JPS63309358A - Twin belt type continuous casting apparatus - Google Patents

Abstract

PURPOSE:To execute casting operation under stable condition by inclining carrying passage of short side molds to carrying direction of belts, to always run the short side molds under pushing condition to guide rails. CONSTITUTION:The carrying passage of the short side molds 5 partitioning both end sides of a pouring basin part are inclined toward center of the belts 4, to make the relative gap narrower as the short side mold 5 goes to lower part. The guide rail 8 is arranged at back side of this short side mold 5 and the rolls 9 arranged in the mold 5 are moved while rolling on the guide rail 8. By this method, good contact between the mold 5 and the metal strip following shrinkage at the width direction of the metal strip, is obtd. Further, as the short side mold 5 is pushed to the guide rail 8 with force F caused by slipping between the belt 4 and the short side mold 5, in spite of the shrinkage and pressure of solidified shell or the metal strip, the carrying passage of the mold 5 is always maintained under stable condition.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a twin-belt type continuous casting apparatus for manufacturing metal ribbon while accurately maintaining the reference plane of a short side mold.

[Conventional technology]

Recently, a number of lIIm close to the final shape has been obtained from molten metal such as molten steel.
Continuous casting methods that directly produce metal ribbons with a thickness of about several tens of millimeters are attracting attention. ``When using this method, the conventional multi-step rolling process can be omitted, so the process and equipment can be simplified.

Furthermore, since the process of heating the material to the processing temperature between each process is essentially unnecessary, an energy saving effect can also be expected.

One type of continuous casting is the twin belt method. FIG. 3 is a diagram schematically showing a twin belt continuous casting machine. In this continuous casting machine, molten metal in a dandying unit 1 is supplied from a nozzle 2 to a casting space. This casting space is formed by partitioning both sides of the opposing gap between a pair of belts 4 made of a heat-resistant material such as steel that run over a pulley 3 with short side molds (not shown). ing. The end of the molten metal enema into this casting space is cooled at 6
The metal is cooled and solidified by the process, and is then transported out as a thin metal ribbon 7.

[Problem that the invention seeks to solve]

The molten metal injected into the casting space is cooled and solidified by heat removal through the belt 4, and shrinks in the process of being carried out as a metal ribbon 7. This contraction also occurs in the width direction of the belt 4. Therefore, the short-side mold 5, which was in contact with both ends of the molten metal at the upper part of the molten metal pool, creates a gap between it and both ends of the solidified shell or the metal ribbon T as it moves downward.

As a result, when viewed from the side of the metal ribbon 7, which is a cast slab, contact with the short-side mold becomes insufficient, heat removal is insufficient, and the required thickness cannot be obtained. Such a hole is likely to break in the mold or on the exit side of the mold, causing unsolidified molten metal to blow out and causing double skin on the thin metal strip 7. Furthermore, if the molten metal blows out to an extreme degree, a breakout will occur, resulting in an inoperable state.

On the other hand, as shown in FIG. 4, in the mobile short-side mold, cooling blocks 5a are connected by links 5b, and a roll 9 provided at the tip of the link 5b is used to move the mold along the guide rail 8 and on the wide side. They rotate almost synchronously while being sandwiched between the belts 4. The relationship between the guide rail 8 and the roll 9 is as follows:
In order to prevent the space from narrowing and causing a locking phenomenon if minute dust etc. enters during this time, a gap Y of around 1 mm should be provided as shown in Figure (a), or a gap Y of around 1 mm should be provided as shown in Figure (b). so that only one side receives the force. Therefore, as mentioned above, if the solidification tube contracts or the surface of the block 5a rises due to thermal expansion, proper contact with the solidification tube or tube cannot be obtained, and the produced metal thin strip 7 appears as defects such as poor surface quality and occurrence of breakouts.

Therefore, the present invention eliminates the gap caused by the contraction of the solidified shell or metal ribbon by feeding the short side mold into the casting space at an angle, and moreover, the short side mold is moved by the thrust force constantly acting from the belt in the direction of width expansion. By pressing against the guide rail, while securing the reference surface of the short side mold,
The purpose is to produce metal ribbon under stable conditions.

[Failure to solve the problem]

In order to achieve the objective, the twin belt type continuous casting apparatus of the present invention is a continuous casting apparatus that manufactures a metal ribbon by cooling and solidifying molten metal injected into a pool between a pair of belts. A short-side mold that partitions both ends of the molten metal pool is disposed so as to be movable along a conveyance path in which the gap between them becomes narrower toward the bottom, and the short-side mold that is running is placed behind the short-side mold. It is characterized by the provision of a supporting guide rail.

3 Embodiments] Hereinafter, the features of the present invention will be specifically explained by way of embodiments with reference to the drawings.

FIGS. 1 and 2 show the running state of the short side mold in the embodiment of the present invention. In addition, since the apparatus as a whole is an improvement of the twin-belt type continuous casting machine shown in Figs. 3 and 4, the numbers in Figs. 3 and 4 will be used as appropriate in the following explanation. ing.

In the actual three-color example, the conveyance path of the short-side mold 5 that partitions both ends of the pool is inclined toward the center of the belt 4. That is, in the short side molds 5 disposed at both ends of the belt 4, the gap between the short side molds 5 becomes narrower toward the bottom. A guide rail 8 is provided on the rear side of this short side mold 5.
A roll 9 provided on the short side mold 5 moves on this guide rail 8.

When the conveyance path of the short-side mold 5 is inclined in this way, it is possible to follow the contraction of the metal ribbon 70 in the width direction and obtain good contact between the short-side molds 5. Then, as the belt 4 and the short-side mold 5 move downward as indicated by the arrow X, slippage occurs between the belt 4 and the short-side mold 5. Therefore, as shown in FIG. 2, the force F that counteracts this slippage is
It is added to the short side mold 5 from. Since this force F pushes the short side mold 5 outward, the roll 9 is pressed against the guide rail 8.

That is, the conventional short-side mold 5 is designed on the premise that the short-side mold 5 is cooled by contacting the short-side mold 5 by bulging due to the pressure of the molten metal or solidification/el inside.
Their positions were determined so that they would run parallel to each other. Therefore, when the solidification tube or metal ribbon 7 contracts, no internal pressure is applied to the short-side mold 5, and the running state of the short-side mold 5 becomes unstable, and contact heat removal becomes unstable. . On the other hand, in this embodiment, since the short side mold 5 is pressed against the guide rail 8 by the force F caused by the slippage between the belt 4 and the short side mold 5, the solidified shell or the metal Regardless of the contraction and pressure of the ribbon 7, the conveyance path of the short-side mold 5 can always be maintained under stable conditions.

Therefore, it is possible to maintain a constant reference plane of the short side mold 5 at an appropriate slope, and the solidified shell is not compressed excessively more than the shrinkage due to the shrinkage of the slab, and the short side mold 5 is can be brought into contact with the bronck 5a to remove heat.

The inclination angle θ of the conveyance path of the short mold 5 with respect to the conveyance direction χ of the belt 4 is determined as follows. That is, in FIG. 2, the population width between the pair of short side molds 5 is Wl,
When the exit width is Wo, the exit width W0 is expressed by the following equation.

Wo=Wl×(1-λ(T,,-TS.

)) However, λ: Coefficient of thermal expansion Tsl: Solidification temperature T. : Outlet surface temperature Therefore, the width reduction amount ΔW (W, -Wo) is ΔW=
W, λ(TSt Tso). Therefore, the inclination angle θ of the conveyance path of the short-side mold 5 is 1, and the length of the casting area is ! When, the following formula method % This inclination angle θ is preferably maintained in the range of 0.05 to 0.2 degrees when steel is continuously cast by a belt type continuous casting machine.

〔Effect of the invention〕

As described above, in the present invention, the conveyance path of the short-side mold is inclined with respect to the conveyance direction of the belt, so that an outward force acts on the short-side mold. Therefore, the short side mold always runs while being pressed against the guide rail, regardless of the gap created between it and the short side mold due to the contraction of the solidification tube or metal ribbon in the casting space. Therefore, the reference plane of the short-side mold is kept constant, making it possible to carry out casting work under stable conditions.

[Brief explanation of drawings]

FIG. 1 shows the conveyance state of the short-side mold in the embodiment of the present invention, and FIG. 2 is a diagram illustrating the force applied to the short-side mold at that time. On the other hand, FIG. 3 shows a conventional twin-belt type continuous casting machine, and FIG. 4 is an explanatory diagram of a conventional countermeasure against the locking phenomenon in a movable short-side mold. Patent Applicant Nippon Steel Corporation Representative Masu Kobori (and 2 others) Figure 1 Figure 2 Figure 3 Figure 4! lI: roll

Claims (1)

[Claims] 1. In a continuous casting machine that manufactures a metal ribbon by cooling and solidifying molten metal poured into a pool between a pair of belts, the short-side molds that partition both ends of the pool are moved downwards toward each other. A series of twin belts, which are disposed so as to be movable along a conveyance path with a narrowing gap, and further include a guide rail provided behind the short-side mold to support the short-side mold while it is running. Casting equipment.