Commonly used refractory materials
Common refractory materials for heat treatment furnace are: light refractory brick, alumina silicate refractory fiber, etc.
1. Lightweight firebrick and ultra-lightweight brick
Light refractory brick is clay brick commonly, also have tall alumina brick. Its composition is the same as general clay brick and high alumina brick, but due to different manufacturing methods, its porosity is very high, the volume density is very small, light clay brick is 0.4g/cm, ultra light clay brick can be less than 0.3g/cm, so good insulation, small heat capacity. However, the high temperature strength is low and the high temperature chemical stability is poor. Suitable for furnace wall and roof. Light clay brick should be selected as far as possible under the condition of high temperature structure strength and fire resistance meeting the requirements.
2. Silicon carbide refractory products
The main chemical composition of silicon carbide refractory is SiC. Its high degree of fire resistance, high temperature structure strength, wear resistance, rapid heat resistance, good thermal conductivity and electrical conductivity, according to the different manufacturing process, can be used as high temperature furnace heating elements, muffle furnace muffle pot, high temperature furnace bottom plate.
3. Fire-resistant fiber
Fireproof fiber is a new kind of fireproof material, which has both the function of fireproof and heat preservation. According to the different raw materials are aluminum silicate, quartz, alumina and graphite refractory fiber. Its volume density is small, heat resistance is high, thermal conductivity is small, specific heat capacity is small, fast cold fast heat resistance is good, can make fiber felt, fiber board, fiber brick, fiber rope. Fiber felt can be fixed on the furnace wall by mechanical fixation or adhesive paste, can also be made into precast block or precast board or sandwiched in two layers of refractory materials. Aluminium silicate fibre for heat treatment furnaces and graphite fibre for vacuum, hot press and atmosphere furnaces. The disadvantage of refractory fiber is limited by the manufacturing process and equipment, some atmosphere has corrosion effect on the refractory fiber, affecting its range of use.