What are the functions of ladle breathable bricks

The ladle breathable brick is the key functional element in the secondary refining process, and its main effects are as follows:

(1) The uniform distribution of molten steel temperature in the ladle can be adjusted to achieve the casting temperature of the existing process.

(2) The alloy and deoxidizer in the ladle can be evenly distributed by blowing and stirring.

(3) The non-metallic impurities in molten steel can be brought into the slag to meet the cleanliness requirements of the molten steel.

In order to realize the above functions, it is necessary to blow the inert gas used in the essence into the ladle through the breathable brick, and on the contact surface of the breathable brick and the molten steel, that is, the working surface of the breathable brick, under sufficient pressure, a large number of bubbles are blown out to form a gas jet. It stirs the molten steel in the whole ladle, promotes the flow of molten steel, homogenizes the temperature and composition in the ladle, and at the same time, the continuously ejected bubbles bring the non-metallic impurities in the molten steel into the slag under the interface effect, and reach the clean molten steel. the goal of.

The functions that the breathable brick should have:

In order to satisfy the above-mentioned metallurgical functions, the breathable brick must have the following main functions:

(1) Good air permeability

Air permeability is one of the important parameters to measure the quality of breathable bricks. Studies have shown that the mixing energy of molten steel is proportional to the flow rate of the blown gas; the mixing can directly affect the mixing rate of the molten steel, and only enough mixing energy can make the molten steel get good mixing results. .When the amount of argon blowing is kept on time, the more argon bubbles are blown out, the better it is for the degassing and stirring of molten steel.

(2) High temperature corrosion resistance

The refining ladle is strict in terms of temperature and time. The temperature often reaches more than 1750 degrees Celsius, and the refining time sometimes reaches tens of minutes. During the refining operation, the alkalinity of the slag has a great influence on the life of the breathable brick. Therefore, the breathable brick will It is corroded by alkaline slag with strong permeability at high temperature, and the damage speed is fast.

(3) High temperature wear resistance

When argon is blown at the bottom of the pure ladle, due to the bottom blowing of argon, the molten steel flows very fast in the ladle, and the erosion and wear of the molten steel on the furnace lining material and the bottom breathable bricks and seat bricks is significantly increased. When the ladle is hot repaired, in order to clean Residual steel and residue on the surface of the breathable brick, to restore the breathable function of the breathable brick, it is necessary to clean the surface of the breathable brick with oxygen blowing to melt the steel slag adhered to the surface of the breathable brick; at the same time, blow gas into the breathable brick to blow away the slag. During the cleaning process, the air-permeable bricks are scoured by the high-speed airflow, so the air-permeable bricks are required to have good high temperature wear resistance.