JPH02205241A - Method for preventing breakout in heated mold type continuous casting apparatus - Google Patents

Abstract

PURPOSE:To produce a cast billet having good quality without any scratch and crack on surface of the cast billet by forming solidified interface to outer part of outlet in a heated mold and acting electromagnetic force to the position, where the solidified interface exists. CONSTITUTION:Molten metal 10 is continuously pulled out from the heated mold 4 and cooled to produce the cast billet 5. Then, the solidified interface B is formed to the outer part of the outlet in the heated mold 4. Further, the electromagnetic force is acted to the position, where the solidified interface B exists, by using the coil 13. High frequency current is conducted to the coil 13 to obtain the electromagnetic force. DC current is conducted to the molten metal and the cast billet, and by applying DC magnetic field orthogonally crossed to the current, the electromagnetic force is generated. By this method, the development of wear and damage in the inner face of the heated mold can be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a method for preventing breakout in a heated mold type continuous casting apparatus.

[Prior art]

Conventionally, a method for manufacturing an ingot by continuously drawing molten metal from a heating mold and cooling it is known, for example, from Japanese Patent No. 1049146.

An example of a device for carrying out this method is shown in FIG. That is, this heating mold type continuous casting apparatus A is provided with a hot water supply pipe 3 on the side of a tongue pusher 2 covered with a heat insulating material 1, and a heating mold 4 on the bottom surface thereof, and furthermore, the ingot discharged from the heating mold 4 is heated. cooling device 6 for cooling 5;
and a pinch roller 7 which is a device for pulling out the ingot 5.

When the metal material 8 is supplied into the hot water supply pipe 3, it is heated by the heater 9, becomes molten metal 10, and is stored in the tank pusher 2. The molten metal 10 in the tongue pusher 2 is drawn out by pulling the ingot 5 from the heating mold 4 by the pinch rollers 7, and is cooled by cooling water spouted from the cooling device 6, and the ingot 5 is cast.

At this time, the operation is normally performed so that the boundary between the molten metal 10 and the ingot 5, that is, the solidification interface B, is located slightly inside the outlet of the heating mold 4 in order to reduce the risk of breakout. 11 is a tongue pusher 2, and 12 is a heater for a heating mold 4, respectively.

[Problem to be solved by the invention]

However, in such an apparatus, since the solidification interface B exists in the heating mold 4, a solid contact area is created between the heating mold 4 and the ingot 5, and as a result, scratches and cracks occur on the surface of the ingot due to friction, resulting in quality deterioration. Not only that, but the inner surface of the heating mold 4 is worn out and damaged, and its maintenance requires a great deal of time and effort.

Furthermore, since the frictional resistance is relatively large, tearing occurs in low-strength parts such as the solid-liquid coexistence layer in the case of low-strength materials such as aluminum or alloy materials, and operation may become impossible.

In order to solve this problem, it is conceivable to form the solidification interface B outside the heating mold 4, but in this case, the molten metal 10 may flow out due to the problem of the surface tension of the molten metal 10.
There is a fear that a so-called breakout phenomenon may occur, and it is extremely difficult to maintain the solidification interface B constant. The upper part of the solidification interface is composed of molten metal and the lower part is solid, so if this solid part is located inside the heating mold 4, it will act as a kind of plug and prevent the molten metal from gushing out, or breaking out. It can be prevented.

However, if we try to prevent solid contact between the ingot and the heating mold as much as possible in order to smooth the surface of the ingot, the molten metal will peek out from the bottom of the heating mold, resulting in an extremely unstable state. There isn't.

For this reason, the inventor of the present invention has conducted intensive studies on means for maintaining the shape of the molten metal, and has developed the present invention by focusing on applying a clamping force from the periphery of the molten metal in a non-contact manner using electromagnetic force. .

[Means to solve the problem]

The present invention has been made to solve the above-mentioned problems, and is a continuous casting device that continuously draws molten metal from a heated mold and cools it to produce an ingot. It is formed outside the exit of the heating mold, and an electromagnetic force is applied to the location where this solidification interface is located, and this electromagnetic force is applied to a coil provided outside the exit of the heating mold. It can be obtained by passing a high frequency current or by passing a direct current through the molten metal and ingot and applying a direct current magnetic field in a direction perpendicular to the direction of this current.

〔Example〕

Hereinafter, an embodiment of the method for preventing breakout in a heated mold type continuous casting apparatus according to the present invention will be described with reference to FIGS. 1 to 5. Note that in these figures, the same reference numerals as in FIG. 6 indicate the same names.

FIG. 1 is an enlarged view of the main part of the heating mold part, and in the present invention, the boundary between the molten metal 10 and the ingot 5 in the heating mold 4, that is, the solidification interface B is located outside the exit part of the heating mold 4. It is characterized by the fact that it is formed.

An electromagnetic force F is applied to the surfaces of the molten metal 10 and the ingot 5 at the position where this solidification interface B is formed by a coil 13 arranged in the circumferential direction, and especially between the outlet end of the heating mold 4 and the solidification interface B. It is possible to press the molten metal 10 present in the molten metal 10 and prevent breakout.

Specifically, as shown in FIG. 2, when a high frequency current J is passed through the coil 13, an alternating current magnetic field H is generated and at the same time an induced current Ja flows on the surfaces of the molten metal 10 and the ingot 5. The interaction between this induced current and the magnetic field causes electromagnetic force F to press the molten metal 10 and the ingot 5 toward the center, thereby preventing breakout.

FIG. 3 is an enlarged view of the main part when the heating mold 4 is arranged laterally and the ingot 5 is pulled out horizontally. In this case, as shown in FIG. 4, the hydrostatic pressure f is lower than the upper part. becomes large.

Therefore, it is preferable that the coil 13 is eccentrically arranged so that the lower part is closer to the molten metal 10 and the ingot 5 than the upper part.

FIG. 5 shows another embodiment, in which an electric path 14 is provided with the molten metal 10 as an anode and the ingot 5 as a cathode, and a direct current is passed through this electric path 14 from a DC power source 15 in a direction perpendicular to this. By applying a DC magnetic field to , a vertically upward electromagnetic force F is generated, thereby making it possible to prevent breakout.

This method is effective when the ingot 5 is a round bar with a relatively small diameter or a wide bar.

〔Effect of the invention〕

As is clear from the above explanation, according to the method for preventing breakout in a heating mold type continuous casting apparatus according to the present invention, breakout of the molten metal can be extremely simply and easily prevented. A solidification interface can be formed. As a result, there is no solid contact between the heating mold 4 and the ingot 5, so that (1) a high quality ingot without scratches or cracks on the surface of the ingot can be produced;

■ There is no wear or damage to the inner surface of the heating mold, so maintenance is easy.

■ There is no frictional resistance, so there is no tearing at low-strength parts such as low-strength materials such as aluminum or solid-liquid coexistence layers of alloy materials, and continuous operation is possible.

[Brief explanation of the drawing]

Figures 1 to 5 show an embodiment of the breakout prevention method in a heated mold continuous casting apparatus according to the present invention, and Figure 1 is an enlarged view of the main part when the heated mold is arranged vertically. Fig. 2 is an explanatory diagram of the electromagnetic force F, Fig. 3 is an enlarged view of the main part when the heating mold is arranged horizontally, Fig. 4 is an explanatory diagram of the action of the hydrostatic pressure r, and Fig. 5 is an illustration of other FIG. 6 is an explanatory diagram of an electromagnetic force generating means, and FIG. 6 is a schematic side sectional view of a general heating mold type continuous casting apparatus. ■... Insulation material, 2... Tongue push, 3... Hot water pipe, -4... Heating mold, 5... Ingot, 6... Cooling device, 7... Pinch roller, 8...Material, 9.11
．． xi--Heater, 10... Molten metal, 13... Coil, 14... Electric circuit, 15... DC power supply. Figure 1 Figure 4 Figure 2 Figure 3 z

Claims (1)

[Claims] 1. In a continuous casting device that continuously draws molten metal from a heating mold and cools it to produce an ingot, a solidification interface is formed outside the outlet of the heating mold; A breakout prevention method in heated mold type continuous casting equipment that applies electromagnetic force to the location where the solidification interface is located. 2. The breakout prevention method according to claim 1, wherein a coil is provided outside the outlet of the heating mold, and the electromagnetic force is obtained by passing a high frequency current through the coil. 3. The breakout prevention method according to claim 1, wherein a direct current is passed through the molten metal and the ingot, and a direct current magnetic field is applied in a direction perpendicular to the direction of the current to generate an electromagnetic force.