ASC Brick (Al₂O₃-SiC-C) for Torpedo Cars & Hot Metal Ladles

ASC brick — Al₂O₃-SiC-C — is the standard working lining material for torpedo cars and hot metal ladles, and it is a good illustration of why single-mechanism materials fail in multi-mechanism service.

Three Attacks at Once

A torpedo car lining is attacked by slag erosion, by thermal cycling on every trip, and by the chemicals used in hot metal treatment. A high-alumina brick handles the first of these and little else; it is stiff, so cycling cracks it, and it has no defence against reagent attack. ASC addresses all three by combining phases:

• Alumina — slag resistance and refractoriness.
• Silicon carbide — erosion resistance, thermal conductivity, and resistance to reagent attack.
• Carbon — non-wetting behaviour against slag and iron, plus the compliance to absorb thermal cycling.

None of these is optional in torpedo service, which is why ASC has largely displaced plain alumina in this application.

Porosity Decides Penetration

XZK-ASC-A is held to 8.5% apparent porosity — low for a carbon-containing brick. That matters because penetration, not surface wear, is what usually ends a torpedo campaign: slag and iron work in through the pore network, the hot face loses cohesion, and material comes away in chunks. Lower porosity means a slower penetration front and a longer campaign.

Grade Selection

• XZK-ASC-A — 53% Al₂O₃, 11.5% SiC, 11.5% C, porosity 8.5%, density 2.75 g/cm³. Maximum slag and penetration resistance. Metal zone and slag line where chemical attack dominates.
• XZK-ASC-B — 62% Al₂O₃, 14% SiC, 5% C, porosity 11%, density 2.90 g/cm³, CCS 50 MPa. Where erosion and mechanical duty dominate over chemical attack.
• XZK-ASC-Mortar — 56% Al₂O₃, 19% SiC, adhesion MOR ≥1.5 MPa, for jointing the working lining.

Don’t Forget the Throat and Mouth

The barrel gets the attention, but throat and mouth failures cause a disproportionate share of downtime because those areas take mechanical damage from cleaning and skull removal. They need dedicated wear-resistant shapes and a mouth castable rather than standard barrel brick. We supply the complete package — barrel, slag line, impact pad, throat and mouth, with mortar and castables — as one matched set with a material schedule and installation drawing.

Quality and Supply

Minimum order 10 metric tons for standard shapes (7–14 days) and 20 metric tons for car-shaped and throat shapes (20–35 days). Density, porosity, crushing strength and chemistry are tested per batch, along with adhesion strength for the mortar, and a Certificate of Analysis ships with every lot.

Where This Grade Sits in the Lining System

Silicon carbide and carbon grades are selected for what they do with heat rather than for what they resist. Thermal conductivity decides whether the cooling system ever sees the load, and the bonding system decides how long the material survives alkali attack and oxidation once it does.

XZK supplies asc brick (al₂o₃-sic-c) as one zone of a zoned package rather than as a standalone item: the grades normally zoned alongside it — among them casthouse asc castable — are documented on the silicon carbide and carbon refractories page, and the vessel-level architecture — where each zone starts and ends, and which mechanism actually limits the campaign — is set out on the casthouse and torpedo car page.

Campaign data measured on this class of lining — including the wear profile that drove grade selection — is published in the Severstal 600 t torpedo car fleet programme project reference.