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Measures to improve the life of tundish
Source: | Author:ChangXing Refractory | Published time: 55 days ago | 159 Views | Share:
Measures to improve the life of tundish

1. The working layer of the tundish adopts dry material

Under certain process conditions and the material and masonry form of tundish refractory materials, the life of the tundish mainly depends on the chemical erosion, high temperature melting loss and mechanical erosion of the molten steel in the tundish working layer. Tundish Dry materials are used to resist erosion and erosion. Strong ability to meet the requirements of long continuous pouring time.


2. The lining is made of magnesia refractory material

Magnesium refractory has a strong adsorption effect on inclusions in steel, and has good corrosion resistance and erosion resistance, which can meet the requirements of high continuous pouring furnaces and improve the quality of molten steel. After use, it is observed that the slag line of the tundish is the thinnest, and the other parts are 30-40mm. After one pouring is completed, it is easy to remove the tundish.


3. Use a current stabilizer

Since the steel flow directly impacts the tundish from the large ladle, the scouring of the tundish is very severe, and it may cause the tundish in severe cases. Therefore, it was decided to use a flow stabilizer. The material of the flow stabilizer is magnesium carbon. The structure of the flow stabilizer is a container-like structure with a hollow inner cavity. The inner cavity of the flow stabilizer has a large bottom and a small mouth. The continuous casting tundish flow stabilizer with this structure has an obvious and stable effect of preventing molten steel from slag entrainment in the ladle nozzle area, the tundish molten steel is of high quality, and the tundish refractory material consumption is low.


4. Improve tundish molten steel level

Originally, the minimum liquid level requirement when pouring steel in the tundish was 600mm, but now it must be larger than 700mm. After the molten steel level is raised, the stagnation time of the molten steel in the tundish is prolonged. The resistance between the two is large, and the flow velocity of the contact surface of the flow stabilizer is small, so that the impact force on the flow stabilizer is small, the continuous pouring time of the flow stabilizer is improved, and the service life of the tundish is also improved.


5. Improve slag overflow operation

It turns out that the slag overflow port is close to the pouring point, and the slag overflow is difficult. As the number of continuous pouring furnaces increases, the amount of slag cannot be discharged in time, and the slag line will seriously erode the lining and affect the quality of molten steel. To this end, the position and shape of the slag overflow port have been changed, and an assessment system has been formulated. The slag thickness cannot exceed 30mm. The slag should be discharged in time at a suitable rhythm. . At the same time, the large contractor should strengthen the operation. While controlling the remaining steel in the large package, avoid a large amount of slag being placed in the tundish, resulting in serious erosion of the slag line on the package wall.


6. Improve the service life of the tundish nozzle

Improve the production scheduling level, reduce the pinching flow caused by other reasons such as steel, stabilize the temperature of the molten steel top, and reduce the secondary pouring caused by operation problems, thereby improving the service life of the tundish nozzle and thus the tundish life.


7. Improve molten steel deoxidation process

The deoxidizer used by Xigang is mainly silicon aluminum barium. In order to improve the deoxidation effect, the addition amount of the deoxidizer is increased, and the molten steel is subjected to a comprehensive deoxidation process of inclusion modification treatment by feeding silicon calcium wire from the ladle. The process not only improves the deoxidation effect of the molten steel in the converter and reduces the inclusion of oxides in the steel, but also improves the pourability of the molten steel and eliminates the junction of the tundish nozzle due to the poor fluidity of the molten steel. At the same time, the free oxygen content in the molten steel is reduced, thereby reducing the erosion of the tundish nozzle and improving the life of the tundish.


8. Reasonable temperature regime

In order to ensure the normal pourability of molten steel, the superheat degree of molten steel in the tundish is strictly controlled at 10-25 °C. In order to improve the success rate of pouring in the first furnace, the tapping temperature of the converter is 30-40°C higher than the normal pouring temperature. The temperature of the molten steel in the tundish is controlled according to the middle and lower limits, and the pass rate is increased from 80% to 95%.


9. Ensure the baking effect

When baking the tundish, the burner in the middle of the roaster should face the center of the flow regulator to ensure the baking effect of the flow regulator. Specific requirements for baking the tundish: medium fire for not less than 30 minutes, high fire for not less than 1 hour, medium fire means that the flame hits the bottom of the bag but no firing, high fire means that the gas valve is fully open or basically full Open, the flame hits the bottom of the bag and rebounds, the air volume is properly matched, and the flame temperature reaches the highest. Once the fire starts, the dry working lining tundish shall not cease fire halfway or reduce the flame to ensure that the temperature of the tundish wall reaches 1000°C or more.


10. Improve the production organization model

Make rational use of the production organization mode, arrange the use of the tundish in a planned way, avoid waste of the tundish, and use the tundish reasonably according to the order of masonry under normal circumstances, so as to give full play to the service life of the tundish.


11. Reasonable production system

The connection of molten steel between the converter and continuous casting is a necessary condition to ensure the normal production of continuous casting. When the level of steel for continuous casting is required, the information transmission of production scheduling should be increased, and the production organization should be reasonable to ensure the stability of the molten steel level in the tundish. At the same time, ensure that the liquid level of the tundish is within the required range to ensure the life of the tundish.