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.

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.

1. 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 and health practices and determine the applicability of regulatory limitations prior to use.

2. Referenced Documents (purchase separately) The documents listed below are referenced within the subject standard but are not provided as part of the standard.

ASTM Standards

C20 Test Methods for Apparent Porosity, Water Absorption, Apparent Specific Gravity, and Bulk Density of Burned Refractory Brick and Shapes by Boiling Water

C830 Test Methods for Apparent Porosity, Liquid Absorption, Apparent Specific Gravity, and Bulk Density of Refractory Shapes by Vacuum Pressure

C914 Test Method for Bulk Density and Volume of Solid Refractories by Wax Immersion

Keywords

oxidation; refractories; silicon carbide; Elevated temperature tests; Oxidative resistance; Refractories (silicon carbide); Silicon carbide;

ICS Code

ICS Number Code 81.080 (Refractories)

Citing ASTM Standards

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