Metal founding – Process – Shaping liquid metal against a forming surface
Patent
1998-04-02
1999-06-29
Ryan, Patrick
Metal founding
Process
Shaping liquid metal against a forming surface
164477, 164486, 164455, B21B 146, B22D 1100, B22D 11124, B22D 1122
Patent
active
059154578
DESCRIPTION:
BRIEF SUMMARY
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to a method for operating a continuous casting plant with a continuous casting machine, which has a stationary mold and is connected via a roller table to an equalizing furnace, The invention further relates to a device for casting strips.
2. Discussion of the Prior Art
From European Reference EP 0 264 459 B1 a process is known for producing hot-rolled steel strip from continuously cast slabs. In this process in which the solidified cast strand is divided into partial pieces of equal length, and these partial pieces are fed one after another into a furnace where they are stored for a period of time before being turned over to a discharge roller table of a finishing train. The molten material for forming the cast strand is cooled in the bow beam or feeding arrangment of the continuous casting machine. The exit temperature of the cast strand at the end of the bow beam is still above 1150.degree. C. The cast strip cools on its way from the mouth of the continuous casting machine to the entrance of the storage furnace, and runs at a temperature of approximately 1150.degree. C. from the roller table into a roller path located in the storage furnace.
The plant needed to implement this process is bound to a set strand thickness and corresponding casting speed. Changes in casting parameters generally result in production declines, reduced quality and increased expense.
For example, a reduction in casting speed at a constant solidification thickness, when no cast-rolling is possible, leads to sharp temperature-output losses, due to the additional cooling of the slab in the continuous casting plant as well as to the long holding time of the strand on its way to the equalizing furnace.
In addition, because no shears are used, the cross-cutting machine known from the aforementioned document leads to high radiant losses as a result of the long process time.
SUMMARY OF THE INVENTION
The object of the present invention is to provide a process and a device with which the casting parameters of a preestablished production chain, comprising a continuous casting plant, equalizing furnace and rolling mill, can be changed, using simple means, while the casting output is at least maintained.
The invention is based on the realization that when the continuous casting stage is linked to the rolling stage during the casting of billets, slabs and, particularly, thin slabs, the energy content of the strand entering the temperature equalizing furnace, roller hearth or cross-transfer furnace that follows the continuous casting plant is of great significance. Surprisingly, the energy content of the slab entering the equalizing furnace can be used as a control variable for the operation of the entire plant. The energy content of the slab upon its entry into the equalizing furnace is thus set to the desired roll temperature of the hot strip to be produced. The furnace can thereby be operated so that no energy need be supplied to the strand; instead, the strand even serves to equalize the slab temperature.
With the selected slab temperature at entry into the equalizing furnace serving as a fixed point, the steel worker is free to vary the parameters in the downstream plant parts. Unexpected solutions are found when, given a basic layout (e.g., solidification thickness of 60 mm at a casting speed of 5 m/min), the solidification thickness of the slab is reduced and influence is exercised on the casting speed, apart from influence variables such as strand cooling or insulation between the strand casting machine and the furnace.
Another possibility of increasing casting output in conjunction with a higher heat content of the slab entering a furnace directly downstream from the continuous casting plant is created by cast-rolling in the casting machine, i.e., by reduction of the casting thickness during solidification.
According to the invention, after the slab format is determined at the mold outlet, the casting parameters are set so that the slab entering the equali
REFERENCES:
patent: 4424855 (1984-01-01), Tsubakihara et al.
patent: 4658882 (1987-04-01), Oba et al.
patent: 5065811 (1991-11-01), Scholz et al.
patent: 5542165 (1996-08-01), Coassin et al.
patent: 5611232 (1997-03-01), Rohde et al.
patent: 5634512 (1997-06-01), Bombardelli et al.
patent: 5771560 (1998-06-01), Meroni et al.
Lin I.-H.
Mannesmann Aktiengesellschaft
Ryan Patrick
LandOfFree
Method for operating a continuous casting plant does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Method for operating a continuous casting plant, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method for operating a continuous casting plant will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1367431