Measures to increase the life of tundish

 

1. The working layer of tundish adopts dry material

Under the condition that the technological conditions and the material and masonry form of tundish refractory are fixed, the life of tundish mainly depends on the chemical erosion, high temperature melting loss and mechanical erosion of the molten steel in the working layer of tundish. The tundish dry material has strong erosion resistance and erosion resistance, which can meet the requirements of long continuous pouring time.

2. The lining is made of magnesia refractory

Magnesium refractory adsorb the inclusion in steel is very strong, and good erosion resistance, erosion resistance, can meet the requirements of high number of continuous casting furnace, but also improve the quality of molten steel. After use, it is observed that the lining slag line of the middle bag is the thinnest, and other parts are 30 ~ 40mm. After a pouring time is completed, it is easy to disassemble the middle bag.

3. Use a current stabilizer

Because the steel flow directly impacts the tundish from the large tundish, the erosion of tundish is very serious, which is likely to cause the penetration of tundish. For this reason, it is decided to use the current stabilizer. The material of the current stabilizer is magnesium carbon, and the structure of the current stabilizer is a container structure with hollow cavity. The bottom of the inner cavity of the current stabilizer is large, and the mouth is small. The continuous casting tundish current stabilizer with this structure can prevent liquid steel from slagging obviously and stably, the tundish steel water quality is high, and the tundish refractory material consumption is low.

4. Raise the water level of the intermediate steel envelope

The original minimum liquid level requirement for tundish pouring was 600mm, but now it must be greater than 700mm. After the liquid level of molten steel is raised, the stagnation time of molten steel in tundish is prolonged. In a deep molten pool, the resistance between molten steel from ladle to flow stabilizer is large, and the flow velocity of the contact surface of flow stabilizer is small, thus the impact on the flow stabilizer is small, and the continuous pouring time of flow stabilizer is improved. The tundish life is also improved.

5. Improve slag overflow operation

The original slag overflow mouth close to the pouring point, slag overflow is difficult. With the increase of the number of continuous casting furnace, slag quantity is large and can not be discharged in time, slag line erosion on the lining is serious, and affect the quality of molten steel. For this reason, the position and shape of the slag overflow mouth is changed, and the assessment system is formulated. The slag thickness should not exceed 30mm, and the slag thickness should be controlled below 30mm in time when the rhythm is appropriate, so as to prevent serious erosion of the slag line of the wall and the occurrence of the wall through the steel. At the same time, the large contractor should strengthen the operation, and avoid a large amount of slag into the tunbale, which will cause serious erosion of the slag line of the bale wall.

6. Improve the service life of tundish water outlet

Improve the level of production scheduling, reduce the choke flow caused by equal steel and other reasons, stabilize the temperature of molten steel stage, reduce the secondary pouring caused by operation problems, so as to improve the service life of tundish water outlet, and then improve the life of tundish.

7. Improve the deoxidation process of molten steel

In order to improve the deoxidation effect, the amount of deoxidizer is increased, and the ladle is fed with silicon calcium wire for inclusion denaturation of molten steel. The process not only improves the deoxidation effect of the converter steel, reduces the oxide inclusion in the steel, but also improves the pouring ability of the steel and eliminates the flow of the tundish nozzle caused by the poor fluidity of the steel. At the same time, the free oxygen content in the molten steel is reduced, which reduces the erosion to the water mouth of the tundish and prolonging the life of the tundish.

8. Reasonable temperature regime

In order to ensure the normal pouring ability of molten steel, the water superheat of intermediate clad steel is strictly controlled within 10 ~ 25℃. In order to improve the success rate of the first furnace, the steel output temperature of the converter is 30 ~ 40℃ higher than the normal pouring temperature. According to the lower limit control the water temperature of the intermediate steel envelope, the qualified rate increased from 80% to 95%.

9. Make sure you bake

When baking tundish, the burner in the middle of the oven should be directly facing the center of the current stabilizer to ensure the baking effect of the current stabilizer. Specific requirements for baking tundish: medium fire baking shall be no less than 30min, and large fire baking shall be no less than 1h. Medium fire baking means that the flame reaches the bottom of the bag but does not launch, and large fire baking means that the gas valve is fully or basically open, the flame reaches the bottom of the bag and rebounds, the air volume is suitable, and the flame temperature reaches the highest. Once the fire starts, the dry lining tundish shall not cease fire or reduce the flame in the middle to ensure that the temperature of the middle bag wall reaches more than 1000℃.

10. Improve the production organization model

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

11. Reasonable production system

The connection of molten steel between converter and continuous casting is a necessary condition to ensure the normal production of continuous casting. The molten steel for continuous casting is required to be on time, the information transmission of production scheduling is increased, and the production organization is reasonable to ensure the stability of the water level of tundish steel, and at the same time, the liquid level of tundish is guaranteed within the required range, so as to ensure the service life of tundish.long water mouth) in order to avoid the oxidation of molten steel.

Article Source: Measures to increase the life of tundish
Company name: Henan Changxing Refractory Materials Co.,Ltd
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