What are the characteristics of the lining material? The following sharing content, everyone take a look!

1, the lining material should have sufficient refractoriness

The refractoriness of the lining material refers to the Celsius temperature at which the conical sample of the lining material can resist the action of high temperature without softening and melting down under the condition of no load. Simply put, refractoriness refers to the performance of the lining material to resist the action of high temperature without melting when there is no load. Refractoriness is the basis to determine whether the material can be used as a furnace lining material. The basic factor that determines the refractoriness of the lining material is the chemical mineral composition and its distribution. Various impurity components, especially those with strong flux, will seriously reduce the refractoriness of the product. Therefore, the main way to improve the refractories of lining materials is to take appropriate measures and improve the purity of raw materials.

2, the lining material should have good chemical stability

Slag erosion is a common damage form of lining materials in the process of use, such as the lining of the medium frequency furnace, the working lining of the ladle, the lower part of the cupola furnace body and the lining of the furnace cylinder, which is mostly caused by this kind of action. In actual use, about 59% of the damage is caused by slag erosion. When choosing the lining material, the lining material with similar chemical composition to the slag should be selected as far as possible to weaken the reaction strength on the interface. For example, when smelting high manganese steel, basic refractory materials should be selected as lining materials; Or try to change the composition of the slag, so that it is close to the composition of the lining material used, is also one of the ways to improve the slag resistance of the lining material.

3, the furnace lining material has good shock resistance

In the process of use, the lining material is often subjected to the rapid change of the ambient temperature. For example, if the furnace temperature changes during the feeding and steel operation in the medium frequency furnace melting, the rapid change of temperature and pressure in the pouring process of the ladle leads to cracks, peeling or even collapse of the lining and the ladle. This kind of damage reduces the heating and cooling speed of the furnace lining, lining and furnace, and limits the strengthening of the furnace operation, which is one of the main reasons for the rapid damage of the furnace lining and lining.

4, the lining material should have a certain high temperature strength

The high temperature compressive strength of the lining material refers to the pressure that the material can withstand per unit area under the high temperature hot state of higher than 1000°C, expressed in N/ram. The compressive strength of the lining material generally changes obviously with the increase of temperature. When the temperature starts from room temperature, it decreases linearly with the increase of temperature. Since then, some materials continue to decline with the increase of temperature; When the temperature rises to a certain range, it rises with the temperature, and reaches a peak value at a specific temperature, and then drops sharply. In the melting process of intermediate frequency furnace, the lining wall should be subjected to the impact force of metal charge, the static pressure of liquid metal, the force of electromagnetic stirring liquid metal movement, and the stress of temperature difference. Because of this, the selection of lining materials should have a certain high temperature strength, under the action of a variety of forces, no cracking, erosion resistance. The high temperature strength of the lining material is directly related to the hardness of the particles that make up the lining material. The adhesion strength between the particles and the porosity of the substrate also affect its wear resistance.

5, the thermal conductivity of the lining material should be small, and the conductivity should be low

When there is a temperature gradient in the lining material, the particle at a higher temperature has stronger thermal vibration and larger amplitude. Because of its interaction with the weak vibration particle at a lower temperature, it drives the neighboring particle with weak vibration, intensifies its vibration and increases the thermal motion energy. In this way, the heat can be transferred and transmitted, so that the overall heat is transmitted from the high temperature to the low temperature, resulting in the phenomenon of heat conduction. In the melting process of intermediate frequency furnace, the temperature difference between the inside and outside of the furnace wall is very large, about 10% to 15% of the heat is lost through the furnace wall, in order to reduce heat loss and improve thermal efficiency, the lining material should have low thermal conductivity. Conductivity is the reciprocal of resistivity. The larger the conductivity, the stronger the conductivity, and the smaller the vice versa. Therefore, the lining material should have a low conductivity, can not contain magnetic induction, especially the lining knotting process is not allowed to have metal or strong conductivity inclusions.

6, the lining material should meet the requirements of environmental protection

The use of the lining material does not release toxic, harmful and environmental pollution to the human body, and the waste after use can not cause harm to the environment.

7, the lining material should have a high cost performance

According to the material and requirements of the smelting, the selection of cost-effective materials. The effect of knotting process on the service life of furnace lining the thickness of the material layer is determined reasonably according to the size of the furnace capacity. The static pressure on the lining produced by the metal liquid in the furnace with different capacity is also different. When designing the lining, it is necessary to consider not only the static pressure force of liquid metal on the lining, but also the influence of electromagnetic stirring force on the lining.

The above content is for reference only. For more material information, please call Hubei Anaijie Lining Material Co., LTD.