JPS61209754A - Nozzle for producing thin metallic strip - Google Patents

Abstract

PURPOSE:To make uniform the thickness in the transverse direction and properties of a thin metallic strip to be produced by a liquid quick cooling method and to improve the yield thereof by projecting the tip of a nozzle only at both ends. CONSTITUTION:The tip of the nozzle for producing the thin metallic strip having >=10mm width is projected by DELTAt only at both ends. The length at both ends to be projected is adequately about DELTAw=0.5-3mm except the length (b) in the thick-walled part. The length DELTAt to be projected is preferably >=0.1mm. However, the distance between the top end face at the root of the nozzle and a cooling roll is <=0.25mm and therefore the DELTAt is preferably <=0.1mm. The satisfactory suppression of the build-up at both ends of the thin metallic film is not possible if the DELTAw is too small and the central part of the thin film builds up if the DELTAw is conversely too large. The deformation of the thin strip is suppressed and the properties thereof are made uniform by producing the thin metallic film by using such nozzle.

Description

Detailed Description of the Invention (Technical Field of the Invention) The present invention relates to a nozzle for manufacturing a metal ribbon, more specifically, a nozzle for manufacturing a wide metal ribbon having a uniform thickness in the width direction by a liquid ultra-quenching method. Concerning useful nozzles.

(Foreground of the Invention) Conventionally, crucibles (
The metal (2) melted in step 1) is passed through the nozzle (3) at the bottom of the crucible.
) toward the circumferential surface of the cooling roll (4) rotating at high speed.

A thin ribbon (5) is produced by rapidly cooling molten metal.

However, when manufacturing a wide metal ribbon with a width of 10 m or more by conventionally using a flat rectangular nozzle outlet shape, the resulting ribbon has both ends of the surface not in contact with the cooling roll in the center, as shown in Figure 4. Height h=approximately 20% compared to part thickness a)
It had a drawback that it had a raised cross-sectional shape and did not have a uniform thickness in the width direction. This means that quenching is not uniform in the width direction, resulting in disadvantages such as deformation of the ribbon, loss of uniformity of physical properties, and lower yield.

(Object of the Invention) Therefore, one object of the present invention is to provide a rapidly solidified metal ribbon having a substantially rectangular cross-sectional shape and a uniform thickness in the width direction.

(Summary of the invention) Traditionally, nozzles are used to produce wide ribbons.

It is as shown in Figure 5, and has a spout (
6) had a flat rectangular shape as shown in FIG. 6 when viewed from below, and the tip surfaces were aligned in one horizontal plane as shown in FIG.

As a result of the research, the corners of the molten metal ejected from the nozzle tip become rounded due to its own surface tension, and as a result, as it falls downward, the cross-sectional shape becomes a rectangular shape. Thin obi □ Yowa 4. Eri f ya-ya. ,. .

If the thickness is less than 51, a thin strip with a rectangular cross section can be obtained, but as shown in Fig. 4, there is a drawback that the edges are raised and the thickness is a)
It was found that there is a proportional relationship between

Therefore, the inventors of the present invention came up with the idea that both ends of the cross-section of the ribbon should be raised, and through experiments, they confirmed that this idea was effective and completed the present invention.

Accordingly, the present invention provides a nozzle for producing a wide metal ribbon (10 f1 or more), characterized in that only both ends of the nozzle tip protrude toward the cooling roll (Fig. 1). reference).

As shown in Figure 2, the length of both ends to protrude depends on the width of the metal ribbon, that is, the length of the long side of the nozzle opening (molten metal spout), but it depends on the length of the thick part b. ) except ΔW
Approximately = 0.5 to 3 mm. If ΔW is less than 0.5, it will not be possible to sufficiently suppress the swelling at both ends of the metal ribbon, and if ΔW exceeds 3, the central part of the cross section of the metal ribbon will become raised, making it difficult to accurately It is difficult to obtain one with a rectangular cross section.

The protruding length Δt is preferably 0.01 fi or more, but if it is too long (then it will come into contact with the cooling roll).

This is because, in the nozzle of the present invention, the distance between the binary tip surface and the cooling roll must be 0.25 mm or less. Therefore, Δt should generally be 0.1 fl or less. However, it is necessary to change Δ.

The nozzle of the present invention may be integrated with or separate from the crucible, and may be made of materials such as quartz, BN, and 5isN.

Made of ceramic such as.

Hereinafter, the present invention will be specifically explained with reference to Examples.

(Example) The nozzle opening shape is a rectangle with a length of 9.3w and a width of 10m, and as shown in Fig. 2, both ends of the tip (ΔW = 0°15m) are Δ
A quartz crucible having a nozzle with a t" of 0.05 wm and a wall thickness b of 2 m was produced.

This crucible was installed in an ultra-quenched metal ribbon manufacturing apparatus as shown in FIG. Then, Fe5Co71Si is placed inside the crucible.
A high-frequency coil wrapped around 9 parts containing raw materials corresponding to the composition of tBus (numbers are atomic %) produces 125
After being heated to 0° C. to melt, the tip surface at the center of the nozzle (the tip surface before protrusion) was fixed to the cooling roll by approaching it to a distance of 0.2 mm.

The molten metal was pressurized to 0.8 kgf/cj (gauge pressure) with argon gas, and was jetted from a nozzle onto a copper cooling roll (rotating at high speed at a circumferential speed of 23 and 56 m/sec).

As a result, it has a width of 9.8m with a uniform rectangular cross section in two width directions.
A metal ribbon having a thickness of 30 μI was obtained.

The bulges at both ends of this ribbon were h=1 μm or less, and the variation in thickness in the longitudinal direction was also +1 μm to −2 μI.

On the other hand, when a conventional nozzle with no protrusion at both ends is used, the swell at both ends is h = 5 to 6 μm,
A thin strip can be obtained, although the cross section cannot be called rectangular. The thickness variation in the longitudinal direction of this ribbon was +2 μm to −2 μm.

(Effects of the Invention) As described above, according to the nozzle of the present invention, a metal ribbon having no bulges at both ends of the ribbon cross section, that is, a metal ribbon having a uniform thickness in the width direction can be obtained. This means that the ribbon is rapidly cooled uniformly in the width direction, which not only suppresses deformation of the ribbon but also provides physical uniformity, leading to an improvement in yield.

[Brief explanation of drawings]

FIG. 1 is a schematic perspective view of the nozzle tip of the present invention, with the top and bottom upside down. FIG. 2 is a front view of the tip of the nozzle of the present invention with the top and bottom turned upside down. FIG. 3 is a conceptual diagram of a general quenched metal ribbon manufacturing apparatus. FIG. 4 is a longitudinal cross-sectional view of a conventional metal ribbon. FIG. 5(1) is a conceptual front view of a conventional nozzle, and FIG. 5(2) is a bottom view. FIG. 6 is a bottom view of a conventional nozzle tip. FIG. 7 is a conceptual perspective view of a conventional nozzle tip section upside down. FIG. [Explanation of symbols of main parts]

Claims (1)

[Claims] A nozzle for producing a wide metal ribbon, characterized in that only both ends of the nozzle tip protrude.