The Castrip Process - Direct Casting of Steel Sheet at Nucor Crawfordsville

摘要

Nucor Steel is in the process of constructing a second plant based on Castrip technology. The development of this breakthrough technology is discussed, along with an update on recent casting results and trends at Nucor's Crawfordsville, Ind., plant. With the announcement in January 2005 that Nucor will build a second commercial plant based on Castrip technology, Sir Henry Bessemer's dream of direct casting of metal sheet became a commercial reality for carbon sheet steel production. Nucor's initial plant, commissioned in Crawfordsville, Ind., in May 2002, has a design capacity of 500,000 tons annually. Over the past two-and-a-half years, the Crawfordsville facility has produced nearly 200,000 tons of UCS (ultrathin casting rolls to form two individual shells that are formed into a continuous sheet at the roll nip. A simple schematic in Figure 1 indicates liquid metal, rolls and the solid sheet. Although the concept of casting a continuous sheet in this manner was developed some 150 years ago by Sir Henry Bessemer, it is only in the past decade or so that availability of highspeed computing, advanced materials, fundamentals of early solidification and industrial casting know-how have been combined to provide the basis for a commercial technology. Previous papers have provided a description of these key breakthrough developments.