LADLE SHROUDS FOR CONTINUOUS CASTING

A ladle shroud is a long ceramic tube that connects the ladle slide-gate to the tundish, protecting the falling steel stream from atmospheric oxygen. Without a shroud, oxygen pickup creates non-metallic inclusions that damage downstream casting quality. Modern continuous casting cannot run safely without shrouds.

The body is typically alumina-graphite (Al₂O₃-C), with 25–35% graphite for thermal shock resistance and slag non-wetting. The slag line is reinforced with zirconia-graphite (ZrO₂-C) for higher slag corrosion resistance. The bore is sometimes lined with a denser, lower-carbon insert to resist erosion from steel flow.

A standard Al₂O₃-C shroud handles 4–8 heats in carbon steel sequence casting. ZrO₂-C reinforced slag-line shrouds extend life to 8–14 heats. Life is limited by slag-line corrosion, thermal cycling fatigue, and erosion at the bore inlet. Argon-purging slots at the shroud-to-gate interface reduce reoxidation but introduce a wear point.

An open shroud discharges into the open tundish bath surface. A submerged shroud (sometimes called a long stopper tube) extends below the tundish slag line, eliminating splashing and reoxidation. Submerged shrouds give better steel cleanness but require shroud manipulators and slag-control practice. Most premium long-product mills use submerged.

No, shrouds are single-campaign items. After a heat sequence, the shroud is discarded and a new one is fitted. Attempting to reuse a shroud risks cold-start cracking, slag spalling, and contaminated steel. The shroud-and-tundish-nozzle pair are matched assemblies designed for one continuous operating window.

We supply alumina-graphite ladle shrouds with bore diameters 60–110 mm and lengths 800–1800 mm to match standard caster geometries. Both straight and bell-mouth designs available. TRL Krosaki is our primary supply partner. Custom dimensions are made to drawing on 4–6 weeks lead time.