Material selection in the production process of heat treatment furnace
Dec. 13, 2021
Material selection in the production process of heat treatment furnace
Most heat treatment furnaces are made of refractory and thermal insulation materials, because the heat treatment furnace is usually in a high temperature state during operation. All non-metallic materials that can withstand high temperature and the physical and chemical effects produced by high temperature are collectively referred to as refractory materials. In the design and construction of heat treatment furnace, the reasonable selection of refractory and thermal insulation materials is of great significance to meet the requirements of heat treatment process, improve the service life of heat treatment furnace and save energy and reduce consumption. Here, we first understand the commonly used refractories.
Refractory materials commonly used in heat treatment furnace include clay brick, high alumina brick, light refractory clay brick, silicon carbide refractory products, aluminum silicate refractory fiber, refractory concrete, etc.
(1) The main raw materials of clay brick are refractory clay and kaolin bonded brick. It is most widely used in heat treatment furnace and can be used to build furnace top and bottom. However, due to its weak acidity, it can corrode iron and aluminum heating elements and can not be used as brick of electric heating elements and lining of high carbon atmosphere furnace.
(2) High alumina brick and corundum products have high fire resistance, the maximum service temperature can reach 1500 ℃, high temperature structural strength and good chemical stability. They are mainly used for lining of high-temperature heat treatment furnace and salt bath furnace, bricklaying of electric heating elements, etc. Corundum products are high alumina bricks with high high temperature structural strength and fire resistance. They are commonly used in resistance wire mandrel, brick thermowell, high temperature furnace bottom brick, etc.
(3) The light refractory bonded earth brick and ultra light refractory bonded earth brick have low fire resistance at the starting point of load, that is, low high temperature strength, poor chemical stability and large volume change. It is suitable to be used as the protective layer of heat treatment lining. When the high-temperature structural strength and fire resistance meet the requirements, light refractory clay bricks shall be selected as far as possible.
