In modern continuous casting (CC) systems, the ladle shroud plays a crucial role in maintaining steel cleanliness by providing a protected, inert-flow channel between the ladle and tundish. To ensure this connection is leak-tight, stable, and resistant to thermal and mechanical shocks, a ladle shroud gasket is installed between the ladle nozzle (ladle slide gate) and the upper end of the shroud. Although the gasket is a relatively small component compared to the overall refractory system, improper installation or handling can lead to serious consequences—air aspiration, reoxidation, excessive turbulence, or even molten steel leakage. Therefore, understanding how to properly use the ladle shroud gasket is essential for steel plants seeking consistent casting performance and improved steel quality.

1. Preparing the Workplace and Components

Before installation begins, several preparatory steps are required:

(1) Inspect the gasket

A high-quality ladle shroud gasket is typically made from:

• Graphite composite felt

• Ceramic fiber paper

• Flexible mica sheet

• Refractory fiber reinforced ring

Before use, ensure:

• No cracks, cuts, or missing sections

• Uniform thickness

• No delamination or moisture

• Correct ID/OD matching the ladle shroud and nozzle set

Gaskets should be kept dry. Any moisture can lead to steam pressure build-up upon contact with molten steel.

(2) Inspect the ladle shroud upper end

Confirm that:

• Contact surface is smooth

• No chipping or uneven wear

• No residual slag or metal

If defects exist, small grinding corrections or surface cleaning may be required.

(3) Inspect the ladle slide gate nozzle surface

A clean, flat mating surface ensures uniform pressure distribution and prevents leakage.

2. Correct Positioning of the Ladle Shroud Gasket

(1) Ensure proper alignment

Place the gasket centrally on the ladle shroud’s upper seating surface. A misaligned gasket may cause:

• Uneven contact pressure

• Steel leakage

• Air aspiration at one side

• Poor operational safety

(2) Avoid stretching or bending

Gaskets—especially fiber-based ones—should not be forcefully stretched. Any deformation reduces sealing performance and may cause early erosion.

(3) Maintain surface dryness and cleanliness

If the gasket absorbs moisture, dry it with a warm air gun (never flame heating). Moisture content will decrease the material’s thermal stability.

3. Installing the Ladle Shroud to the Ladle Nozzle

Step 1: Bring shroud into position using manipulator

The ladle shroud manipulator should hold the shroud firmly while maintaining precise alignment between the taper surface and the ladle nozzle.

Step 2: Compress the gasket evenly

As the shroud is pushed upward against the ladle nozzle, the gasket begins to compress. This compression is essential for:

• Sealing

• Cushioning thermal expansion

• Preventing steel and gas leakage

A typical compression ratio is 15–25%, depending on gasket type.

Step 3: Lock or clamp the shroud

After achieving proper compression:

• Tighten the clamping system (mechanical clamp or quick-lock device)

• Ensure there is no lateral movement

Improper locking may allow vibration during casting, which can break the seal.

4. Operating Considerations During Casting

During molten steel flow, the ladle shroud and gasket experience:

• Thermal shock

• Steel flow vibration

• Slide gate movements

• Mechanical impact from shroud manipulation

To ensure stable operation:

(1) Avoid excessive manipulator adjustments

Frequent repositioning increases mechanical stress on the gasket.

(2) Maintain inert gas sealing (if used)

Some plants use N₂ purging through the shroud–nozzle interface. The gasket must maintain adequate sealing to keep the inert environment effective.

(3) Monitor for leakage

Operators must observe:

• “Sweating” or tiny steel droplets at the interface

• Flames indicating air aspiration

• Abnormal vibration

Any such signs mean the seal is failing.

5. After-Casting Removal

After the heat is finished:

(1) Allow controlled cooling

Do not remove the shroud while the gasket is still glowing hot.

(2) Inspect the gasket condition

Assess:

• Compression uniformity

• Burn marks

• Steel penetration

• Cracks or erosion

These observations help determine:

• Shroud alignment quality

• Nozzle flatness

• Proper gasket material selection

(3) Clean surfaces before installing a new gasket

Remove residual gasket fiber and metal to ensure proper sealing for the next heat.

Conclusion

Using a ladle shroud gasket correctly is essential for safe, stable, and high-quality continuous casting. Although it is a simple component, its performance directly affects steel cleanliness, nozzle life, shroud stability, and operational safety. Proper inspection, correct alignment, controlled compression, and disciplined handling during casting all contribute to maximizing the gasket’s effectiveness. By following the procedures above, steel plants can significantly reduce leakage risk, avoid air aspiration, and maintain optimal casting performance.

More information please visit Henan Yangyu Refractories Co.,Ltd