JP2917733B2 - Continuous casting method and apparatus - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a continuous casting method and an apparatus therefor, and more particularly to a continuous casting method and an apparatus for improving the quality of a cast bar without reducing productivity.

[0002]

2. Description of the Related Art FIG. 3 shows a typical continuous casting and rolling apparatus (trade name: Conti Rod System) of a typical Hesley-Krupp process (twin belt method).
The continuous casting and rolling apparatus is for producing a rough drawn wire such as a copper wire, for example, and includes a shaft furnace 30 for melting a metal material (for example, copper), and a holding furnace 31 for temporarily storing and discharging molten metal. , A casting machine 32 for continuously casting molten metal supplied from a holding furnace 31, and a rolling machine for hot-rolling a cast bar discharged from the casting machine 32 through a multi-stage rolling roll to produce a rough drawing wire. 33, a cleaning device 34 for removing the surface oxide film and the like of the rough drawing line, and a winding machine 35 for winding the rough drawing line.

FIG. 4 shows a perspective view of a casting machine 32. The casting machine 32 has a tundish 1 that receives a supply of molten metal 7 from a holding furnace 31, a casting space 18 provided by drive belts 2 a and 2 b arranged vertically and dam blocks 16 arranged on both side surfaces of the drive belts 2 a and 2 b. The casting bar 17 is formed by injecting the molten metal 7 supplied to the tundish 1 into the casting space 18 from here and continuously cooling and solidifying it with the drive belts 2a and 2b.

In such continuous casting, improvement of economy and quality has recently become an important issue.
In order to improve the quality, it is required to reduce blowholes in the cast bar which cause defects in the coarse drawing.

[0005] Blow holes are mainly caused by the following causes. (1) Entrainment of the air of the molten metal itself when pouring the molten metal from the tundish into the casting space (2) Generation of bubbles generated when the gas dissolved in the molten metal falls below the solubility during the cooling and solidification process Of these, the blowholes caused by the cause of the above item (2) have a small effect on the quality because they are crushed by high compression in the subsequent rolling process because the bubbles are minute.

On the other hand, blowholes caused by the cause of the above item (1) can be dealt with by adjusting the pouring speed when pouring the molten metal from the tundish into the casting space.

[0007]

However, according to the conventional continuous casting method and the conventional apparatus, the economy is improved in order to satisfy the above-mentioned requirements, that is, the injection rate is increased to increase the output per hour. Attempting to do so will result in the formation of blow holes in the cast bar. This is because, as shown in FIG. 5, the flow of the molten metal 7 in the casting space 18 collides with the molten metal 7 in the casting space 18 due to the increase in the injection speed, as shown in FIG. This is because air bubbles are generated. Therefore, there is an inconvenience that the improvement in productivity and the improvement in quality cannot be simultaneously satisfied.

Accordingly, it is an object of the present invention to provide a continuous casting method capable of reducing blowholes in a cast bar while improving productivity, improving economic efficiency and improving the quality of rough drawing simultaneously. It is to provide the device.

[0009]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and is intended to reduce the number of blow holes in a cast bar while increasing productivity. The present invention provides a continuous casting method in which the molten metal is guided and poured.

Further, the continuous casting apparatus of the present invention that achieves the above object is supplied from a melting furnace and an endless belt disposed vertically, a casting space formed by dam blocks disposed on both side surfaces. A tundish for pouring the molten metal into the casting space, and a pouring guide member provided at a pouring opening of the casting space, the tip of which is located in the molten metal of the casting space with a predetermined distance from the pouring bottom surface. I have.

The pouring guide member can be constituted by a plate-like member having one end fixed to the upper surface of the tundish and the other end positioned in the molten metal as the above-mentioned tip.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a continuous casting method and apparatus of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 shows a sectional structure of a casting machine 32 of a continuous casting apparatus as one embodiment of the present invention. Other structures of the continuous casting and rolling device are the same as those of FIG. Further, in the casting machine 32, the same portions as those in FIGS. 4 and 5 are denoted by the same reference numerals and symbols, and thus the duplicate description will be omitted.

In the casting machine 32, a separate plate (a pouring guide member) whose tip is located in the molten metal 7 of the casting space 18 with a predetermined distance δ from the drive belt 2b at the pouring portion of the casting space 18. 11 is provided.

As shown in FIG. 2, the separate plate 11 is mounted on the other end of a holding rod 12 having a mounting hole 13 at one end via a mounting bracket 15, and is mounted on the top of the tundish 1 by the mounting hole 13 of the holding rod 12. And the casting space 18 is fixed so as to be inclined at a predetermined angle, and the tip portion 11a is inserted a predetermined distance 1 (preferably l = 20 to 50 mm) from the surface of the molten metal 7. The tip portion 11a is tapered so as to gently peel the pouring water 3 injected from the tundish 1, that is, to reduce the collision energy of the pouring water 3, and to provide the above-mentioned interval δ at the bottom portion. It has a spacer 14.

In the above embodiment, a visualization device (model) of a part flowing from the tundish 1 of the casting machine 32 into the casting space 18 was manufactured, and an experiment of generating bubbles was performed. In the experiment, we tried to make the flow of the real device and the model similar. That is, since the kinematic viscosity of the molten copper is the same as that of water near 70 ° C., a model having the same dimensions as the actual apparatus was manufactured, and hot water was used instead of the molten metal.

Next, a molten metal (warm water) 7 was poured into the casting space 18 from the model tundish 1 and the generation of bubbles was observed. As a result, as shown in FIG. 1, it was confirmed that there was no collision between the free surface of the molten metal 7 located in the casting space 18 and the pouring metal 3 injected along the wall surface, and most of the bubbles were not generated. In other words, since the molten metal 3 injected from the tip 11a of the separate plate 11 diffuses into the molten metal 7, a shear layer is generated between the diffused flow and the molten metal 7 based on a speed difference, and some bubbles are generated. 4 was observed, but the number of bubbles generated was 80 compared to that before the separation plate 11 was inserted.
It was clarified from the result of the image processing by the high-speed camera that the image was reduced by 90%.

As can be seen from the above embodiment, in the continuous casting method and apparatus according to the present invention, the tip of the separate plate is inserted into the molten metal in the casting space by a predetermined distance from the surface of the molten metal, and the separated plate is inserted. Since the pouring is performed as a pouring guide member, collision between the pouring and the molten metal in the casting space is eliminated, so that even when the molten metal is poured at a high speed, entrainment of air of the molten metal can be prevented. For this reason, generation of bubbles in the molten metal can be prevented, blow holes in the cast bar can be reduced, and the quality of rough drawing can be improved.

In the above embodiment, the interval δ and the distance 1 can be arbitrarily determined according to the casting speed, that is, the injection speed of the molten metal. In addition, various shapes can be applied to the shape of the separate plate. When the material is molten copper, stainless steel, ceramics, or the like is preferable.

[0020]

As described above, according to the continuous casting apparatus and the apparatus according to the present invention, the molten metal is guided and poured from the tundish into the molten metal in the casting space by a predetermined distance. In addition, it is possible to reduce the number of blowholes in the cast bar while improving the productivity, and it is possible to simultaneously improve the economy (increase the casting speed) and the quality of the rough drawing.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an embodiment of the present invention.

FIG. 2 is an explanatory view showing a separate plate according to one embodiment.

FIG. 3 is an explanatory view showing a typical continuous casting and rolling device.

FIG. 4 is a perspective view showing a conventional casting machine.

FIG. 5 is a cross-sectional view showing a state of generation of bubbles in a conventional casting machine.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Tundish 2a, 2b drive belt 3 Pouring 4 Bubbles 7 Melt 11 Separate plate 11a Tip 12 Holding rod 13 Mounting hole 14 Spacer 15 Mounting bracket 16 Dam block 17 Cast bar 30 Shaft furnace 31 Holding furnace 32 Casting machine 33 Rolling machine 34 Cleaning device 35 Winding machine

──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Yoshiro Sano 4-10-1, Kawajiri-cho, Hitachi City, Ibaraki Prefecture Inside the Toyoura Plant of Hitachi Cable Corporation (72) Inventor Daisuke Ikeda 4-chome, Kawajiri-cho, Hitachi City, Ibaraki Prefecture No. 1 Nippon Cable Co., Ltd. Toyoura Plant (72) Inventor Masahiro Sakamoto 4-10-1, Kawajiri-cho, Hitachi City, Ibaraki Pref. Nippon Cable Co., Ltd. Toyoura Plant (56) References JP-A-64-40149 JP, A) JP-A-59-130653 (JP, A) JP-A-58-218361 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) B22D 11/06 340 B22D 11 / Ten

Claims (3)

(57) [Claims] 1. A continuous casting method in which a tundish is poured into a casting space formed by endless belts arranged vertically and dam blocks arranged on both sides to continuously cast the casting space. In the hot water part, the tip is
Move the pouring guide member inserted into the hot water to the lower end
Place it at a predetermined distance from the belt and pouring
Pass between the guide member and the lower endless belt
Way continuous casting, characterized in that the pouring Te. 2. A casting space formed by endless belts arranged vertically and dam blocks arranged on both side surfaces; a tundish for pouring molten metal supplied from a melting furnace into the casting space; Provided at the pouring port of the space, the tip of which is in front of the lower side
Serial with a predetermined gap between the endless belt has a pouring guide member positioned in the molten metal of the casting space, the molten metal is the pouring guide member and the lower from the tundish
Continuous casting apparatus characterized in that the molten metal is poured between the endless belt and the endless belt . 3. The continuous casting apparatus according to claim 2, wherein said pouring guide member is constituted by a plate-like member having one end fixed to an upper surface of said tundish and the other end positioned in said molten metal as said tip.