Patent Application
20200276635
The present disclosure relates to a production method and a production apparatus for a continuously cast metal rod for producing a continuously cast material made of metal such as aluminum.
Note that in this specification and claims, unless otherwise specified, the term “aluminum (Al)” is used to include the meaning of an aluminum alloy (Al alloy), and the terms “continuous casting” and “continuously cast” are used to include the meaning of “semi-continuous casting” and “semi-continuously cast”, respectively.
In various aluminum products based on aluminum materials, a forged product produced by forging, a rolled product produced by rolling, and an extruded product produced by extrusion are often used for products requiring high quality and high strength with less variation. A forging material, a rolling material, and an extrusion material to be subjected to the above processing are often produced based on a continuously cast material obtained by continuously casting aluminum.
For example, as a production apparatus (continuous casting apparatus) for producing a continuously cast material, as described in Patent Documents 1 and 2 listed below, a vertical-type continuous casting apparatus in which the casting direction is vertically downward is known. In this vertical-type continuous casting apparatus, a molten metal is passed through a mold, and a surface of an ingot is solidified, and cooling water as a cooling liquid (cooling medium) is ejected to the ingot from the entire periphery of the ingot right under the mold to rapidly cool down the entire ingot.
As a conventional cooling water ejection method for cooling an ingot, as shown in Documents 1 and 2, a method of ejecting cooling water from slit-like or circular hole-like cooling water spouting ports provided around the outer periphery of an ingot is generally used.
In such aluminum continuous casting, the step of cooling an ingot is a very important step, and by being rapidly solidified from the entire periphery of the ingot to the inside thereof (central portion) in a balanced manner, the ingot structure can be controlled in a good state, so that the material crystal structure, the crystalline, and the precipitation behavior become uniform in the entirety of the ingot. Thus, a high quality continuously cast material having a good ingot structure with no variation can be produced.
In a conventional continuous aluminum casting method, in order to improve productivity, etc., a so-called multiple continuous casting has been often used in which a number of molds are arranged in parallel and a number of continuously cast rods are continuously cast simultaneously in parallel when a molten metal passes through each mold. In such a multiple continuous casting, since the outer peripheral surface of the continuously cast rod has a complex temperature distribution due to thermal influences between adjacent continuously cast rods, not all continuously cast materials could be cooled in a balanced manner. Therefore, there was a problem that it was difficult to assuredly produce a high quality continuously cast material.
The preferred embodiments of the present invention have been made in view of the abovementioned and/or other problems in the related art. The preferred embodiments of the present invention can significantly improve upon existing methods and/or apparatuses.
The present invention has been made in view of the aforementioned problems and aims to provide a production method and a production apparatus of a continuously cast metal rod capable of cooling all of ingots in a balanced manner and producing a high quality continuously cast material.
The other purposes and advantages of the present invention will be apparent from the following preferred embodiments.
In order to solve the aforementioned problems, the present invention is provided with the following means.
[1] A method of producing a continuously cast metal rod in which a cooling liquid is supplied to each of outer peripheral surfaces of a plurality of ingots extracted from a plurality of molds in parallel to cool each of the plurality of ingots,
wherein when a region of an outer peripheral surface of the ingot which is open and does not face another ingot is defined as an open region, and a region of the outer peripheral surface of the ingot which faces another ingot is defined as an ingot facing region, the open region is cooled with weak cooling in which a degree of cooling by the cooling liquid at the open region is less than a degree of cooling by the cooling liquid at the ingot facing region.
[2] The method of producing a continuously cast metal rod as recited in the aforementioned Item [1],
wherein a supply quantity of the cooling liquid to the open region is set to be less than a supply quantity of the cooling liquid to the ingot facing region.
[3] The method of producing a continuously cast metal rod as recited in the aforementioned Item [1] or [2],
wherein supply pressure of the cooling liquid to the open region is set to be lower than supply pressure of the cooling liquid to the ingot facing region.
[4] An apparatus of producing a continuously cast metal rod, comprising:
a plurality of molds arranged in parallel; and
a plurality of cooling liquid spouting ports provided corresponding to each mold,
wherein a cooling liquid is supplied from the plurality of cooling liquid spouting ports to each of outer peripheral surfaces of a plurality of ingots extracted in parallel from the plurality of molds to cool the plurality of ingots, respectively,
wherein when a region of an outer peripheral surface of the ingot which is open and does not face another ingot is defined as an open region, and a region of the outer peripheral surface of the ingot which faces another ingot is defined as an ingot facing region, a supply quantity adjustment means configured to adjust such that a supply quantity of the cooling liquid to the open region is less than a supply quantity of the cooling liquid to the ingot facing region is provided.
[5] The apparatus of producing a continuously cast metal rod as recited in the aforementioned Item [4],
wherein the plurality of cooling liquid spouting ports is arranged at intervals along an outer periphery of a corresponding ingot and is configured such that the cooling liquid is spouted from respective cooling liquid spouting ports to be supplied to the outer peripheral surface of a corresponding ingot,
wherein a total opening area of the cooling liquid spouting ports arranged corresponding to the open region of the ingot among the plurality of cooling liquid spouting ports is set to be smaller than a total opening area of the cooling liquid spouting ports arranged corresponding to the ingot facing region among the plurality of cooling liquid spouting ports, and
wherein the plurality of cooling liquid spouting ports serves as the supply quantity adjustment means.
[6] The apparatus of producing a continuously cast metal rod as recited in the aforementioned Item [5],
wherein a caliber of the cooling liquid spouting port arranged corresponding to the open region of the ingot among the plurality of cooling liquid spouting ports is set to be smaller than a caliber of the cooling liquid spouting port arranged corresponding to the ingot facing region.
[7] The apparatus of producing a continuously cast metal rod as recited in the aforementioned Item [5] or [6],
wherein an interval of the plurality of cooling liquid spouting ports arranged corresponding to the open region of the ingot among the plurality of cooling liquid spouting ports is set to be wider than an interval of a plurality of cooling liquid spouting ports arranged corresponding to the ingot facing region among the plurality of cooling liquid spouting ports.
[8] The apparatus of producing a continuously cast metal rod as recited in any one of the aforementioned Items [4] to [7], further comprising:
supply pressure adjustment means configured to adjust such that supply pressure of the cooling liquid to the open region is set to be lower than supply pressure of the cooling liquid to the ingot facing region,
wherein the supply pressure adjustment means serves as the supply quantity adjustment means.
According to the method of producing a continuously cast rod according to the aforementioned Item [1], since the open region of the outer peripheral surface of the ingot which does not face another ingot is cooled with weak cooling compared with the ingot facing region which faces another ingot, the open region which receives a small heat effect from another ingot and can be effectively cooled can be cooled with weak cooling, and the ingot facing region which receives a large heat effect from another ingot and cannot be effectively cooled can be cooled with strong cooling. Therefore, each ingot can be cooled in a well-balanced manner from the entire periphery to the center portion, so that the entirety of the ingot can be formed to have an even and excellent ingot structure. Thus, it is possible to assuredly cast a continuously cast material as a high-quality ingot with no variation.
According to the method of producing a continuously cast metal rod as recited in the aforementioned Items [2] and [3], the above-mentioned effects can be obtained more assuredly.
According to the apparatus of producing a continuously cast metal rod as recited in the aforementioned Item [4], since it is equipped with a supply quantity adjustment means to adjust such that the supply quantity of the cooling liquid to an open region of the outer peripheral surface of the ingot which does not face another ingot is less than the supply quantity of the cooling liquid to the ingot facing region which faces another ingot, the open region can be cooled with weak cooling compared with the ingot facing region. Therefore, similarly to the above, each ingot can be cooled in a balanced manner from the entire circumference to the center portion, so that the entire ingot can be formed to have an even and excellent ingot structure. Therefore, a cast material as a high-quality ingot with no variation can be assuredly produced.
According to the apparatus of producing a continuously cast metal rod as recited in any one of the aforementioned Items [5] to [8], it is possible to obtain the above-mentioned effects more assuredly.
As shown in
The mold 2 is cooled by cooling water M as primary cooling water supplied therein. The spouting ports 3 provided on the lower end portion of the mold 2 are configured to eject the cooling water (cooling liquid) M in the mold 2 as secondary cooling water. As shown in
In this casting apparatus, an aluminum molten metal W1 as a metal fed in each molten metal receiving tank 4 in each casting machine 1 is supplied into each cooled mold 2. The molten metal W1 supplied into each mold 2 is primarily cooled by coming into contact with each mold 2 to form an ingot W2 in a semi-solidified state. The ingot W2 in the semi-solidified state is in a state in which a coagulation film is formed on its outer peripheral portion.
Each ingot W2 in this state continuously passes downward inside the mold 2, and cooling water M is ejected from each spouting port 31 to the ingot W2 immediately after passing through each mold 2, so that the cooling water M comes into direct contact with the outer peripheral surface of each ingot W2 to cool each ingot W2. In this manner, the ingot W2 is secondarily cooled while being extracted downward, so that the large part thereof is solidified. Thus, three pieces of round bar-shaped continuously cast materials (billets) are simultaneously produced in a state in which they are arranged in parallel.
Next, a method of cooling the ingot W2 in the casting apparatus of this embodiment will be described.
As shown in both diagrams, in this embodiment, three pieces of ingots W2 are cast in parallel in a parallel arrangement, and the outer peripheral surface of each ingot W2 to be cast is divided into four regions in the circumferential direction.
That is, the outer peripheral surface of the ingot W2 is divided into four equal regions in the circumferential direction. Among the divided regions, the region of the front side (the upper region in
In this embodiment, when cooling the ingot W2 by ejecting cooling water M, the degree of cooling to the open region x is set to be less than the degree of cooling to the ingot facing region y so that the open region x is cooled with weak cooling and the ingot facing region y is cooled with strong cooling.
Here, in this embodiment, it should be noted that reducing the degree of cooling means that the amount of heat absorbed from the ingot W2 is reduced, and on the contrary, increasing the cooling degree means that the amount of heat absorbed from the ingot W2 is increased. Also note that, in the present invention, the open region x denotes a region not facing another ingot W2, and is not required to be completely open. For example, in the present invention, even if the open region x is closed by a member other than an ingot, such as, e.g., a housing wall, it can be regarded as an open region as long as it does not face another ingot W2.
Next, a specific example of a method of cooling an ingot W2 in this embodiment will be described. As shown in
Further, in the casting machine 1 shown in
As described above, by setting the total open area of the spouting ports 3 corresponding to the open region x to be smaller than the total open area of the spouting ports 3 corresponding to the ingot facing region y, the open region x can be cooled with weak cooling as compared with the ingot facing region y. Note that in this embodiment, a supply quantity adjustment means is composed of a plurality of spouting ports 3 different in caliber and pitch.
In the above-mentioned embodiment, the shape of the spouting port 3 is formed in a circular shape, but the shape of the spouting port 3 is not particularly limited. In the present invention, an oval shape, an elliptical shape, a slit shape, a polygonal shape such as a triangle and a quadrangle, a different shape, a mixture of these shapes or the like can be employed. Further, even when a spouting port 3 having a shape other than a circular shape is employed, the degree of cooling can be adjusted by adjusting the caliber and/or the pitch in the same manner as described above.
Specifically, when a slit-like spouting port 3 is adopted, the slit width is changed stepwise or continuously so that the slit width is 1 mm in the spouting port 3 for weak cooling and the slit width is 2 mm in the spouting port 3 for strong cooling. When a circular spouting port 3 is adopted, the hole diameter is changed stepwise or continuously so that the hole diameter is φ2 mm in the spouting port 3 for weak cooling and the hole diameter is φ3 mm in the spouting port 3 for strong cooling, or the pitch is changed stepwise or continuously so that the interval (pitch) between adjacent spouting ports is 15 degrees in the portion for weak cooling and the pitch is 10 degrees in the portion for strong cooling.
In this embodiment, the open region x can also be cooled with weak cooling by adjusting the supply pressure (water pressure) of the cooling water M from the spouting port 3. For example, as shown in
Here, in the cooling method of
In the present invention, a water pressure adjustment means capable of adjusting the water pressure of the cooling water M may be provided for each spouting port 3. In this case, the water pressure of the cooling water M can be finely adjusted for each spouting port 3, so that the cooling degree can be more finely adjusted, which in turn makes it possible to cast a higher-quality continuously cast material. However, if a water pressure adjustment means is provided for each spouting port 3, the number of installed water pressure adjustment means increases. For this reason, there is a risk that the structure may become complicated and the cost may increase.
In the examples of
Note that, in this embodiment, the degree of cooling is adjusted by adjusting the caliber and the pitch of the spouting port 3 or by adjusting the water pressure of the cooling water M from the spouting port 3, but the present invention is not limited to this. In the present invention, the degree of cooling can be adjusted by changing the temperature of the cooling water or the type of the cooling water (cooling liquid). For example, by setting the temperature of the cooling water M sprayed to the open region x to be higher than the temperature of the cooling water M sprayed to the ingot facing region y, the open region x can be cooled with weak cooling. Further, as the cooling liquid to be sprayed to the ingot facing region y, by adopting a cooling liquid having a higher cooling capacity than the cooling liquid to be sprayed to the open region x, the open region x can be cooled with a weak cooling weaker than the ingot facing region y.
As described above, according to this embodiment, in the continuous casting apparatus in which a plurality of ingots (continuously cast material) W2 is cast in parallel, the open region x of the outer peripheral surface of a predetermined ingot W2 which does not face another ingot W2 is cooled with weak cooling with respect to the ingot facing region y facing another ingot W2. Therefore, all of the ingots W2 can be cast with high quality.
That is, of the outer peripheral surface of the ingot W2, the open region x is hardly affected by heat from another ingot W2, and therefore the cooling efficiency is high, whereas the ingot facing region y is easily affected by heat from another adjacent ingot W2, and therefore the cooling efficiency is low. Therefore, in this embodiment, since the open region x having a high cooling efficiency is cooled with weak cooling as compared with the ingot facing region y having a low cooling efficiency, the respective ingots W2 can be cooled in a well-balanced manner from the entire circumference to the center portion. Thus, the entire ingot can be formed into a uniform and good ingot structure. For this reason, a high-quality ingot (continuously cast material) W2 with no variation can be assuredly cast.
Besides, in this embodiment, by cooling the open region x with weak cooling, excessive cooling can be prevented, so that the energy required for cooling can be prevented from being wasted unnecessarily. As a result, cooling can be more efficiently performed, which in turn can improve the productivity of a cast product.
In the aforementioned embodiment, a case in which the present invention is applied to three ingots W2 arranged in one row is exemplified, but the present invention is not limited to this. The present invention can also be applied to a plurality of ingots arranged in two or more rows and two or more columns in the same manner as described above.
For example, as shown in
In this another embodiment of
In the embodiment of
For example, in the ingot W2 arranged in the 1st row and ath column (upper left in
In the ingot W2 arranged in the 1st row and cth column (upper right in
Further, in the ingot W2 arranged in the 2nd row and the bth column, the left back region LB, and the right back region RB are defined as open regions x, and the left center region LC, the left front region LF, the right front region RF, and the right center region RC are defined as ingot facing regions y. Therefore, the open regions x are cooled with weak cooling.
As described above, for ingots W2 which are cast in an equilateral triangular arrangement, the outer peripheral surface thereof may be divided into six equal regions in the circumferential direction, and either the open region x or the ingot facing region y may be set for each region LC, LF, LB, RC, RF, and RB divided into six equal regions.
In the aforementioned embodiments, the present invention is applied to a vertical-type continuous casting apparatus in which the casting direction is set in a vertical direction as an example, but the present invention is not limited to this, and can also be applied to, for example, a horizontal-type continuous casting apparatus in which the casting direction is set in a direction other than a vertical direction.
The production apparatus of a continuously cast metal rod of the present invention can be suitably used for producing a continuously cast material used as a material for an extrusion material, a rolled material, a forged material, etc., made of metal such as aluminum.
The present application claims priority to Japanese Patent Application No. 2019-36612 filed on Feb. 28, 2019, the entire disclosure of which is incorporated herein by reference in its entirety.
It should be understood that the terms and expressions used herein are used for explanations and have no intention to be used to construe in a limited manner, do not eliminate any equivalents of features shown and mentioned herein, and allow various modifications falling within the scope of the present invention.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2019-036612 | Feb 2019 | JP | national |
