JPH0366452A - Twin roll type continuous casting machine - Google Patents

Abstract

PURPOSE:To prevent involution of scum into solidified shell by separately submerging refractory parting plates extended to longitudinal direction of casting rolls into molten metal and arranging exothermic means to the parting plates. CONSTITUTION:Various kinds of oxides (scum) 19 are developed on the surface 9a of molten metal 9. The scum 19 is shifted toward intersectional lines A, B of the casting rolls 2, 3 and the surface 9a by molten metal flow developed with rotation of the casting rolls 2, 3, but the shift thereof is prevented with the parting plates 12, 13 and this is not involved into the solidified shells 10, 12. The parting plate is constituted with heating refractory material 15 integrally composed of exothermic means 14 and refractory casing 16, and the refractory casing 16 is changed at suitable interval. As the parting plate 12, 13 is held to high temp. with the exothermic means 14, the scum 19 is not solidified to stick. Surface characteristic of the cast strip can be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention is a double casting method that continuously casts a thin plate directly from the molten metal by supplying molten metal into the gap between a pair of cooling casting rolls rotating in opposite directions. This invention relates to a roll-type continuous casting machine (hereinafter referred to as a continuous casting machine).

[Conventional technology]

A twin-roll type in which molten metal is supplied between a pair of cooling casting rolls that are placed opposite each other and rotate synchronously in opposite directions, and a solidified shell is formed by contact cooling of the molten metal on the surface of the rolls to continuously cast thin plates. Continuous casting machines are already known.

Furthermore, in Japanese Patent Application Laid-Open No. 60-21161, in order to improve the surface properties of the thin plate cast in the above-mentioned continuous casting machine, a heated refractory is brought into contact with the intersection line where the casting roll and the surface of the molten metal intersect. A continuous casting apparatus has been disclosed in which the influence from the surface of the molten metal is reduced by moving the solidification start point below the intersection line.

[Problem to be solved by the invention]

By the way, in the twin roll type continuous casting machine mentioned above, the oxide (scum) generated on the surface of the molten metal moves toward the intersection line between the casting roll and the molten metal due to the rotation of the casting roll, and finally may be caught up in the solidified shell that begins to form at the intersection, and may be exposed as foreign matter on the surface of the cast thin sheet. As a result, the aesthetic appearance of the product may be impaired, and in some cases, cracks may occur starting from this scum. This problem is the same in the above-mentioned continuous casting equipment with refractories, and the scum adheres to the solidified shell beyond the refractory placed in contact with the intersection of the roll and the molten metal surface, damaging the surface quality of the thin plate. It is possible that

The present invention has been made in view of the current situation, and it is an object of the present invention to provide a twin-roll continuous casting machine that can prevent scum from being caught in the solidified shell and can cast thin plates with excellent surface properties. With the goal.

[Means to solve the problem]

For the above purpose, according to the present invention, a pair of casting rolls rotating in opposite directions are disposed in parallel and facing each other, and side weirs are crimped to both end faces of the pair of casting rolls, so that the outer peripheral surface of the rolls In a twin-roll continuous casting machine that defines a pool of molten metal with a side weir and continuously casts a thin plate through a gap between casting rolls, the surface of the molten metal intersects with the first casting roll. A fire-resistant partition plate is provided which is spaced apart from the intersection line on the other casting roll side, is immersed in the molten metal, and extends in the longitudinal direction of the casting roll, and is provided with a heat generating means on the fire-resistant partition plate. A twin roll continuous casting machine is provided.

[For production]

Casting of scum is achieved by placing a refractory partition plate along the entire length of the roll on the opposite roll side from the line of intersection between the molten metal surface and the roll, which is the starting point of solidification, and by immersing this partition plate in the molten metal. Prevents movement toward roll. In addition, the above-mentioned partition plate is equipped with a heat generating means to prevent scum from adhering to the partition plate and from forming coagulum around the partition plate.
Entrainment or joining of these impurities into the solidified shell is avoided.

〔Example〕

Hereinafter, the present invention will be described in detail with reference to the drawings.

FIG. 1 shows a longitudinal section of a twin-roll continuous casting machine, which is equipped with a tongue pusher 1, two casting rolls 2.3, and two side weirs. The tank pusher 1 is an intermediate container lined with a refractory material, and has a hot water tap nozzle 6 at its bottom. The casting rolls 2゜3 have a water-cooled structure in which cooling water flows inside, and are arranged facing each other with a gap 8 corresponding to the thickness of the thin plate 7 to be cast. They are designed to rotate synchronously. The side weirs 4 and 5 are made of fire-resistant and heat-insulating material, and the casting roll 2
．． 3 to seal them so that the molten metal 9 accumulated between the two casting rolls 2.3 does not leak out from both sides. Initially, the molten metal 9 is supplied to the tamp pusher 1, and is continuously injected in fixed amounts through the tapping nozzle 6 into a sump surrounded by the casting roll 2.3 and the side weir 4.5. The molten metal 9 collected in this pool is
Molten metal surface 9a and casting roll 2.3 surface 2a+3a
touch the surfaces 2a, 3a of the roll 2.3 at the line of intersection (indicated by points A, B in FIG. 1) and begin to form a solidified shell 10.11, respectively. This solidified shell 10.11 moves downward as the casting roll 2.3 rotates, and the two solidified shells 10.11 are rolled together and one thin plate 7 is cast.

According to the present invention, in the twin-roll continuous casting machine configured as described above, the intersection line A serves as the solidification start point.

By B, one casting roll related to the intersection lines A and B (casting roll 2 for the intersection line A, casting roll 3 for the intersection line B) and the opposite casting roll 3°2 side, that is, in other words Then, a fire-resistant partition plate 12,13 is provided which is spaced apart from the tapping nozzle 6 and immersed in the molten metal 9.

FIG. 2 shows a cross section of the partial continuous casting machine taken along the line ■--■ in FIG. 1, and FIG. 3 is a cross-sectional view of the partition plate taken along the line m--m in FIG.

As is clear from these figures, according to the present embodiment, the partition plate (only the partition plate 12 is shown in the figures) includes a heating refractory material 15 that incorporates a heat generating means 14 such as a high frequency coil or a nichrome wire, and this refractory material 15. The fireproof casing 16 is removably fitted to the partition plate 1 and can be replaced at appropriate intervals depending on the frequency of use.
2 extends substantially over the entire length of the casting roll 2 in its longitudinal direction (axis direction in FIG. held through.

Further, the heat generating means 14 of the partition plate 12.13 is connected to a power source 18 as shown in FIG.
3 is heated and the temperature rises.

Hereinafter, the function of the partition plates 12, 13 according to the present invention will be explained. As shown in FIG. 4, various oxides (scum) 19 are generated on the surface 9a of the molten metal 9 during casting. This scum 19 is moved toward the intersection lines A and B between the casting roll 2.3 and the surface 9a by the molten metal flowing surface 9a (indicated by arrows) caused by the rotation of the casting roll 2.3. According to the invention, the scum 19 is prevented from moving due to the partition plate 12.13, so that contact between the scum 19 and the casting roll 2.3 is avoided. Furthermore, since this partition plate 12.13 is brought to a high temperature state by the built-in heat generating means 14, scum 19 does not adhere to it, and no solidified matter is formed around the partition plate 12.13 (such as scum 19 or solidified matter). The solidified shell 10.
11 and damage the surface quality of the thin plate 7, and the solidified shell 10.11 itself and the scum 19/solidified material will not bond and break the shell 10.11 itself. It disappears.

Note that the present invention is not limited to the above-described embodiments, and for example, the partition plate may be formed curved along the outer peripheral surface of the roll, or the partition plate may be constantly immersed in response to the fluctuating molten metal surface level. It may also be held so that it can move up and down as much as possible.

〔Effect of the invention〕

As explained above, according to the present invention, by providing a refractory partition plate equipped with a heat generating means, entrainment of scum into the solidified shell is prevented, and the surface quality of the cast thin plate is improved. In addition, cracking of the solidified shell due to scum entrainment and bonding of the solidified material/scum and the solidified shell within the molten metal is prevented.

[Brief explanation of drawings]

Fig. 1 is a longitudinal sectional view of a twin roll continuous casting machine according to the present invention; Fig. 2 is a partial sectional view of the continuous casting machine taken along line ■-■ in Fig. 1; Fig. 3 is a partial sectional view of the continuous casting machine in Fig. 2 - (2) A sectional view of the partition plate taken along the line; FIG. 4 is a perspective view of a partial continuous casting machine showing the function of the partition plate according to the present invention. 2.3...Casting roll, 4,5...Side weir,
9... Molten metal, 12.13... Fire-resistant partition plate, 14... Heat generating means, A, B... Solidification start point at the intersection of the molten metal and the roll>
.

Claims (1)

[Claims] 1. A pair of casting rolls that rotate in opposite directions are arranged in parallel and facing each other, and side weirs are crimped on both end faces of the pair of casting rolls, and the molten metal is heated by the outer circumferential surface of the rolls and the side weir. In a twin-roll continuous casting machine that defines a reservoir and continuously casts a thin plate through a gap between the casting rolls, the casting roll other than the one casting roll is located beyond the intersection line where the surface of the molten metal intersects with the one casting roll. A twin-roll continuous casting machine, characterized in that a refractory partition plate is provided which is spaced apart from the side and immersed in molten metal and extends in the longitudinal direction of the casting roll, and the refractory partition plate is provided with a heat generating means.