JPH0275443A - Continuous casting apparatus - Google Patents

Abstract

PURPOSE:To control the generation and growth of solidified shell and to obtain an ingot having beautiful surface by constituting a casting device with heating part arranging heating means at outside of a cylindrical body and cooling part of a water cooled copper mold having the same inner side cross sectional shape as this heating part. CONSTITUTION:Molten metal 6 poured into a tundish 3 from a ladle 4, is flowed in the heating part 1 and heated with induction current with a coil 12 and successively, the molten metal is cooled with the water cooled copper mold 2 to form a strand 7. While shifting from the heating part 1 to the cooling part 2, the solidified shell 9 is generated. The generating point of the solidified shell is generated, at where the heating degree in the heating part 1 is balanced with the cooling degree in the cooling part 2. Therefore, by controlling heating - colding degrees, the position of the generating point of the solidified shell can be controlled, and together with this, velocity of the growth of the solidified shell 9 can be controlled in the some degree.

Description

[Detailed description of the invention]

[Industrial Field of Application] The present invention relates to improvements in continuous casting equipment for metals, particularly steel. [Prior Art] The development of continuous steel casting technology is progressing toward casting small cross-section billets so that processing after casting is easy.
゛In the typical existing continuous billet casting technology, molten steel from the tundish is poured into a water-cooled copper mold through an immersion nozzle, drawn out vertically to obtain a strand curved with a constant radius of curvature, and then horizontally drawn. straighten it with a roll and then cut it. The general problem with this method is that so-called oscillation marks are formed on the surface of the slab, and the skin is not smooth.Also, the main problem with aluminum-containing steel is that the immersion nozzle is easily clogged. Can be mentioned. As a continuous casting technique that particularly focuses on removing inclusions, there is a method using a rotary mold. In the rotary molding method, the slab is handled vertically, so the equipment is tall, and the rotating mechanism becomes large because the mold and guide rolls must also be rotated. Billets are naturally limited to those with a circular cross section, and billets intended for aluminum-containing steel also carry the risk of nozzle clogging. Meanwhile, the technology of horizontal continuous casting is also evolving, which has the benefit of lower construction costs than vertical continuous casting, and because it does not use nozzles, it is free from blockage problems. but,
In the method currently in use using break rings, cold shut cracks that inevitably occur on the surface of the slab tend to cause skin defects, and the types of steel that can be used are limited. [Problems to be solved by the invention] In this way, existing continuous casting technologies all have advantages and disadvantages, and they can construct equipment without requiring a huge amount of money. However, continuous casting that can be carried out and produces slabs with beautiful skin has not yet been realized. An object of the present invention is to provide a continuous casting apparatus that satisfies the above conditions. [Means for Solving the Problems] The continuous casting apparatus of the present invention has a casting apparatus installed at the bottom of a tundish (3) containing molten metal (6), as shown in FIG. The casting device is directly connected to the heating means (12) on the outside of the cylindrical body (11) made of refractory material.
), and a cooling part (2) which is a water-cooled copper mold having the same inner cross-sectional shape as the heating part. In Fig. 1, C1 (4) is a ladle, (5) is a guide roll, (6) is molten metal, (7) is a strand, and (8) is a molten metal.
is a slab. As the heating means (11), it is preferable to use a high frequency induction heating coil as shown in FIG. In this case, it goes without saying that conductive substances should not be used in the cylinder made of refractory material. [Function] The molten metal (6) transferred from the ladle (4) to the tundish (3) may once form a solidified portion (9') as shown by the broken line when it is transferred to the casting device. , enters the heating section (1).Here, the molten metal is heated by an induced current, for example by the coil (12) shown in Figure 2, and the temperature of the molten metal rises, so no solidification occurs.The molten metal is then heated by water-cooled copper. It is cooled by the mold (2) to form a strand (7). During the transition from the heating section to the cooling section, a solidified shell (9) is generated. The generation point (P) of the solidified shell is located at the heating point (P). This occurs when the degree of heating in the part and the degree of cooling in the cooling part are balanced, so by controlling the degree of heating and cooling, the position of P can be controlled, and at the same time, the solidification shell (9
) growth rate can also be controlled to some extent. In conventional continuous casting, the only consideration was to cool the prepared molten metal, but the present invention goes beyond the conventional continuous casting method by adding the operation of heating it once.

【Effect of the invention】

If continuous casting is carried out using the apparatus of the present invention, a slab with beautiful skin without oscillation marks can be obtained by forming strands while controlling the generation and growth of solidified shells using the above-described mechanism. Since this device does not use a submerged nozzle, there is in principle no risk of nozzle clogging regardless of the type of steel. Of course, there are no restrictions on the shape of the slab cross section. The construction costs and operating costs for the equipment will remain the same as in the past. Although high frequency power is consumed in the heating section, the amount is small. With conventional continuous casting, the smaller the cross-sectional billet you aim for, the more difficult it is to control, so there is a limit to the size that can be achieved.However, with the present invention, precise control is now possible, making it easier to produce billets of small size. Now it can be manufactured. This also helps streamline the manufacturing process for steel products.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a conceptual longitudinal sectional view showing the configuration of a continuous casting apparatus of the present invention together with related devices. FIG. 2 is an enlarged sectional view showing the main parts of the apparatus shown in FIG. 1 and the state of solidification of molten metal therein. 1... Heating part 11... Refractory cylinder 12... Heating means 2.
...Cooling part 3...Tandish 6.
...Molten metal 7...Strand 8...
Slab 9... Solidified shell P... Solidified shell generation point Patent applicant Daido Steel Co., Ltd. Agent Patent attorney Souo Suga

Claims (1)

[Claims] (1) A casting device is directly connected to the bottom of a tundish that accommodates molten metal, and this casting device is connected to a heating section with heating means provided on the outside of a cylindrical body made of refractory material, and an inner cross-sectional shape that is the same as that of the heating section. 1. A continuous casting device characterized by comprising a cooling section which is a water-cooled copper mold having a cooling section. (2) Claim 1 in which a high frequency induction heating coil is used as the heating means.
Continuous casting equipment.