JPS6199549A - Production of thin metallic strip - Google Patents

Abstract

PURPOSE:To produce a long-sized thin metallic strip having excellent surface accuracy at a good yield by ejecting a molten metal onto the surface of a rotating roll to form the thin strip and ejecting a gas to the thin metallic strip. CONSTITUTION:The molten metal 1 is ejected from a slit 3 provided to the ejection port of a nozzle 2 onto the surface of the roll 4 under rotation and is cooled by the roll which is kept rotated toward A to form the thin strip 1'. The gas is ejected from the nozzle 5 to the thin metallic strip 1' on the surface of the roll 4 in the direction B to increase the contact distance l between the strip 1' and the roll 4, by which thorough cooling is executed. The distance between the ejection position of the molten metal and the ejection position of the gas is kept within about 10cm. An inert gas such as Ar or He is used for the gas to be ejected and the flow rate thereof is kept preferably at about 3l/min or above.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to a method for directly manufacturing a ribbon from molten metal by jetting molten metal onto the surface of a rotating roll and cooling the molten metal.

[Background technology]

Recently, a single roll method, a twin roll method, a disk method, and the like have been developed as methods for manufacturing amorphous alloy ribbons, and these are attracting attention as technologies for directly manufacturing metal ribbons from a molten state.

Therefore, Fe-6,5wt%Si (hereinafter referred to as rwt%)
is abbreviated as “%”) and Sendust (Fe-9,6%5i-
Crystalline magnetic materials, such as 5.4% AI), which have excellent characteristics as soft magnetic materials but whose use has been limited because they are brittle and difficult to process, are made into thin ribbons by the above method, and magnetic cores are made. Attempts have been made to use it as a However, even if these crystalline materials are made into thin ribbons, Fe-
Compared to an amorphous ribbon such as B-5i, only a short length can be obtained, and the surface precision of the ribbon is poor. In particular, it is known that these drawbacks become more noticeable when a thinner ribbon is obtained and a single roll method is used which requires a simple device.

FIG. 1 shows the production of metal ribbon by the conventional single roll method. As shown in the figure, molten metal 1 is ejected through a slit 3 provided at the ejection port of a nozzle 2 onto the surface of a roll 4 rotating in the direction of arrow A. The molten metal spouted onto the surface of the roll 4 comes into contact with the surface of the roll 4 for a certain distance 2, then separates from the roll 4 and flies out in front of it. The metal is cooled while the roll is in contact with (wet) the molten metal. However, if the distance l is short, cooling will be insufficient, and the metal ribbon may break midway or gas may be drawn into the contact surface with the roll, resulting in poor surface precision.

[Purpose of the invention]

In view of the above, an object of the present invention is to provide a method for manufacturing a metal ribbon that improves the yield and produces a longer ribbon with excellent surface precision.

[Disclosure of the invention]

In order to achieve the above object, the present invention provides a method for generating a metal ribbon on the surface of a rotating roll by jetting molten metal from a nozzle above the roll onto the surface of the rotating roll to cool it. The gist of this paper is a method for manufacturing thin metal strips, which is characterized by blowing gas against the thin metal strips. A detailed explanation will be given below with reference to the drawings.

FIG. 2 shows an embodiment of the method for manufacturing a metal ribbon according to the present invention. As seen in the figure, in front of the nozzle 2 that spouts the molten metal l [on the side further along the rotation direction of the roll 4 (direction of arrow A) than the nozzle 2, that is, on the left side of the nozzle 2 in the figure], Gas is ejected as indicated by arrow B toward the metal ribbon 1' on the surface of the roll 4. 5 is a gas jet nozzle. The molten metal 1 is ejected from the slit 3 provided at the ejection port of the nozzle 2 onto the surface of the rotating roll 40 . The metal ejected onto the surface of the roll 4 travels in the direction of rotation while being in contact with the roll 4, during which time it is cooled and becomes a ribbon. Since the metal ribbon 1' is pressed down by the gas ejected from the gas jet nozzle 5, the contact distance l between the metal ribbon 1' and the roll 4 is longer than in the conventional method.
The metal is sufficiently cooled. For this reason, it is longer and
It becomes possible to obtain a metal ribbon 1' with excellent surface precision.

If the gas used in the production method of the present invention is reactive such as oxygen, the metal will oxidize and a good metal ribbon cannot be obtained, so inert gases such as Ar and He are preferred. However, it is not limited to this. The flow rate of gas varies depending on the width of the metal ribbon, but if it is too small, it will not be effective. For example, if the metal ribbon is l cm wide, the gas flow rate is 34! /min or more is desirable. Of course, the gas
It is desirable to eject it uniformly in the width direction of the ribbon, and it is preferable to use a slit nozzle for ejection. Further, it is of course preferable that the gas is ejected as close as possible to the molten metal ejecting position because the effect will be greater. Moreover, although it is preferable that these re-ejection positions are on the same circumference centered on the rotation center of the roll, this need not be the case. The effect differs depending on the type of metal and the shape of the ribbon, but the molten metal ejection position and the gas ejection position are
When the distance is above cmJ2/, the effect of gas jetting is almost eliminated. Also, regarding the direction of the gas jetting nozzle (that is, the gas jetting direction), the direction in which the gas is jetted forward in the rotational direction of the roll (in the direction of the arrow), such as the direction of the nozzle 5C in FIG. 3, has a better gas jetting effect. is highly desirable.

Even in a direction in which the gas is ejected backward in the rotational direction of the roll (in the direction of arrow C), such as in the direction of the nozzle 5a in FIG. 3, an effect can be obtained to some extent.

According to the manufacturing method of this invention, crystalline metal materials such as Fe~6.5%Si and sendust, which have excellent characteristics as soft magnetic materials but are brittle and difficult to process, can be processed using the conventional single roll method. In comparison, it is possible to produce a longer metal ribbon with excellent surface precision at a high yield. Note that amorphous metal materials can be used in the same way and similar effects can be expected. Examples and comparative examples are shown below.
The method for manufacturing a metal ribbon of the present invention is not limited to the examples.

(Example 1) After melting 50 g of an alloy with a composition of Fe-9,7%5t-5,6%^l in a quartz nozzle, it was rotated at high speed (1500 to 2000 rpm) through a 1 cm wide slit under Ar pressure.
) onto an iron roll (diameter 30 cm) to produce a metal ribbon with a thickness of 25 μm (by single roll method)
. At this time, a slit nozzle with a width of 1.5 am was placed 2 cm in front of the molten metal spouting nozzle, and Ar was
7! It was ejected at a flow rate of /min. The direction of gas ejection was the vertical direction (in the direction of arrow B in FIG. 3, 5b corresponds to the slit nozzle at this time). As a result of producing a metal ribbon using this method, 45 g of a ribbon with a good surface condition was obtained, and the length of each ribbon was 5 to 7 m. The yield was (45+50)×100=90%.

(Comparative Example 1) A metal ribbon was produced in the same manner as in Example 1 except that 50 g of the same alloy as in Example 1 was used and Ar was not ejected.

As a result, the ribbon with good surface condition weighed 35 g, and the length of one ribbon was 1.5 to 3 m. The yield was (35÷50)×100=70%.

(Example 2) 50 g of an alloy having a composition of Fe-6, 5% Si was melted and a metal ribbon having the same shape as in Example 1 was produced.

As a result, the ribbon with good surface accuracy weighed 40 g, and the length of one ribbon was 3 to 6 m. The yield was (40÷50)×100=80%.

(Comparative Example 2) A metal ribbon was produced in the same manner as in Example 2, except that 50 g of the same alloy as in Example 2 was used and Ar was not ejected.

As a result, the ribbon with good surface condition weighed 30 g, and the length of one ribbon was 1.5 to 2.5 m. The yield was (30÷50)×100=60%.

From the results of Examples 1 and 2 and Comparative Examples 1 and 2, when using the manufacturing method of this invention, compared to when using the conventional method,
It can be seen that the surface precision is good and longer metal thin strips can be manufactured with a high yield.

〔Effect of the invention〕

As we have seen above, the method for manufacturing the metal ribbon of this invention is as follows:
When cooling the molten metal by jetting it onto the surface of the rotating roll, the gas is jetted against the metal on the roll surface, which increases the contact distance between the metal and the roll, causing the metal to cool down. Cooling is sufficient. Therefore, according to this manufacturing method, a long metal ribbon with excellent surface precision can be manufactured with a higher yield than when using the conventional method.

[Brief Description of the Drawings] Fig. 1 is a side view showing the production of metal ribbon by the conventional single roll method, and Figs. 2 and 3 are side views showing one embodiment of the manufacturing method of the present invention. be. 1... Molten metal 1'... Metal ribbon on the roll surface 2... Molten metal spouting nozzle 4... Roll 5
．． 5a, 5b, 5c... Gas jet nozzle agent Patent attorney Takehiko Matsumoto Figure 1

Claims (2)

[Claims] (1) In a method of generating a metal ribbon on the surface of a rotating roll by jetting molten metal from a nozzle above the roll and cooling it, a gas is jetted against the metal ribbon on the roll surface. A method for manufacturing thin metal strips that is characterized by (2) The method for producing a metal ribbon according to claim 1, wherein the gas is an inert gas.