Patent ID: 6533876
Filing Date: 2003-03-18
Classification: B21B,C21D

Abstract:
Process for producing a steel strip, the process comprising:casting liquid steel in a continuous-casting machine to form a thin plate; making use of the casting heat while feeding the plate through a furnace device; roughing the plate in a roughing stand to consecutively reduce the plate's thickness to a pass-over thickness to form a steel strip; rolling the strip in a finishing rolling stand to consecutively reduce the strip's thickness to a desired final thickness; wherein consecutive reductions of thickness occur in the roughing stand and finishing rolling stand; wherein the rolling in the finishing rolling stand is selected from the group consisting of ferritic rolling (a) and austenitic rolling (b), wherein ferritic rolling (a) and austentic rolling (b) respectively include the following: a. feeding the strip, the plate or a part thereof without interruption or delay, at least due to the furnace device, from the roughing stand to a processing device disposed downstream of the finishing rolling stand, at speeds which essentially correspond to the speed of entry into the roughing stand and to the consecutive reductions of thickness that occur in the roughing stand and finishing rolling stand, cooling the strip coming out of the roughing stand to a temperature at which the steel has an essentially ferritic structure, wherein between the casting machine and the finishing apparatus the steel is cut such that there is no material connection between the steel in the casting machine and the steel rolled in the finishing apparatus; b. feeding the strip, the plate or a part thereof without interruption or delay, at least due to the furnace device, from the roughing stand to a processing device disposed downstream of the finishing rolling stand, at speeds which essentially correspond to the speed of entry into the roughing stand and to the consecutive reductions of thickness that occur in the roughing stand and finishing rolling stand; heating or maintaining the temperature of the strip coming out of the roughing stand in the austenitic range, rolling the strip in the finishing rolling stand to the final thickness, essentially in the austenitic range, then cooling to the ferritic range, wherein between the casting machine and the finishing apparatus the steel is cut such that there is no material connection between the steel in the continuous casting machine and the steel rolled in the finishing apparatus; cutting the ferritically rolled strip of step (a) or austenitically rolled strip of step (b), after reaching the desired finished thickness, to portions of the desired length of respective coils; and coiling the cut portions.