JPS6021166A - Tundish for continuous casting - Google Patents

Abstract

PURPOSE:To decrease the degree of overheating of a molten metal and to form a uniformly solidified shell in a short time by segmenting a tundish to a receiving chamber and a pouring chamber which are communicated with each other via a space, providing a heating means and stirring means to the pouring chamber and pouring the molen metal via a valve and nozzle. CONSTITUTION:A tundish is segmented by refractory gates 9, 9' to a receiving chamber 10 having a small volume and a pouring chamber 11 having a large volume which are communicated with each other via a space 23. The inside of the respective chamber is maintained in an inert gaseous atmosphere. A molten metal 16 is conducted from a ladle 17 into the chamber 10 where nonmetallic inclusions 18 are floated on the molten metal. The molten metal 16 moves through the space 23 between the gates 9 and 9' to the chamber 11 and the molten metal surface is detected with a detector 22. The molten metal 16 is heated to a target temp. by a heating means 12 until a prescribed head 19 is attained. The temp. of said metal is measured with a thermocouple 20 and weak circulating flow 21 is given to the molten metal by a stirring means 13. When the molten metal is heated to the target temp., a slide-type valve 14 is opened to start casting through a nozzle 8.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a tantie in a continuous thin plate casting apparatus for gold IZs.

Equipment for continuous casting of thin plates of 1 to 10 mm directly from molten metal includes -e゛ twin roll type and twin bell 1.7 (+2
A synchronous continuous casting machine is known. In these thin plate continuous gun making machines (thin & continuous casting machines), in order to ensure the same production volume as before, the casting speed is the conventional slab i11! It is several dozen times more powerful than a casting machine. Therefore, in continuous thin plate casting, it is important to control the initial solidification state, and it is necessary to control the growth rate of the solidified shell to an appropriate level. That is, especially in the case of the twin roll method,
If the point of completion of solidification is too "+", it will be difficult to pull out the plate, and if the point of completion of solidification is too late, the plate will cause pulsing or breakout. Therefore, the overheating expansion of the molten metal should be minimized. It is necessary to form a uniform solidified shell during the rising time.However, the tundish provided in conventional continuous casting machines requires the maintenance of a small degree of superheating and highly accurate control of the degree of superheating to enable continuous casting of thin sheets. It is difficult.

Also, unlike the mold section of conventional continuous casters, the casting nozzle of a thin plate continuous caster does not have the function of separating non-metallic inclusions in the molten metal into floats, and the inclusions are simply separated into floats. There is no residence time for the molten metal. In other words, non-metallic inclusions introduced into the casting nozzle are directly trampled into the solidified shell, resulting in product defects.Therefore, the tundish needs to be able to separate and remove non-metallic inclusions more effectively than conventional tundishes. .

The present invention has been made to solve the following two problems. iI Small fluctuation in heat and superheat
, nonmetallic inclusions float on top] - The separated molten metal is
i! l! The purpose is to provide a tandy that can be supplied to a casting machine.

According to the present invention, the molten metal is divided into a small volume receiving chamber that receives the molten metal from the ladle and a large capacity molten metal supply chamber that supplies the molten metal to the continuous casting device by a weir that divides the surface of the molten metal and communicates it at the bottom. There is provided a tundish for continuous metal casting, which is characterized in that a heating means and a stirring means for changing the circulation tit are provided in the hot water supply chamber, and a valve means and a nozzle are provided at the molten metal supply port.

Hereinafter, one embodiment of the present invention will be described with reference to FIG. 1.2.

The tandish container consists of an iron shell and a refractory material inside, and is divided into two large and small chambers by refractory weirs 9 and 9'. The weir 8 that divides the surface of the molten metal is essential, but the weir 9 is exposed from the bottom.
' may be omitted. The chamber with a small volume is a hot water receiving chamber 10, and the chamber with a large volume is a hot water supply chamber +1. A channel type induction furnace 12 is installed on the side wall of the hot water supply chamber, and an electromagnetic stirring device 13 is attached to the opposite side wall. A slide valve 14 is provided at the molten metal supply port at the bottom of the hot water supply chamber, and a pouring nozzle 8 is further connected thereto. The pouring nozzle faces a twin-roll or twin-rut mold (not shown) for continuous casting.

Note that the hot water receiving room IO and the hot water supply room 11 are covered by 415,
The interior of the room is made into an inert scum atmosphere by an Ar barrier. The molten metal 1B is guided from the ladle 17 to the receiving chamber 10, and the nonmetallic inclusions 18 at this point are floated. Molten metal 16 is weir 9.8'
It passes through the gap 23 and moves to the hot water supply room 11. Before the start of casting, the slide valve 14 is closed, and the slide valve 14 is closed to a predetermined position.)"1
! The molten metal is stored until it reaches It. At that time, the hot water level is detected by a hot water level detector 22 installed on the side wall of the tandy. There, the temperature is measured continuously or intermittently by a thermocouple 20, and the channel-type induction furnace 12 heats it until the target temperature is reached. Thereafter, the M1 temperature result is fed back for power control of the channel type induction furnace 12. In order to prevent the temperature of the molten metal in the hot water supply chamber from becoming non-uniform depending on the position, a weak circulation flow 21 is applied to the molten metal by an electromagnetic stirring device 13 as shown in FIG. At this time, stir gently to avoid getting the inclusions caught.

Since the amount of molten metal accommodated in the hot water supply chamber is sufficiently large, sufficient residence time of the molten metal is provided for inclusions to float and separate in the hot water supply chamber. Furthermore, since a heating device is provided, there is no need to worry about the temperature of the molten metal dropping, and the molten metal can stay there for a long time.

When the molten metal temperature reaches the 11 standard temperature, the slide valve 14 is opened to start casting. The hot water supply speed is a sliding type.
Adjustment is made by changing the area of one opening of No. 4. In order to prevent the temperature of the molten metal in the hot water supply room from being greatly disturbed by the molten metal flowing in from the hot water receiving room, the molten metal in the hot water supply room is made thick.

Due to the reason 1-- mentioned above, the hend 19 becomes large, which tends to cause uneven temperature of the molten metal in the downward direction, so the electromagnetic stirring device 13 is provided.

The molten metal outlet at the bottom of the hot water supply chamber may be located at the lower part of the side wall of the tundish and extend in the direction of the water 41. Further, the valve for discharging molten metal 1 may be a stopper as shown in 24 in FIG.

The present invention has made it possible to supply molten metal with a low degree of superheating and small variations in the degree of superheating to a continuous thin plate caster.

In addition, a clean molten metal with few nonmetallic inclusions can be obtained at the same time. The present invention solves the problems of sheet shape and inclusions, which are important problems in continuous casting of thin sheets, and also significantly improves operability.

The tandy caster according to the present invention can be used not only in twin-roll, twin-belt continuous sheet casting machines, but also in conventional continuous casting machines.

[BRIEF DESCRIPTION OF THE DRAWINGS] FIG. 1 is a conceptual diagram showing a vertical cross-sectional view of an apparatus according to an embodiment of the present invention, FIG. 2 is a cross-sectional view of the apparatus of FIG. 1, and FIG. 3 is a stopper FIG. In these figures, 10: Hot water receiving room 11: Hot water supply room 8: Hot water pouring nozzle 8.9°: Weir 12: Heating means 13: Wl, Stirring means Patent patent attorney Masahiro Matsui, agent of Nisshin Steel Co., Ltd. (1 other person) 1st day 2nd cause 30 5

Claims (1)

[Claims] 1. By means of a weir that divides the molten metal at the surface and communicates it at the bottom,
A small volume receiving chamber that receives the molten metal from the ladle, and Tsukasa! It is divided into a large-capacity hot water supply chamber for supplying molten metal to the casting equipment, and is equipped with a heating means and one stage of stirring r for providing circulation flow, and a valve means and a nozzle 41 are installed in the molten metal supply chamber. Features: Tantinsh for continuous metal casting.