JPH11320042A - Method and apparatus for continuously casting light alloy - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the development of defective casting surface caused by the outlet of spouting passage for lubricating oil in a light alloy cast block. SOLUTION: At the time of producing cast block I composed of light alloy by disposing a cylindrical water-cooling mold 13 having an inner radius (r1 ) larger than the inner radius (r2 ) of the outer 16 of the molten metal just below a spout 15 having an upward molten metal receiving hole and a downward molten metal outlet 16 and using a continuous casting apparatus 1 provided with spouting passage 44 for lubricating oil at the lower side of the spout 15 to supply the lubricating oil L between the water-cooling mold 13 and the molten metal (m) brought into contact with this mold; lubricating oil L having >=30% vaporizing ratio at 300 deg.C is used and an annular gas storing part G for separating the molten metal (m) from the outlet (t) of the spouting passage 44 for lubricating oil is formed at the lower side of the annular projecting part 15a of the spout 15 by vaporizing the lubricating oil L.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a continuous casting method for a light alloy and a continuous casting apparatus for a light alloy.

[0002]

2. Description of the Related Art Conventionally, light alloys (Al alloy, Mg alloy, etc.)
As a continuous casting method, there is known a method of manufacturing a light alloy ingot using the following continuous casting apparatus. The apparatus arranges a cylindrical water-cooled mold having an inner radius larger than the inner radius of the molten metal outlet immediately below a spout having an upward molten metal receiving port and a downward molten metal outlet, and between the water-cooled mold and the molten metal contacting the same. In order to supply lubricating oil, a discharge path for lubricating oil is provided below the spout. In this case, a plurality of lubricating oil discharge passages are generally arranged along the circumferential direction of the water-cooled mold.

[0003]

However, according to the above-mentioned method, when the molten metal exits the spout and descends in the water-cooled mold, a part of the molten metal on the outer peripheral side is slightly located at the outlets of several discharge paths. Phenomena, and then go out of each exit and along the inner peripheral surface of the water-cooled mold. As a result, there is a problem that the outer surface of the ingot is torn off and casting surface defects such as rough skin occur. This becomes even more severe when a circumferential electromagnetic stirring force is applied to the molten metal.

On the other hand, the kinematic viscosity of the lubricating oil changes significantly depending on the temperature and does not become constant in each discharge path, so that a difference occurs in the discharge resistance of the lubricating oil in each discharge path. The amount of the lubricating oil delivered from the steel tends to be uneven, which also causes the casting surface to be defective.

[0005]

According to the present invention, by employing relatively simple means, it is possible to avoid the occurrence of defective casting surface due to the outlet of the discharge passage for lubricating oil in a light alloy ingot. It is an object to provide the continuous casting method.

[0006] In order to achieve the above object, according to the present invention,
A cylindrical water-cooled mold having an inner radius larger than the inner radius of the molten metal outlet is disposed immediately below a spout having an upwardly directed molten metal receiving port and a downwardly directed molten metal outlet. In order to supply an ingot made of a light alloy using a continuous casting apparatus having a discharge path for lubricating oil below the spout,
As the lubricating oil, a gas having a vaporization rate of 30% or more at 300 ° C. is used, and by vaporizing the lubricating oil, an annular gas for separating the molten metal from the outlet of the lubricating oil discharge passage below the annular overhang portion of the spout. A continuous casting method for a light alloy is provided that forms a pool.

[0007] According to the continuous casting method, since the inflow of the molten metal into the outlet can be prevented by the annular gas reservoir, it is possible to avoid the occurrence of casting surface defects in the light alloy ingot due to the outlet. The lubricating oil that has not vaporized lubricates between the water-cooled mold and the molten metal.

In this case, the vaporization rate of the lubricating oil at 300 ° C. may be 100%. The reason is that at the lower end side of the gas reservoir, the gas is cooled by the water-cooled mold and liquefied, and the liquefied oil contributes to lubrication between the water-cooled mold and the molten metal. However, 300 ° C of lubricating oil
If the vaporization rate is less than 30%, a gas reservoir having a pressure sufficient to separate the molten metal from the outlet cannot be formed.

The gas reservoir exhibits a function of preventing the molten metal from entering the outlet even in a continuous casting method for applying a circumferential electromagnetic stirring force to the molten metal.

[0010] In the continuous casting method, it is desirable to use a mixed lubricant obtained by mixing a solid lubricant with a lubricating oil. Accordingly, it is possible to prevent insufficient lubrication between the water-cooled mold and the molten metal due to the vaporization of the lubricating oil. In this case, the mixing amount A of the solid lubricant is 1 wt% ≦ A ≦ 10 wt%
Is set to When the mixing amount A is A <1 wt%, there is no significance in using a solid lubricant. On the other hand, when A> 10 wt%, the amount of the solid lubricant becomes excessive and oil scorching occurs on the outer peripheral surface of the ingot.

Further, the kinematic viscosity ν of the lubricating oil at the entrance of the lubricating oil discharge passage is preferably set to ν ≦ 30 mm ² / s.
With this setting, the change in viscosity of the lubricating oil due to the change in temperature can be made extremely small, and the amount of lubricating oil delivered from each discharge path can be equalized. However, when the kinematic viscosity ν is ν>
At 30 mm ² / s, ingot casting surface defects are likely to occur.

[0012] It is an object of the present invention to provide the continuous casting apparatus capable of easily performing the above method.

According to the present invention for achieving the above object,
A spout having an upward molten metal receiving port and a downward molten metal outlet, and an inner radius r ₁ that is disposed immediately below the spout to cool the molten metal from the molten metal outlet and is larger than an inner radius r _{2 of the} molten metal outlet. A cylindrical water-cooled mold having
A stirrer for imparting electromagnetic stirring force in the circumferential direction to the molten metal and a lubricating oil between the water-cooled mold and the molten metal contacting the water-cooled mold are provided between an annular lower end surface of the spout and an annular upper end surface of the water-cooled mold. A continuous casting apparatus for light alloys, comprising: a discharge path for lubricating oil; and a coating layer provided on the annular upper end surface and having a thermal conductivity lower than a thermal conductivity of the water-cooled mold.

According to this device, the temperature decrease of the lubricating oil due to the water-cooled mold can be suppressed by the coating layer, whereby the vaporization of the lubricating oil can be promoted and the intended purpose can be achieved.

[0015] In the above-mentioned device, the lubricating oil discharge path may be formed by a discharge path forming plate. In this case, the discharge passage forming plate is made of a material having a lower thermal conductivity than that of the water-cooled mold in order to promote the vaporization of the lubricating oil.

[0016] Further, as the apparatus, there is provided an apparatus in which a lubricating oil supply path includes the discharge path, and a portion of the lubricating oil supply path connected to the discharge path is arranged around the spout. With such a configuration, it is possible to heat the lubricating oil with the spout to stabilize the kinematic viscosity.

Further, as the above-mentioned apparatus, there is provided an apparatus in which a heater for heating a lubricating oil is disposed near an inlet of a discharge path. With this configuration, the lubricating oil is heated by the heater,
As described above, the kinematic viscosity can be stabilized.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of a continuous casting apparatus 1 shown in FIGS. 1 and 2 has a body 2 whose axis is oriented vertically. The body 2 includes an inner peripheral wall 3, an outer peripheral wall 4 arranged at a predetermined interval on the outer peripheral side, an annular upper end wall 5 on the upper end side of the two walls 3, 4, And an annular lower end wall 6 located at the lower end side.

The inner peripheral wall 3 is composed of an upper cylindrical body 7 and a lower cylindrical body 8, and an inward annular portion 10 of an annular rubber seal 9 fitted to a lower outer peripheral surface of the upper cylindrical body 7 is provided between the two cylindrical bodies 7, 8. It is sandwiched and seals between them. The lower half of the upper cylindrical body 7 is formed to be thicker than the upper half so as to form an annular step inside, thereby forming a cylindrical water-cooled mold 13. Therefore, the water-cooled mold 13 is provided with the cylindrical portion 12 composed of the upper half.
And an annular upper end surface 11 composed of an annular step. The water-cooled mold 13 is made of an Al alloy (for example, A5052).

The cylindrical portion 12 surrounds the spout 15 through a thin cylindrical body 14, and an annular lower end surface 17 forming a downward molten metal outlet 16 of the spout 15 abuts on the annular upper end surface 11 of the water cooling mold 13. Touch An annular retaining plate 18 is fitted to a portion of the spout 15 projecting from the upper end wall 5, and the retaining plate 18 is fixed to the upper end wall 5. Spout 15
Is composed of calcium silicate having adiabatic fire resistance. Alumina, silica, and the like are also used as spout constituent materials. The inner radius r ₁ of the water-cooled mold 13 is
Is larger than the inner radius r _{2 at} the molten metal outlet 16 of the spout 15, and therefore, the periphery of the molten metal outlet 16 of the spout 15 has an annular overhang portion 15 a.

Above the spout 15, a molten metal supply gutter 19 for performing horizontal pouring is disposed, and its downwardly directed hot water supply port 2 is provided.
0 communicates with the molten metal receiving port 21 facing upward of the spout 15.

In the body 2, the outer peripheral wall 3,
An electromagnetic induction type stirrer 23 is provided in the cylindrical closed space 22 between the four, and the stirrer 23 applies a circumferential electromagnetic stirring force to the molten metal m in the spout 15. The stirrer 23 includes a laminated iron core 24 having a cylindrical shape, and a plurality of coils 25 wound around the laminated iron core 24. As shown in FIG. 3, the laminated iron core 24 includes a cylindrical portion 26 and a plurality of ridges 27 arranged on the inner peripheral surface thereof at equal circumferential intervals and extending in the generatrix direction. Each coil 25 has a pair of adjacent ridges 2 such that a part of the two coils 25 overlaps on one ridge 27.
7 is wound.

A thin-walled coil stopping cylinder 28 is fitted inside the laminated iron core 24 so that the tips of the ridges 27 are in close contact with each other. 9 and is fixed in the cylindrical closed space 22. The stratified iron core 24 is mounted on an annular support member 29 of the lower end wall 6 and a plurality of bolts 30 and nuts 3
Fixed by 1. A plurality of connecting tools 32 are prepared in two ratios for one coil 25, and each connecting tool 32 is attached to the lower end wall 6 by watertight means through the lower end wall 6.

A plurality of water supply ports 33 are formed in the outer peripheral wall 4,
Cooling water w is supplied into the closed space 22 through each water supply port 33. A plurality of through holes 34 are formed in the cylindrical body 28 inside the laminated iron core 24 near the upper end thereof, so that a cooling water reservoir 35 exists above the annular rubber seal 9. The water-cooled mold 13 is cooled by the cooling water sump 35 and has a plurality of jet holes 36 for jetting the cooling water w of the cooling water sump 35 obliquely downward.

[0025] In order to supply lubricating oil between the water-cooled mold 13 and the molten metal m, lubricating oil supply path F _L as follows is present around the spout 15. In the inner peripheral wall 3, the upper cylindrical body 7
A lower plate 37 of the upper end wall 5 is integrally provided at an upper end of the upper end of the lower end. An annular path 39 surrounding the spout 15 and a plurality of straight paths 40 extending radially from the annular path 39 are provided between the upper plate 38 and the lower plate 37 of the upper end wall 5.
An introduction path 41 formed in the upper plate 38 communicates with an end of each straight path 40, and the introduction path 41 is connected to the refueling pump P. As shown in FIG. 2, a cylindrical path 42 is formed around the spout 15, in the illustrated example, between the outer peripheral surface of the cylindrical body 14 and the inner peripheral surface of the cylindrical portion 12, and the cylindrical path 42 and the annular path 39 are formed.
A plurality of obliquely downwardly facing through holes 43 communicating with each other are formed in the cylindrical portion 12.
And the lower plate 37 are formed at a continuous portion. The lower end of the cylindrical passage 42 communicates with a plurality of discharge passages 44 formed at equal intervals on the circumference of the water-cooled mold 13. Each of the discharge paths 44 has an L-shape, and an inlet a at the tip of the vertical portion thereof has a cylindrical path 4.
The outlet b at the end of the horizontal portion is opened at the inner peripheral surface to open with the annular upper end surface 11 so as to communicate with 2. As described above, the lubricating oil supply passage _FL includes the introduction passage 41, the straight passage 40, and the annular passage 3
9, through hole 43, cylindrical path (portion continuing to discharge path 44) 42
And the discharge path 44.

As the lubricating oil L, those having a vaporization rate of 300% or more at 300 ° C., such as Showa Shell Terrace Oil # 46, # 32, and # 22 under the trade name, are generally used alone. This may be mixed with other lubricating oils. Solid lubricants that are mixed with the lubricating oil L to form a mixed lubricant include PTFE powder, graphite powder, BN
Powder, molybdenum compound powder (for example, molybdenum disulfide powder) and the like are used. The mixing amount A of the solid lubricant is set so that 1 wt% ≦ A ≦ 10 wt%.

In the above arrangement, the molten metal m made of, for example, an Al alloy is supplied from the hot water supply port 20 of the molten metal
When the molten metal m is supplied into the spout 5, the molten metal m is given an electromagnetic stirring force by the stirrer 23 in the spout 15, and then cooled by the water-cooled mold 13 to obtain the ingot I.

In the casting process, the lubricating oil L is heated by the spout 15 while flowing through the cylindrical path 42, in the illustrated example, by the cylindrical body 14 which receives heat from the spout 15, thereby stabilizing its kinematic viscosity. As a result, the amount of lubricating oil delivered from each discharge path 44 is equalized. Since the temperature of the molten metal m near the outlet b of each lubricating oil discharge passage 44 is 300 to 400 ° C., the lubricating oil L existing at the outlet b and the vicinity thereof is further heated by the molten metal m, and its 30% The above is vaporized, whereby an annular gas reservoir G for separating the molten metal m from each outlet b is formed below the annular overhang 15a of the spout 15.

According to such a continuous casting method, the inflow of the molten metal m into each of the outlets b can be prevented by the annular gas reservoir G, so that the occurrence of casting surface defects caused by the outlet b on the outer peripheral surface of the ingot I can be reduced. Can be avoided. The lubricating oil L and / or the solid lubricant that has not been vaporized lubricate the space between the water-cooled mold 13 and the molten metal m.

Since the above-described annular gas reservoir G is formed even when the above-described electromagnetic stirring is performed,
It is naturally formed even in the ordinary continuous casting method without the electromagnetic stirring. Since the high-melting-point crystallized substance is spheroidized by the electromagnetic stirring, an ingot I optimal for thixocasting can be obtained.

The second embodiment of the continuous casting apparatus 1 shown in FIGS. 4 and 5 differs from the first embodiment only in the structure of the discharge passage 44 for lubricating oil. In the second embodiment, a plurality of linear discharge passages 44 are provided between the annular lower end surface 17 of the spout 15 and the annular upper end surface 11 of the water-cooled mold 13. In the example shown,
A plurality of V-grooves 45 are radially formed on the annular upper end surface 11 of the water-cooled mold 13, and the upward opening of the V-grooves 45 is closed by the annular lower end surface 17 of the spout 15 and the lower end surface of the cylindrical body 14 so that each of the discharge paths 44 is formed. Is formed. Water cooling mold 1 made of Al alloy (A5052) on annular upper end surface 11
A coating layer 46 having a thermal conductivity lower than the thermal conductivity [0.331 cal / (cm · s · deg)] is provided.
In the illustrated example, both coating layers 46 are made of a stainless steel foil [0.0617 cal / (cm · s · deg)] having a thickness of about 50 μm, and these stainless steel foils are stuck on the inner surface of each V groove 45 and the upper surface of each land 47, respectively. You. With this configuration, the temperature of the lubricating oil L caused by the water-cooled mold 13 is reduced by the coating layer 4.
6, the vaporization of the lubricating oil L can be promoted more than in the first embodiment.

The third embodiment of the continuous casting apparatus 1 shown in FIGS. 6 to 10 differs from the first embodiment only in the structure of the discharge passage 44 for lubricating oil, as described above. In the third embodiment, a discharge path forming plate 48 that forms a plurality of discharge paths 44 is disposed between the annular lower end face 17 of the spout 15 and the annular upper end face 11 of the water-cooled mold 13. The discharge path forming plate 48 is provided with a heat conductivity of the water-cooled mold 13 [0.331 cal / (cm · s · deg)].
It is made of a material having a lower thermal conductivity, for example, phosphor bronze [0.202 cal / (cm · s · deg)], stainless steel [0.0617 cal / (cm · s · deg)], or the like.

The discharge path forming plate 48 is made up of a thin upper and lower annular plates 49 and 50 which are disposed so as to overlap between the spout 15 and the water-cooled mold 13. As clearly shown in FIGS. 8 and 9, the lower annular plate 50 extends from the inner peripheral surface to the outer peripheral portion,
And a plurality of discharge path slits 51 radially arranged so that the opening on the inner peripheral surface serves as the outlet b.
An outer peripheral end of 1 is formed in a circular hole 52. FIG.
As shown in FIG. 0, the upper annular plate 49 has a plurality of U-shaped notched inlets a radially arranged on an outer peripheral portion thereof,
Each inlet a is provided with a lower annular plate 50 as shown in FIGS.
And is connected to the cylindrical passage 42 on the lubricating oil supply side. Each inlet a has a sufficiently larger area than each circular hole 52.

As described above, the annular lower end face 17 of the spout 15
By arranging the upper annular plate 49 on the side, the narrowing of the discharge path 44 due to the thermal deformation of the spout 15 can be avoided. When each slit 51 is provided with a circular hole 52 and the area of each inlet a is increased, the lubricating oil L from the cylindrical passage 42 is supplied to the slit main portion 54 through the inlet a and the circular hole 52.
Can be guided smoothly. The lower annular plate 50 functions as the discharge path forming plate 48 by itself. Embodiment 1 The first embodiment of the continuous casting apparatus 1 shown in FIGS. 1 to 3 was used, and JIS was used as a raw material Al alloy.
Using AC2B, lubricating oil (including mixed lubricant) L
Casting speed: 170 mm / min: lubricating oil supply: 1 cc / min; cooling water supply: 80 l / min
The temperature of the molten metal at the molten metal receiving port 21 of the spout 15: 650 to 690 ° C .; electromagnetic stirring: 4-pole coil, 50H
Example 1 of ingot I having a diameter of 152 mm under conditions of z and 30A
~ 11 were cast.

Table 1 shows the types of the lubricating oils L used in the castings of Examples 1 to 11, their vaporization rates at 300 ° C. and 400 ° C., the mixing amount A of the PTFE powder as a solid lubricant, and the casting of the ingot I. Indicates skin condition. In the table, “OK” means that the casting surface of ingot I is smooth, and “Good” means that the degree of smoothness is better than that of “OK”. In the mixed oil, Showa Shell Terrace Oil # 22: Castor Oil = 9: 1 (weight ratio).

[0036]

[Table 1]

As shown in Table 1, in order to smooth the casting surface of the ingot I, it is necessary to use a lubricating oil L having a vaporization rate of 30% or more at 300 ° C. It is understood that A must satisfy 1 wt% ≦ A ≦ 10 wt%. Embodiment 2 A second embodiment of the continuous casting apparatus 1 shown in FIGS. 4 and 5, shown in FIGS.
The third embodiment of the continuous casting apparatus 1 in which 0 is made of phosphor bronze and the fourth embodiment of the continuous casting apparatus 1 in which only the lower annular plate 50 made of phosphor bronze is used as the discharge path forming plate 48 are used. JIS AC2B as an Al alloy
Casting speed: 170 mm / min; lubricating oil: Showa Shell Terrace Oil # 46; lubricating oil supply: 1 cc / min;
Cooling water supply: 80 liter / min; temperature of molten metal at molten metal receiving port 21 of spout 15: 650 to 690 ° C .;
Electromagnetic stirring: Examples 1 to 3 of ingot I having a diameter of 152 mm were cast under the conditions of a quadrupole coil, 50 Hz, and 30 A.

Table 2 shows the lubricating oil discharge path 4 for Examples 1 to 3.
4 shows the characteristics of No. 4 and the state of the casting surface of the ingot I. In the table,
“Excellent” means that the degree of smoothness of the casting surface in ingot I is better than the above “good”.

[0039]

[Table 2]

As is clear from Table 2, in the case of Examples 1 and 2, the supply of the lubricating oil L to the discharge path 44 is performed smoothly, and thereafter, the vaporization of the lubricating oil L is promoted and the water-cooled mold 13 is cooled. The lubricating oil is sufficiently supplied to the inner peripheral surface of the ingot I, that is, between the water-cooled mold 13 and the molten metal m in contact therewith, so that the casting surface condition of the ingot I becomes excellent. In the case of Example 3, since only the lower annular plate 50 is used, the supply of the lubricating oil to the discharge path 44, the vaporization thereof, and the water-cooled mold 13
Since the supply of the lubricating oil L to the inner peripheral surface side is somewhat hindered by the thermal deformation of the spout 15, the casting surface condition of the ingot I is slightly inferior to Examples 1 and 2. In the second embodiment of the continuous casting apparatus 1 shown in FIGS. 4 and 5, the coating layer 46 made of Cu foil instead of stainless steel foil, that is, the water-cooled mold 1 is used.
Thermal conductivity [0.923 cal / (cm · s · deg)] higher than the thermal conductivity [0.331 cal / (cm · s · deg)]
)], The ingot I
Of the cast surface was “OK”. From this, the coating layer 46
It is clear that the thermal conductivity of the water cooling mold 13 is lower than that of the water cooling mold 13. [Embodiment 3] As a fifth embodiment of the continuous casting apparatus 1 capable of avoiding the occurrence of casting surface defects caused by the outlet b in the light alloy ingot I without forming the gas reservoir G as described above. The following can be mentioned.

That is, the fifth embodiment has substantially the same structure as that shown in FIGS. 6 to 10 and has a spout 15 having an upward molten metal receiving port 21 and a downward molten metal outlet 16.
And a cylindrical water-cooled mold 13 disposed immediately below the spout 15 to cool the molten metal m from the molten metal outlet 16, a stirrer 23 for applying a circumferential electromagnetic stirring force to the molten metal m, and the water-cooled mold 13 and the The annular lower end face 17 of the spout 15 and the water-cooled mold 13 are formed so as to form the lubricating oil discharge passage 44 having an outlet b large enough to supply the lubricating oil L between the contacting molten metal m and prevent the molten metal m from entering. Between the annular upper end surfaces 11 of the thin upper and lower annular plates 49,
50. The lower annular plate 50 has a plurality of outlet slits 51 extending from the inner peripheral surface to the outer peripheral portion and having an opening in the inner peripheral surface as the outlet b.
Has a plurality of U-shaped notch-shaped inlets a that are aligned with the circular holes 52 and are connected to the cylindrical passage 42 on the lubricating oil supply side, at the ends of the slits 51 present on the outer peripheral portion of the lower annular plate 50. .

In this case, the upper and lower annular plates 49 and 50 are made of stainless steel (JIS SUS304H).
The thickness T (FIG. 6) of both plates 49, 50 is 50 μm each.
m, the width W (FIG. 9) of each slit 51 is set to 0.5 mm, and the diameter D (FIG. 9) of the circular hole 52 is set to 1.0 mm. Therefore, the opening size of each outlet b is 50 μm in length and 0.5 mm in width. Under the electromagnetic stirring conditions, if the vertical length of the opening dimension is 100 μm or less, the molten metal m
Can be prevented. Fourth Embodiment A fifth embodiment of the continuous casting apparatus 1 shown in FIG. 11 is the same as the third embodiment, except that a heater 55 for heating a lubricating oil is arranged near the inlet a of the discharge path 44. Things. In the illustrated example, the annular groove 5 facing the cylindrical path 42 just above the discharge path forming plate 48 below the inner peripheral surface of the cylindrical section 12.
6, and an annular electric heater 55 was installed therein.
With such a configuration, the lubricating oil L is actively heated by the heater 55 to stabilize the kinematic viscosity, whereby the lubricating oil L can be sent out from each discharge path 44 substantially uniformly. In this case, the portion connected to the discharge passage 44 of the lubricant supply passage F _L may not be disposed around the spout 15.

Next, the relationship between the kinematic viscosity ν of the lubricating oil L and the number of defective casting surfaces in the ingot I was examined using the fifth embodiment.

Table 3 shows the types of the lubricating oils L and the mixing amount A of the PTFE. Examples 1 to 4 correspond to the cases of Ingots I and Examples 1 to 5 in Table 1, respectively, and thus the vaporization rate at 300 ° C. is 30% or more.

[0045]

[Table 3]

FIG. 12 shows the relationship between the temperature of the lubricating oil L and its kinematic viscosity ν for Examples 1-4. From this figure, the kinematic viscosity ν
≦ 30 mm ² / s, the kinematic viscosity ν
Is very small.

As for the casting conditions, the temperature of the molten metal is set to 730 ° C.
Example 1 was repeated except that the temperature at the inlet a was changed variously. Further, the “number of defective casting surface” was determined as the average number of defective casting surface existing within a range of 1 m in the outer peripheral surface of the ingot.

FIG. 13 shows the result of the consideration. As is clear from this figure, the kinematic viscosities ν of the lubricating oil examples 1 to 4 are given by ν ≦ 30.
When it is set to mm ² / s, an ingot I having a good casting surface can be obtained.

[0049]

According to the first aspect of the present invention, by adopting the relatively simple means as described above, a good casting surface can be obtained despite the presence of the outlet of the lubricant oil discharge passage. It is possible to provide a continuous casting method which does not involve electromagnetic stirring and can obtain a light alloy ingot having the same.

According to the second aspect of the present invention, by adopting the above relatively simple means, it is possible to obtain a light alloy ingot having a good casting surface despite the existence of the outlet. It is possible to provide a continuous casting method with electromagnetic stirring, which is possible.

According to the third aspect of the present invention, it is possible to further improve the casting surface of the light alloy ingot by using the mixed lubricant.

According to the fourth aspect of the present invention, since the kinematic viscosity ν of the lubricating oil is set as described above, the change in viscosity due to the temperature change of the lubricating oil is extremely small, and the lubricating oil from each discharge path is reduced. Can be equalized.

According to the fifth and sixth aspects of the present invention, it is possible to provide an apparatus capable of easily performing the continuous casting method with electromagnetic stirring.

According to the seventh aspect of the present invention, a good casting surface can be obtained without using special lubricating oil despite the presence of the outlet of the lubricating oil discharge passage. It is possible to provide a continuous casting apparatus capable of obtaining a light alloy ingot having the following.

According to the eighth and ninth aspects of the invention, it is possible to heat the lubricating oil to stabilize its kinematic viscosity.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a first embodiment of a continuous casting apparatus.

FIG. 2 is an enlarged view of a main part of FIG.

FIG. 3 is a plan view of a main part showing a relationship between a laminated core and a coil.

FIG. 4 is a longitudinal sectional view of a main part of a second embodiment of the continuous casting apparatus.

FIG. 5 is an enlarged sectional view taken along line 5-5 of FIG.

FIG. 6 is a longitudinal sectional view of a main part of a third embodiment of the continuous casting apparatus.

7 is a view of the discharge path forming plate as viewed in the direction of arrow 7 in FIG. 6;

FIG. 8 is a plan view of a lower annular plate.

FIG. 9 is an enlarged view of a portion indicated by an arrow 9 in FIG.

FIG. 10 is a plan view of an upper annular plate.

FIG. 11 is a longitudinal sectional view of a main part of a sixth embodiment of the continuous casting apparatus.

FIG. 12 is a graph showing a relationship between lubricating oil temperature and its kinematic viscosity.

FIG. 13 is a graph showing the relationship between the kinematic viscosity of lubricating oil and the number of defective casting surfaces.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Continuous casting apparatus 11 ... Annular upper end surface 13 ... Water-cooling mold 15 ... Spout 15a ... Annular overhang part 16 ... Molten outlet 17 ... Annular lower end surface 21 ... Molten metal Receiving port 23 Stirrer 42 Tubular path (portion connected to discharge path) 44 Discharge path 46 Coating layer 48 Discharge path forming plate 49 Upper annular plate 50 … Lower annular plate 51… Slit 55… Heater F _L … Lubricating oil supply path G…… Annular gas reservoir I… Ingot L… Lubricating oil a …… Inlet b ……… Outlet m ……… Molten r ₁ , r ₂ ... Inner radius

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[Procedure amendment]

[Submission date] April 20, 1999

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0042

[Correction method] Change

[Correction contents]

In this case, the upper and lower annular plates 49 and 50 are made of stainless steel (JIS SUS304H).
The thickness T (FIG. 6) of both plates 49, 50 is 50 μm each.
m, the width W (FIG. 9) of each slit 51 is set to 0.5 mm, and the diameter D (FIG. 9) of the circular hole 52 is set to 1.0 mm. Therefore, the opening size of each outlet b is 50 μm in length and 0.5 mm in width. Under the electromagnetic stirring conditions, if the vertical length of the opening dimension is 100 μm or less, the molten metal m
Can be prevented. Fourth Embodiment A sixth embodiment of the continuous casting apparatus 1 shown in FIG. 11 is the same as the third embodiment, except that a heater 55 for heating a lubricating oil is disposed near the inlet a of the discharge passage 44. Things. In the illustrated example, the annular groove 5 facing the cylindrical path 42 just above the discharge path forming plate 48 below the inner peripheral surface of the cylindrical section 12.
6, and an annular electric heater 55 was installed therein.
With such a configuration, the lubricating oil L is positively heated by the heater 55 to stabilize the kinematic viscosity, so that the lubricating oil L can be sent out from each discharge path 44 substantially uniformly. In this case, the portion connected to the discharge passage 44 of the lubricant supply passage F _L may not be disposed around the spout 15.

[Procedure amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0043

[Correction method] Change

[Correction contents]

Next, the relationship between the kinematic viscosity ν of the lubricating oil L and the number of defective casting surfaces in the ingot I was examined using the sixth embodiment.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI B22D 11/10 350 B22D 11/10 350A (72) Inventor Kiyonobu Mizogami 1-10-1 Shinsayama, Sayama City, Saitama Prefecture Honda Engineering Co., Ltd. In-house (72) Inventor Takashi Ide 1-10-1 Shinsayama, Sayama City, Saitama Prefecture Honda Engineering Co., Ltd.

Claims (9)

[Claims] An inner radius r ₁ that is larger than an inner radius r ₂ of the molten metal outlet (16) is provided immediately below a spout (15) having an upward molten metal receiving port (21) and a downward molten metal outlet (16). A cylindrical water-cooled mold (13) having a lubricating oil is provided below the spout (15) so as to supply the lubricating oil (L) between the water-cooled mold (13) and the molten metal (m) in contact therewith. In producing an ingot (I) made of a light alloy using a continuous casting apparatus (1) having a discharge path (44), a lubricating oil (L) having a vaporization rate at 300 ° C. of 30% or more is used. And the lubricating oil (L)
By the vaporization, the annular gas reservoir (G) for separating the molten metal (m) from the outlet (b) of the lubricating oil discharge passage (44) below the annular overhang portion (15a) of the spout (15).
A continuous casting method for light alloys, characterized by forming Directly under the 2. A spout having an upward melt inlet (21) and downward of the molten metal outlet (16) (15), a large internal radius r ₁ of the inner radius r ₂ of the melt outlet (16) A cylindrical water-cooled mold (13) having a lubricating oil is provided below the spout (15) so as to supply the lubricating oil (L) between the water-cooled mold (13) and the molten metal (m) in contact therewith. In producing an ingot (I) made of a light alloy using a continuous casting apparatus (1) having a discharge path (44) and having a stirrer (23) for applying a circumferential electromagnetic stirring force to a molten metal (m). 300 as lubricating oil (L)
The lubricating oil (L) is vaporized at a temperature of 30 ° C. or more, and the lubricating oil (L) is vaporized, so that the lubricating oil discharge passage (44) is located below the annular overhang portion (15a) of the spout (15). A continuous casting method for a light alloy, wherein an annular gas reservoir (G) for separating a molten metal (m) from an outlet (b) is formed. 3. A mixed lubricant obtained by mixing a solid lubricant with the lubricating oil (L), and the mixed amount A of the solid lubricant is 1 w
3. The continuous casting method for a light alloy according to claim 1, wherein t% ≦ A ≦ 10 wt%. 4. The kinematic viscosity ν of the lubricating oil (L) at the inlet (a) of the lubricating oil discharge passage (44) is set to ν ≦ 30.
4. The continuous casting method of a light alloy according to claim 1, wherein the light alloy is set to mm ² / s. 5. A spout (15) having an upward molten metal receiving port (21) and a downward molten metal outlet (16);
In order to cool the molten metal (m) from the molten metal outlet (16),
Wherein is disposed directly under the spout (15), wherein a tubular water-cooled mold from the inner radius r ₂ having a large inner radius r ₁ of the molten metal outlet (16) (13), the molten metal in the circumferential direction of the (m) Electromagnetic A stirrer (23) for applying a stirring force;
3) Lubricating oil (L) between and molten metal (m) in contact with it
In order to supply the spout (15), the annular lower end face (1
7) and an annular upper end surface (11) of the water-cooled mold (13)
A lubricating oil discharge passage (44) provided therebetween, and a coating layer (46) provided on the annular upper end surface (11) and having a thermal conductivity lower than that of the water-cooled mold (13). And a continuous casting apparatus for light alloys. 6. A spout (15) having an upward molten metal receiving port (21) and a downward molten metal outlet (16),
In order to cool the molten metal (m) from the molten metal outlet (16),
Wherein is disposed directly under the spout (15), wherein a tubular water-cooled mold from the inner radius r ₂ having a large inner radius r ₁ of the molten metal outlet (16) (13), the molten metal in the circumferential direction of the (m) Electromagnetic A stirrer (23) for applying a stirring force;
3) Lubricating oil (L) between and molten metal (m) in contact with it
And a discharge path forming plate (48) disposed between the spout (15) and the water-cooled mold (13) to form a discharge path (44) for lubricating oil. A continuous casting apparatus for light alloys, characterized in that the plate (48) is made of a material having a lower thermal conductivity than the water-cooled mold (13). 7. A spout (15) having an upward molten metal receiving port (21) and a downward molten metal outlet (16);
In order to cool the molten metal (m) from the molten metal outlet (16),
A cylindrical water-cooled mold (13) disposed directly below the spout (15), a stirrer (23) for applying a circumferential electromagnetic stirring force to the molten metal (m), and the water-cooled mold (13) and contact therewith In order to form a lubricating oil discharge passage (44) having an outlet (b) large enough to supply the lubricating oil (L) between the molten metal (m) and to prevent the molten metal (m) from entering, the spout ( 15) and a thin-walled upper and lower annular plate (49, 50) arranged in a superposed manner between the water-cooled mold (13), and the lower annular plate (50) is arranged from the inner peripheral surface to the outer peripheral portion thereof. And a plurality of discharge passage slits (51) having an opening on the inner peripheral surface as the outlet (b), and the upper annular plate (49) is provided on the outer peripheral portion of the lower annular plate (50). A plurality of slits (51) that match the end of Mouth (a) continuous casting apparatus for light alloy, characterized in that it comprises a. 8. The lubricating oil supply path (F)
_L ) and a portion (42) of the lubricating oil supply path (F _L ) connected to the discharge path (44) is connected to the spout (15).
The continuous casting apparatus for a light alloy according to claim 5, which is disposed around the periphery. 9. A heater (55) for heating a lubricating oil is disposed near an inlet (a) of the discharge passage (44).
9. The continuous casting apparatus for a light alloy according to 6, 7, or 8.