Fire resistance and evaluation of refractory for casting
The products to be tested are broken and ground, adding organic binders (usually dextrin) that do not affect the refractoriness. Water is used to make standard sized test cones, as shown in figure 1-2-1. Test cone is positive, three edge cone, the bottom side length of 8.5mm, the top side length is 2mm.Test, the equivalent of high standard cone refractoriness of the 2 products to be high, No. 1 and No. 1 high temperature low standard cone of each one, and the 2 to be tested in accordance with regulations frustum cone plug made of high aluminum material, a cone prism and vertical 8 degrees. 1 degrees tilt angle. Then, the cone is heated in a high temperature furnace. When the test cone with a high temperature and bending down to the standard cone top contact cone, the high standard cone refractoriness refractoriness is running.
Because of their different shapes and conditions, various refractories are used to explain their fire resistance with different indexes, and the test methods are also different. In general, the refractoriness of unshaped refractories; the softening temperature of formed refractory products; the change of the reheating line of heat insulation materials at high temperature.
The refractory degree of refractory material at high temperature is called refractoriness. Refractory products all contain substances from fusible sintering action, the melt crystal as unlike at a fixed temperature, but the temperature in a wide range. At a lower temperature, a small amount of melt is formed, and as the temperature increases, the amount of the melt increases, and the product gradually softens. Refractoriness and melting point (crystal) are different concepts.
