JPH03114631A - Method for assembling short side plate used to mold for continuously casting cast strip - Google Patents

Abstract

PURPOSE:To assemble short side plates without penetrating molten metal into joint part during casting in a short time by assembling a refractory into a recessed part in a casing-like metal frame of the short side plate squeezing the intermediate part into the shape of top-widening and bottom-narrowing and causing the molten metal to flow into gap between the metal frame and the refractory to form the joint part. CONSTITUTION:A mold for cast strip continuous casting, is constituted of long wall faces with circulating bodies composed of one pair of metal belts 1, 2 and short wall faces with one pair of the short wall side plates 4, 5. The short side plate 4, 5 is constituted of the metal frame 8 and refractory 9, and the metal frame 8 is formed to the shape squeezing the intermediate part, top-widening and bottom-narrowing, and the recessed part 11 is formed to the part remaining the side edge casing part 10 in the range from the widening upper end to the squeezing part at the intermediate part. In this recessed part 11, the refractory 9 is set so as to be apart from the casing part 10 with gap 12 (about 2-4mm) and in the gap 12, the molten metal 13 is poured and solidified to form the joint part 14. By this method, the short side plates 4, 5 without penetrating the molten metal into the joint part during casting, can be assembled in a short time.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a method for assembling a short side plate used on a short side of a mold in a continuous thin slab casting machine that directly produces thin slabs from molten metal.

(Prior Art) Recently, various types of continuous casting machines have been proposed that continuously produce thin slabs such as sheet bars directly from molten metal (the following will be explained using the example of "molten steel"). . For example, belt casters, block casters, twin roll casters, etc. are shown in FIG. 5 as a typical example of a belt caster.

The illustrated synchronous belt caster is of the narrowing type and is cast through a plurality of guide rolls 3a, 3b, 3c, respectively, while maintaining a gap for holding the cast material such as molten steel or solidified shell over a predetermined distance. metal belts 1 and 2 that support a pair of long side surfaces that are arranged opposite to each other and move axially; The concave short side plates 4.5 on the upper and lower sides confine the casting space on four sides.

When molten steel is supplied into the casting space from the immersion nozzle 6, the metal healds 1 and 2 are cooled by cooling pads 7a and 7b.
The molten steel that has come into contact with 2 is drawn downward while forming a solidified shell.

In order to delay solidification on the short sides, it is advantageous to form the inner surfaces of the short side plates in contact with the molten steel with a refractory material. A short side plate is disclosed in which a metal frame (cooled copper plate) is provided with a refractory supported by a frame part.

In order to perform stable casting using such short side plates,
It is important that molten metal is not inserted into the boundary between the metal frame and the refractory on the short side plates.

Therefore, when installing the refractory inside the metal frame, the shape of the refractory is adjusted by cutting the side edges of the refractory so that the gap between the metal frame and the refractory is approximately 0.1 to 0.3 mm. It was being corrected.

(Problem to be solved by the invention) However, it takes a long time to grind the refractory, and the metal frame in which the refractory is installed tends to deform during use, so it is necessary to correct this. In addition to being time consuming, this work was difficult and required skill.

In addition, if the boundary between the refractory and the metal frame is large, the mortar that fills the boundary during the installation of the refractory will melt away during casting.
Molten steel is inserted into this melted part (hereinafter referred to as jointer),
A shell develops on the short sides of the mold, inducing breakout.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to propose a method for assembling short side plates that allows easy assembly of refractories into a metal frame and does not cause joints after assembly.

(Means for Solving the Problems) The present invention provides continuous casting of thin cast slabs whose long sides are circulating bodies arranged opposite to each other, which circulate while maintaining a gap for holding molten metal over a certain distance. In the mold for
A side plate used as a short side of a mold having a shape in which the middle part is narrowed by a concave area at both side edges between the circulating bodies, the metal frame having both side edges in contact with the circulating body shaped like a picture frame;
When assembling the short-side side plates made of refractories placed inside the metal frame, the refractories are placed inside the metal frame with gaps between them, and then molten metal is poured into the gaps to fill the gaps. This is a method for assembling short side plates used in a mold for continuous casting of thin slabs.

Now, with reference to FIG. 1, this invention will be specifically explained.

First, as shown in the figure, a metal frame 8 and a refractory 9 constituting a short side plate are prepared. The metal frame 8 is formed, for example, by forming a copper plate into a shape in which the middle part is narrowed with a constriction at the top and bottom, and is further formed into a shape in which the frame part 10 on the side edge is left in the area from the wide upper end to the narrowed part in the middle part. , recess 1 into which refractory 9 is installed
1 is formed.

Further, it is common to provide a cooling path through which cooling water flows inside the metal frame 8 to cool the metal frame 8 from the inside.

Next, the refractory 9 is placed in the recess 11 between the frame parts 10 of the metal frame 8. Here, it is important that the frame portion 10 of the metal frame 8 and the refractory 9 be separated by a predetermined gap 12. Then, into this gap 12, molten metal 13 is passed from the heated crucible.
When poured, cooled and solidified, the gap 12 is filled,
A joint 14 is formed as shown in FIG.

The gap 12 is preferably 2 to 4 mm, because if it is less than 2 mm, it will be difficult to pour the molten metal, and it may not flow in due to the surface tension of the molten metal, whereas if it exceeds 4 mm, the poured metal will not be cooled enough. This is because the joints may melt during use (casting).

Further, recesses 15A and 15B are formed on the inner surface of the frame portion 10 and the outer surface of the refractory 9 facing the gap 12, respectively, and if the molten metal 13 is poured into these recesses 15A and 15B and solidified, the refractory 9 from falling off from the frame portion 10 can be further strengthened.

If the molten metal 13 poured into the gap 12 is made of the same material as the metal frame 8 (mainly copper) or a low melting point metal such as lead, the joint sealing work will be made easier. When using low-melting point metals, in order to prevent elution of the joints during casting, it is necessary to take measures such as moving the cooling path installed inside the metal frame closer to the joint side or increasing the flow rate of cooling water in the cooling path. It is desirable to give lectures accordingly.

(Function) By grinding the short side plate obtained by the above assembly method and the refractory (conventional method), the gap between the boundary between the metal frame and the refractory is reduced to 0.3 mm or less, 0.4 to 0.6 mm. and 0.7m
FIG. 3 shows the results of an investigation into the incidence of breakouts caused by joints when a short-side side plate adjusted to a diameter of m or more was used for continuous casting of thin slabs.

From the same figure, when using the short side plate obtained according to the present invention, the gap can be reduced to 0.3 m with the strictest shape control in the past.
As in the case of using short side plates with a length of less than m, there were no joints during casting.

Furthermore, when the time required for assembling the short side plates was investigated in accordance with the present invention and in the case of following the conventional method (gap: 0.2 mm), as shown in Fig. 4, the assembly time was reduced to 178 by following the present invention. Shortened.

(Example) In assembling the short side plate according to the present invention, the first
As shown in the figure, Sialon refractories 9 are placed in the frame part 10 of the copper metal frame 8 with a gap 12 of 3.5 mm in width, and molten steel is poured into the gap 12, and the metal The frame 8 was cooled to solidify the copper. The poured copper was almost integrated with the frame portion 10. When the obtained short side plate was applied to the belt caster shown in Fig. 5 and a thin slab was cast, the copper at the joints was cooled through the metal frame 8 and did not elute, and normal casting was performed. I was able to implement it.

(Effects of the Invention) According to the present invention, it is possible to assemble short side plates without joints during casting in a short time, and this invention greatly contributes to the industrialization of continuous casting of thin slabs.

[Brief explanation of drawings]

Fig. 1 is a perspective view explaining the present invention in detail, Fig. 2 is a schematic diagram showing a short side plate obtained according to the invention, Fig. 3 is a graph showing the incidence of breakout, and Fig. 4 is an assembled A graph showing time. Fig. 5 is an explanatory diagram of the Heltcaster. 12...Metal heald 3a 3b, 3c...Guide roll 4.5...
Short side plate 6...Immersion nozzle 7a, 7b...
Cooling pad 8...Metal frame 9...Refractory
10... Frame part 11... Recess 1
2... Gap 13... Molten metal 14...
Joint 158, 15B...concavity) JP-A-114631 (4)

Claims (1)

[Claims] 1. In a mold for continuous casting of thin slabs whose long sides are a pair of opposing circulating bodies that circulate while maintaining a gap for holding molten metal over a certain distance, both edges between the circulating bodies A side plate used as the short side of the mold, which has a narrowed middle part with a concave area at the top and bottom at the top, and a metal frame with frame-like edges on both sides in contact with the circulation body, and a metal frame arranged inside the metal frame. Continuous casting of thin cast slabs, which is characterized in that when assembling short side plates made of refractories to be installed, refractories are placed inside a metal frame with gaps between them, and then molten metal is poured into the gaps to fill the gaps. How to assemble the short side plates used in molds.