The Tundish: Continuous Casting's Steel Buffer
When one ladle empties, the next must take over — but if steel supply breaks, the strand breaks and the whole caster stops. The tundish solves this.
Two Identities
Buffer: 30~60 tons (100+ for slabs) of steel stored between ladle and mold. During ladle change it keeps feeding the mold — the foundation of sequence casting.
Purifier: steel slows and dwells, inclusions float to the slag. Internal weirs, dams and filters guide flow and improve inclusion removal.
Temperature Management
Too hot → thin shell, breakout risk; too cold → sticky steel, nozzle clogging. Ideal superheat 15~30°C, fluctuating over hours with ladle changes. Manual 20~30-minute readings lag behind high-end casting needs — hence the shift to continuous temperature measurement: real-time curves, trend prediction, data logging, one installation per cast or more.
Hidden Functions
- Level control via stopper/slide gate
- Optional calcium treatment for castability
- Argon sealing against reoxidation
- Covering flux for insulation and inclusion absorption
Summary
The tundish is a buffer, a purifier and a temperature regulator. Sequence casting continuity and slab quality depend heavily on its temperature and flow control.