materials for specific end-use environments.
• Quality Assurance: Enables engineers, technologists, and quality control personnel to perform standardized tests for consistency in product performance, particularly where oxidation is of critical concern.

Related Standards

Referenced Standards and International Context
ASTM C863 aligns with recognized principles for international standardization and references several related ASTM standards, including:

• ASTM C20: Test Methods for Apparent Porosity, Water Absorption, Apparent Specific Gravity, and Bulk Density of Burned Refractory Brick and Shapes.
• ASTM C830: Test Methods for Apparent Porosity, Liquid Absorption, Apparent Specific Gravity, and Bulk Density of Refractory Shapes by Vacuum Pressure.
• ASTM C914: Test Method for Bulk Density and Volume of Solid Refractories by Wax Immersion.

These related methods support preparation and measurement requirements, ensuring accurate and consistent testing practices for silicon carbide and other refractories.

Summary

ASTM C863-00(2022) serves as a foundational test method for evaluating the oxidation resistance of silicon carbide refractories at elevated temperatures. By simulating oxidizing environments using steam and high heat, the standard enables manufacturers and users to better understand material performance, drive innovation, and specify the most durable solutions for demanding industrial applications. Compliance with this standard supports product quality, reliability, and safety in critical high-temperature installations.

Keywords: ASTM C863, oxidation resistance, silicon carbide refractories, high temperature, steam atmosphere, SiC, amorphous silica, crystalline silica, refractory standard, industrial furnaces, material degradation, international standards.

Standards Content (Sample)

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: C863 − 00 (Reapproved 2022)
Standard Test Method for
Evaluating Oxidation Resistance of Silicon Carbide
Refractories at Elevated Temperatures
This standard is issued under the fixed designation C863; 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 these refractories.The product of oxidation is amorphous silica
or cristobalite, depending upon the temperature at which
1.1 This test method covers the evaluation of the oxidation
oxidation takes place. This oxide formation is associated with
resistance of silicon carbide refractories at elevated tempera-
expansion and degradation of strength. The quantity of water
tures in an atmosphere of steam. The steam is used to
vapor in the atmosphere greatly affects the rate of oxidation.
accelerate the test. Oxidation resistance is the ability of the
silicon carbide (SiC) in the refractory to resist conversion to 3.2 The test, which creates and measures the expansion, is
silicon dioxide (SiO ) and its attendant crystalline growth. suitable for guidance in product development and relative
comparison in application work where oxidation potential is of
1.2 This standard does not purport to address all of the
concern. The variability of the test is such that it is not
safety concerns, if any, associated with its use. It is the
recommended for use as a referee test.
responsibility of the user of this standard to establish appro-
priate safety, health, and environmental practices and deter-
4. Apparatus
mine the applicability of regulatory limitations prior to use.
4.1 Heated Chamber—The chamber shall be muffled (Note
1.3 This international standard was developed in accor-
1) to confine the atmosphere. The size of the chamber and the
dance with internationally recognized principles on standard-
heat source are optional. The temperature capability within the
ization established in the Decision on Principles for the
chamber shall be at least 1200 °C (2190 °F) with an allowable
Development of International Standards, Guides and Recom-
deviation of 615 °C (27 °F) measured across the hearth.
mendations issued by the World Trade Organization Technical
Barriers to Trade (TBT) Committee. NOTE 1—Silicon carbide refractory material is recommended for use as
the muffle but other suitable refractory materials may be used.
2. Referenced Documents
4.2 Instrument—Control and record the temperature of the
2.1 ASTM Standards: chamber by a suitable instrument capable of maintaining the
C20 Test Methods for Apparent Porosity, Water Absorption, requirements in 4.1. Recommended thermocouple location is
Apparent Specific Gravity, and Bulk Density of Burned within 1 in. (25 mm) of the top of the specimens and over the
Refractory Brick and Shapes by Boiling Water center of the same assemblage.
C830 Test Methods for Apparent Porosity, Liquid
5. Test Specimen
Absorption, Apparent Specific Gravity, and Bulk Density
5.1 Specimen Size—Obtain a quarter-brick size from a
of Refractory Shapes by Vacuum Pressure
229-mm (9-in.) straight by cutting the brick along planes
C914 Test Method for Bulk Density and Volume of Solid
parallel to both the 229-mm by 64-mm (9-in. by 2 ⁄2-in.) and
Refractories by Wax Immersion
1 1
the 114-mm by 64-mm (4 ⁄2-in. by 2 ⁄2-in.) faces. Alternative
3. Significance and Use
specimens may be tile, 165 mm by 114 mm by 22 mm
1 1 7
(6 ⁄2 in. by 4 ⁄2 in. by ⁄8 in.), or other convenient shapes.
3.1 The oxidation of silicon carbide refractories at elevated
temperaturesisanimportantconsiderationintheapplicationof
5.2 Three specimens are required for each set of conditions.
6. Conditions
This test method is under the jurisdiction of ASTM Committee C08 on
Refractories and is the direct responsibility of Subcommittee C08.04 on Chemical 6.1 Atmosphere—Steam is passed into the chamber (4.1)at
3 3
Behaviors.
the rate of 32 kg/m (2 lb/ft ) of chamber volume per hour.
Current edition approved Nov. 1, 2022. Published November 2022. Originally
Provisionsshouldbemadetouniformlydistributesteamwithin
approved in 1977. Last previous edition approved in 2016 as C863 – 00 (2016).
the chamber.
DOI: 10.1520/C0863-00R22.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
6.2 The standard test temperatures are as follows wi
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