JP3266404B2 - Metal ribbon manufacturing method and apparatus - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for producing an amorphous ribbon having excellent surface properties and a thickness of 35 .mu.m or more in quenched ribbon casting by a single roll method.

[0002]

2. Description of the Related Art In recent years, metal ribbons have been produced directly from molten metal by a liquid quenching method such as a single roll method or a roll method. An important requirement in such a direct plate making technology is a plate making technology relating to the uniformity of the plate thickness and the surface properties. In particular, in the case of using a laminate such as an amorphous alloy ribbon used as a transformer material, the superiority of the surface properties affects the characteristics of the transformer (here, the transformer is enlarged due to a decrease in the space factor of the ribbon).

[0003] The cause of the deterioration of the surface properties of the metal ribbon is that a boundary layer is formed on the surface of the cooling roll with the rotation of the cooling roll, and the air riding on the boundary layer causes a gap between the molten metal paddle on the cooling roll and the cooling roll. And the air was trapped in the ribbon. The mechanism by which air enters this boundary layer is vibrated by an external force with a paddle, the wetting angle between the cooling roll and the paddle changes, and an air entrapment portion (air pocket) is created periodically each time the paddle becomes easy to enter. This forms a periodic, seemingly fish-scale pattern (fish scale) in the ribbon. There have been two types of paddle vibration that have been reported so far that deteriorate the surface properties of the ribbon. One is a kinematic cause (capillary wave) in which the paddle membrane vibrates when air hits the paddle. One is a chemical reaction (Marangoni effect) that vibrates as a result of the air hitting the paddle and unevenly oxidizing the molten steel surface, resulting in uneven surface tension.

[0004] As a technique for preventing the deterioration of the surface properties due to these causes, the conventional idea is to dilute the air colliding with the paddle or replace it with a low-density inert gas or reducing gas. It seeks to eliminate both kinematic and chemically reactive causes. For example, Japanese Unexamined Patent Publication No. 51-109221 discloses a method of manufacturing an improved alloy filament in a reduced pressure chamber. This manufacturing method is possible in a laboratory or in the case of small-scale manufacturing, but has a lot of problems in mass production in terms of equipment and running costs.

[0005] Japanese Patent Application Laid-Open No. 59-209457 discloses a method and apparatus for casting a thin metal strip, which uses a low-density and high-temperature inert gas, which solves the facility problems of the above method. In this case, an effective low-density inert gas such as helium, krypton, or xenon is expensive, and the problem of running cost still remains. Further, the air trapped between the roll surface and the molten metal significantly increases the heat transfer resistance of the roll surface and lowers the cooling capacity of the molten metal. For this reason, it was conventionally difficult to cast an amorphous ribbon having a ribbon thickness of 35 μm or more.

[0006] On the other hand, Japanese Patent Publication No. 3-28254 discloses that a CO gas is burned upstream of a molten metal on a roll to reduce the gas density of a gas boundary layer generated around the roll and to reduce the molten metal. It is shown that the heat transfer resistance between the molten metal and the roll is reduced by providing a reducing atmosphere around the roll, and a thinner ribbon than before can be obtained. In the method using CO gas to reduce the heat transfer resistance between the molten metal and the roll, the CO gas has a danger of toxicity and explosion,
Requires many safety measures. Therefore, when used industrially, it is difficult to handle gas, and there is a problem of cost increase.

In US Pat. No. 4,154,283,
It shows a technique for solving the problem that the gas around the roll enters the molten metal by performing casting in a vacuum.
Performing casting in a vacuum requires a huge and complicated apparatus in an industrial-scale facility and raises the problem of cost increase. There is also known a technique of injecting a plasma arc toward a roll near a molten metal and heating a gas around the roll, thereby reducing gas intrusion into the molten metal.
(For example, International Journal
of Rapid Solidification,
1991, Vol. 6 pp 285-295). The method using the plasma arc also requires a complicated device, and has a problem of cost increase.

Further, it is disclosed that gas entrainment is reduced by injecting a CO ₂ gas into a molten metal on a roll (Materials Science).
ceand Engineering, A133
(1991) pp657-661). In the method of injecting the CO ₂ gas onto the molten metal on the roll, the nozzle for injecting the molten metal is inevitably subjected to strong cooling due to the collision of the CO ₂ gas, so that there is a problem that the nozzle temperature is reduced and the nozzle is clogged. Was. Furthermore, since ambient air is easily mixed into the CO ₂ gas jet, there is a problem that it is difficult to stably reproduce the effect of the CO ₂ gas.

Also, the German Democratic Republic patent DD26
No. 6046A1 shows that the amount of gas entrained between a molten metal and a roll is greatly reduced by spraying a CO ₂ gas onto a pool of molten metal (paddle). However, this is shown in Examples of Patent, a method of blowing CO ₂ by a flat nozzle from around the injection nozzle of the molten metal, in particular the width of the ribbon is 50
If the width exceeds mm, there is a difference in the gas entrainment reduction effect between the center and the end of the ribbon, and a uniform ribbon in the width direction cannot be obtained.

Furthermore, Japanese Patent Application Laid-Open No. 4-356336 discloses a method in which a portion to which molten metal is injected is covered with a chamber and a CO ₂ atmosphere is formed. It is necessary to strictly control the gap between the injection nozzle and the roll surface, and the use of a chamber that hinders observation of the gap complicates the control system of the casting apparatus.

On the other hand, JP-A-57-159247 discloses a method for removing a gas boundary layer on the surface of a roll.
A method is shown using a protective shielding wall located proximate to the roll surface. However, since the air flow is re-formed even at a very short distance between the shielding wall and the molten metal, the air flow cannot be completely removed, and this shielding wall alone can provide a sufficient effect of reducing gas entrapment on the surface of the thin ribbon. Absent.

[0012]

SUMMARY OF THE INVENTION An object of the present invention is to reduce the problem of cost increase by a simple and safe method, to reduce gas entrainment between a roll and a molten metal, Technology to cast a thicker amorphous alloy than before, reducing surface roughness,
An object of the present invention is to provide a technique for improving the quality of a ribbon.

Another object of the present invention is to provide a simple apparatus which avoids an increase in cost and a decrease in controllability due to an enormous and complicated apparatus.

[0014]

The present invention achieves the above object.
The first method invention is a single cooling method.
In the method of manufacturing a metal ribbon using a roll,
The carbon block is located upstream of the metal injection position in the roll rotation direction.
Place the blade in contact with the generatrix on the roll surface, and
Roll surface along the surface of the molten metal side of the carbon blade
CO towards _Two Inject the gas to the molten metal injection position
Near the upstream roll surface_Two Keep gas atmosphere
And a method for producing a metal ribbon.

According to a second method of the present invention, the molten metal is further added to the first method of the present invention at a pressure of 20 kPa to 90 kPa.
Inject onto a roll at a pressure of Pa or less and set the roll peripheral speed to 15
The requirement that the thickness be between 3 m / s and 27 m / s is added.
A method for producing a metal ribbon, comprising producing an amorphous ribbon having a thickness of 5 μm or more and 100 μm or less. A third method invention of the present invention is a method of manufacturing a metal ribbon using a single cooling roll, wherein the molten metal paddle injected onto the cooling roll is heated to 500 ° C to 800 ° C using a nozzle. A method for producing a metal ribbon, wherein a heated CO ₂ gas is sprayed to make the CO ₂ gas concentration around the paddle 35% or more.

[0016] In the first method invention or the second method the invention, using a CO ₂ heated to 500 ° C. or higher 800 ° C. or less as CO ₂ gas, is preferable that the CO ₂ gas concentration near the paddle to more than 35% is there. According to a fourth method of the present invention, in a method of manufacturing a metal ribbon using a single cooling roll, the metal ribbon is formed along a roll parallel to a generatrix on a roll surface on a roll rotation upstream side from a molten metal injection position. A shielding wall having a thickness of 2 mm or more and 100 mm or less is disposed such that a gap between the surface and the roll is 0.05 mm or more and 2 mm or less, and the surface of the shielding wall facing the molten metal is directed toward the roll surface. CO ₂ gas is blown out to maintain the vicinity of the roll surface upstream of the molten metal injection position in a CO ₂ gas atmosphere, and the molten metal is injected onto the roll at a pressure of 20 kPa or more and 90 kPa or less, and the peripheral speed of the roll is 15 m / more than 27s
/ S or less, and a method for producing an amorphous ribbon having a thickness of 35 μm or more and 100 μm or less.

The fifth method invention of the present invention is the fourth method invention, wherein the CO ₂ gas heated to 500 ° C. to 800 ° C. is used as the CO ₂ gas, and the CO ₂ concentration around the paddle is reduced to 3%.
By adding technical means of 5% or more, thickness 3
A method for producing a metal ribbon, comprising producing an amorphous ribbon having a thickness of 5 μm or more and 100 μm or less. A first apparatus invention for carrying out the above method invention is an apparatus for manufacturing a metal ribbon using a single chill roll, wherein a roll is formed from an intersection between a center line of a molten metal injection nozzle hole and a roll surface. On the upstream side in the rotation direction, a carbon blade that comes into contact with the generatrix on the roll surface, and a CO ₂ gas ejection nozzle that ejects CO ₂ gas toward the roll surface along the surface of the carbon blade on the molten metal side are provided. An apparatus for producing a metal ribbon.

According to a second device invention of the present invention, the carbon blade of the first device invention is provided with a roll surface circumferential length on the upstream side in the rotation direction of the roll from the intersection of the center line of the molten metal injection nozzle hole and the roll surface. An apparatus for manufacturing a metal ribbon, provided at a distance of 20 mm or more and 100 mm or less. Further, in the first device invention or the second device invention, the CO ₂ gas ejected toward the roll surface is reduced by 50%.
It is preferable to provide a device for heating the temperature to 0 ° C or higher and 800 ° C or lower.

According to a third aspect of the present invention, a roll surface circumference of 20 mm or more and 100 mm upstream from the intersection of the center line of the molten metal injection nozzle hole and the roll surface in the rotation direction of the roll.
mm or less and 0.05 m parallel to the generatrix on the roll surface
A shield wall having a thickness of 2 mm to 100 mm along a roll having a gap of m to 2 mm, and a C extending toward the roll surface along the surface of the shield wall on the molten metal side.
An apparatus for producing a metal ribbon, comprising: a CO ₂ gas ejection nozzle for ejecting O ₂ gas.

[0020]

As schematically shown in FIG. 2, in a conventional apparatus,
When the cooling roll 2 rotates in the direction of arrow 6, an air boundary layer 3 is generated near the surface of the roll 2. The air in the boundary layer is entrained between the molten metal 4 injected from the nozzle 1 and the surface of the roll surface 2 to generate entrained air 5. The entrained air 5 forms a gap having a thickness of about 0.1 to 5 μm between the cooling roll 2 and the molten metal 4 and has a large heat transfer resistance. This gap is transferred to the surface of the manufactured ribbon.

To solve this problem, the present inventors
An amorphous ribbon was cast using a small single roll casting machine in a container having a CO ₂ gas partial pressure of 98% or more. As a result, no gas layer was mixed between the cooling roll and the molten metal, and the heat transfer resistance was significantly reduced, so that an amorphous ribbon having a thickness of 35 μm or more could be produced with good reproducibility. Ar, N ₂ , O
_When a gas other than CO ₂ such as ₂ was present at 30 vol% or more at the interface between the roll and the molten metal, a gap was generated due to the gas. If it is CO _2, cause that the gap does not occur, not clear. Based on this finding, it was determined that the method of forming a CO ₂ gas boundary layer around the roll in the atmosphere was suitable, and the present invention was completed as a result of conducting experiments by changing the CO ₂ gas inflow method and casting conditions.

At the time of industrialization, in order to enclose a large casting facility in a box and put it in a CO ₂ atmosphere, costs are required for sealing and the like, but this is not required in the present invention. FIG. 1 is an explanatory diagram of an embodiment of the present invention. Single chill roll 2 in air
Is rotated in the direction of arrow 6 to inject molten metal 4 from nozzle 1 into roll 2. The carbon blade 7 is placed in contact with a position L away from the point at which the center line 11 of the nozzle 1 intersects the surface of the roll 2 on the upstream side in the roll rotation direction. This carbon blade is for blocking the gas adhering to the roll surface and flowing around. The carbon blade 7 is in contact with the surface of the roll 2. A CO ₂ gas nozzle 8 with the roll 2 is provided on the surface of the carbon blade 7, and CO ₂ gas 9 is injected toward the surface of the roll 2 on the surface of the carbon blade 7. The CO ₂ gas flows along the surface of the roll 2 and the interface between the molten metal 4 and the roll 2 is in a CO ₂ high concentration atmosphere, so that no gas gap occurs and the heat transfer resistance is small.

According to the present invention, since casting can be performed in the atmosphere without the need for complicated equipment, there is no problem of cost increase, and the lateral direction of the nozzle 1 and the downstream side of the roll rotation are open. Therefore, there is an advantage that the gap between the nozzle 1 and the roll can be easily observed and controlled. In a conventional technique using a CO gas atmosphere, a lean gas is produced by heat generation ΔH due to gas combustion represented by the following formula: CO + 1/2 O ₂ → CO ₂ + ΔH. On the other hand, the CO ₂ gas atmosphere of the present invention is: CO ₂ + Δh → CO + 1 / 2O ₂ (O) + (Fe, Si, B) → (Fe ₂ SiO ₄ , Si
O ₂ , B ₂ O ₃ ) which gives a calorific value to the CO ₂ by external heat such as a heater or molten steel, causes a gas decomposition reaction by heating, and uniformly forms a molten metal oxide film in the decomposed gas. I have.

In particular, it is preferable that the gas colliding with the paddle has a high emissivity, that is, a gas body having a high temperature.
Among them, CO ₂ gas has the greatest effect. as a result,
A great effect can be obtained if the CO ₂ gas colliding with the paddle is diluted to a high temperature of 500 ° C. to 800 ° C., and Pco ₂ % is controlled to 35% or more and the surface is oxidized by a decomposition reaction in the paddle.

Further, since CO ₂ is carried along with the rotation of the roll surface, forced cooling by the impinging flow of CO ₂ gas to the nozzle 1 does not occur. Therefore, the problem of nozzle clogging can be avoided. The carbon blade 7 is used because lubricity with the roll is good and the roll is not scratched.

If the carbon blade 7 is not separated from the intersection of the center line of the nozzle 1 and the roll surface by at least 20 mm upstream, the splash of fine molten metal scattered at the start of molten metal injection will bite between the blade and the roll. , Causing the roll to be scratched. When the blade is separated beyond the circumference of more than 100 mm, a large amount of air is mixed into the CO ₂ gas flowing into the molten metal on the roll, so that a gap is generated at the interface between the molten metal and the roll.

Furthermore, since the CO ₂ gas flows on the roll along the carbon blade, the CO ₂ gas is made laminar, so that mixing of ambient air is reduced. To stably cast an amorphous ribbon having a thickness of 35 μm or more, the injection pressure of the molten metal must be 20 kPa or more and the roll peripheral speed must be 27 m / s or less. When the injection pressure is less than 20 kPa, the contact force between the molten metal and the roll is weak, and heat transfer is insufficient, so that the roll does not become amorphous. Further, when the roll is rotated at a roll peripheral speed exceeding 27 m / s, the flow rate of the molten metal must be increased in order to make the thickness of the ribbon 35 μm or more. Become. On the other hand, when the injection pressure of the molten metal is 90 kPa or more, the molten metal flows in the direction opposite to the roll rotation direction, and stable casting is impossible. If the roll peripheral speed is less than 15 m / s, the ribbon thickness increases, but the cooling rate of the molten metal decreases, and an amorphous ribbon cannot be obtained.

Only when all the above conditions are satisfied, an amorphous alloy having a thickness of 35 μm or more and 100 μm or less can be obtained with good reproducibility. Further, the temperature of the CO ₂ erupting is 500
It is preferred to heat to above ℃. This is necessary to keep the temperature of the nozzle 1 of 500 ° C. or higher in order to keep the temperature of the slit-shaped nozzle 1 usually having an interval of 2 mm or less and to prevent nozzle clogging due to solidification. However, heating the CO ₂ gas at a temperature exceeding 800 ° C. is not preferable because the size of the heating device is increased and the required amount of heat is increased.

If the CO ₂ atmosphere is not more than 35%, gas entrainment cannot be prevented. If it is less than 35%, the surface roughness of the ribbon is 0.8 μm or more, the characteristics are poor as an amorphous metal for a transformer, and the effect cannot be obtained. Further, when the surface roughness is 50% or more, there is no significant change when the surface roughness is about 0.4 μm, and there is little difference in the effect.

In particular, when casting is performed for a long time by a large machine, if the carbon blade is in contact with the roll surface, fine dust and thin strips gradually enter between the carbon blade and the roll surface, and May damage the surface. In order to prevent this, a device that does not contact the roll and that blocks the air flow on the surface is required.
For this purpose, instead of the carbon blade, a shielding wall 12 as shown in FIG. 8 is used. The circumferential dimension 13 of the portion closest to the surface of the roll 2 is 2 mm or more and 100 mm or less, and the gap 14 between the roll surface and the surface is 0.1 mm. It is effective to dispose it between 05 mm and 2 mm. This is roll 2 and shielding wall 12
This is to make the flow velocity of the air flow attenuate while passing through the small and long gap between.

In order to effectively remove the airflow passing through the gap, the circumferential dimension 13 of the portion of the shielding wall 12 closest to the roll surface is 2 mm or more, and the gap with the roll surface is 2 mm.
It is necessary to: When the circumferential dimension 13 of the portion of the shielding wall 12 closest to the roll 2 exceeds 100 mm, the force of the air flow generated by the rotation of the roll to pull the shielding wall increases, and the shielding wall 12 is caused by a slight flow or the like. There is a risk of contact with the roll surface. In addition, the gap 14 with the roll surface
If it is less than 0.05 mm, dust and thin strips cannot pass through, and it may bite into the gap between the shield wall and damage the roll surface.

The bottom surface of the shielding wall 12 does not need to be flat. If a groove 15 having a rectangular or saw-like cross section extending in the roll axis direction is provided as shown in FIG. It is preferred to increase. Further, as shown in FIG. 10, a gas hole 16 which is opened on the bottom surface of the shielding wall 12 is provided,
It is preferable to blow CO ₂ gas from the gas holes 16 to the surface of the roll 2 because the effect of blocking the air flow increases.

[0033]

【Example】

Example-1 An experiment for manufacturing a metal ribbon was performed using a single cooling roll. The experimental conditions are as follows: Cooling roll: 300 mm in diameter, 70 mm in width, made of copper alloy Molten metal: Fe-3 wt% B-5.3 wt% Si Injection nozzle for molten metal: Slit interval: 0.7 mm Slit width: 10 mm roll nozzle gap: a 0.25 mm (1) CO ₂ gas injection method, FIGS. 1, 3, 4, 5, and experiment with five system shown in FIG. FIG. 1 shows an embodiment, and FIGS. 3 to 6 show CO ₂ gas ejection nozzles 8 and CO ₂ gas.
The position direction of the gas flow 9 is changed. Figure 3 is a rear with respect to the molten metal, FIG. 4 is a front, FIG. 5 from both sides, Fig. 6 is a rear and front, in which blowing CO ₂ gas, respectively. Reference numbers in the figure are the same as those in FIG. Roll peripheral speed 21m / s, CO ₂ gas injection is φ1
This was performed at a pressure of 400 kPa at a rate of 25 liters / min from a 0 mm nozzle. The embrittlement rates of the resulting ribbons are 0% in FIG. 1, 60% in FIG. 3, and 55% in FIG.
%, 70% in FIG. 5, and 10% in FIG.

(2) The circumferential length L of the roll from the point where the center line of the molten metal injection nozzle intersects the roll surface to the contact point of the carbon blade is changed from 5 mm to 110 mm, and the roll circumferential speed is 21 m / s, CO ₂ With a φ10mm nozzle
It spouted at 0 KPa, 25 liter / min. L is 5m
When the length is not less than m and less than 20 mm, a small splash of molten metal generated at the beginning bites between the carbon blade 7 and the roll 2, causing a flaw on the roll 2, and a concave portion on the ribbon surface corresponding to the position.

When L is more than 100 mm and 110 mm or less, the ribbon becomes brittle at a rate of 10 to 15%. L is 20mm
Up to 100 mm, an amorphous ribbon without embrittlement was obtained. Particularly stable was L = 30 to 50 mm. (3) In FIG. 1, L = 40 mm, CO ₂ gas is φ1
400 kPa, 25 l / min with 0 mm nozzle
And the injection pressure of the molten metal is increased from 10 kPa to 100 k
The experiment was performed at Pa and a roll peripheral speed of 10 m / s to 30 m / s. FIG. 7 shows the result. The symbols in FIG. 7 are as follows.

Δ: Stable casting was performed, and an amorphous ribbon having a thickness of 35 to 80 μm with little embrittlement was produced. Δ: Molten metal flowed out in the direction opposite to the roll rotation direction. ●: Embrittlement occurs when the ribbon thickness is 35 μm or more. ×: The thickness of the ribbon was less than 35 μm.

(4) In FIG. 1, the roll peripheral speed is 21 m /
s, molten metal injection pressure 24 kPa, CO ₂ gas φ10
The center line average roughness of the roll surface side of a thin strip cast and ejected at 400 KPa, 25 liter / min in mm, and a thin strip cast by a conventional method without using a carbon blade or a CO ₂ gas nozzle in the atmosphere. When the degree Ra was measured and compared, Ra = 1.0 to 1.2 μm in the conventional method, but Ra = 0.3 to 0.4 μm in the example. Example 2 Next, an experiment was conducted in which a wide ribbon was manufactured by a large-sized machine for a long time. The experimental conditions are as follows.

Cooling roll: diameter 1000 mm, width 400
mm, made of copper alloy, internal water-cooled type Molten metal: Fe-3wt% B-5.3wt% Si Injection nozzle for molten metal: Slit interval: 0.7mm Slit width: 200mm Gap between roll nozzles: 0.25mm (1) CO ₂ gas was blown out as shown in FIGS. 1 and 6 to produce a ribbon. Roll peripheral speed is 21m / s, CO ₂ gas is 2
It was ejected from a slit nozzle having a width of 40 mm. The embrittlement rates of the resulting ribbons were 0% in FIG. 1 and 50% in FIG. 6, respectively, and the embrittlement was particularly large at the end portions of the ribbon in FIG.

(2) When the ribbon is manufactured by the method shown in FIG. 1, the molten metal injection nozzle is clogged, and the ribbon is not formed partially and the ribbon may be broken. When the temperature of the CO ₂ gas was heated to 500 ° C. to 750 ° C., clogging of the nozzle did not occur. CO ₂
When the temperature of the gas was 300 to 490 ° C., the frequency was lower than that of blowing CO ₂ at room temperature, but the nozzle clogging was not completely prevented.

(3) When a ribbon is manufactured by the method shown in FIG. 1, if the continuous production time of the ribbon exceeds 10 minutes, a continuous flaw may be formed on the roll surface of the ribbon in the longitudinal direction. It was found that foreign matter was caught between the carbon plate and the roll, so that the roll surface was damaged and the flaw was transferred to a thin ribbon. On the other hand, when the shielding wall 12 is provided and the CO ₂ gas is jetted as shown in FIG. 8, the ribbon production continuation time exceeds 10 minutes, and even when it reaches 30 minutes, no scratch is generated on the roll surface. A stable manufacturing experiment was possible. When the experiment was performed while changing the circumferential dimension 13 of the shielding wall 12 to 10 to 60 mm and changing the gap 14 between the shielding wall 12 and the roll 2 between 0.03 to 5 mm, the gap 14 was 0.05 to 2 mm.
Under the condition of mm, an amorphous alloy ribbon having an embrittlement rate of 0% was obtained stably. On the other hand, an experiment was performed under the condition that the gap 14 between the shielding wall 12 and the roll 2 was 0.2 to 1 mm and the circumferential direction 13 of the shielding wall 12 was 0.5 to 180 mm. When the circumferential dimension 13 is less than 2 mm, the embrittlement rate is 0.
%, And when the circumferential dimension 13 of the shielding wall 12 exceeded 100 mm, the shielding wall 12 was vibrated and came into contact with the rolls, so that a stable ribbon could not be manufactured.

FIG. 11 shows the case where L = 40 mm in FIG. 1 and the case where L = 40 mm in FIG.
m, when the gap 14 between the shielding wall 12 and the roll 2 is 3 mm, the surface roughness of the roll contact surface of the ribbon manufactured while changing the CO ₂ concentration around the paddle by adjusting the CO ₂ gas ejection flow rate. (Ra). In the region where the CO ₂ concentration is 35% or more, the surface roughness of the ribbon becomes smaller than 0.8 μm, so that a ribbon having better surface properties than the air atmosphere (CO ₂ concentration of 0%) can be manufactured.

Example 3 The method of the present invention was carried out using the apparatus shown in FIG. The molten metal is injected from the pouring nozzle 1 onto the rotating cooling roll 2 to produce the ribbon 23. 24 is an air knife. CO gas is supplied from the atmosphere gas nozzle 25 to the paddle 22 of the supplied molten metal.
₂ Gas 28 is blown. CO ₂ gas 28 is a gas heater 2
Heated at 7. The atmosphere cover 26 surrounds the periphery of the paddle 22.

Plate making was performed in the apparatus shown in FIG. 13 under the following conditions. Molten metal; Fe ₈₀ B ₁₀ Si ₉ C _I (at%) Melting temperature; 1300 ° C. Pouring nozzle; 200 mm width slit Cooling roll; 1 m outer diameter made of water-cooled copper alloy Cooling roll peripheral speed; 25 m / sec 500 as atmospheric gas The carbon dioxide gas of ° C. was supplied from the back of the paddle 22 while changing the flow rate using various nozzles 25 to form a ribbon 23, and its surface roughness was measured. 14 to 17 were used as the shape of the atmosphere gas nozzle. FIG. 14 shows a gas nozzle 25 in which a number of narrow slits are provided in parallel as shown in the front view of FIG.
(B) is a side view. The slit is for example 20m long
38 pieces with m and 0.7 mm width were provided. FIG. 15A is a front view of FIG. 15A, and FIG.
Is a gas nozzle 25 having a round hole. FIG. 16 shows a wide-open gas nozzle 25. The central opening in the front view (a) is 25 mm × 8.
In the side view, the nozzle tip is cylindrical as shown in FIG. FIG. 17 shows a narrow slit shape with an opening of width 1
The gas nozzle 25 has a size of 175 mm × mm × 175 mm. FIG.
Shows the results. Especially the carbon dioxide gas flow rate is 80m
^{The 3} / h and 25 mmφ round nozzle of FIG. 15 was effective. The condition that the surface roughness Ra required as an amorphous material for a transformer satisfies the condition of 0.8 μm or less is Pco ₂ %.
Is 35% or more.

FIG. 12 shows the magnetic characteristics of the ribbon produced under each condition. As is clear from FIG. 12, the iron loss required as-cast (as cast), W15 / 50 (50
(Hz, 1.5 T) = 0.4 W / kg or less is obtained when the CO ₂ concentration% is 35% or more. ADVANTAGE OF THE INVENTION According to this invention, the ribbon with favorable surface properties can be manufactured effectively and inexpensively, and mass commercial production is attained. This effect provides an amorphous alloy for a transformer, which can save a great amount of energy, and is extremely useful in industry.

[0045]

According to the present invention, since the air is mixed into the CO ₂ gas so that the air flows into the molten metal on the roll, no gap is generated at the interface between the roll and the molten metal, and Since the casting conditions have been optimized, the heat transfer resistance between the molten metal and the roll has been reduced, improving the heat transfer,
It is now possible to produce a thicker amorphous ribbon with good reproducibility. In addition, since the transfer of the gap to the ribbon surface due to the gas generated at the interface between the roll and the molten metal is reduced, there is also an effect of reducing the surface roughness of the ribbon.

[Brief description of the drawings]

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

FIG. 2 is a conceptual diagram showing air entrainment in a conventional method.

FIG. 3 is an explanatory view showing an experimental example of a CO ₂ gas ejection method.

FIG. 4 is an explanatory view showing an experimental example of a CO ₂ gas ejection method.

FIG. 5 is an explanatory diagram showing an experimental example of a CO ₂ gas ejection method.

FIG. 6 is an explanatory view showing an experimental example of a CO ₂ gas ejection method.

FIG. 7: Roll peripheral speed, molten metal injection pressure and ribbon thickness,
It is a graph which shows the relationship of embrittlement and casting instability.

FIG. 8 is an explanatory diagram showing an experimental example using a shielding wall.

FIG. 9 is an explanatory diagram showing an example in which a groove is provided at the bottom of the shielding wall.

FIG. 10 is an explanatory diagram showing an example in which gas holes are provided.

FIG. 11 is a graph showing the relationship between carbon dioxide concentration and ribbon surface roughness.

FIG. 12 is a graph showing a relationship between carbon dioxide concentration and iron loss.

FIG. 13 is a schematic view of an apparatus according to an embodiment of the present invention.

FIG. 14 is an explanatory diagram of a shape of a gas nozzle.

FIG. 15 is an explanatory diagram of a shape of a gas nozzle.

FIG. 16 is an explanatory diagram of a shape of a gas nozzle.

FIG. 17 is an explanatory diagram of a shape of a gas nozzle.

[Explanation of symbols]

Reference Signs List 1 nozzle 2 roll 3 boundary layer 4 molten metal 5 entrained air 6 arrow 7 carbon blade 8 CO ₂ gas nozzle 9 CO ₂ gas flow 11 center line of nozzle hole 12 shielding wall 13 circumferential dimension 14 gap 15 groove 16 gas hole 22 Paddle 23 Thin strip 24 Air knife 25 Gas nozzle 26 Atmosphere cover 27 Gas heater 28 CO ₂ gas

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Kimimada Midorikawa 1 Kawasaki-cho, Chuo-ku, Chiba Kawasaki Steel Corp. (72) Inventor Kenzo Osu 1 Kawasaki-cho, Chuo-ku Chiba-shi Kawasaki Steel (56) References JP-A-4-356336 (JP, A) JP-A-5-23800 (JP, A) JP-A-62-161443 (JP, A) JP-A-61-96046 (JP, A) JP-A-60-261647 (JP, A) JP-A-5-269549 (JP, A) JP-A-5-62813 (JP, A) JP-A-3-133551 (JP, A) JP-A-61-63346 (JP, A) JP-A-4-28459 (JP, A) JP-A-60-177936 (JP, A) JP-A-60-187452 (JP, A) JP-A-5-135919 (JP JP, A) JP-A-56-1250 (JP, A) JP-A-57-159247 (JP, A JP-A-51-109221 (JP, A) JP-A-59-209457 (JP, A) JP-A-53-12720 (JP, A) JP-A-5-138308 (JP, A) 138309 (JP, A) Japanese Utility Model Showa 60-52051 (JP, U) Japanese Patent Publication No. 3-28254 (JP, B2) Japanese Patent Publication No. 1-501924 (JP, A) (58) Fields surveyed (Int. ⁷ , DB name) B22D 11/06 360 B22D 11/106

Claims (9)

(57) [Claims] In a method of manufacturing a metal ribbon using a single cooling roll, a carbon blade is arranged in contact with a generatrix on a roll surface upstream of a molten metal injection position in a roll rotation direction. The CO ₂ gas is blown out toward the roll surface along the surface of the blade on the molten metal side, and CO near the roll surface upstream from the molten metal injection position is CO.
_{(2) A} method for producing a metal ribbon, characterized by maintaining the gas atmosphere. 2. The method according to claim 1, further comprising:
Inject onto a roll at a pressure of kPa or less and set the roll peripheral speed to 1
5 m / s or more and 27 m / s or less, and a thickness of 35 μm or more and 1
The method for producing a metal ribbon according to claim 1, wherein an amorphous ribbon having a thickness of 00 µm or less is produced. 3. A method for producing a metal ribbon using a single cooling roll, wherein a CO ₂ gas heated to 500 ° C. to 800 ° C. using a nozzle is placed on a molten metal paddle injected onto the cooling roll. A method for producing a metal ribbon, comprising: spraying and setting a CO ₂ gas concentration around a paddle to 35% or more by Pco ₂ %. 4. C heated to 500 ° C. or higher and 800 ° C. or lower.
O ₂ is blown out, and the CO ₂ gas concentration around the paddle is reduced to Pco ₂
3. The method according to claim 1, wherein the percentage is 35% or more.
A method for producing a metal ribbon as described above. 5. The method according to claim 1, wherein a shielding wall having a thickness of 2 mm or more and 100 mm or less along the roll is disposed so as to have a gap of 0.05 mm or more and 2 mm or less with respect to the roll surface instead of the carbon blade. The method for producing a metal ribbon according to any one of claims 1, 2 and 4. 6. In a metal ribbon manufacturing apparatus provided with a single cooling roll, a contact is made with a generatrix on the roll surface upstream from the intersection of the center line of the molten metal injection nozzle hole and the roll surface in the rotational direction of the roll. carbon blade and apparatus for manufacturing a thin metal strip, characterized in that a CO ₂ gas ejection nozzle for ejecting molten metal side CO ₂ gas toward the roll surface along the surface of the carbon blades. 7. The apparatus for manufacturing a metal ribbon according to claim 6, wherein the carbon blade is located at a distance of not less than 20 mm and not more than 100 mm in roll surface circumferential length on the upstream side in the rotation direction of the roll. 8. A metal strip casting apparatus provided with a single cooling roll, wherein a device for heating CO ₂ gas jetted toward the roll surface to 500 ° C. or more and 800 ° C. or less is provided. Item 8. An apparatus for manufacturing a metal ribbon according to item 6 or 7. 9. In place of the carbon blade, 0.05 mm parallel to the generatrix of the roll surface on the upstream side in the rotation direction of the roll.
The metal ribbon according to any one of claims 6, 7 and 8, further comprising a shielding wall having a gap of at least 2 mm and a thickness along a roll of 2 mm to 100 mm. manufacturing device.