Inspection of cross-section of refractory products
Refractory products are those materials which have higher temperature resistance, higher strength and higher hot temperature resistance than ordinary materials. Refractory products such as firebricks, refractory castables, refractory shapes, etc. are used in furnaces and heaters, boilers and thermal equipment of all kinds. The quality of these refractory products has an important influence on the service life and performance of these equipments. Therefore, when procuring and using refractory products, cross-section inspection should be done for testing structure, performance, size and thickness.
In the cross-section inspection of refractory products, the physical properties and parameters of the sample should be observed first, and then the cross-section of the sample should be cut with cutting tools. After cutting, the sample is placed on a clean horizontal surface, and the pictures of the cross-section should be taken with micrograph of microscope. The morphology of the sample and the distribution of inclusions are observed. In addition, if there are cracks, slag balls, bubbles, honeycomb holes, etc. in the cross-section of the sample, they should also be noted and recorded.
After taking the photographs of the sample, the size, shape, relative position and other parameters of the sample can be measured with a ruler or a plotting instrument. Generally, the cross-sectional particle size requirements of the sample should not be greater than 0.3mm, and the thickness of the sample should meet the requirements of the design drawings. In addition, the linearity of the sample should also be measured, and the distance of each point in the sample should not be greater than 0.15mm.
The cross-section of refractory products is also tested for porosity to detect the number, size and distribution of pores in the sample. Generally, it is not suitable to use a microscope method to test the porosity of refractory materials, since the pore distribution of most materials is extremely uneven and chaotic. Therefore, a more suitable method is the porosity absorption test. In the absorption test, the sample is immersed in the liquid and then easy to dry, and the weight variation before and after absorption is measured to calculate the porosity.
Finally, the cross-section of refractory products should also be tested for strength. Generally, the compressive strength of refractory materials should not be lower than the design strength. Therefore, pressurization test should be done for refractory materials to calculate the compressive strength. Generally, the force of pressurization is not great, so it is not easy to deformation or damage the samples.
In conclusion, the cross-section inspection of refractory materials is an important procedure before the procurement and use of refractory products. This method can detect the structure, performance, size and thickness of the materials, and judge the quality of the products. Therefore, the interior of the material should be observed in its cross-section if the structure and performance of the material must be known.
