JPS6030554A - Continuous casting and cooling device for square ingot - Google Patents

Abstract

PURPOSE:To provide a titled device which improves remarkably the quality and characteristics of a square casting ingot in the stage of casting continuously said ingot by the constitution in which the amt. of the cooling water to be applied to the casting ingot in the lower part of a casting mold is properly changed by operating a divided member connected by means of a flexible member provided to a part where a nozzle is formed. CONSTITUTION:A divided member 5 is disposed in the bottom 4 of a casting mold 1 on the nozzle 2 side provided in the part facing casting ingot 10 so as to discharge cooling water 3 as shown in the figure A. The member 5 is connected watertightly in the mold 1 by a flexible member 6 consisting of a rubber- or plastic base material. An operating member 9 is attached to the member 5 and the free end side of the member 9 is brought into contact with a driving body 8 such as a cam body. An operating cylinder or the like acting on the free end side of the member 9 is usable for the body 8. The nozzle 2 can be throttled by the crest part of the body 8 as shown in the figure B when a rotary periphery cam is used for said body 8. The deformation in the initial period of casting a square casting ingot is effectively prevented and the crystal is improved by such constitution. The crank, etc. in the initial period of casting are also adequately averted.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a continuous casting cooling device for rectangular ingots, and the present invention relates to a continuous casting cooling device for rectangular ingots. The object is to provide a device whose properties can be improved separately.

In continuous casting of aluminum, etc., generally a rectangular water-cooled mold with open top and bottom is used, and molten metal is continuously supplied from above the mold onto a vertically movable pedestal inserted into the bottom of the mold. A cooling method is adopted in which the ingot solidified in the mold is continuously pulled out from the lower part of the mold by lowering a pedestal, and cooling water is directly applied to the ingot from a nozzle provided at the lower part of the mold. In other words, in such a semi-continuous casting method, the high-temperature molten metal is cooled to near room temperature by the water-cooled mold and the cooling water applied directly to the ingot from below the mold, so the ingot is rapidly cooled. Although this generally gives good properties to the structure, there are some problems caused by rapid cooling. In other words, it is sometimes considered desirable to cool such ingots as slowly as possible; for example, ■A1050, Al1
By improving the crystal orientation of 00 alloys, etc., ■ prevention of deformation in the initial stage of casting of square ingots, that is, warping of the end face of the ingot against the pedestal (butt curl); ■ hot and cold cracking of high strength alloys, i.e. This includes prevention of cracks in the initial stage of casting, and cracks in the center and surface. However, the easiest way to obtain such slow cooling is to reduce the supply of cooling water, but reducing the supply of cooling water causes an imbalance in the amount of cooling water supplied to each part of the circumference of the ingot. Therefore, stable and balanced cooling and thereby casting cannot be obtained. Therefore, special methods such as Noculus cooling, multistage cooling, and cooling using wipers have been developed to avoid such disadvantages and achieve stable cooling and casting, but when trying to apply them to the current semi-continuous casting method, There are unavoidable disadvantages such as not having enough equipment space, requiring major equipment modification, complicating no-end operations, or incurring high costs.

The present invention was devised after repeated studies in view of the above-mentioned circumstances, and is a relatively simple and compact device that can cool the ingot by appropriately changing the amount of cooling water applied to the ingot at the bottom of the mold. We succeeded in obtaining a mechanism that can be easily adopted and operated in conventional continuous (fully continuous or semi-continuous) casting equipment for aluminum ingots. That is, a specific embodiment of the present invention will be described with reference to the attached drawings. As shown in FIG. 1, a square ingot 10
As is well known, the mold 1 which is designed to semi-continuously obtain cooling water and other refrigerants is configured to cool the egg mass 10 by discharging cooling water 3 from the inside of the mold 1. In this case, a divided part body 5 is used on the nozzle 2 side in the bottom part 4 of such a mold 1, and the divided part body 5 is made watertight in the mold 1 by a flexible member 6 made of rubber or synthetic resin. In addition, an operating member 9 is attached to the divided body 5, and the free end side of the operating member 9 is engaged with a driving body 8 such as a cam body. It is possible to employ an operating cylinder, a rack member, etc. that acts on the free end side of 9. The one in Figure 1 is B in the same figure when a rotating circumferential cam is used as the drive body 8.
As shown in FIG. The nozzle 2 can be narrowed down, and in this case, a sealing material I made of rubber or the like is attached to the inside of the divided body 5. It is clear that even if a rotary cam is used as the drive body 8 as shown in FIGS. 1.2, the same effects can be obtained even if an end cam or a groove cam is used.

Note that under conditions where the driving body 8 is continuously rotated by a motor or the like during casting, the discharge of the cooling water 3 is controlled only in the initial stage of casting, and then a uniform cooling water supply is attempted. In some cases, a clutch mechanism or the like may be employed to appropriately turn on and off the actuating system of the drive body 8 from the motor.

According to the results of practical studies conducted by the present inventors, it is sufficient to interrupt the supply of cooling water only to the longitudinal side surfaces of a steel ingot with a rectangular cross section in order to prevent deformation (butt curl) of the ingot in the initial stage of casting. 6, especially in the longitudinal middle part
The purpose can be appropriately achieved by intermittent cooling water supply. Also, if both sides of the mold in the longitudinal direction are closed at the same time while a constant amount of cooling water is being supplied into the mold 1, the pressure of the cooling water inside the mold 1 will increase and the cooling water will leak from the closed nozzle. 18 without making the phases of the left and right cams symmetrical.
0°, so that the left and right nozzle sections open and close alternately. In any case, the ingot can be smoothly cast without any change in its structure.

Specific operational examples according to the present invention will be explained below.

Using the equipment shown in Fig. 2, an ingot of 250 x 40 (111 ingots 1
0, casting speed 7o/min, cooling water 1501/min
The results of measuring the occurrence of butt curl when casting was performed by supplying min. were shown in Table 1 below.

As is clear from the results in Table 1, it is effective to use the cooling water nozzle on the middle long side of mold 1 to prevent butt curl. If you do this, the Batcurl will be halved, and if you open and close 250 dragons, you can reduce it to almost zero.

In addition, in the above operation example, the optical microscopic structure of the part corresponding to 1/4 of the ingot thickness when the 92.5 candy on the long side of the mold was opened and closed was as shown in Figure 3. Compared to the structure shown in Fig. 4, which shows the optical microscopic structure of 1/4 of the thickness of the ingot when operated by the conventional method, the ingot was It is clear that the dendrites were very coarse and had undergone favorable cooling.

According to the present invention as explained above, it is possible to effectively prevent deformation of a rectangular ingot at the initial stage of casting, improve its crystallization, and appropriately avoid cracking at the early stage of casting. Since the purpose can be effectively achieved with slight improvements and a compact driving body or operating member, it has the advantage of being able to be easily adopted in existing continuous casting equipment without the need for major improvements or changes. This invention is industrially very effective.

[Brief explanation of the drawing]

The drawings show embodiments of the present invention, and FIG. 1 is a partial sectional view showing one embodiment of the invention, and FIG. 2 is a partial sectional view showing another embodiment thereof. In each case, A shows the nozzle part open state, and B shows the nozzle part closed state. FIG. This figure shows a micrograph at a magnification of 50 times, similar to that in Figure 3. In these drawings, 1 is a cooling mold, 2 is a nozzle thereof, 3 is a cooling water, 4 is a bottom of the mold, 5 is a divided part body,
6 is a flexible member, T is a sealing material, 8 is a drive body 1.9 is an operation part body 1. '10 indicates an ingot. rA) 1 Figure CB) (/4) Figure (B)

Claims (1)

[Claims] In a mold in which a nozzle is formed for storing cooling water inside and discharging the cooling water to the ingot side at the bottom so as to continuously cast square ingots, a divided part is provided in the nozzle forming part of the bottom of the mold. , the divided body is connected by a flexible member made of rubber or synthetic resin, an operating member is attached to the divided body, and a driving body is engaged with the free end side of the operating member. A continuous casting cooling device for square ingots, characterized by: