JPH02290650A - Twin roll type continuous casting machine - Google Patents

Abstract

PURPOSE:To prevent the development of solidified shell on molten metal pool surface and to obtain a cast slab with uniform quality by spreading molten metal supplied on gap between twin rolls through a core on the whole surface of the molten metal pool from a supplying hole parted with a cover. CONSTITUTION:The molten metal M is supplied on the gap S between the twin rolls 2, 2 rotated in the arrow mark direction from a tundish 3 through the core 4, and the molten metal pool 5 is formed between the twin rolls 2, 2 and the side weirs 6, and the molten metal is cooled. Then, the solidified shells 7 formed on the rolls 2 are joined at kissing point 8 to draw out the cast slab 9. In the above twin roll type continuous casting machine 1, vertical and horizontal passages 12, 13 are arranged in the above core 4 submerged into the molten metal pool 5, and the molten metal M is spouted to the horizontal directions. Further, a molten metal supplying hole 10 having L-shape cover 11 in the cross section is arranged. The above spouted molten metal M is supplied so as to spread to the whole surface of the molten metal pool 5 through this supplying hole 10 and the development of the solidified shell on this surface is prevented. By this method, the solidified shell 7 having uniform thickness is formed and the cast slab 9 with uniform quality is obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a twin-roll continuous casting machine with an improved structure for preventing solidification shells from developing on the surface of a molten pool.

[Prior art] Molten metal (also referred to as molten metal) is supplied through a core onto the gap between twin rolls to form a molten pool, and the twin rolls are rotated to continuously produce slabs from the gap. Such a twin roll continuous casting machine is already known. This casting machine forcibly cools the molten metal on the surfaces of twin rolls to develop a solidified shell, and the two solidified shells are united at the kissing point where the twin roll surfaces are closest to form a gong piece. A solidified shell or film may develop on the surface (meniscus) of the molten pool due to cooling. In this case, the solidified film that develops on the surface of the molten pool is drawn along the twin roll surface and further develops as a solidified shell that develops on the twin roll surface, but the solidified film that develops on the surface of the molten pool is uniform. As long as it is thick, there will be no problem.

[Problems to be Solved by the Invention] However, the solidified shell that develops on the free surface of the molten pool due to natural cooling has a non-uniform thickness. When this reaches a point, there are problems such as localized rolling force being applied to the thicker parts, causing cracks in the slab, or breakouts in which molten metal spews out from the thinner parts. In particular, when the roll is made wider, the surface area of the meniscus increases, so the problem of solidified shells increases. Note that a method for preventing solidified shells from forming on the side weir of a twin roll Fukube is disclosed in JP-A-62-45456, but this method does not prevent solidified shells from forming on the surface of the molten pool. I can't.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a twin-roll continuous slag machine that can solve the above problems, prevent solidified shells from developing on the surface of the molten pool, and produce homogeneous slabs. It is in.

[Means for Solving the Problems] In order to achieve the above object, the present invention supplies molten metal onto the gap between twin rolls through a core to form a molten pool, and rotates the twin rolls to form a molten metal pool. In a twin-roll continuous casting machine that continuously produces slabs from the gap, a method for supplying molten metal so that the molten metal newly ejected on both sides of the core in the axial direction of the rolls is distributed over the entire surface of the molten pool. It is equipped with a supply port.

[Operations] According to the above structure, molten metal is supplied from the supply port formed in the core over the entire surface of the molten pool. Therefore, the surface of the molten pool is always maintained at a high temperature by the supplied molten metal, which prevents the development of solidified shells due to natural cooling, thereby preventing slab cracking and breakouts. , it is possible to produce homogeneous pieces.

[Example] Hereinafter, an example of the present invention will be described in detail based on the accompanying drawings. As shown in FIGS. 1 and 2, the twin roll continuous casting machine 1 has a set of two horizontal rolls (twin rolls) 2, and both ends of these rolls 2 are attached to a support frame (not shown). In addition to being rotatably supported, one or both of the rolls 2 can be adjusted to move horizontally so that the gap S between the rolls can be appropriately set. The inner surface of roll 2 is a water-cooled jacket. A tundish 3 for receiving molten metal M from a ladle is arranged above the mouth and the hole 2, and at the bottom of this tundish 3, the molten gold gMt! : The core 4 to be supplied is installed. Among these, 1-4 are roll 2
The molten metal M is supplied into the molten pool 5 while being immersed in the molten metal pool 5 which is stored in the gap S between the two.

In order to form the melt pool 5, sides 11!6 are arranged at both ends of both rolls 2. The roll 2 is rotationally driven in the direction of the arrow to forcibly cool the molten metal M in the molten pool 5 on the roll surface -F, developing a solidified shell 7 and reaching a kissing point 8, solidifying on the surfaces of both rolls. By integrating the shell 7, slabs 9 are continuously produced and discharged from below the gap S. The core 4 has a longitudinal direction (roll axis direction).
Molten metal aM is applied to the entire surface of the molten boule 5 formed on both sides.
A supply port 10 for supplying the water is formed. Specifically, covers 11 having an L-shaped cross section are attached to both sides of the core 4 to continuously cover the surface of the molten pool 5 in the roll axis direction, and the inside of the core 4 is provided with a cover 11 that covers the inside of the tundish 3 and the inside of the tundish 3. A vertical passage 12 is formed as appropriate, and a horizontal passage 13 is branched horizontally from the vertical passage 12 and opened into the cover 11.
is formed appropriately. Note that the vertical passage 12 may penetrate to the lower end of the core 4, in other words, the passage 12.1
3, it is sufficient if the supply amount necessary to maintain the predetermined molten pool 5 can be secured. The supply port 10 has a core 4 and a cover 11.
A downward opening is formed by the molten metal M, so that the surface of the molten boule 5 is always maintained at a high temperature by the supplied molten metal M. The tip of the cover 11 is located on the surface of the melting boule 5 and is formed facing in the tangential direction of the roll 2 so that the molten metal M supplied from the supply port 10 does not directly hit the roll surface. Next, the operation of the above embodiment will be described.

The molten metal M received in the tundish 3 is the core 4
The melt is supplied to the entire surface of the melt pool 5 via the vertical passage 12 and horizontal passage 13, filling the supply port 10 defined by the core 4 and the cover 11. As a result, the surface of the molten pool is always maintained in a hot state by the supplied molten metal M, thereby inhibiting the development of a solidified shell due to natural cooling. Therefore, the solidified shell 7 is uniformly developed only on the roll surface by forced cooling, so even when the solidified shell 7 passes through the kissing point 8, slab cracking or breakout does not occur, and a homogeneous slab is formed. 8 can be manufactured.

The supply port 10 is designed to supply molten gold Ff! from the side of the core 4 to the entire surface of the molten glue 5! JM like rain lI
- The cover 11 may also be provided, and in this case as well, it is preferable to provide the cover 11.

``Effects of the Invention'' In summary, according to the present invention, the surface of the molten pool is always maintained at a high temperature by the supplied molten metal, so the development of a solidified shell due to natural cooling can be assisted, and the It is possible to produce homogeneous spun pieces by eliminating splits and breakouts.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a twin roll continuous casting machine showing an embodiment of the present invention, and FIG. 2 is a sectional view taken along the line A--A in FIG. In the figure, 2 is a roll, 4 is a melting hole, 5 is a molten pool, 9 is a slab, and 10 is a supply port.

Claims (1)

[Claims] 1. In a twin-roll continuous casting machine that supplies molten metal through a core onto the gap between twin rolls to form a molten pool, and rotates the twin rolls to continuously produce slabs from the gap, A twin roll continuous casting machine characterized in that supply ports are provided on both sides of the core in the roll axis direction for supplying molten metal so that the newly spouted molten metal is distributed over the entire surface of the molten pool.