Compact Strip Production: The breakthrough for flat products

After the successful introduction of minimills in the US, technology suppliers and steel producers strove to adapt the concept for flat products. SMS was the first company to solve the technological issues.

The key was the newly developed funnel-shaped copper mold and the optimized submerged entry nozzle that made near-net-shape slab casting possible.

The slabs, just 50 mm thick, passed through a short tunnel furnace before being directly rolled down to their final dimensions in a finishing mill. As a result, the energy-intensive slab reheating and roughing processes were no longer required.

Yet finding the first customer for the revolutionary plant concept proved to be just as difficult. Nucor decided to take a chance on it and in the summer of 1989, SMS and Nucor put the first thin slab casting-rolling plant into operation. The technology was called Compact Strip Production, or CSP for short.

Every new CSP plant brought with it a further enhancement, and CSP quickly developed into a technology that enabled the production of modern, sophisticated steel grades. Before long, CSP customers were producing strip for the automotive industry, high-strength grades, and tube steels.

At the same time, CSP expanded the product range to include ultrathin (down to 0.8 mm) and thick strip (up to 25.4 mm).