The steelwork tundish coating appeared to fall off in the baking process.
Rongsheng Group technicians and engineers went to the site to investigate the phenomenon of karst in the slag wall and investigated the slag wall.
The Steel Mill Overview is Roughly as Follows
There are 2 converters, the actual steel output is about 105 tons, the daily steelmaking is about 60 furnaces, the tapping temperature is 1550-1660 °C, and the tapping time is about 4.5 min.
There are 3 refining furnaces, LF refining furnace, 1 RH furnace, and argon blowing during the LF furnace refining. The refining temperature is between 1535-1635 ℃.
There are 2 continuous casting machines, and the pouring temperature is generally between 1530 and 1620 ℃.
The investigation found that the problem occurred in the tundish of the steel mill was that it was found to fall off during the routine inspection of the continuous casting platform for baking. The falling position was 2100 mm on the side of the impact zone and 20-50 mm from the bottom to the edge of the package.
The Reasons for Our Technical Analysis are as Follows
1. The tundish is narrower. The flame of the roasting burner is closer to the wall. The free water in the baking process is vaporized during the baking process. The water vapor cannot be quickly discharged, and the accumulation causes the material to collapse.
2. The permanent layer of the tundish is more serious, and the steel shell is partially exposed, and the smear is partially applied thicker.
3. During the application process, it was found that the second and third passes, the paint had blistering, indicating that the breathability of the paint was not very good.
There are fewer construction workers on site, lack of construction experience on the spread material, poor construction quality, slow progress, insufficient drying and baking time, and poor air permeability of the spread.
Solution Given
1. For the construction of the coated material, use Ø2mm steel nails to puncture the hole, the depth is about 2/3 of the thickness of the spread (the actual depth is about 50mm), and the spacing is 200×200mm.
After the phenomenon of roasting and falling off, the steel mill also adjusted the baking time. It was originally prepared on the baking machine of the workshop. After baking for 6 hours on low heat, the plug was installed for use, and then it was placed on the continuous casting platform. Bake in small and medium fire for 6h (2h for small and medium fires). After the adjustment, prepare the workshop for small fire for 8h, and the continuous casting platform for 8h (small fire 4h, medium fire 2h, fire 2h)
Karst Wall Phenomenon
After the phenomenon of roasting and falling off, the steel mill also adjusted the baking time. It was originally prepared on the baking machine of the workshop. After baking for 6 hours on low heat, the plug was installed for use, and then it was placed on the continuous casting platform. Bake for 6 hours on fire (2h for small and medium fires). After the adjustment, prepare the workshop for small fire for 8h, and the continuous casting platform for 8h (small fire 4h, medium fire 2h, fire 2h)
The Reasons Given by Our Technology are
There is a great relationship between the penetration of the slag line and the construction of the slag line at the contact between the slag wall and the wall of the impact zone. Our on-site construction personnel are not in the place of smearing. At present, the permanent layer of the tundish is seriously off, especially at the triangle of the impact zone. A large amount of paint filling is required between the slag wall installation and the wall of the package. If the slag is not applied well, it may cause hidden danger and cause perforation.
Karst Wall Phenomenon
After the phenomenon of roasting and falling off, the steel mill also adjusted the baking time. It was originally prepared on the baking machine of the workshop. After baking for 6 hours on low heat, the plug was installed for use, and then it was placed on the continuous casting platform. Bake for 6 hours on fire (2h for small and medium fires). After the adjustment, prepare the workshop for small fire for 8h, and the continuous casting platform for 8h (small fire 4h, medium fire 2h, fire 2h)
The Reasons Given by Our Technology are
There is a great relationship between the penetration of the slag line and the construction of the slag line at the contact between the slag wall and the wall of the impact zone. Our on-site construction personnel are not in the place of smearing. At present, the permanent layer of the tundish is seriously off, especially at the triangle of the impact zone. A large amount of paint filling is required between the slag wall installation and the wall of the package. If the slag is not applied well, it may cause hidden danger and cause perforation.
