JPH07303946A - Manufacture of irregular cross-section thin strip and nozzle for its manufacturing - Google Patents

Abstract

PURPOSE:To suppress stripe flaws and to provide a manufacture and nozzle for producing an improved irregular cross-section thin strip in manufacturing such strip by means of a multi-nozzle. CONSTITUTION:The method is such that a plural number of openings 2 with a long side provided in parallel to the advancing direction of the cooling base plate is arranged nearly vertically to the moving direction of a cooling base plate; that a nozzle 3 with a recessed part with a specific depth covering at least over the opening part and the entire spaced part of the opening is used only on the side for oppositely facing the cooling base plate; and that the shape of the plural openings on the upper part of the nozzle is specified as well as the shape of the recessed part in the lower part of the nozzle. Since the stripe flaws are suppressed which used to be caused on an irregular cross-section thin strip, the strength of the strip is improved, and the yield in the manufacture of the product is also improved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thin ribbon having a distribution of sheet thickness in the width direction of a thin strip by a rapid solidification method, that is, a thin metal or alloy having a so-called irregular cross section (hereinafter simply referred to as "metal"). The present invention relates to a method for manufacturing a band and a nozzle for manufacturing.

[0002]

2. Description of the Related Art As one of the methods for producing a wide metal ribbon by a rapid solidification method, there is an invention described in JP-A-53-133531. In this method, a circular multi-hole nozzle is jetted and impinges on the surface of a moving cooling substrate (usually the outer or inner circumference of a rotating roll or drum), and the molten metal is spread on the substrate to integrate adjacent molten metals. , To produce a wide metal ribbon.

Although not disclosed in the above-mentioned publication, this method is not limited to a wide ribbon and a thin wire depending on the control of the diameter and interval of the nozzle hole, the ejection pressure, the interval between the nozzle and the substrate, the substrate moving speed, and the like. It is also possible to manufacture a large number. Therefore, the inventors of the present invention tried various studies on the possibility of manufacturing a ribbon having an irregular cross section by using this technique, but the overlapping of the molten metal was insufficient and a transparent portion was formed in a droop shape, or the width was wide. Only thin ribbons having no regularity in shape were obtained due to poor synchronism of thickness in the directions.

The present inventors have already proposed a new casting method in Japanese Patent Laid-Open No. 63-149053 in order to eliminate such a conventional problem. This conventional method is a method for manufacturing a ribbon having an irregular cross section by using a nozzle 3 in which each of the openings 2 has a rectangular shape as shown in FIG. 5, and a single roll rapid solidification ribbon manufacturing apparatus shown in FIG. 5, a nozzle 3 as shown in FIG. 5 is provided below the crucible 8 and the molten metal 6 melted by the heating device 7 is jetted onto the surface of the cooling roll 4 which is rotating at a high speed to form a ribbon having an irregular cross section. is there.
That is, this method uses a nozzle in which a plurality of rectangular openings are arranged in the plate width direction of the cooling substrate to cool a molten metal pool (hereinafter referred to as “paddle”) formed between each opening and the cooling substrate. This is a method of obtaining a modified cross-section thin ribbon by integrating it in a direction perpendicular to the substrate movement direction and forming a thin ribbon at a position corresponding to the nozzle opening and having a plate thickness larger than that between positions corresponding to the nozzle openings. .

[0005]

However, it is necessary to further improve the following points in order to stably produce a modified cross-section ribbon by using the method described in JP-A-63-149053. It was That is, on the roll surface of the obtained ribbon, a dent defect (hereinafter,
Occasionally, "streak defects" occurred. This streak-like defect is generated at a position corresponding to the opening of the nozzle used, but is generated by preferentially drawing in the atmospheric gas at the joint between the individual paddles.

The method of forming the streak defects will be described below. FIG. 6 is a single roll rapid solidification production apparatus, and FIG. 7 is an enlarged schematic view of the behavior of the molten sample in the vicinity of the nozzle and roll surface of this apparatus. When the molten sample is jetted onto the roll surface through the nozzle 3, the above-mentioned paddle 9 is formed between the nozzle opening and the roll surface. Immediately below the paddle, a thin strip 5 is formed on the roll surface. Figure 7
FIG. 3 is a schematic view of the state of casting as seen from the side, and the paddle shows one of a plurality of nozzle openings and a paddle formed on the roll surface.

Further, FIG. 8 shows a schematic view of the state of this casting seen through from above. In FIG. 8, the individual nozzle openings 2 are shown by dotted lines, but integrated paddles 9 are formed around these openings, and a ribbon 5 is formed immediately below the paddles 9. The contour of the integrated paddle in the rear direction with respect to the roll rotation direction is almost a straight line, but sometimes it is not a perfect straight line between the nozzle openings, and a slight dent 10
Is formed. When such a dent 10 is formed,
Atmosphere gas brought in by the moving roll is preferentially drawn between the paddle and the roll surface, and the streak defects 11 are formed on the roll surface of the ribbon. Such streak-like defects are not preferable because they lead to deterioration in strength when used as a magnetic shield material, floor material, pipe-shaped heat dissipation material, absorbent material, or the like.

The present invention suppresses the generation of streak defects, which has been an obstacle to the production of such irregularly shaped cross-section ribbons, and provides a method and a manufacturing nozzle for producing good irregularly-shaped cross-section ribbons. Has an aim.

[0009]

Means and Actions for Solving the Problems The gist of the present invention is as follows. (1) A plurality of openings provided so that their long sides are parallel to the traveling direction of the cooling substrate are arranged at right angles to the moving direction of the cooling substrate, and further, at least on the side facing the cooling substrate, A nozzle provided with a recess having a constant depth over the opening and the opening interval is provided so as to face the cooling substrate, and the molten metal is ejected from the nozzle onto the surface of the cooling substrate for rapid solidification. (2) The depth d _{0 of the} recess provided on the side of the nozzle facing the cooling substrate is 0.05.
mm or more, the length d ₁ from the front end and the length d ₂ from the rear end of the plurality of openings in the upper part of the nozzle in the cooling substrate moving direction are both 3 mm or less, and further, Lengths d ₃ and d ₄ from the outer ends of the openings are both 1 mm or less, (3) The method for manufacturing a modified cross-section ribbon, (3) The individual openings of the nozzles. The length a in the cooling substrate moving direction is 1 to 20 mm, and the length b in the direction perpendicular to the cooling substrate moving direction is 0.2 to 5.0 m.
m, the distance c between individual openings is 0.2 to 2.0 mm, and a> b
And the depth d _{0 of the} recess provided only on the side facing the cooling substrate is 0.05 mm or more, the length d ₁ from the front end of the plurality of openings in the nozzle upper part in the cooling substrate moving direction and the rear All of the lengths d ₂ from the end are 3 mm or less, and further, the lengths d ₃ and d ₄ from the outer ends of the openings at the outermost ends of the plurality of openings on the nozzle are both 1 mm or less. A characteristic nozzle for manufacturing thin ribbon.

The present invention will be described in detail below. First,
The nozzle of the present invention is schematically shown in FIG. FIG. 1B is a view of the nozzle as seen from the side. When actually used for casting, the cooling substrate is placed below the position shown in FIG. 1B. 1A and 1C are views seen from above and below the nozzle, respectively. As can be seen from FIG. 1, the nozzle of the present invention is characterized by having a recess 1 only on the side of the nozzle 3 facing the cooling substrate. By using the nozzle having such a depression to eject the molten metal onto the surface of the moving cooling substrate to perform casting, it is possible to manufacture a ribbon having a deformed cross section without streak defects.

By using the nozzle of the present invention, the reason why streak defects are not produced on the roll surface of the ribbon having an irregular cross section is as follows.
It can be considered as follows. That is, the molten samples ejected from the plurality of openings 2 on the upper part of the nozzle are connected to each other at the recess 1 provided on the lower part of the nozzle in a direction perpendicular to the moving direction of the cooling substrate, and the paddles are easily integrated. Since the place where the atmospheric gas is preferentially involved in the integrated paddle disappears, the streak-like defect is not generated. Although the reason will be described later, it is necessary to integrally provide the plurality of openings in the upper part and the depressions in the lower part as a nozzle member.

The reason why the dimension of the recess 1 is limited to the above numerical values will be described below. That is, the depth d _{0 of the} depression shown in FIG. 1B was set to 0.05 mm or more. However, when the value of d ₀ is less than 0.05 mm, the effect of suppressing the generation of streak defects is almost recognized. It depends. That is, as shown in FIG. 2, when the value of d ₀ is less than 0.05 mm, the occurrence rate of streak defects is as high as 10% or more and further 20% or more. This is because when the value of d ₀ is less than 0.05 mm, the individual paddles formed in the plurality of openings in the upper part of the nozzle are integrated even if a depression is provided in the lower part of the nozzle, but at the joints of these individual paddles, it is preferentially performed. This is because the atmospheric gas is also easily involved. Further, as can be seen from FIG. 2, when the value of d ₀ is 0.5 mm or more, there are no streak-like defects, so the value of d ₀ is preferably 0.5 mm or more.

Further, since it is impossible to manufacture a ribbon having an irregular cross section when the value of d ₀ reaches the thickness of the nozzle, it goes without saying that the value of d ₀ is less than the thickness of the nozzle used. In the present invention, the thickness of the nozzle is not particularly specified, but if the thickness of the nozzle becomes too large, it takes time to process the nozzle opening and preheat the nozzle before casting, so make the thickness of the nozzle too thick. Is not preferable. The thickness of the nozzle is preferably about 20 mm or less. On the other hand, it is preferable that the value of d _{0 be} a value smaller than the thickness of the nozzle by several mm even if it is large, in consideration of the strength of the openings above the nozzle.

Next, as the length of the depression 1 in the direction of movement of the cooling substrate, the length d ₁ from the front end of the plurality of openings in the upper part of the nozzle in the direction of movement of the cooling substrate and the length d ₂ from the rear end thereof are both 3 mm or less. The reason for limiting is as follows. First, here, “the length d ₁ from the front end and the length d ₂ from the rear end of the plurality of openings in the upper part of the nozzle in the cooling substrate moving direction” are used.
Are the lengths of d ₁ and d ₂ shown in FIG. 1 (c), respectively. The range of these d ₁ and d ₂ values is 3 mm
The reason for the following is that, as shown in FIG. 3, if the thickness exceeds 3 mm, the occurrence rate of streak defects becomes as high as 20% or more.
Further, it is considered that setting the values of d ₁ and d ₂ to 3 mm or more is the same as not forming a depression in the lower portion of the nozzle. That is, since the atmospheric gas is preferentially drawn in at the joint between the individual paddles of the integrated paddle, streak defects are generated. Note that d
The values of ₁ and d ₂ may be the same value or different values within this range.

Further, as the length of the depression 1 on the lower surface of the nozzle in the direction perpendicular to the moving direction of the cooling substrate, the lengths d ₃ and d from the outer ends of the openings at the extreme ends of the plurality of openings in the upper portion of the nozzle.
₄ was limited to 1 mm or less. The “differences d ₃ and d _{4 from the} outermost ends of the plurality of openings in the upper part of the nozzle with the outside” are the lengths d ₃ and d ₄ shown in FIG. 1C. The range of the values of d ₃ and d ₄ is 1
What was limited to less than or equal to mm is that if both are over 1 mm,
This is because the plate thickness becomes thin at both edge portions of the obtained ribbon. The values of d ₃ and d ₄ are preferably the same within this range.

The size of the depression 1 may be appropriately selected within the above range according to other casting conditions. It should be noted that the optimum combination of values for the dimensions of the nozzles actually used will be specifically shown in the examples.

The nozzle of the present invention should not have an upper part composed of a plurality of openings as shown in FIG. 4 and a lower part composed of rectangular holes separated from each other. During actual casting, the nozzle is maintained at a high temperature, but at this time, the nozzle is easily deformed due to thermal expansion. When a nozzle in which two nozzles are overlapped as shown in FIG. 4 is used, the upper portion is less likely to be deformed due to thermal expansion, but the lower rectangular hole is narrowed in the central portion in the longitudinal direction.
Alternatively, it may become wider, which may hinder the connection with the openings in the upper part.

The parameters that define the shape of the plurality of openings in the upper part of the nozzle are the length a in the cooling substrate moving direction of each opening 2 shown in FIG. 5, the length b in the direction perpendicular to the cooling substrate moving direction, and the individual openings. Is the interval c.

Explaining the range of the size of each parameter, a is 1 to 20 mm, preferably 1 to 10 mm.
Is the range. b is in the range of 0.2 to 5.0 mm, preferably 0.2 to 2.0 mm. Further, c is in the range of 0.2 to 2.0 mm. What is important here is that the shape of the opening is a> b. By setting a> b, the molten metal ejected from the individual openings can be integrated by overcoming the surface tension of the molten metal, and it becomes possible to manufacture a ribbon having a deformed cross section with a regular thickness different in the plate width direction. .

The range of the size of each parameter will be described below. When the value of a is less than 1 mm, it becomes difficult to stably integrate the molten metal from the individual openings even if a considerably large ejection pressure is used. On the other hand, the value of this a is 20
If it exceeds mm, the cooling becomes insufficient with respect to the flow rate of the molten metal, and it becomes difficult to produce a thin ribbon having a good shape.

The value of b is set so that a> b depending on the value of a. However, if the value of b exceeds 5.0 mm, the molten metal can be stabilized from the individual openings even if the value of a is increased. It was difficult to integrate. The lower limit of the range of the value of b is provided because it becomes difficult to set it to less than 0.2 mm due to processing of the opening. c is the above-mentioned a and b in order to integrate the molten metal ejected from each opening into a thin ribbon of irregular cross section.
It is also an important parameter. The value of this c is 2.0m
When it exceeds m, it becomes difficult to stably integrate the molten metal from the individual openings even if a considerably large ejection pressure is used. As with the case of b, the lower limit of the value of c is limited due to the difficulty in processing the opening.

The basic manufacturing apparatus adopted in the method of the present invention is a so-called liquid quenching apparatus of the liquid quenching apparatus in which molten metal is jetted onto a cooling substrate through a nozzle and rapidly cooled and solidified by thermal contact. It is a single roll device. Of course,
Centrifugal quenchers using the inner wall of the drum, devices using endless belts, improved versions of these, such as auxiliary rolls, roll surface temperature control equipment, or under reduced pressure or in vacuum or in inert gas. Casting is also included.

Next, the casting conditions adopted in the method of the present invention and the concrete casting work will be described. The ejection pressure of the molten metal is 0.01 to 3 kg / cm ² , and the rotation speed (surface speed) of the roll is in the range of 5 to 60 m / sec. Optimum values are selected for these conditions in accordance with the target strip pressure and other manufacturing conditions. As a casting operation, the optimum gap position between the nozzle and the roll is set in advance before the start of melting, assuming the time of casting, and then the crucible is once moved into the work coil for melting the metal and then the metal is melted. After the melting, the roll is rotated and the jet pressure is set, and then the crucible is returned to the preset optimum gap position with the roll to start casting. For this reason, the position of the work coil is preferably set at a position slightly away from the roll surface.

[0024]

EXAMPLES The present invention will be further described below with reference to examples. Using the various nozzles shown in Table 1, an irregular-shaped cross-section ribbon was produced by an in-air single-roll ribbon producing apparatus. Charge NO. Nos. 1 to 14 are the present invention, and charge NO. 15 ~
18 is a comparative example. The cooling roll used is made of copper,
The diameter is 300 mm and the width is 50 mm. The metal melting method is high frequency induction. Other casting conditions than those shown in Table 1 are as follows. Melting component: Fe-Si _6.5 -B ₁₂ -C ₁ (amorphous alloy) Weight of molten metal: 100 g crucible, nozzle material: transparent quartz Aperture shape at the top of the nozzle: Distance between both ends of the aperture (L in FIG. 5) ): Approximately 25 mm Number of openings above the nozzle: 23 Roll surface speed: 22 m / s Nozzle gap: 0.3 mm Jet pressure: Charge NO. 14 is 0.5kg / cm ^2, the other charge is 0.3kg / cm ²

[0025]

[Table 1]

As a result, a ribbon having a width of about 25 mm was obtained for each of the charges. When the free surface of the obtained ribbon was observed carefully, it was a modified cross-sectional area in which the plate thickness was regularly changed in the plate width direction. For all ribbons, a magnifying projector was used to examine the roll surface of the ribbons for the presence of streak defects. Regarding the ribbon in which streak defects were observed,
Measure the length, find the ratio to the length of the entire ribbon,
The occurrence rate of streak defects was arranged. The results are shown in Table 1. In addition, when the streak defects were generated in the width direction of the thin strip, the total length of all the streak defects was defined as the length of the generated streak defects.

Further, with respect to all the ribbons, the length of the ribbon, the maximum thickness, the average thickness and the width were measured, and these data are also shown in Table 1. The maximum plate thickness is a value obtained by a micrometer, and the average plate thickness is a value calculated from the alloy density (7.26 g / cm ³ ), the plate width and the length.

As can be seen from Table 1, the occurrence rate of streak defects was as low as less than 10% in all the ribbons of all the charges of the present invention, and the cross-sectional area was good. On the other hand, when casting was performed under the conditions as shown in the comparative example, the occurrence rate of streak defects was as high as 10% or more with any of the charges.

[0029]

As described above, according to the present invention,
In a continuous liquid quenching method such as a single roll method, by using a nozzle having a specified shape and size, a ribbon having an irregular cross section having an excellent shape can be obtained. The thin ribbon having an irregular cross section can be used as a magnetic shield material because, for example, a magnetic material having irregularities on the surface has a better magnetic sealing property than a thin ribbon having a flat surface. Further, one of the corrugated amorphous ribbons is hard and has corrosion resistance, so that when it is used as a flooring material or the like, the sliding of an object is improved and it is convenient for moving heavy objects. Further, if it is formed into a pipe shape, it can have a large surface area, which is advantageous for heat dissipation and absorption.

According to the present invention, it is possible to suppress the streak defect which has been generated in the ribbon having the irregular cross section, and therefore the strength of the ribbon having the irregular cross section can be improved. It also becomes possible to improve the manufacturing yield of products.

[Brief description of drawings]

FIG. 1 is a schematic diagram illustrating a nozzle according to a method of the present invention.

FIG. 2 is a diagram showing the relationship between the depth (d ₀ ) of a rectangular recess at the bottom of a nozzle and the streak defect occurrence rate on the ribbon roll surface according to the method of the present invention.

FIG. 3 is a diagram showing the relationship between the lengths (d ₁ , d ₂ ) of the rectangular recesses in the lower part of the nozzle in the cooling substrate moving direction and the streak defect occurrence rate on the ribbon roll surface according to the method of the present invention.

FIG. 4 is a schematic view showing an example in which an upper nozzle having a plurality of openings and a lower nozzle having a rectangular opening are separated and which do not correspond to the present invention.

FIG. 5 is a schematic view of a conventional porous nozzle for producing a ribbon having a modified cross section.

FIG. 6 is a schematic view showing a single roll rapid solidification ribbon production apparatus.

FIG. 7 is an enlarged schematic diagram for explaining a state of casting, particularly formation of a paddle, using a single roll rapid solidification ribbon production apparatus.

FIG. 8 is a schematic diagram for explaining generation of streak defects when a conventional porous nozzle for producing a ribbon having an awe-in-cross section is used.

[Explanation of symbols]

1 Dimple provided in the lower part of the nozzle 2 Opening provided in the upper part of the nozzle 3 Nozzle 4 Cooling roll 5 Thin strip 6 Molten metal 7 Heating device 8 Crucible 9 Integrated paddle 10 Dimple behind paddle 11 Streak defect a Cooling of opening Length in the direction of substrate movement b Length in the direction perpendicular to the direction of movement of the cooling substrate c Distance between individual openings L Distance between the two extreme ends of the opening d ₀ Depth of rectangular recess at the bottom of the nozzle d ₁ Plural nozzles at the top of the nozzle Lengths of the openings from the front end of the cooling substrate moving direction d ₂ Lengths of the plurality of openings above the nozzle from the rear end of the cooling substrate moving direction d ₃ and d ₄ Outer ends of the outermost ends of the plurality of openings above the nozzle Length from

[Procedure amendment]

[Submission date] August 16, 1994

[Procedure Amendment 1]

[Document name to be corrected] Drawing

[Name of item to be corrected] Figure 2

[Correction method] Change

[Correction content]

[Fig. 2]

[Procedure Amendment 2]

[Document name to be corrected] Drawing

[Name of item to be corrected] Figure 3

[Correction method] Change

[Correction content]

[Figure 3]

Claims (3)

[Claims] 1. A plurality of openings, whose long sides are provided so as to be parallel to the traveling direction of the cooling substrate, are arranged at right angles to the moving direction of the cooling substrate, and further, only on the side facing the cooling substrate.
A nozzle provided with a recess having a constant depth over at least the opening and the opening interval is provided so as to face the cooling substrate, and molten metal is ejected from the nozzle onto the surface of the cooling substrate to rapidly solidify. And a method for manufacturing a ribbon having a modified cross section. 2. The depth d _{0 of the} recess provided on the side of the nozzle facing the cooling substrate is 0.05 mm or more, and the length d ₁ and the rear end of the plurality of openings in the upper portion of the nozzle from the front end in the cooling substrate moving direction. length d ₂ from both 3mm or less, further, the length d ₃ and d ₄ from an outer end of the opening of the top ends of the plurality of openings of the nozzle upper, characterized in that both at 1mm or less The method for producing a modified cross-section ribbon according to claim 1. 3. The individual openings of the nozzle have a length a in the moving direction of the cooling substrate of 1 to 20 mm and a length b in the direction perpendicular to the moving direction of the cooling substrate of 0.2 to 5.0 mm. Has a rectangular shape with a distance c of 0.2 to 2.0 mm and a> b, and has a depth d _{0 of} a recess provided only on the side facing the cooling substrate.
Is 0.05 mm or more, the length d ₁ from the front end and the length d from the rear end of the plurality of openings in the upper part of the nozzle in the cooling substrate moving direction.
₂ is 3 mm or less, and further, the lengths d ₃ and d ₄ from the outer ends of the openings at the outermost ends of the plurality of openings at the top of the nozzle are both 1 mm or less. Thin strip manufacturing nozzle.