JPH0478384B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a pouring nozzle used when manufacturing a metal ribbon by rapidly cooling and solidifying molten metal on the circumferential surface of a cooling roll.

(Prior Art) In a single roll system or a twin roll system, molten metal is supplied to the circumferential surface of a rotating cooling roll.
This molten metal is rapidly cooled and solidified by heat removal via a cooling roll to produce a solidified shell, which is sent out from the casting space as a metal ribbon.

The present inventors have developed an apparatus for continuous casting of metal ribbon using rolls of different diameters, which is a type of this twin roll system, and have published this device in Japanese Patent Application No. 60-76800 (Japanese Patent Application No. 61-253149). The application was filed as Publication No. FIG. 2 shows an example of the continuous casting apparatus introduced in this prior application. That is, the small-diameter roll 22 is opposed to a part of the circumferential surface of the large-diameter roll 21, and both ends in the axial direction are partitioned off by side walls 25 of a pouring nozzle 24 provided at the tip of a pouring device 23. Then, by transmitting driving force to the drive shafts 26 and 27 of the large diameter roll 21 and the small diameter roll 22, respectively, the large diameter roll 21 and the small diameter roll 22 are rotated in the directions shown by the arrows. As a result, the molten metal 29 supplied to the molten metal reservoir 28 of the pouring device 23 is sent out to the circumferential surface of the rolls as the large diameter roll 21 and the small diameter roll 22 rotate.
There, it is cooled and solidified to form a solidified shell.

The pouring nozzle 24 used here includes a side wall 25 having an end surface 30 formed in a shape corresponding to the circumferential surface of the large-diameter roll 21, as shown in FIG. Further, the space between the left and right pair of side walls 25 is formed to be slightly larger than the axial length of the small diameter roll 22, and the space between the left and right side walls 25 is formed to be slightly larger than the axial length of the small diameter roll 22. It forms a housing portion for the small diameter roll 22. The lower portions of the side walls 25 are connected to each other by a bottom plate 33.
The end surface 34 of is also formed into a shape corresponding to the circumferential surface of the large diameter roll 21. In this way, the end surfaces 30 and 34 of the side wall 25 and the bottom plate 33 maintain a very close positional relationship between the pouring nozzle 24 and the circumferential surface of the large-diameter roll 21 to prevent melt leakage, and remove the molten metal from the metal. Cast a thin strip. In addition, a molten metal cap 35 is installed between the molten metal pool 28 and the pouring nozzle 24 so that the waves of the molten metal 29 in the molten metal pool 28 are not transmitted to the casting space defined by the rolls 21, 22 and the side walls 25. It is set up.

(Problems to be Solved by the Invention) The tip surface of the pouring nozzle 24 facing the large-diameter roll 21 is designed to prevent melt leakage from the casting space.
It must be manufactured with extremely high processing precision. Furthermore, since it is used in a high-temperature atmosphere where it comes into contact with molten metal, high-grade refractories that are less likely to deform at high temperatures are used. However, processing refractories with high precision is an extremely difficult task, and furthermore, processing costs are high.

Furthermore, the conventional pouring nozzle 24 has the left and right side walls 2.
5, 25, the top cover 32, and the bottom plate 33, it was extremely difficult to achieve sufficient dimensional accuracy during assembly. Additionally, all conventional pouring nozzles were discarded and replaced with new ones after every casting operation. Making expensive pouring nozzles disposable like this means
Not only does this impose a huge burden on the nozzle manufacturing work, but
This also causes an increase in the manufacturing cost of the metal ribbon.

Therefore, the present invention integrates the contact surfaces 30 and 34 of the nozzle with the roll and has a structure in which only the tip of the nozzle that requires high-precision processing can be replaced, thereby making it possible to repeat the nozzle body. The purpose is to provide a usable and inexpensive pouring nozzle.

(Means for Solving the Problems) The pouring nozzle of the present invention has a pouring nozzle formed by the peripheral surface of a cooling roll consisting of a small-diameter upper roll and a large-diameter lower roll, left and right side walls, a top cover, and a bottom wall. A continuous casting device that divides a casting space and cools and solidifies the molten metal supplied to the casting space by removing heat through the cooling roll to produce a metal ribbon, A tip block formed into a curved shape corresponding to the circumferential surface of the cooling roll is attached to an end surface facing the circumferential surface of the cooling roll extending from one side wall of the pouring nozzle through the bottom wall to the other side wall. It is characterized by

Here, the tip block can be attached to the nozzle body via plastic ceramics.

(Function) The features of the present invention will be explained below with reference to the drawings.
This will be explained in detail along with its effect.

As shown in FIG. 1, the pouring nozzle of the present invention comprises side walls 1, 1 that partition both sides of a casting space, and an upper lid 6 thereof.
and a bottom wall 2 that partitions the lower part (hereinafter referred to as the nozzle body), side walls 1 on both sides and a tip block 3 attached in contact with the end surface of the bottom wall 2.

Therefore, the end surfaces of the side walls 1, 1 and bottom wall 2 on both sides facing the large diameter roll 21 (see FIG. 2), that is, the end surfaces of the pouring nozzle main body of the present invention, are as shown in FIG. 3. Unlike , it does not face the circumferential surface of the diameter roll, so it does not need to be processed with such high precision.

The tip block 3 attached in contact with the end faces of the side walls 1, 1 and the bottom wall 2 on both sides is machined with high precision so as to directly face the peripheral surface of the roll.

This tip block 3 is made of a material with high resistance to heat shock. Such materials include, for example, fused silica, silicon nitride, boron nitride, alumina graphite, and the like.
The tip block 3 provided from one side wall 1 through the bottom wall 2 to the other side wall 1 is integral, so as explained in FIG. The madness will disappear.

The end surface of this tip block 3 (in front of the paper in FIG. 1) is arranged close to the circumferential surface of the large diameter roll,
A casting space is formed. Therefore, the only member that requires precision machining is the tip block 3.
The nozzle body including the side walls 1, 1, the bottom wall 2, etc. is manufactured by normal processing. Furthermore, since the nozzle body does not directly partition the casting space, it can be used repeatedly even if it undergoes some thermal deformation.

Moreover, plastic ceramics 4 can be interposed as a coupling between the tip block 3 and the nozzle main body. When the plastic ceramics 4 are in between, the plastic ceramics 4 absorb vibrations caused by part or all of the tip block 3 coming into contact with the circumferential surface of the large diameter roll. Therefore, damage to the tip block 3 or the nozzle body is prevented. As the plastic ceramic 4, an inorganic fiber having excellent heat resistance such as ceramic fiber is used.

In this way, only the tip block 3, which is the most important component in casting thin metal strips and is prone to thermal deformation and wear due to being used in a harsh atmosphere, is molded separately from the nozzle body. are doing. By replacing the tip block 3 according to the degree of thermal deformation or wear, it becomes possible to cast a metal ribbon under stable conditions in which an accurate gap between the tip block 3 and the large-diameter roll is always maintained. Further, since the nozzle body can be used repeatedly, the burden on the production work and manufacturing cost of the pouring nozzle is also reduced.

In order to accurately attach the tip block 3 to the nozzle tip, it is preferable that the notch 5 continuous to the side walls 1, 1 and the bottom wall 2 be formed to correspond to the shape of the tip block 3. By fitting the tip block 3 into this notch 5, the tip block 3 can be secured at a predetermined position. Further, the tip block 3 is attached to the nozzle body using a suitable adhesive such as fireproof mortar.

(Example) A large diameter roll with a diameter of 1400 mm and a width of 1000 mm has a diameter of 400 mm.
Small diameter rolls with a width of 650 mm were placed opposite each other, and both rolls were rotated at a circumferential speed of 20 m/min. Stainless steel is supplied from the molten metal pool into the casting space defined by these rolls and both side walls 1, 1 of the pouring nozzle.
We manufactured 400 kg of metal ribbon with a width of 650 mm from molten steel with SUS304 composition. At this time, a pouring nozzle having a tip block 3 made of fused silica attached to the end face of the roll was used. This tip block 3 accurately maintains the gap between the nozzle tip and the circumferential surface of the large-diameter roll, so casting can be completed under stable conditions without leakage. Ta. Moreover, the obtained product also had a constant shape from the initial stage to the final stage of casting. Moreover, even when the tip block 3 was replaced with a new one and casting was performed, there was no substantial change in the shape of the manufactured metal ribbon.

On the other hand, a metal ribbon was cast under similar conditions using a conventional pouring nozzle that combined a bottom plate with a side wall whose end face was shaped to match the circumferential shape of a large-diameter roll. In this case, since the roll-side end face of the pouring nozzle changes depending on the combination of the side wall and the bottom plate, the shape of the manufactured metal ribbon varies between charges.

(Effects of the Invention) As described above, in the present invention, the end surface of the pouring nozzle on the cooling roll side is constituted by an integral tip block, and the tip block is opposed to the circumferential surface of the cooling roll. Therefore, the gap between the pouring nozzle and the circumferential surface of the cooling roll can be accurately maintained, and there is no dimensional variation during assembly as seen with conventional nozzles. Therefore, it is possible to produce a metal ribbon with excellent shape characteristics under stable conditions without causing defects such as melt leakage.

[Brief explanation of drawings]

FIG. 1 is a diagram for explaining a pouring nozzle according to an embodiment of the present invention. FIG. 2 shows a twin-roll type continuous casting device equipped with rolls of different diameters, which was previously proposed by the present inventors, and FIG. 3 shows a pouring nozzle used in the device. DESCRIPTION OF SYMBOLS 1...Side wall, 2...Bottom wall, 3...Tip block, 4...Plastic ceramics, 5...Notch part.

Claims (1)

[Claims] 1. A casting space is defined by a cooling roll consisting of a small-diameter upper roll and a large-diameter lower roll, a pouring nozzle formed by the left and right side walls, a top cover, and a bottom wall. In a pouring nozzle for a continuous casting device that produces a metal ribbon by cooling and solidifying supplied molten metal by removing heat through the cooling roll, the molten metal is formed into a curved shape corresponding to the circumferential surface of the cooling roll. A pouring tip for a continuous metal ribbon casting apparatus, characterized in that a tip block is attached to an end surface of the pouring nozzle, which is opposite to the circumferential surface of the cooling roll, extending from one side wall of the pouring nozzle to the other side wall via the bottom wall. nozzle. 2. The pouring nozzle for a metal ribbon continuous casting apparatus according to claim 1, wherein the tip block is attached to the nozzle body via plastic ceramics.