Start-up of the casting-rolling mill at Thyssen Krupp Stahl AG and experience gained so far

摘要

On April 2, 1999, Thyssen Krupp Stahl AG started up operation of its new casting-rolling mill on schedule, only 24 months after placement of the order.The reasons and concepts for the construction of this mill and the course of the construction project are already the subject of other articles (1;2).The main objective of the investment was to use the additional converter steel capacity still available in one of the two BOF steel plants at the Duisburg production location. The new plant and the three hot strip mills available over the long term in Duisburg and Bochum now provide Thyssen Krupp Stahl AG with an annual hot wide strip capacity totaling 14.6 million metric tons. The refined and treated steel required for this purpose is supplied by the two steel plants in Duisburg-Bruckhausen and -Beecker-werth, as well as partly by the steel plant of Huttenwerke Krupp Mannesmann in Duisburg-Huckingen.As with probably any decision to invest in a thin slab casting-rolling line, the low operating costs expected through the minimization of energy and labor costs played an important role. Also, the relatively low capital outlay costs involved in combining the casting and rolling production stages made it economically viable for a large, integrated iron and steel maker to under-take such an investment and at the same time to decommission existing casting and rolling capacity elsewhere.However, the potential product innovations and the high product quality were ultimately the factors that decided this bold step towards the future.This progressive technology makes it possible to produce hot strips in ultra-light final gauges.By exploiting the high and homogeneous "thin slab" temperatures it is possible to realize completely new products with new rolling strategies.The inherent advantages of the casting-rolling process with regard to product tolerances are being developed further through best-possible rolling technology and constant process conditions, leading to products with a previously unachievable low variance in geometry and properties.This article sets out to present the most important data of the casting-rolling mill, as well as to report on the operating results so far and on the status of the mill after some one and a half years of production (3).