JPS6055210B2 - Mold cooling device for horizontal continuous casting - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in a mold cooling device for horizontal continuous casting.

In horizontal continuous metal casting equipment, for example, when splitting an ingot with a square, thick wall, or wide rectangular cross section, it is necessary to cool the mold uniformly and to control cooling according to the quality of the ingot. It is already known that this is the best means to obtain a defect-free and sound ingot.

However, this method is not always easy; for example, when using a graphite mold and a metal water-cooled jacket that cools it in contact with it, the graphite mold may become distorted due to the temperature difference between the side in contact with the molten metal and the side of the water-cooled jacket. As a result, an air gap is created between the contact surfaces between the two, which significantly impairs cooling.

Therefore, conventionally known methods for preventing cooling failure due to air gaps at the contact surface between the water-cooling jacket and the mold include, for example, methods of forcibly tightening the mold and water-cooling jacket tightly with bolts, etc., and methods that prevent the flow of molten metal from the inside of the mold. There is a method of preventing distortion by inserting a heat-resistant block with the same dimensions as the inside of the mold near the inlet and receiving the distortion force with this block, or by making many small holes in the water cooling jacket all over the surface and applying vacuum through these small holes. There are methods such as adsorbing the template using an apparatus.

Another method of preventing an air gap caused by distortion or unevenness of the contact surface during assembly of the mold and water cooling jacket is to fill the J gap by inserting a low melting point metal into the contact surface and heating and melting it.

However, with the method using bolts and blocks described above, if the mold is made of a material with relatively low mechanical strength, such as graphite, the forcing force against strain will exceed the mold's destruction limit, resulting in damage to the bolt holes or damage to the bolt holes. Furthermore, there is a risk that the entire mold may be damaged and an accident may occur in which the molten metal leaks from that location.

Further, in the method using vacuum adsorption, it is almost impossible to generate sufficient adsorption force corresponding to the thermal stress of the mold. Furthermore, although there is no air gap during assembly in the method using a low melting point metal, there is a drawback in that the mold similarly generates thermal distortion at the start of casting, and this cannot be compensated for. As described above, in the past, it was extremely difficult to uniformly cool the mold and to freely control cooling during casting.

As a result of studies to solve these drawbacks, the present invention has been developed by applying external bending to the water cooling jacket to cause distortion so as to follow the distortion of the mold in order to eliminate the above air gap. It provides a device that improves contact, and specifically, it casts an ingot with a square or thick-walled wide rectangular cross section in a mold that is cooled with a water-cooled jacket, and continuously draws it out. The horizontal continuous casting apparatus is characterized by being equipped with a water-cooling jacket pending device for reducing an air gap generated between the contact surfaces of the mold and the water-cooling jacket during ingot casting.

In implementing the present invention, the following embodiments may be adopted. (1) A mold, a water cooling jacket to cool it, a water cooling jacket mounting block to hold the water cooling jacket, and a pen with the water cooling jacket. Equipped with a casting cooling device that is a unit with a pending device for casting.

(2) The water-cooling jacket has a thickness and structure that easily generates strain against bending force, and the water-cooling jacket is in a positional relationship in which it is suspended in the required strain direction with respect to the water-cooling jacket mounting block lock. be fixed with fixing bolts. (3) The pending device has pressure adjusted by remote control using a hydraulic or pneumatic cylinder, making it possible to change the bending force freely and easily.

Next, the present invention will be explained in detail with reference to an embodiment shown in FIG. 4, but prior to this, a conventional example will be explained with reference to FIGS. 1 to 3. As shown in Fig. 1, in a horizontal continuous casting device that continuously draws out thick-walled and wide strip-shaped ingots, if no special measures are taken to prevent air gaps, the contact surface between the mold 1 and the water-cooling jackets 2 and 3 before casting is They are in close contact.

However, as shown in Figure 2, during casting, the molten metal 13 is mixed into the mold 1.
When the ingot flows into the mold and is continuously drawn out as an ingot while being solidified by the water cooling jackets 2 and 3, the temperature difference between the molten metal side of the mold 1 and the water cooling jacket sides 2 and 3 causes a temperature difference of Δ.
An air gap of h is created. In an ingot manufactured in such a state, as shown in FIG. 3, the solidification line is shifted by a length H between the center and the ends with respect to the width direction of the ingot.

It is known that as the length H becomes larger, that is, as the air gap Δh becomes larger, defects are more likely to occur at the ends or the center of the ingot, and the cooling capacity becomes significantly worse. In FIG. 4 showing an embodiment of the present invention, molten metal 13 that has flowed into a mold 1 is continuously drawn out while being cooled and solidified in water cooling jackets 2 and 3. Cooling water is constantly flowing into the cooling channels 14 in the water cooling jackets 2 and 3 through the cooling vibes 9 and 10. The water cooling jackets 2 and 3 are fastened to water cooling jacket mounting blocks 4 and 5 at both ends thereof with a plurality of bolts 7 and 8.

Furthermore, one or more water-cooled jacket pending cylinders 11 and 12 are attached to the central portions of the water-cooled jacket mounting blocks 4 and 5 along the ingot drawing direction, and the rods of these cylinders are attached to the water-cooled jacket mounting blocks 4 and 5. and 5 to contact the central portions of the water cooling jackets 2 and 3.

Upper and lower cooling units 15 and 16 having such a structure
are assembled using upper and lower unit assembly bolts 6 such that the mold 1 is sandwiched between them.

If a strain of Δh occurs in the mold 1, the water cooling jacket 2 is placed on the water cooling jacket pending cylinders 11 and 12.
and 3 by Δh, the rods of the cylinders 11 and 12 can press the central portions of the water cooling jackets 2 and 3 to reduce or eliminate the distortion of Δh.

In this way, the air gap is reduced or eliminated, and uniform cooling in the width direction of the ingot becomes possible, making it possible to obtain a healthy ingot without defects.

For example, in a horizontal continuous casting machine for copper or copper alloy with a plate thickness of 5 to 30 TIn and a plate width of 100 to 50 mm, more specifically, the mold 1 is made of a material that has relatively good heat conduction and is heat resistant and oxidation resistant. A certain graphite mold is used, and its external dimensions should be such that the width direction is sufficient for the width of the ingot, and the external thickness is sufficient to withstand the tightening of the upper and lower cooling units. It may be as thin as possible, at least twice the thickness of the ingot. This is because if the outer thickness becomes too thin, mechanical strength problems will arise, and if the outer thickness becomes too thick, the cooling capacity will decrease. The water cooling jacket is preferably made of copper or brass, which has good thermal conductivity, but steel or stainless steel may also be used in view of its yield strength.

It is advantageous for the water cooling jacket to be as thin as possible within the range that allows the cooling water passages to be secured, since bending force can be reduced, and the capacity of the cylinder can also be reduced, making the entire device more compact. In addition, in order to have sufficient rigidity for the water cooling jacket mounting block to prevent distortion due to the reaction of the bending force, it is desirable that the material be made of copper or other material, and that its thickness be at least twice the thickness of the water cooling jacket. In addition to hydraulic or pneumatic cylinders, there are other ways to hold the water cooling jacket as described above, such as using bolts and springs, but the method using cylinders is preferable because it can be remotely controlled and the bending force can be adjusted accurately and easily. desirable.

It is recommended that the bolts used to assemble the upper and lower cooling units be tightened with a constant force using a torque wrench or the like.

In the ingot cast by the above-mentioned apparatus, the solidification line is almost straight in the width direction of the ingot (H in Fig. 3).
:0), and as a result, an ingot with a uniform structure without defects was obtained. In addition, the cooling capacity has been improved to several or more than the conventional one, and the casting capacity has also increased dramatically compared to this. As described above, according to the present invention, the uniform cooling effect, which is the most important problem in horizontal continuous casting, has been fully satisfied.The effects of the present invention will be summarized as follows.

(1) Due to uniform cooling, there were no defects such as cracks or segregation in the ingot.

(2) Casting capacity has improved dramatically due to improved cooling capacity.

(3) The bending force of the water cooling jacket can be adjusted freely by using a hydraulic or pneumatic cylinder.

(4) Since the mold is not damaged, accidents such as hot water leaks do not occur.

[Brief explanation of drawings]

Figure 1 is a sectional view showing the state of the mold and water-cooling jacket before conventional casting, Figure 2 is a sectional view showing the state of the mold and water-cooling jacket during casting, and Figure 3 is the solidification of the ingot in the above. FIG. 4 is a cross-sectional view of a mold cooling device according to an embodiment of the present invention. 1... Mold, 2, 3... Water cooling jacket, 4, No. 5... Water cooling jacket mounting block, 6... Cooling unit assembly bolt, 7 ,8...
...Water cooling jacket mounting bolts, 9, 10...
...Cooling vibe, 11,12...Water-cooled jacket pending cylinder, 13...Molten metal, 1
4... Cooling water channel, 15, 16... 7... Upper and lower cooling units.

Claims (1)

[Scope of Claims] 1. In a horizontal continuous casting device for casting an ingot having a square or thick-walled wide rectangular cross section in a mold cooled by a water-cooled jacket and continuously drawing out the ingot, A mold cooling device for horizontal continuous casting, characterized in that it is equipped with a water cooling jacket bending device for reducing an air gap that sometimes occurs between the contact surfaces of the mold and the water cooling jacket. 2. A mold, a water cooling jacket for cooling it,
2. The apparatus according to claim 1, wherein a water cooling jacket mounting block for holding the water cooling jacket and a bending device for bending the water cooling jacket form a unit.