Stabilizing the mechanical properties of the rolled products after reconstruction of the laminar cooling system on a 1700 continuous hot-strip mill

The Ispat Karmet plant rebuilt the strip cooling system on the runout table of its 1700 hot-strip mill in 2001. The new laminar cooling system ensures the required mechanical properties by using different cooling regimes for different product sizes and grades. Use of the appropriate cooling regime produces a microstructure characterized by minimal variation of grain size through the thickness of the product. Introduction of the new cooling system increased the percentage of rolled metal with the specified mechanical propenies from 97.1% in 2002-2003 to a present level of 98.9%. The system has also stabilized the distribution of those properties both along individual products and within given product batches.