JPH11188458A - Take up method for quickly coagulated magnetic thin band - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a take up method having high percentage of success wherein a thin band is taken up by rotation of a take up roll having a magnetism on the face by resolving a trouble used to happen at the time to catch a tip end of the band. SOLUTION: In a take up method wherein a quickly coagulated band 11 having a magnetism obtained by jetting a molten metal onto a moving cooled substrate is taken up in succession by rolling a take up roll bearing a magnetism on its surface, a difference (V1 -V2 ) between a moving speed (V1 ) of the cooled substrate and a take up roll time surface speed (V2 ) at a rolling start up time is set in a range of 0.01 m/s or above, 2 m/s or less.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid quenching method for rapidly solidifying a molten metal, that is, a metal and / or alloy in a liquid state, on a moving cooling substrate to obtain a thin band of metal and alloy. The present invention relates to a method of winding a rapidly solidified ribbon (hereinafter, simply referred to as a ribbon) on-line immediately after production.

[0002]

2. Description of the Related Art In a liquid quenching method for producing a ribbon, a so-called single-roll method in which a molten alloy is supplied onto a single high-speed rotating cooling roll to obtain a ribbon, or a pair of high-speed rotations is used. There is a twin roll method for supplying a molten metal between cooling rolls to obtain a ribbon. In the method of forming a ribbon by the liquid quenching method, for example, a case where a single roll quenched and solidified ribbon manufacturing apparatus shown in FIG. 3 is used will be described as an example. In FIG. 3, molten metal 1 is supplied to tundish 2 so that the level of the molten metal is constant. A tuyere brick 3 is provided on the bottom wall of the tundish 2, and an intermediate nozzle 4 and a nozzle holder 5 are connected to the tuyere brick 3. Holes are provided in the tuyere brick 3, the intermediate nozzle 4, and the nozzle holder 5, and these holes are connected to form the molten metal flow path 6 and the enlarged internal space 12 in the nozzle holder. A nozzle tip 7 is attached to the tip of the nozzle holder 5, and a nozzle slit 8 provided inside the nozzle tip 7 communicates with the molten metal flow path 6. The enlarged internal space 12, the nozzle tip 7, and the nozzle slit 8 in the nozzle holder are shown in FIG. The nozzle slit 8 refers to an opening for jetting molten metal provided in the nozzle tip 7.

When the stopper 9 is raised, the molten metal 1 in the tundish 2 flows out of the nozzle slit 8 through the molten metal flow path 6 toward the cooling roll 10. At this time, the flow rate of the molten metal flowing out from the nozzle slit 8 toward the cooling roll 10 is controlled according to the molten metal static pressure in the tundish 2. The molten metal flowing out of the nozzle slit 8 is rapidly cooled on the surface of the cooling roll 10 to become a thin strip 11.

In FIG. 3, the cooling roll 10 is drawn at a scale larger than the scale of the tundish 2 to facilitate understanding of the entire apparatus.

Various methods have heretofore been proposed as a method of winding a ribbon obtained by the liquid quenching method online immediately after casting. Basically, using a winding roll, a method of winding by rotating the winding roll is adopted.However, in any method, at the start of winding, that is, how to attach the thin ribbon tip to the winding roll The point is how to catch them.

In the case where the ribbon has magnetism, a method in which the ribbon is caught by the force of a magnet using, for example, a winding roll in which a permanent magnet is embedded in the surface, and then the winding is performed by rotating the winding roll. Japanese Patent Laid-Open No. 57-944
No. 53 has proposed this. This winding method, after rapid cooling and solidification on the rotating cooling substrate, peels off the magnetic ribbon that rotates while being in close contact with the cooling substrate surface, with a sharp high-pressure gas jet, and at the same time, the tip of the strip after peeling Is magnetically attracted and captured by a winding roll having a magnetic surface on a surface rotating at a peripheral speed higher than the moving speed of the rotary cooling substrate, and then continuously wound. The above publication discloses that a roll having a permanent magnet such as a rare earth cobalt magnet embedded in the surface can be used as a winding roll.

[0007] The present inventors have attempted to wind a thin strip by this method in order to wind the obtained thin strip online, for example, when producing a thin strip having magnetism by a single roll method. As a result, although the ribbon formed on the cooling roll could be peeled off with a jet of high-pressure gas, the success rate of capturing the ribbon tip with the take-up roll was as low as about 30%, and the capture of the tip failed. In that case, the production of ribbons had to be stopped. As described above, failure to capture the leading end of the ribbon is not preferable because it leads to a decrease in ribbon production yield.

Accordingly, the present inventors have proposed a method for stably capturing the leading end of a ribbon by a conventional method using a winding roll having a permanent magnet embedded in the surface thereof as disclosed in Japanese Patent Application Laid-Open No. 8-31.
No. 8352 has proposed a method. This method
This is a method in which the surface speed of the winding roll at the start of winding is in the range of 90% or more and less than 100% of the surface speed of the cooling roll to capture the leading end of the ribbon.

In general, a ribbon does not break even when a certain amount of tension is applied, but the tip portion is generally thin and has many defects, so that it is easily broken even with a slight tension. For this reason, if the surface speed of the winding roll is set to 100% or more of the surface speed of the cooling roll, even if the tip of the ribbon is once captured,
Immediately after the action of the tension, the ribbon breaks, and the subsequent winding of the ribbon becomes impossible. On the other hand, when the surface speed of the take-up roll is less than 90% of the surface speed of the cooling roll, the ribbon may break due to loosening of the roll, or the flattening may occur, and subsequent winding may be broken. In other words, the method proposed by the present inventors makes it possible to capture the leading end of the ribbon without difficulty and to enable the winding of the ribbon without hindering the subsequent winding of the ribbon. It is now possible to wind up thin ribbons.

[0010]

However, it has been found that in this ribbon winding method, further improvement is necessary in order to more stably capture the leading edge of the ribbon when winding the ribbon. . That is, in an experiment under various casting conditions, when the ribbon is wound by this method, if the surface speed of the cooling roll is set to, for example, 30 m / s or more, it may sometimes hinder the capture of the ribbon tip. found. Then, it was found that it is more preferable to limit the relationship between the surface speed of the cooling roll and the surface speed of the winding roll at the start of the winding of the ribbon by the difference between the two rather than by the ratio of the two, and completed the present invention. I came to.

The present invention is intended to stably capture the leading end of a ribbon and to wind the ribbon with a higher success rate even when the surface speed of the cooling roll during the production of the ribbon is changed in a wide range. The purpose is to provide a method that enables it.

[0012]

The gist of the present invention is as follows. (1) A method for continuously winding a rapidly solidified thin ribbon having magnetism obtained by ejecting a molten metal onto a moving cooling substrate by rotating a winding roll having a magnetic surface on the cooling substrate. (V ₁ −V ₂ ) between the moving speed (V ₁ ) of the roll and the surface speed (V ₂ ) of the winding roll at the start of winding.
In a range of 0.01 m / s or more and 2 m / s or less.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail.
In the present invention, as shown in FIG. 1, the winding roll 13 having a magnetic surface is brought close to the cooling roll 10, and the surface speed (V ₂ ) of the winding roll 13 is reduced to the surface speed (V ₁ ) of the cooling roll. ) Is slightly slower in the range of 0.01 m / s to 2 m / s, the tip of the ribbon 11 formed as described above is captured, and then winding is continuously performed.

Here, the surface speed (V ₁ ) of the cooling roll and the surface speed (V
₂ ), the difference (V ₁ −V ₂ ) is not less than 0.01 m / s and 2 m
The reason for limiting to the range of / s or less will be described. First, we describe the lower limit of the limited range of V ₁ one V _2.
Was provided the lower limit to the range of V ₁ -V ₂ is a V ₁ one V ₂ less than zero, that is, the V ₂ larger than the same or V ₁ and V _1, it can be stably caught by the leading end of the ribbon By going away. According to the experimental results of the present inventors, V ₁ −V
_{When 2} was less than or equal to zero, the success rate of ribbon tip capture was as low as 30% at best. Observation using video showed that although the ribbon tip could be captured instantaneously, the ribbon broke shortly thereafter, and eventually the ribbon could not be captured in a stable manner.

It is considered that the reason is that if V ₁ -V _{2 is set} to zero or less, tension acts on the ribbon immediately after capturing the leading end of the ribbon. Generally, a ribbon does not break even when a certain amount of tension is applied, but the tip is generally thinner,
It is easy to break even with some tension due to many defects. For this reason, if V ₁ -V _{2 is set} to zero or less, even if the tip of the ribbon is once caught, the ribbon is broken immediately afterwards because of the tension, and the subsequent winding of the ribbon is impossible. Becomes

However, when actually setting the surface speeds of the cooling roll and the winding roll in the ribbon manufacturing apparatus, V ₁ −
From difficulty operational to set a very small value the value of V _2, and the convenience 0.01 m / s the lower limit of the limited range of V ₁ -V ₂ in the present invention.

On the other hand, the upper limit of the limited range of V ₁ -V ₂ is 2
The reason why m / s is set is that if V ₁ -V ₂ is more than 2 m / s,
This is because the success rate of catching the ribbon tip is as low as about 60%, and it is easy to fall down during winding.
If V ₁ -V ₂ is more than ₂ m / s, even if the tip can be successfully captured, the winding will be loosened in the subsequent winding, and if the amount of the thin ribbon to be wound is large, the winding will be likely to collapse. If rollover occurs, casting cannot be continued, such as breakage of the ribbon, which is not preferable in operation. Note that V ₁ -V
There is a preferred combination of the value of ₂ and the surface speed of the chill roll.

The distance between the take-up roll and the cooling roll at the time of catching the leading end of the ribbon is preferably as small as possible without causing collision, and is preferably, for example, about 10 mm or less. However, if the leading end of the ribbon can be captured and the winding can be performed stably, it is necessary to keep the winding roll away from the cooling roll in consideration of thickening of the winding roll. The timing at which the winding roll is moved away will be described in detail in Examples.

Further, in the method of the present invention, when the leading end of the ribbon is captured and the winding of the ribbon is stabilized, V ₂ is made slightly larger than V ₁ immediately, and an appropriate tension is applied to the ribbon. It is preferable to wind while winding. This is because V ₂ is slightly smaller than V ₁ , so that winding is loosened, and if winding is continued as it is, winding is likely to occur. Of course, it takes place some of the winding slack before increasing the V ₂ from V _1, if the value of V ₁ one V ₂ is 2m / s or less, during this time of winding slack fell winding then should not the problem It does not occur. On the other hand, the value of V ₁ -V ₂ is 2 m /
If it exceeds s, the winding slack is large until V ₂ is made larger than V _1, so that the winding is likely to fall as described above. As described above, the tip of the stagnant portion is easily broken, but the tension can be applied to the ribbon to some extent in other places. Preferred values of the tension applied to the ribbon will be described in Examples.

Incidentally, in order to mass-produce the ribbon by using the method of the present invention, it is necessary to rotate the disk 15 as shown in FIG. Assuming that the spare take-up reel 13 'is on standby on the cooling roll side, a system can also be adopted. When the thin ribbon forms a long pass line, the support roller 16
The use of enables stable winding.

The winding roll that can be employed in the method of the present invention is a roll in which a permanent magnet such as a rare earth cobalt magnet or samarium-cobalt is embedded so as to be exposed on the surface. In addition, a roll in which magnetism is generated on the surface by an electromagnet method may be used.

As a method of forming a ribbon, a single roll method has been described above.
The present invention can also be applied to other liquid quenching methods such as a twin roll method in which a molten metal is supplied between a pair of high-speed rotating cooling rolls to obtain a ribbon. The preferred casting conditions for forming the ribbon will be described in detail in Examples.

[0023]

Embodiments of the present invention will be described below. [Example 1] by using a single roll spinning apparatus in the atmosphere shown in FIG. 3, Fe-Si _6.5 one B ₁₂ -C ₁ (atomic%) to produce a thin strip of amorphous alloy, winding the winding roll Tried. The nozzle opening shape of the molten sample ejection nozzle tip used for casting was 1.2 mm × 150 mm. Also,
The flow rate of the molten sample of the above alloy melted by the high frequency induction method was set to 50 kg / min, and sprayed on the peripheral surface of a cooling roll made of copper to form a ribbon.

As a winding roll, the surface is 10 mm in diameter.
A round bar-shaped samarium-cobalt having a height of 6 mm is embedded so that adjacent magnetic poles are different from each other.
An aluminum take-up roll of mm was used.

The experimental levels were set to 9 levels, and in each of the experimental levels, the difference between the surface speeds of the cooling roll and the winding roll was changed by changing at least one of the surface speeds. In addition, the experiment was performed for each level at 5 charges. Table 1 shows the surface speed (V ₁ ) of the cooling roll, the surface speed (V ₂ ) of the winding roll, and the difference (V ₁ −V ₂ ) between the _{two at} each experimental level. Other casting and winding conditions were constant.

[0026]

[Table 1]

As the winding conditions, the relative positions of the winding roll and the cooling roll at the time of catching the leading end of the ribbon have a positional relationship as shown in FIG. 1, and a line connecting the nozzle tip for ejecting the molten sample and the center of the cooling roll. The take-up roll was disposed at a position rotated by 150 ° from the direction indicated by the arrow. Also, the rotation speed of the winding roll was adjusted so that a load of 2.5 kgf was applied after 0.5 seconds from the start of winding. Further, the interval between the winding roll and the cooling roll was initially 2 mm, and two seconds after the start of winding, the winding roll was retracted at a speed of 25 mm / sec for 10 seconds.

The results are shown in Table 1 under No. 1-9, N
o. With all 5 charges except the 7 level, all of the ribbons could be wound well without falling over. N
o. At the level of 7, only one charge out of five charges,
Casting was stopped halfway because the ribbon broke at the start of winding (at the time of capturing the leading edge of the ribbon).

The results are shown in FIG. It shows that the ribbon tip was successfully captured by all the charges except for one charge at the level of 7, and the value of V ₁ -V ₂ at the time of supplementing the ribbon tip was 0.01 m / s or more and 2 m / s. It was found that the following ranges could capture the ribbon tip with a fairly high success rate.

The obtained ribbon was a good ribbon having a width of about 150 mm and a plate thickness of about 30 μm for each charge.

[Comparative Example] Using the apparatus for manufacturing a single roll ribbon in air used in the example, Fe-Si _6.5- B ₁₂ -C
_A ribbon of ₁ (at.%) Amorphous alloy was manufactured, and winding was attempted with a winding roll. However, the difference between the surface speed (V ₁₎ and the surface speed of the winding roll of the cooling roll _{(V 2) (V 1 -V} 2) is in Table 1 No. As shown in 10 to 15,
At any level, it was more than 2 m / s or less than zero. The other casting and winding conditions were the same as in the case of Example 1, and each level was tested by 5 charges.

The results are shown in Table 1. 10-15,
At all levels, the success rate of capturing the ribbon tip was as low as 60% or less. No. In No. 12, although the leading end of the ribbon was successfully captured with two charges, the ribbon collapsed in the middle and the ribbon was broken at that point, so the casting had to be stopped halfway.

From this result, the value of V ₁ -V ₂ was changed to 2 m / s
It was found that when the ratio was more than or less than zero, the success rate of capturing the thin ribbon tip was low, or the flattening was caused to cause a decrease in the production yield.

[0034]

According to the present invention, the rapid production of a rapidly solidified thin ribbon such as an amorphous alloy is presumed to be performed on-line winding. With the ability to capture without problems, it has become possible to produce ribbons at high yields.

[Brief description of the drawings]

FIG. 1 is a schematic diagram for explaining a method of the present invention.

FIG. 2 is a schematic diagram showing a state in which a ribbon is wound by the method of the present invention.

FIG. 3 is a schematic diagram for explaining a single roll method as an example of a liquid quenching method.

FIG. 4 is an explanatory view in which a peripheral portion of a nozzle holder is enlarged.

[Explanation of symbols]

 1: Molten metal 2: Tundish 3: Tuyere brick 4: Intermediate nozzle 5: Nozzle holder 6: Molten channel 7: Nozzle tip 8: Nozzle slit 9: Stopper 10: Cooling roll 11: Thin ribbon expanding internal space 12: Take-up roll 13: Preliminary take-up roll 14: Take-up device 15: Disk 16: Support roller

Claims (1)

[Claims] 1. A method for continuously winding a rapidly solidified ribbon having magnetism obtained by ejecting a molten metal onto a moving cooling substrate by rotating a winding roll having a magnetic surface. The difference (V ₁ −V) between the moving speed (V ₁ ) of the cooling substrate and the surface speed (V ₂ ) of the winding roll at the start of winding.
₂ ) The method for winding a rapidly solidified thin ribbon having magnetism, wherein the value of the range is 0.01 m / s or more and 2 m / s or less.