JPS61253148A - Method and apparatus for producing quickly cooled thin strip - Google Patents

Abstract

PURPOSE:To improve the surface characteristic of a product by melting and injecting a metal in a vacuum state under the specific pressure. CONSTITUTION:A nozzle 1 provided with a heater 3 is disposed above a rotating roll 2 for cooling and both are housed into a hermetic vessel 4. A part 5 for recovering the quickly cooled thin strip is provided to the vessel 4 and a vacuum pump R.P and oil diffusion pump D.P are connected thereto. The pump R.P and pump D.P are driven to maintain the inside of the hermetic vessel 4 in a vacuum state of <=10<-4> Torr and to eject the metal heated by a heater 3 from the tip of the nozzle 1 to the surface of the roll 2. The characteristic of the free surface of the metal on the side where the metal does not contact with the surface of the roll 2 in the quick cooling and solidifying stage of the molten metal is improved by the above-mentioned method, by which the surface characteristics of both surfaces of the thin strip product are improved.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to the production of quenched ribbons by the so-called single roll method or centrifugal method.

(Prior art and problems) In recent years, since the material properties of amorphous metals and alloys have attracted attention, there has been a remarkable amount of research and development into their manufacturing technology. Research on manufacturing technology for quenched ribbons is actively being conducted.

Methods for producing quenched ribbons can be roughly divided in principle into centrifugal methods, single roll methods, twin roll methods, and the like.

In either method, metals, alloys, ceramics, etc. are melted in an electric furnace, high-frequency furnace, etc., and the molten metal is jetted from a nozzle onto the surface of a cooling rotating body using gas pressure to rapidly solidify it, producing a so-called quenched ribbon. The latter method, the twin roll method, has good surface quality on the front and back surfaces because both sides are quenched and solidified using a pair of cooling rotors, but it is difficult to adjust the manufacturing conditions and it is difficult to produce quenched ribbons. There is a limit to the width, and it is not possible to manufacture something that is too wide.

On the other hand, the former two methods, the single roll method and the centrifugal method, can produce products with relatively wide dimensions.
It is possible to produce a wide quenched ribbon with a width of about 0 mm. However, these methods have the drawback that since only one side is rapidly cooled, the surface properties of the one-rotating member side and the free surface side are significantly different, and the surface properties of the free surface side are poor. It is recognized that these drawbacks are inevitable due to the manufacturing principle of quenched ribbons.

In particular, although the rapidly quenched ribbon produced by the single roll method has the advantage of being able to be made wider, the current situation is that the expansion of its applications is limited.

(Objective of the Invention) The present invention eliminates the drawbacks associated with the conventional single roll method or centrifugal method described above, and significantly improves the properties of the free surface side of the quenched ribbon, making both the front and back surfaces extremely beautiful. It is an object of the present invention to provide a method and apparatus capable of producing a quenched ribbon with excellent surface properties.

(Structure of the Invention) In order to achieve the above object, the present invention provides melting, spouting, etc. of the metal material in the single roll method or centrifugal method described above.
The main idea is to carry out the process in a vacuum of 4 torr or less, thereby making it possible to significantly improve the surface properties of the free surface side of the quenched ribbon.

The present invention will be explained in detail below based on examples.

In the conventional method for manufacturing the quenched ribbon described above, molten metal is jetted onto the surface of a cooling rotating body through a nozzle to quench it.
This process is carried out in air or, if necessary, in an inert gas atmosphere. The inventors investigated the effect of such an atmosphere on the surface quality of the free surface of the single-roll method or the centrifugal method, and found that by carrying out the process in a vacuum, the free surface of the quenched ribbon was extremely beautiful without any irregularities. I discovered that

However, simply creating a vacuum has no effect;
It is necessary to perform the process in a vacuum state of less than ↓O-4 torr, preferably 1-0-4 torr or more. If the vacuum is lower than 1 O'-4 torr, no improvement in the properties of the free surface of the quenched ribbon can be expected, and if an induction furnace is used as the melting means, a discharge phenomenon is likely to occur. In addition, if the vacuum is set to a high vacuum of 10'''5 torr or less, the cooling ability of the cooling rotating body that comes into contact with the jets from the nozzle, and the cooling ability of the running ribbon that is separated from its surface will decrease, causing the thin ribbon to deteriorate. There is a tendency for the linearity to deteriorate due to the generation of cracks.As a countermeasure for this, it is effective to use a water-cooled type for the cooling rotating body and increase the cooling capacity of the ribbon.
The quenched ribbon is produced by the single roll method (b) and the centrifugal method (a) shown in FIG. 1 while the working atmosphere is kept in a vacuum, thereby making it possible to prevent the occurrence of wrinkles.

In the figure, 1 is a nozzle, 2 is a cooling rotating body, and 3 is a heating device.

Figure 2 shows the manufacturing equipment for the single roll method.

A nozzle 1 equipped with a heating device 3 is arranged so as to be movable up and down above a roll 2 as a cooling rotary body, and these are placed in a closed container 4.
Store inside. The airtight container 4 has a collection section 5 for the quenched ribbon, and is also equipped with a vacuum pump R, for example, to evacuate the inside.
, P, and oil diffusion pumps D, P,. As the heating device 3 for the nozzle 1, use one that can rapidly heat and melt the metal material inside the nozzle 1 in a vacuum using a resistance furnace, an induction furnace, etc.
A gas pressure supply device (not shown) is connected to the gas pressure supply device (not shown) which causes the gas pressure to be ejected from the tip.

The cooling rotating body 2 may be of a conventional type, and its material is selected depending on the molten metal, such as iron or copper. If water-cooled rolls are used, various types can be used, as shown in FIG. 3 by way of example. In the figure, a cooling water jacket 7 is provided inside the roll body 6, and this is airtightly connected to a water guide pipe 8 having a double pipe structure. Note that 9 is a rotating shaft and 10 is a lid.

It goes without saying that the present invention is applicable to the production of quenched ribbons made of any material, including iron-based materials (e.g., Fe).
It is possible to produce a quenched ribbon of non-ferrous materials, etc., with excellent properties on both sides.

Next, examples of the present invention will be shown.

(Example 1) Using the apparatus shown in FIG. 2, quenched ribbons of Fe-6,5% Si alloy and Fe-6,5%5i-3,5% B alloy were produced.

First, the above alloy was filled into a transparent quartz nozzle equipped with an induction furnace, and the inside of the sealed container was brought into a vacuum state of 10"" torr. Next, the above alloy is heated and melted in an induction furnace, and the ejection pressure is set to the above vacuum level (10-5 torr) plus 0.2
Ar gas was supplied to the nozzle so that the amount of molten metal was 1.5 kg/crn, and the nozzle was lowered to the ejection position, and the molten metal was ejected from its tip onto the surface of an iron rotating roll (SKDll).The circumferential speed of the roll was normally The circumferential speed is within the range of 5 to 20 m/s, but in this example, the circumferential speed was 10 m/s. The obtained quenched ribbon had a film thickness of 2 μm, and the surface roughness on the free surface side was As a result of the investigation, the surface roughness was ±2 μm to ±3 μm, which was similar to the surface roughness of the roll side surface.
This shows that the surface properties were significantly improved compared to µm to ±10 µm.

(Example 2) Sendust alloy (Fe-9,6
%5i-5.5%Afl) was produced.

However, the rotating roll is made of stainless steel 19 (s u 5303
), a water-cooled structure shown in Figure 3 was used.

As in Example 1, the obtained quenched ribbon exhibited excellent uniform surface properties on both the front and back surfaces, and was also substantially free of wrinkles and excellent in linearity.

In addition, in the conventional method, one period is usually around 10non, which is about 30m.
Since "wrinkles" indicating height fluctuations occur, when the quenched ribbon wound around a coil is pulled out, it becomes wrinkled as shown in FIG. remained straight.

(Effects of the Invention) As is clear from the detailed description above, according to the present invention, the properties of the free surface on the side that does not come into contact with the surface of the cooling rotor during rapid solidification of molten metal are significantly improved. , it is possible to produce a quenched ribbon with excellent surface properties that are very beautiful and uniform on both the front and back sides, and also to produce a quenched ribbon with less wrinkles and excellent linearity. This greatly contributes to expanding the uses of various quenched ribbons manufactured by the roll method or centrifugal method.

[Brief explanation of drawings]

FIGS. 1(a) and (b) are explanatory diagrams schematically showing the principles of the centrifugal method and the single roll method, respectively. FIG. 2 is a schematic diagram showing an example of a quenched ribbon manufacturing apparatus used in an embodiment of the present invention. 3 is a schematic sectional view showing an example of a water-cooled rotary roll, and FIG. 4 is an explanatory view showing wrinkles in a quenched ribbon according to a conventional method. 1... Nozzle; 2. ...Rotating body for cooling, 3
...Heating device, 4. Airtight container, 6. Rotating roll, 7. Water cooling jacket, 8. Water pipe. Patent applicant: Daido Steel Co., Ltd. Patent attorney Hisashi Nakamura Figure 1 (C1) (b) Figure 2 Figure 3

Claims (1)

[Scope of Claims] 1. In a single roll method or centrifugal method in which a quenched ribbon is produced by jetting melted molten metal from a nozzle onto the surface of a rotating body using gas pressure, the above melting and jetting are performed for 10^-^ 4t
A method for producing a quenched ribbon, characterized in that it is carried out in a vacuum of less than orr. 2. The method according to claim 1, wherein the rapid cooling rotating body is water-cooled to increase cooling capacity. 3. In a quenched ribbon manufacturing apparatus that manufactures a quenched ribbon by spouting molten metal onto the surface of a rotating body using a nozzle equipped with a heating device for obtaining molten metal, the quenched ribbon manufacturing apparatus is placed in a closed container. A quenched ribbon manufacturing apparatus comprising: a gas pressure supply device for spouting the molten metal in the nozzle; and a vacuum device for evacuating the inside of the closed container. 4. The apparatus for manufacturing a quenched ribbon according to claim 3, further comprising a cooling liquid circulation path provided in the rotating body and a device for supplying the cooling liquid into the circulation path. 5. The apparatus for manufacturing a quenched ribbon according to claim 3 or 4, further comprising a quenched ribbon recovery section in the airtight container.