Main performance index of the refractory materials
Main performance index of the refractory materials include:
1: Refractory performance as refractoriness to withstand high temperature without melting called refractoriness. Refractory Material has no definite melting point, so that refractoriness is actually refers to the refractory material softening temperature to a certain extent. Refractoriness is one of the important indicators, refractory material selection,refractory refractoriness, should be higher than the highest temperature.
2 Thermal stability: Refractory materials under rapid temperature change but not crack, not damage’s ability and the ability to resist rupture or broken in use, called thermal stability.
3 Slag resistance: Refractory’s furnace slag erosion resistance at high temperature is called the slag resistance.
4 Volume stability: Refractory materials at high temperature for a long time, said the ability of resistance to volume change when heated. For volume stability, also called heavy burn contraction or expansion
5 Refractoriness under load: Refractory materials at high temperature, 2 kg per square centimeter under static load, a certain amount of deformation caused by temperature, known as refractoriness softening temperature. In the actual load in production, materials is less than 2 kg/cm2, at the same time it is a single side of the heat, the cooler side to bear most of the load, so the maximum use temperature of refractory is often higher than its load softening temperature.
6 Volume density: Ratio of the quality of the refractory material after drying under 110 degree to volume is referred to as the bulk density, the unit is g/cm3.
7 True density: Ratio of the quality of the refractory material after drying under 110 c to the real volume,called true density, the unit is g/cm3.
8 Porosity:
Porosity include:
Apparent porosity, ratio of the opening pore volume of the refractory materials which with atmosphere are interlinked to the total volume.
True porosity: Ratio of total pore volume of refractory material (including open and closed pore volume) to the total volume.
9 Room temperature compressive strength: Refractory materials at room temperature bear load ability per square centimetre. The unit is Kgf/cm2 (0.1Mpa).
Addition to the above performance indexes, refractory materials also have some important indexes such as thermal conductivity, electrical conductivity, plasticity, permeability and water absorption. Refractory material shapes and sizes, also has a great influence in the practical application, it directly affect the masonry brick seam. Refractory materials’appearance inspection items include: size tolerance, missing angle, lack of edge, distortion, crack and molten slag corrosion hole, etc. The size of the general product tolerance shall not exceed + / – 3%.