JPS6138750A - Pouring method of twin-roll type casting machine - Google Patents

Abstract

PURPOSE:To prevent the generation of a solidified shell in a gate for the molten metal on twin-rolls in the stage of casting continuously a steel plate, etc. with a twin-roll type continuous casting machine by passing electric current to the molten steel flowing down from a tundish and applying a magnetic field to the molten metal flow. CONSTITUTION:The molten steel 5 is supplied from the tundish 3 through nozzle, 4, 4' into the molten steel pouring basin constituted of side gates 2, 2' provided on the both sides of the twin rolls 1 and the rolls 1 are rotated, by which a steel ingot 8 is produced. Magnetic field generators 7, 7' such as coils are installed alongside the gates 2, 2' to form the magnetic field. Electricity is at the same time conducted to the molten steel 5 in the tundish as the anode and the rolls 1 or the ingot 8 as the cathode, by which the molten steel flows 9, 9' from the nozzles 4, 4' are shifted toward the gates 2, 2' accoring to the Fleming's left- hand rule. The steel ingot 8 having good quality is thus produced without cooling of the molten metal in contact with the side gates and the consequent formation of the solidified shell.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a method of pouring metal into a twin-roll casting machine for continuously casting strips.

[Prior art]

Slab rolling is a common method for producing strips from molten metal, but in recent years a twin-roll continuous strip casting machine has been proposed that can directly cast strips from molten metal.

As shown in Fig. 1, this twin-roll continuous casting machine has a pair of cooling rolls whose inner surfaces can be cooled with water, etc.
α) are arranged in parallel with a gap G corresponding to the thickness of the strip plate (b) to be cast, the molten metal (c) is introduced into the gap G, and while both rolls (α) are rotated, the gap G Yoshi strip (b
) is cast out continuously.

However, as shown in Figure 2, the tundish (d) has only one nozzle (e) and can only pour in one direction, and the cooling roll (α) has a water-cooled structure. The solidified shell (+7
) was formed, which developed and sometimes continued to form a solidified shell on the cooling roll (α) side.

Therefore, the solidified shell on the cooling roll (α) side becomes the solidified shell (σ).
This may cause cracks to occur due to the pulling and deterioration of the product quality of the strip (b), or the solidified shell (gl is
It was dragged by the solidified shell on the cL) side and peeled off from the side weir (1), and at this time, the side weir (1), which is a refractory material, had the drawback of being partially damaged by the force.

[Purpose of the invention]

An object of the present invention is to provide a method of pouring molten metal in a twin roll casting machine in which the direction of molten metal pouring is variable and solidified slag is formed at the weir.

[Structure of the invention]

In the present invention, the molten metal poured from the nozzle of the tundish,
A current is passed from the nozzle side toward the pool in the weir of the twin roll casting machine, and the direction of the molten metal flow is varied by a magnetic field directed perpendicular to the direction of the current, thereby solidifying shells into the weir. This invention relates to a method for pouring metal into a twin-roll casting machine that prevents the formation of molten metal and achieves the effect of agitating the pool within the weir.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 3 shows an example of a twin-roll casting machine for carrying out the present invention, in which (1) is a roll, (2) (25 is a side weir, (3) is a tundish, and the tundish (25) is a side weir. 3) are provided with nozzles (4) (45) at two locations above the gear of the twin rolls (1), so that the molten metal (5) can flow down into the weir to form a pool (6), and each A magnetic field forming device (7) such as a coil (75) is installed on the side of the side weir (2) (25), and a magnetic field is generated at point This allows a vertically downward magnetic field to be generated.

When a current is passed through the molten metal (5) in the tundish (3) as an anode and the roll (1) or the casting strip (8) as a cathode, a flow of molten metal (9) (9) flows down from the nozzle (4) (45).
) flows in the flow direction. Each of the molten metal flows (9) (95
becomes a conductor through which current flows, so each magnetic field forming device (n
(It will be affected by the magnetic field formed by -f+, but the magnetic field forming devices that are close to each other < -t) (Because it is strongly influenced by 75, the direction of the magnetic field at point
Since the direction is perpendicular to the top of the drawing, the molten metal flow (9) flows down toward the side weir (2) according to Fleming's left-hand rule. Also, at point Y, the direction of the magnetic field is perpendicular to the downward direction of the plane of the paper, so the molten metal flow (95) is biased toward the side weir (25) according to Fleming's left-hand rule.

The above molten metal flow (9) (9'l bias 9 phenomenon is shown by the following formula, so -BI (F: force, B: strength of magnetic field, F: current) change the magnetic field B or current I. By this, the molten metal flow (9) (95) can be swung to a desired position in the longitudinal direction of the gap.

Note that the pouring method of the twin roll casting machine of the present invention is not limited to the above-mentioned embodiments, and the number of nozzles provided in the tundish may be one or more, and the position of the nozzle is not particularly limited. It goes without saying that various changes can be made without departing from the gist of the present invention, such as shifting the molten metal flow in a desired direction by changing the direction of the magnetic field by changing the installation position of the magnetic field forming device, etc. It is.

〔Effect of the invention〕

As described above, according to the pouring method for a twin roll casting machine of the present invention, various excellent effects as described below are exhibited.

(1) Molten metal flow flowing down from the tundish nozzle (
5) Since the molten metal is poured while passing a current in the downstream direction and applying a magnetic field to the molten metal flow, the direction of the molten metal flow can be changed.

(m) Since the direction of the pouring metal flow can be directed in the direction of the layer, it is possible to prevent the formation of solidified shells in the weir. (Turn) If the molten metal is poured while changing the pouring direction, the molten metal in the pool can be stirred, and a good cast plate can be obtained without forming a solidified shell in the pool.

[Brief explanation of the drawing]

Figure 1 is an explanatory diagram showing an example of a twin-roll continuous casting machine, Figure 2 is a diagram showing the state of solidified shell formation on the side weir in the twin-roll continuous casting machine shown in Figure 1, and Figure 3 is an illustration of the main body. It is an explanatory view showing an example of the device used for carrying out the pouring method of the invention. (1) is a roll, (2) (21 is a side weir, (3) is a tundish, (4) (45 is a nozzle, (7) (7'
) indicates a magnetic field forming device, (9) (95 indicates a molten metal flow).

Claims (1)

[Claims] 1) A current is applied to the molten metal poured from the nozzle of the tundish in the direction of the pool in the weir of the twin roll casting machine from the nozzle side, and the pouring direction of the molten metal flow is controlled by a magnetic field directed in a direction perpendicular to the direction of the current. A method for pouring molten metal into a twin-roll casting machine, characterized in that the molten metal is made variable.