Energy and yield-optimized method and plant for producing hot steel strip

摘要

A method is disclosed for continuously or semi-continuously producing hot steel strip which, starting from a slab guided through a slab-guiding device, is rolled in, for example, an at least four-stand roughing train to form an intermediate strip and, in a further sequence in a finish rolling train, into a final strip. The thickness of a slab cast in a die is reduced in the liquid core reduction process by means of the adjoining slab-guiding device to between 85 and 120 mm, a slab support length measured between the meniscus, i.e., the bath level, of the die and an end of the slab-guiding device facing the roughing train being at least 18.5 m, a casting speed ranging from 3.8 to 7 m/min, and slabs of different thicknesses being cast as a function of given casting speeds. Using the disclosed casting parameters, high-quality finishing may be provided with high production capacities.

主权项

1. A method for continuous or semi-continuous production of hot steel strip, comprising:
casting a slab by guiding the slab through a slab-guiding device, feeding the slab directly to a roughing train; rolling the slab in the roughing train to an intermediate strip within a period of at most 80 seconds in at least four passes using at least four roughing stands, and further rolling the slab in a finish rolling train to a final strip, wherein the slab guiding device performs a Liquid Core Reduction method to reduce the thickness of the slab from an initial thickness in the range 105 to 130 mm, while the slab has a liquid cross-sectional core, to a slab thickness of between 95 and 120 mm, wherein a slab support length measured between an end of the slab-guiding device facing a meniscus and the roughing train is greater than or equal to 18.5 m, wherein a casting velocity lies in a range of 3.8-7 m/min, and wherein slabs are cast as a function of the following casting velocities: for casting velocities between 3.8 and 5.0 m/min, a slab thickness between 100-120 mm, for casting velocities between 5.0 and 5.9 m/min, a slab thickness between 95-110 mm, and for casting velocities greater than or equal to 5.9 m/min, a slab thickness between 95-102 mm, and heating the intermediate strip emerging from the roughing train by an inductive heating device using a cross field heating method starting from a temperature above 770° C. and ending at a temperature of at least 1110° C.