JPH0938751A - Mold device for continuous casting - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a cast block having good outer appearance and stable quality by eliminating variation of the inner diameter of molten metal receiving vessel part, in a mold device for continuous casting. SOLUTION: In the mold device for continuously casting the cast block 4 by cooling the molten metal 3 supplied from a descending tube 2, the mold 11 constituted by containing a slow cooling zone part and a cooling zone part arranged at the lower part of the slow cooling zone part, is manufactured by using the same material and integrally worked to prevent the variation of the inner diameter accompanied with the casting.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a continuous casting mold apparatus for producing a metal ingot.

[0002]

2. Description of the Related Art For example, when manufacturing a wire or the like, a metal (molten metal) obtained by melting copper or a copper alloy is poured into a mold and continuously taken out from a mold whose lower portion is cooled (cooling mold) to form an ingot. A wire rod is manufactured by continuously rolling the obtained ingot (bloom or billet) which is continuously produced.

Molds for copper and copper alloys include a type in which the inner surface is hard plated, a type in which a sleeve made of carbon is attached, or a type in which machining is simply performed to a diameter of a desired size. When the molten metal is aluminum, a method called hot top casting is used to improve the casting surface. A mold for this purpose has a structure in which a molten metal receiving tank is provided on the cooling mold as described above, that is, a structure having a slow cooling zone and a cooling zone.

FIG. 3 is a sectional view showing a schematic construction of a conventional casting apparatus for continuous casting. The casting mold apparatus 1 includes a molten metal receiving tank 1a (slow cooling zone) which has a cylindrical shape or a similar shape and is formed by using a heat insulating material, and a casting mold portion 1b (cooling zone) which is connected to a lower portion of the molten metal receiving tank 1a to form an initial shell. ) And.
As described above, the casting mold portion 1b is configured such that the inner surface is hard-plated or a carbon sleeve is attached, and the outer diameter of the molten metal receiving tank 1a is formed with the hollow portion 1f formed on the outside thereof. Water cooling case 1
c is provided. A cooling water inlet 1d and a cooling water outlet 1e are provided below the water cooling case 1c. Water for water cooling is continuously introduced into the water cooling case 1c. At the center of the molten metal receiving tank 1a, a downcomer pipe 2 for supplying molten metal (molten metal) into the casting mold device 1 from a furnace, a ladle, or the like.
Are arranged.

In the above structure, a fixed amount of molten metal is supplied from the downcomer pipe 2 to the casting mold apparatus 1 under the control of a controller (not shown), and the casting mold apparatus 1 is filled with the molten metal. Mold part 1b
Is water-cooled, the lower part of the molten metal 3 in the casting mold device 1 is cooled, and solidification of the molten metal 3 is started to form an initial shell, and an ingot 4 is generated. In general,
The cooling mold and the molten metal receiving tank are made of different materials, and the boundary between the two may adversely affect the skin of the ingot. For this reason, conventionally, a method of attaching a special ring to the boundary portion, or a means of blowing a gas with a minute pressure has been taken. In addition, when the molten metal is slowly cooled in the molten metal receiving tank to start solidification, it may adversely affect the skin of the ingot to be generated.
Therefore, a heating zone is also installed around the outer circumference of the molten metal receiving tank.

Regarding this kind of technique, for example,
Japanese Examined Patent Publication (Kokoku) No. 42-14734 (providing a taper in the solidified layer according to the solidified state to improve the thermal conductivity), Japanese Patent Laid-Open No. Hei 2
-123846 (providing an inner surface curvature at the upper or upper part of the mold to prevent the metal from partially adhering to the heat insulating part), JP-A-59-120349 (wetting the upper part of the cooling surface of the water-cooled mold) Insulating refractory material with poor properties is lined up, the cooling capacity of the upper part of the mold is suppressed, and the contact between the molten metal and the casting wall is cut off, so that an ingot with stable internal structure and surface properties can be continuously manufactured), Japanese Unexamined Patent Publication No. 2-220736 (Ceramics are affixed to the inner wall surface of a copper mold, the thickness thereof is changed stepwise, solidification of molten metal is started below the molten metal surface portion, without using powder or the like. To enable the production of ingots with stable surface properties), Japanese Patent Publication No. 4
No. 2-4049 (The mold is structured to incline downward,
In addition, the inclination gradient can be changed as required), Japanese Patent Publication No. 56-51857 (considering shrinkage of molten steel due to cooling and solidification after casting, a downward taper is provided on the short side of the mold, The width of the slab can be changed without stopping the casting into the mold), JP-B-4-8915
No. 7 gazette (providing a taper of a predetermined angle on the inner surface of the break ring installed between the steel receiving tank and the mold, which is in contact with the molten metal,
Further, a liquid storage chamber is provided in the break ring, and a fluid having a predetermined pressure is blown toward the molten metal from the liquid storage chamber,
Obtaining a slab having no surface defects), JP-A-4-135045
Publication (providing slits on the flange of the segment part and the uppermost end of the mold, and arranging the current-carrying coil in multiple turns so as to circulate the lower part of the slit to prevent surface defects from occurring in the cast product), JP-A-4-162939 (Providing a plurality of slits extending in the casting direction in a region including a triple point where the nozzle, the mold and the liquid metal are in contact at the same time, and arranging the coil so as to circulate around the mold portion where the slit exists, To prevent surface defects from occurring in cast products).

[0007]

By the way, in hot-top casting of a molten metal containing a low concentration, a high concentration (each component is several% or more) and a component which is easily oxidized, the mold part (cooling zone) is used.
It is important that the solidification of the melt begins. This solidification start point is the shell formation point, and the appearance of the cast ingot is greatly influenced by how this is adjusted.

Shell formation is accelerated by excessive cooling,
Oxides on the surface of the molten metal and foreign substances contained in the molten metal may be caught near the outer periphery of the ingot. In addition, shell formation is slowed by insufficient cooling, in which case secondary melting occurs in the mold, which can significantly deteriorate the casting surface, which may cause breakout.

Conventionally, the molten metal receiving tank, which is mainly made of refractory heat insulating material, wears the inner diameter (wearing portion 5 shown in FIG. 3) or deforms (deforming portion 6 shown in FIG. 3) as the number of castings increases. Changes in the inner diameter of the. The property may be due to a difference in thermal expansion due to different materials, a difference in accuracy when applied with a refractory heat insulating material, or due to eccentricity with respect to the center of the mold during replacement. The change of the inner diameter has a great influence on the shell forming point which is a starting point for obtaining a good-looking ingot. That is, regardless of the shape of the mold such as round size or square size, the shell formation points become non-uniform in the circumferential direction of the inner surface, which causes defects in the appearance of the ingot (sag, wrinkles, etc.). .

This solution is to completely remake the molten metal tank part made of refractory heat insulating material, but the water during processing and the crystal water of the refractory penetrate into the molten metal in the casting after manufacturing, which causes pinholes. As a result, there is a problem that it remains in the ingot. For this reason, a preheating drying time is required, and a decrease in productivity due to this is unavoidable. It is an object of the present invention to provide a continuous casting mold device capable of eliminating a change in inner diameter of a molten metal receiving tank portion, having a good appearance, and capable of obtaining an ingot of stable quality.

[0011]

According to the above-mentioned means,
In a continuous casting mold apparatus for continuously manufacturing an ingot by cooling a molten metal supplied from above, including a slow cooling zone portion into which the molten metal is injected and a cooling zone portion provided below the slow cooling zone portion, the same. It is possible to provide a mold integrally formed of the material.

The mold may be a carbon mold. Further, the mold may be provided with a taper whose diameter decreases from the boundary between the slow cooling zone and the cooling zone toward the opening at the start end and the rear end. Further, a backup sleeve may be externally fitted to the slow cooling zone, and a copper sleeve may be externally fitted to the cooling zone.

Further, the slow cooling zone portion may have a structure in which a heat insulating material is arranged on the outer peripheral portion thereof. In order to achieve the above-mentioned object, the present invention provides a mold comprising a slow cooling zone and a cooling zone provided under the slow cooling zone, which has been conventionally separated into separate structures. On the other hand, the same material is used for integral processing such as molding. As a result, the inner diameter does not change, so that uniform casting is possible and a good casting surface can be obtained.
Since the quality of the casting surface is improved, it is possible to reduce the number of man-hours for appearance processing or the face-shaping cost for appearance. Further, since the appearance quality at the start and end of casting is improved, the cutting yield per charge and the unit power consumption for melting are improved.

By using a carbon mold as the mold, heat resistance can be ensured and a mold structure that is difficult to react with flux can be obtained. By providing the inner diameter (caliber) of each of the slow cooling zone and the cooling zone with a taper, it is possible to obtain a good casting surface. The loose cooling zone and the sleeve fitted over the cooling zone act to prevent thermal deformation of the mold.

Further, the heat insulating material disposed outside the slow cooling zone portion functions to prevent supercooling and perform slow cooling.

[0016]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a sectional view showing a schematic configuration of a continuous casting mold apparatus according to the present invention. The casting mold apparatus 10 according to the present invention has a structure in which a conventional molten metal receiving tank and an integral casting mold 11 having a total length (height) corresponding to the length of the casting mold made of a carbon mold or the like are arranged at the innermost circumference. ing. The mold 11 has a taper 11 extending vertically from the middle part.
a, 11b are provided. Each taper is provided so that the inner diameter becomes smaller toward the end portion. For example, the taper 11a is set to have a gradient of 15 ° ± 5 °, and the taper 11b is formed.
Is set to 10 ° ± 5 ′, which is a gentler slope than the taper 11a.

Further, on the outside of the mold 11, two pieces are vertically arranged.
A divided sleeve is provided. That is, in a portion corresponding to the molten metal receiving tank portion, a backup sleeve 12 is coaxially and closely arranged in a substantially upper half of the mold 11 in order to prevent thermal deformation of the mold 11. Further, a copper sleeve 13 for the same purpose as the sleeve 12 is coaxially and closely arranged on the outer periphery of the lower half of the mold 11. The connecting portion between the backup sleeve 12 and the copper sleeve 13 is the uneven portion 1
A fitting shape based on 2a is adopted to prevent displacement and the like.

A heat insulating material is arranged so as to cover the outer circumference of the backup sleeve 12 to form a heat insulating portion 14. The heat insulating portion 14 is provided to delay the start of solidification of the molten metal 3. As the material, materials such as refractory mortar and ceramic fibers can be used. In addition, 14a is a case for heat insulating materials. In addition, while being connected to the lower portion of the heat insulating portion 14, the copper sleeve 13
The hollow portion 15a, the cooling water inlet 15b, and the cooling water outlet 15c are respectively formed with respect to the water cooling case 15
Are arranged. Water for water cooling is continuously introduced into the water cooling case 15.

In the configuration of FIG. 1, a fixed amount of molten metal is continuously supplied from the downcomer pipe 2 to the casting mold device 10 (under the control of a control device (not shown)) and filled in the casting mold device 10. At this time, the cooling water is supplied to the space inside the water cooling case 15, and the lower portion of the mold 11 is water-cooled by the cooling water.
The lower part of the molten metal 3 in 1 is cooled, and an ingot 4 is continuously generated.

Although the upper portion of the mold 11 becomes extremely high in temperature due to the high-temperature molten metal 3, since the backup sleeve 12 is arranged on the outer side, the mold 11 is not likely to be thermally deformed. Further, by integrally processing the mold 11 with the mold, no mechanical boundary is formed between the slow cooling zone and the cooling zone. For this reason, even if the cooling start point slightly fluctuates, the shell formation is not affected, and flexibility can be greatly improved. Further, since carbon is used for the mold 11, it becomes difficult to react with the flux for the molten metal surface coating agent, so that it can be used even when the heat insulating portion 14 is eroded by the flux and cannot be cast.

As described above, since the mold 11 according to this embodiment is an integral type, it is difficult for the inner diameter to change. As a result, since uniform casting can be performed, a good ingot can be manufactured. FIG. 2 is a sectional view showing a detailed configuration of the continuous casting mold apparatus according to the present invention. In the figure, the same components as those shown in FIG. 1 are designated by the same reference numerals, and duplicate explanations are omitted.

A centering groove 16 having a concavo-convex structure is provided at the joint between the backup sleeve 12 and the copper sleeve 13.
Are provided to prevent formation of a gap and displacement. Further, in order to integrate the backup sleeve 12 and the copper sleeve 13, bolts are fixed by a fixing bolt 17 at a position adjacent to the centering groove 16. A ring-shaped pressing flange 18 having an L-shaped cross section is arranged outside the vicinity of the bolt tightening position and at the lower end of the heat insulating portion 14.

The upper end surface of the water cooling case 15 is in contact with the lower end surface of the pressing flange 18. A cylindrical cooling water straightening plate 19 is erected at a substantially intermediate position of the internal space of the water cooling case 15. Further, at least one cooling water inlet 20 is provided in a part of the outer peripheral portion of the water cooling case 15. The cooling water introduced from the cooling water inlet 20 rises through the outer space 21 a of the cooling water straightening plate 19, flows into the inner space 21 b of the cooling water straightening plate 19, further descends, and flows out to the cooling water outlet 22. To do. The lip 2 for adjusting the cooling water injection angle is provided on the ceiling surface of the water cooling case 15 so that the rising water flow on the outer side of the cooling water straightening plate 19 is likely to be a downflow on the inner side.
3 is formed, and an inward slope is provided.

Further, a cooling water outlet rectifying plate 24 for forming an outlet 22 of the cooling water is provided on the lower end surface of the inner space 21b partitioned by the cooling water rectifying plate 19, and the lower end of the copper sleeve 13 is formed. A cooling water outlet gap 25 is formed between them. When forming the cooling water outlet gap 25, the lower end portion of the copper sleeve 13 is cut obliquely so that the cooling water can easily flow out. Note that t ₁ and t _{2 on} the inner surface of the mold 11 correspond to the angles of the taper 11a and the taper 11b.

As shown in FIG. 2, since the cooling water straightening plate 19 is provided upright in the water cooling case 15 so that the ascending flow and the descending flow are formed, it is possible to effectively solidify the molten metal 3. become. Since the molten metal does not solidify in the mold of the present invention in which the molten metal tank portion and the mold are integrated, casting of the ingot 4 having a polygonal cross section (hexagon, quadrangle, triangle, diamond, star, etc.) is also possible. It is possible.

The target melt (molten metal) is copper,
In addition to metals such as copper alloys, iron and aluminum, resin materials such as plastics may be used.

[0027]

As described above, according to the present invention, the mold having the slow cooling zone and the cooling zone provided under the slow cooling zone is integrally processed by using the same material. Since the inner diameter does not change, uniform casting is possible and a good casting surface can be obtained. Since the quality of the casting surface is improved, it is possible to reduce the number of man-hours for appearance processing or the face-shaping cost for appearance. Further, since the appearance quality at the start and end of casting is improved, the cutting yield per charge and the unit power consumption for melting are improved.

[Brief description of drawings]

FIG. 1 is a sectional view showing a schematic configuration of a continuous casting mold apparatus according to the present invention.

FIG. 2 is a sectional view showing a detailed configuration of a continuous casting mold apparatus according to the present invention.

FIG. 3 is a cross-sectional view showing a schematic configuration of a conventional continuous casting mold device.

[Explanation of symbols]

 10 Mold Device 11 Mold 12 Backup Sleeve 13 Copper Sleeve 14 Heat Insulation Part 15 Water Cooling Case

Claims (5)

[Claims] 1. In a continuous casting mold apparatus for cooling molten metal supplied from above to continuously produce ingots, a slow cooling zone into which the molten metal is injected, and a cooling zone provided below the slow cooling zone. A casting apparatus for continuous casting, characterized in that the casting apparatus includes a casting mold that is integrally formed using the same material. 2. The continuous casting mold apparatus, wherein the mold is a carbon mold. 3. The mold according to claim 1, wherein the mold has a taper whose diameter decreases from the boundary between the slow cooling zone and the cooling zone toward the opening at the start end and the opening at the rear end. The casting apparatus for continuous casting according to 2. 4. The casting apparatus for continuous casting according to claim 1, wherein a backup sleeve is externally fitted to the slow cooling zone, and a copper sleeve is externally fitted to the cooling zone. . 5. A heat insulating material is provided on an outer peripheral portion of the slow cooling zone portion, wherein the heat insulating material is disposed.
The continuous casting mold device described.