JPH0225248A - Production of rapidly cooled thin strip - Google Patents

Abstract

PURPOSE:To make mass production of thin strips having good edge shapes by ejecting an inert gas from the gate plates provided with a specified spacing onto the rotating plane at both ends of a pair of cooling rolls to said spacing and applying oscillation to said gate plates. CONSTITUTION:After a molten metal 7 supplied from a nozzle 6 is temporarily held between twin rolls 8, 8 and the gate plates 1, 1, the molten metal is fed downward as a thin strip 9. The gate plates 1, 1 are fixed to have some spacing from the rolls 8, 8 and the inert gas is injected 3' from the gate plates 1, 1 toward the roll 8, 8 surfaces. The penetration of the molten steel 7 to the spacing between the rolls 8, 8 and the gate plates 1, 1 is, therefore, prevented by this gas injection. The gate plates 1, 1 are slightly moved forward and backward in a horizontal direction by the operation of an exciter 5. The solidified shell developing on the inner side of the gate plates 1, 1 is, therefore, shaken off toward the kiss part when the shell grows to some size.

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention relates to a method for manufacturing a quenched ribbon, and in particular, to prevent wear of the edge weir plate and prevention of molten steel from penetrating into the contact area between the edge weir plate and the rolls and solidifying. It is about the method.

<Prior art> In the so-called twin-roll quenching ribbon process, in which molten metal is continuously supplied from above to a pair of cooling rolls that rotate close to each other and rapidly solidified to produce a ribbon, the molten metal is It is a known method to arrange a pair of side weirs in contact with the side ends of the cooling roll in order to prevent the liquid from flowing out toward the ends of the roll, as seen in Japanese Patent Laid-Open No. 60-30556.

Since this method is a so-called extrapolation method in which side dams are pressed against the sides of the two rolls, boiling is likely to occur if relative displacement occurs in the rolls.

In contrast, the object of the present invention is a so-called interpolation system in which weir plates are arranged at both ends of the roll so as to be substantially in contact with the rotational circumferential surface of the roll.

This method differs from the extrapolation method in that it has the advantage of not causing boiling even if relative displacement occurs in the rolls. However, in this case as well, there is a drawback that if a certain gap occurs between the weir plate and the roll circumferential surface, hot water will form there, resulting in poor edge shape of the ribbon. In addition, since the inside of the inserted weir plate is always in contact with molten steel, a solidified shell develops there, and when it reaches a certain size, it collapses onto the roll kissing surface due to its own weight, leading to plate breakage and roll surface scratches. There was also a risk.

<Problems to be Solved by the Invention> The present invention solves these drawbacks of the interpolation type weir plate, namely (1) insertion of the rope between the weir plate and the roll circular surface, and (2) solidification shell on the weir plate surface. The purpose of the present invention is to propose a method for manufacturing cold ribbon, which can eliminate the development of cold ribbons and thereby mass-produce ribbons with good edge shapes.

<Means for Solving the Problems> The present invention comprises a pair of cooling rolls that rotate close to each other and a pair of cooling rolls that are disposed at both ends of the cooling rolls with a constant gap on the rotating surface of the cooling rolls. When producing a quenched ribbon while continuously supplying molten metal into the space formed by the weir plate, inert gas is ejected from the weir plate into the gap and vibration is applied to the weir plate. This is a method for producing a quenched ribbon, which is characterized by:

Function> Fig. 1 is an explanatory diagram of the area around the weir plate adopted in the present invention.
FIG. 2 is a diagram showing the rod in which it is attached to twin rolls and cast.

In FIG. 1, reference numeral 1 denotes an internal weir plate, and inert gas 3 is supplied from a hose 2 and is ejected as 3' from the end face of the weir plate in contact with the roll rotation surface. Further, the weir plate 1 is connected to a vibrator 5 by a connecting rod 4, and vibration in the horizontal direction is applied by driving the vibrator 5.

In Fig. 2, molten gold rf47 supplied from nozzle 6
After being temporarily held between the twin rolls 8.8 and the weir plate 1.1, it becomes a ribbon 9 and is sent downward.

At this time, the weir plate 1.1 is fixed to the roll 8.8 with a certain gap, and inert gas is blown out from the weir plate toward the roll surface. Therefore, this gas jetting can prevent molten steel from pouring into the gap between the cooling roll and the weir plate.

The size of the gap between the weir plate and the roll surface is 0.1 to 5.0.
- is preferred.

Furthermore, the weir plate 1.1 performs a slight reciprocating motion in the horizontal direction by the operation of the vibrator, so that the solidified shell that develops inside is sieved off toward the kiss portion when it reaches a certain size. The maximum amplitude of the micromovement is preferably 2 to 3 m from the viewpoint of the coil edge shape.

In this example, the vibration of the weir plate is in the horizontal direction, but it may also be vibration in the vertical direction or a composite vibration in the vertical and horizontal directions.

<Example> In order to confirm the effects of the present invention, the following manufacturing experiment was conducted.
It was.

(+) Class Species 4.5% Si -Fe(2
)Pouring speed 6kg/5 (3) Roll peripheral speed 5m/5 (4) Weir
Temporary copper, nozzle hole 5φ x 20 (5) Gap between roll surface and weir plate 0.2 Decoration (6) Inert gas Ar,
4Nnf/h (7) Vibrator ■ Excitation force 100k
gf■ Frequency +0011z ■Displacement 3 cylinders (81 elephants, cold ribbon size 300m width x 0.56!
11 thickness or conventional internal weir plate (roll close contact, no vibration)
A similar manufacturing experiment was conducted using the same method, and the edge shape and plate breakage frequency were compared. The results are shown in the table below, and it can be seen that in the case of the present invention, the degree of defective edge shape was reduced to about 1/7, and the number of plate breaks was reduced to about 115.

<Effects of the Invention> The method of the present invention has made it possible to stably produce a coil with a far better edge shape than the conventional method.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an explanatory diagram of the vicinity of the weir plate employed in the present invention, and FIG. 2 is a conceptual diagram showing the operational status of the present invention. 1... Weir plate, 2... Gas hose, 3゜3'... Inert gas, 4... Connecting rod, 6... Nozzle, 8... Cooling roll, 5... Vibration vessel, 7... molten metal, 9... quenching PW zone.

Claims (1)

[Claims] Molten metal is placed in a space formed by a pair of cooling rolls that rotate close to each other and a pair of weir plates that are disposed at both ends of the cooling rolls with a certain gap above the rotating surface of the cooling rolls. 1. A method for producing a quenched ribbon, which comprises blowing out an inert gas from the weir plate into the gap and applying vibration to the weir plate when producing the quenched ribbon while continuously supplying the quenched ribbon.