What are the requirements for the refractory of the induction furnace lining
Sufficient refractoriness. Materials with a refractoriness higher than 1580 degrees Celsius are called refractories. The working temperature of the induction furnace lining is generally lower than the temperature of the molten metal. However, based on the requirements for the life of the furnace lining, the occasional or frequent overtemperature of the molten pool and the ditch must also be considered. It is not safe to use materials with low refractoriness and low softening temperature in cast iron induction furnaces.
Good thermal stability induction. The electric furnace transfers energy by electromagnetic induction exchange. In order to protect the electric furnace with high electrical efficiency, the thickness of the lining of the induction coil is limited. This allows the lining to work with a large radial temperature gradient. In addition, due to the effects of feeding, tapping, and even furnace shutdown during furnace operation, the temperature of the furnace lining is constantly changing, and the furnace lining often generates cracks due to uneven heating, which reduces the service life of the furnace lining. Therefore, as a refractory for induction furnaces, it should have excellent thermal stability.
Good chemical stability. The chemical stability of the material is closely related to the life of the lining. The lining material must not be hydrolyzed and differentiated at low temperatures, and should not be easily decomposed and reduced at high temperatures, and it should not be easy to form low-melting substances with the slag during the smelting process, and it is not easy to chemically react with metal solutions and additives, and will not pollute the metal solution.
The coefficient of thermal expansion is small. With the change of temperature, the volume should be relatively stable, without sharp expansion and contraction.
It has high mechanical properties and can withstand the impact of the furnace charge at low temperature; when the metal is in the high temperature melting state, it should be able to withstand the static pressure of the liquid metal and strong electromagnetic stirring; in the long-term liquid metal Wear and erosion resistance under scour
Good insulation performance. The furnace lining must not conduct electricity under high temperature, otherwise it will cause leakage and short circuit, resulting in serious accidents.
The construction performance of the material is good, the repairability and the sintering performance are better, the furnace construction and maintenance are convenient