Test method for refractoriness of refractories

Refractoriness refers to the property of refractory materials to resist high temperature, not melt and soften under no-load conditions. The chemical composition, mineral composition, distribution of each phase, and combination of refractory materials have a decisive influence on their refractoriness.

一. National standard test method for refractoriness of refractory materials

The test material is made into a screenshot triangle cone, each side of the upper bottom is 2mm long, each side of the lower bottom is 8mm long, and the height is 30mm. The cross-section is an equilateral triangle; the bending of the test material test cone and the standard temperature measuring cone The triangular pyramid deforms and bends under the action of high temperature. When the node of the triangular pyramid bends and touches the bottom plate, the temperature at this time is called the refractoriness of the material.

二. Common test methods for refractoriness

1. Thermal stability test: Place the refractory material to be tested in a high-temperature environment, and gradually heat up until the refractory material undergoes structural changes or performance declines. Determine the maximum temperature a refractory material can withstand by observing a sample for appearance changes, dimensional changes, or performance measurements.

2. Thermal expansion rate test: measure the linear thermal expansion rate of refractory materials at high temperature. Using equipment such as a thermal dilatometer or microscope, heat the sample within a certain temperature range and measure its length change to determine the deformation of the refractory material under high temperature conditions.

3. Softening start temperature test: measure the temperature at which the refractory material starts to soften at high temperature. Commonly used methods include thermal microscopy, thermomechanical analysis, etc., to determine the softening start temperature by observing the changes in the morphology and mechanical properties of the sample.

4. Refractoriness test: The refractoriness of the refractory material is determined by heating the sample to a certain temperature and observing its behavior. Commonly used methods include ablation test, high temperature load test, etc.

5. Thermal shock stability test: simulate the performance of refractory materials in the process of rapid cooling at high temperature, and evaluate their thermal shock resistance. Commonly used methods include rapid cooling test, thermal shock test, etc.

6. Thermal conductivity measurement: measure the thermal conductivity of refractory materials at high temperatures to understand their thermal conductivity. It can be measured with a thermal conductivity instrument.

These test methods can evaluate the performance and stability of refractory materials under high temperature conditions. Which test method to use depends on the type of refractory material, application scenario and needs. When conducting a refractoriness test, it is recommended to refer to relevant standards and specifications, and conduct the test operation by a professional laboratory or qualification institution to ensure the accuracy and reliability of the results.