JPS60177943A - Nozzle - Google Patents

Abstract

PURPOSE:To improve the degree of freedom of shape in the small hole part for ejecting a melt by forming fine grooves to the inside wall part of a metallic nozzle which contacts with a molten metal and can be cooled. CONSTITUTION:A metallic nozzle is inscribed with plural fine grooves 2 on the inside wall part to contact with a molten metal 3 and can be cooled with water. The molten metal 3 cannot contact with the inside of the grooves 2 on account of surface tension, thus resulting in the decreased contact area between the metal 3 and the nozzle metal 1. The possibility of solidification of the metal 3 during passage through a small hole part 4 is thus eliminated and even if the diameter is, for example, 0.5mm., the molten metal is stably ejected without solidifying in the mid-way and the degree of freedom of the shape of the small-hole part 4 is improved.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention is a liquid quenching method in which a substance is melted and the substance is cooled and solidified at a high cooling rate by injecting it onto the surface of a roll rotating at high speed. This relates to a nozzle used in the device.

(Prior Art) In the past, liquid quenching equipment has been developed for obtaining quenched thin ribbons of alloys, and the quenched alloys obtained by such equipment are unlike those obtained by ordinary solidification methods. It has unique states such as an amorphous state and a non-equilibrium phase state, and has been attracting a lot of attention in recent years.

However, conventional liquid quenching equipment is often made for materials with relatively low melting points, such as iron-based alloys, and most of them use a method in which quartz nozzles are heated by resistance heating or high-frequency heating. . Therefore, the maximum operating temperature is limited by the refractory rating of quartz, and is 1200 to 1
The limit is about 300°C. In addition, when the temperature increases, sample contamination may occur due to reaction with quartz. Even if the material of the nozzle is changed from quartz to other ceramics, it will still be 2,000 yen at most when considering heat resistance, reactivity, etc.
The limit is about ℃.

The present inventors have already proposed a liquid quenching device that solves the above problems and can be used even with high melting point substances having a melting point of 2000° C. or higher. It is a liquid quenching device characterized in that the nozzle part that melts and sprays the substance is water-cooled and made of nine metals. If this device is used, even if a high melting point substance with a melting point of 2000°C or higher is melted in the nozzle, if the nozzle metal is sufficiently water-cooled, the temperature of the nozzle metal will be too low and it will melt with the 1 nozzle metal. Almost no reaction occurs with substances. This device therefore basically allows liquid quenching of high-melting substances.

However, when using a water-cooled metal nozzle, care must be taken regarding the shape of the small hole portion through which the molten material is ejected. This is because if the diameter of the small hole is too small or the length is too long, the molten material will solidify while passing through the small hole. Therefore, if the diameter of the small hole is set to 1 m or less, K is
Usually involves considerable difficulty. Such difficulties are almost never seen in conventional quartz nozzles. This is because the thermal conductivity of quartz is so low that the melt is hardly cooled while passing through the small hole. However, in the case of a water-cooled metal nozzle, the cooling capacity is so large that the molten material solidifies while passing through the small hole, resulting in a situation where the molten material cannot be injected. . In order to avoid this situation, the diameter of the small hole can be made larger than a certain level, but if this is done, the molten material may naturally drip down from the small hole, making it difficult to control the eruption i. A problem arises.

(Object of the invention) The present invention solves the above problems and dissolves and melts high melting point substances.
The purpose of this invention is to significantly increase the degree of freedom in the shape of the small hole portion through which liquid is jetted in a liquid quenching nozzle.

(Structure of the Invention) The present invention is a water-coolable metal nozzle characterized by having a plurality of fine grooves in an inner wall portion that comes into contact with liquid.

(Description of the structure of the invention) Since the liquid quenching nozzle of the present invention is made of water-cooled metal, even if a high melting point substance with a melting point of 2000°C or higher is melted, the molten substance and the metal of the nozzle hardly react with each other. do not. Moreover, because the inner wall that comes into contact with the liquid has many fine grooves, the cooling capacity for the molten sample is much smaller than that of conventional water-cooled metal nozzles, and the molten material is #1: There is almost no risk of solidification while passing through the small hole.

That is, the molten sample cannot come into contact with the inside of the fine grooves on the nozzle surface due to its surface tension, and as a result, the contact area between the molten sample and the nozzle metal is significantly reduced. The effect can be further enhanced by flowing a gas such as argon into the fine grooves on the nozzle surface. The reason for this is that the gas flowing through the groove not only further reduces the contact area between the molten sample and the nozzle metal, but also forms a thin layer of gas over the entire inner wall of the nozzle, causing direct contact between the molten sample and the nozzle metal. This is thought to be due to the fact that most of the contact is cut off. Principle diagrams for understanding this are shown in FIGS. 1 to 3. FIG. 1 shows a metal surface and a molten sample in a previously proposed water-cooled metal nozzle. FIG. 2 shows the nozzle of the present invention, and FIG. 3 shows the nozzle surface and molten sample when gas is flowed through the nozzle of the present invention. In the figure, 1 is a water-cooled metal, 3 is a molten sample, and 5 is a gas layer.

The water-cooled metal material may be a material with high thermal conductivity (5), such as copper, silver, or an alloy thereof. It is necessary that the plurality of grooves include at least grooves having a shape extending from the nozzle periphery toward the liquid ejection hole, and may be linear or curved. Furthermore, in addition to the grooves described above, grooves intersecting with these grooves may be formed. Hereinafter, the present invention will be explained in more detail according to examples.

1 is a water-cooled metal, 2 is a groove formed on the inner wall of the water-cooled metal, 3 is a sample, and 4 is a small hole through which the sample is injected. What is important is that a large number of fine surface grooves are formed on the inner wall of the nozzle, which may come into contact with the sample during melting and injection of the sample. Preferably, these grooves have a shape that allows gas to flow smoothly. Copper was used as the water-cooled metal 1, and the small hole 4 had an inner diameter of 0.5 mm and a length of 2 tm. The groove inside the small hole is 0.15 mm wide and 0.2 mm deep.
This was completed (6). Sample 3 was Nb75S i2. which was prepared in advance by arc melting. An alloy ingot was used. The melting point of this alloy is approximately 2130°C. Melt this sample using an argon plasma torch.

It was sprayed from the nozzle hole 4 onto the surface of a copper roll rotating at high speed under a pressure of about 0.05 atm. Almost all of the sample was ejected from the nozzle hole and turned into a quenched ribbon, with almost no remaining inside the nozzle. Also, no evidence of reaction between the sample and the water-cooled steel was detected.

It's just that there are no comparative examples. Copper was used as the material for the water-cooled metal 1, and the small hole 4 had an inner diameter of 0.5 fin and a length of 2. Similarly to the example, when an Nb, S i , alloy ingot was melted and an attempt was made to inject it by applying a pressure of 0.5 atm, the molten sample advanced to the vicinity of the exit of the small hole 4, but did not reach that point. It solidified (7) and there was no problem in spraying it.

As can be seen from the above Examples and Comparative Examples, the liquid quenching nozzle according to the present invention can be used even if the shape of the small hole portion through which liquid is injected is as small as 0.5 m in diameter.
Once it solidifies midway through, stable injection is possible.

As described above in detail, the liquid quenching nozzle according to the present invention has an extremely large degree of freedom in the shape of the small hole portion through which liquid is injected, and is highly effective.

[Brief explanation of the drawing]

1 to 3 are an embodiment of the present invention for understanding the present invention, and FIG. 5 is a comparative example of the prior art. In the figure

Claims (1)

[Claims] A coolable metal nozzle characterized by having a plurality of fine grooves on the inner wall portion that comes into contact with liquid.