JPH01321050A - Shifting mold type continuous casting machine - Google Patents

Abstract

PURPOSE:To prevent breakout, etc., of a cast slab and to obtain good quality of the cast slab by arranging heaters for raising temps. of shifting molds by heating the outer faces of both shifting molds approaching to one pair of the shifting molds at positions, where do not form mold space, in shifting mold type continuous casting machine. CONSTITUTION:Before starting the continuous casting by using the shifting mold type continuous casting machine 3, radiation heater 1 in No.1-4 heater banks 16-19 are worked. Then, by driving the shifting molds 2, the outer surfaces of the molds 2 are heated and temps. of the molds 2 are made as higher as possible under controlling (for example, 100-200 deg.C). By this method, moisture and oil attached to the surface of the mold 2 are removed. Successively, the temps. of the molds 2 are controlled with the heaters 1 so as to become the fixed temp. by casting condition, for example 60-100 deg.C. After that, the molten metal 8 in a tundish 11 is poured 10 into the mold space 7 between the molds 2, 2 to start the continuous casting.

Description

[Detailed description of the invention] [Industrial application field] This invention relates to a moving mold type continuous casting machine.

[Prior Art] A moving mold type continuous casting machine is known, which is constituted by a moving mold with an endless track consisting of a plurality of blocks connected in an endless manner, or a moving mold with an endless track consisting of an endless metal belt. There is.

FIG. 6 is a schematic explanatory diagram showing an example of such an endless orbit moving mold type continuous casting machine consisting of a plurality of blocks.

In FIG. 6, reference numeral 2 denotes a pair of upper and lower moving molds on an endless track of the moving mold type continuous casting machine 4.

The movable mold 2 consists of a plurality of endlessly continuous blocks 5, which are arranged vertically at predetermined intervals in the longitudinal direction.

The upper and lower movable molds 2 each have a pair of sprockets 12.
The hook is rotated so that it is rotated at the same speed by a drive device (not shown) provided on one of the pair of sprockets 12.

On both sides of the upper and lower movable molds 2, left and right movable molds of an endless track (not shown) are arranged close to each other on both sides of the mold space 7 formed by the upper and lower movable molds 2. 2 together form a mold space 7.

The left and right movable molds are composed of a plurality of blocks connected in an endless manner similar to the upper and lower movable molds 2, and like the upper and lower movable molds 2, the hooks are each rotated by a pair of sprockets, The sprockets are rotated at the same speed by a drive device installed on one of the sprockets.

The upper and lower movable molds 2 and the left and right movable molds are rotationally driven synchronously so that the parts forming the mold space 7 move at the same speed from the upstream side to the downstream side.

The tip of a molten metal injection nozzle 10 whose base end is attached to the lower side wall 11a of the tundish 11 is inserted into the entrance 2a of the movable mold 2.

The molten metal 8 in the tundish 11 is injected into the mold space 7 through the injection nozzle 10, and the slab 9 is formed in the mold space 7.
A solidified shell of is formed.

As the upper and lower movable molds 2 and the like move, the slab 9 is pulled out from within the mold space 7 by the pinch rolls 13 in the direction of the arrow, and thus the slab 9 is continuously cast.

When casting slabs using the above-mentioned continuous caster 4, the gap between the tip 10a of the molten metal injection nozzle 10 and the movable mold 2 is created to prevent leakage of the molten metal 8 supplied into the mold space 7. Make it as small as possible.

As a continuous casting method using such a moving mold type continuous casting machine 4, an open casting method or a closed casting method is performed.

In the closed casting method, as shown in FIG. 7(a), which is a schematic diagram showing an example of a conventional endless orbit continuous casting machine consisting of a plurality of blocks, molten metal is poured into a mold space 7 through a molten metal injection nozzle 10. When injecting the molten metal 8, the mold space 7 is filled with the molten metal 8, and casting is performed in such a manner that no cavity is formed in the mold space 7 on the supply side.

On the other hand, in the open casting method, as shown in FIG. 7(b), which is a schematic explanatory diagram showing another example of a conventional endless orbit continuous casting machine consisting of a plurality of blocks, a molten metal injection nozzle 10 is used. When injecting the molten metal 8 into the mold space 7 through the molten metal 8, a predetermined cavity 14 is formed in the mold space 7 on the supply side so that the molten metal 8 does not fill the mold space 7.
This is a method of casting in a state where it is formed.

When casting by open casting method.

Injection nozzle 10 inserted into mold space 7 and moving mold 2
There is an advantage that the molten metal 8 does not enter between the block 5 and the block 5. However, with this method, it is very difficult to maintain the meniscus (molten metal level) of the molten metal 8 in the mold space 7 at a constant position, and the meniscus tends to fluctuate.

As a result, a gap is created between the upper surface of the molten metal 8 and the block 5, and ripples occur in the meniscus.
It is difficult to cast slabs stably.

Furthermore, according to the open casting method, the rate of withdrawal of the slab 9 may be faster than the amount of molten metal 8 supplied into the mold space 7. There is a problem that breakouts may occur.

On the other hand, in contrast to the open casting method which has such problems, when casting is performed by the closed casting method, there is no problem of fluctuations in the meniscus of the molten metal 8 in the mold space 7, so stable and good surface quality can be achieved. There is an advantage that it is possible to obtain slabs having the following properties.

[Problems to be Solved by the Invention] When performing closed casting, it is important that the injected molten metal 8 be in a good condition when it comes into contact with the movable mold 2 in order to produce high-quality slabs without defects. It is important to obtain

That is, when the molten metal 8 is injected into the mold space 7 through the injection nozzle 10 in closed casting, the mold space 7 is filled with the molten metal 8 as described above, and a cavity is formed in the mold space 7 on the supply side. It is kept in a state where it does not occur.

In such a state, if moisture or oil is attached to the surface of the movable mold 2 at the start of continuous casting,
Gas is generated when the mold space 7 is filled with molten metal 8, and the pressure inside the mold space 7 increases accordingly.
Molten metal 8 spouted out from a small gap between the injection nozzle 1o and the movable mold 2, causing damage to the injection nozzle 10.

Moreover, in this case, molten metal spouts out from the joint between the upper and lower movable molds 2, causing cracks to occur in the slab 9 and surface defects such as vertical cracks.

Further, the temperature of the movable mold 2 during continuous casting must be maintained within a range determined by the casting conditions, for example, 30'C to 200C.

The reason is that when the temperature of the moving mold 2 is low, for example 30
If the temperature is less than ℃, the speed of heat transferred from the moving mold 2 to the molten metal 8, that is, the cooling rate of the molten metal 8, is too fast, and the solidification of the molten metal 8 becomes uneven, resulting in surface defects such as vertical cracks. This is because there are problems that arise.

On the other hand, when the temperature of the movable mold 2 exceeds 200° C., for example, the rate of heat transmitted from the movable mold 2 to the molten metal 8, that is, the cooling rate of the molten metal 8 is slow, and especially the casting speed of the continuous casting machine 4 is fast. When the solidified shell becomes thinner, there is a problem that breakout occurs in the slab 9.

At the start of continuous casting, the temperature of the movable mold 2 is often a low temperature of less than 30° C., and the above-mentioned defects often occur.

Therefore, an object of the present invention is to be able to raise the temperature of the moving mold to a predetermined value before starting continuous casting in order to prevent breakout of the slab and to cast a good slab. An object of the present invention is to provide a moving mold type continuous casting machine capable of removing moisture and oil adhering to the surface.

[Means for Solving the Problems] This invention provides at least one upper and lower surface arranged at a predetermined interval so that opposing surfaces move in the same direction and at the same speed.
A pair of endless track-shaped moving molds is used for injecting molten metal in a tundish into the mold space formed by the moving molds, the base end of which is attached to the tundish, and the distal end of which is attached to the tundish. In a moving mold type continuous casting machine, the mold space comprises a molten metal injection nozzle inserted into an inlet, and the molten metal injected by the moving mold is cooled and solidified, thereby casting a slab. Proximate to the moving mold in a position where it does not form,
The present invention is characterized in that a heater is provided to heat the outer surface of the movable mold and raise the temperature of the movable mold.

Next, the present invention will be explained with reference to the drawings.

FIG. 1 is a schematic explanatory diagram showing a first embodiment of the present invention.

As shown in FIG. 1, the moving mold type continuous casting machine 3 forms a mold space 7 at the overlapping portion of a pair of upper and lower moving molds 2 which are overlapped at a predetermined interval. 11
8 is a molten metal, and 10 is a molten metal injection nozzle.

On the upstream side of each of the outer parts of the movable mold 2 that do not form the mold space 7, supports 6, 6 are provided outside the movable mold 2, close to the movable mold 2, and parallel thereto.

A plurality of radiant heaters 1 are attached to the support body 6.6 at predetermined intervals toward the movable mold 2.
It constitutes a heater bank 16 and a lower second heater bank 17.

On the outside of the curved part of the movable mold 2 that does not form the mold space 7, which is connected to the upper upstream sprocket 12a and the lower upstream sprocket 12c, there is an arch-shaped support 15° that matches the movable curved surface of the movable mold 2. 15 are provided.

A plurality of radiant heaters 1 are attached to the support 15.15 at predetermined intervals toward the movable mold 2, and include a third heater bank 18 at the top and a fourth heater bank 1 at the bottom.
9.

The radiant heater 1 is disposed across the width direction of the moving mold 2 between both ends thereof.

The supports 6, 6 are attached to an upper frame or a lower frame (not shown).

The first heater bank 16 has an upper upstream sprocket 1
2a and the upper downstream sprocket 12b, the second heater bank 17 starts heating the movable mold 2 from approximately the midpoint between the lower upstream sprocket 12c and the lower downstream sprocket 12d, respectively. It is arranged so that it can be done.

The radiant heater 1 is one that can emit strong radiant energy, and the amount of fuel supplied can be carefully adjusted so that flames do not come out from the burner housing (not shown), such as a gas-fired radiant heater. It is preferable to use

A specular reflector 20 is attached to each of the radiant heaters 1 so as to face the movable mold 2.

The specular reflector 20 has a wide opening so that as much of the effective radiant energy of the radiant heater 1 as possible is reflected over the entire width of the outer surface of the movable mold 2.

Further, the radiant heater 1 is installed at a position a little distance (for example, 25++n) from the outer surface of the movable mold 2 so that the radiant energy is distributed throughout the movable mold 2, and the specular reflector 20 has an incident angle of It is attached so as to be perpendicular to the outer surface of the movable mold 2.

The first to fourth heater banks can each operate independently.

Contact (or non-contact) temperature sensors 21 to 24 are attached to each support and suspended support to detect and control the temperature of the movable mold 2 adjacent to each heater bank.

The movable mold 2 is heated by each radiant heater 1 while being driven, and its temperature gradually increases.

In order to slow down the rate of increase in temperature of the heated movable mold 2, it is desirable to arrange as many radiant heaters 1 as possible over a long distance and heat the movable mold 2 over a long distance.

The temperature of the heated moving mold 2 is determined by temperature sensors 21 to 2.
4 and controlled to the desired temperature.

Furthermore, depending on the casting conditions, the heating zone can be changed to
The temperature of the main center in the width direction of the movable mold 2 can be increased independently of both ends in the width direction, or vice versa.

[Function] Before starting continuous casting using the moving mold type continuous casting machine 3, the radiant heaters 1 of the first to fourth heater banks are activated, and the moving mold 2 is driven. The outer surface is heated to raise the temperature of the moving mold 2 as high as possible in a controlled manner (eg, 100° C. to 200° C.) to dry and remove moisture and oil adhering to the surface of the moving mold 2.

After moisture and oil are removed from the surface of the movable mold 2, the temperature of the movable mold 2 is controlled by the radiant heater 1 to a temperature determined by the casting conditions, for example, 60°C to 100°C.

After this, molten metal is injected and continuous casting begins.

FIG. 2 is a schematic explanatory diagram showing a second embodiment of the present invention, FIG. 3 is a sectional view taken along line A-A in FIG. 2 showing the structure of the heater, and FIG. 4 is a cross-sectional view of the heater. Figure 5 is a longitudinal sectional view of the same.

As shown in FIGS. 2 to 5, this embodiment differs from the first embodiment in that a heater using electric energy is used as a heating means for the movable mold 2.

As shown in FIG. 3, this embodiment is applied to the case where a movable mold 2 having a side wall 2c at only one end in the width direction and having an abbreviated cross-section is used.

A pair of upper and lower movable molds 2 stacked on top of each other with a predetermined interval
In the overlapping part, the movable mold 2 forming the mold space 7 is hooked to the upstream side of each of the outer parts not forming the mold space 7, and to the upper upstream sprocket 12a and the lower upstream sprocket 12c. A cover 26 (indicated by a broken line in FIG. 2) for covering the outer part of the movable mold 2 is provided on the upper frame and the lower frame (not shown) on the outside of the curved part of the part that does not form the mold space 7. It is supported by a support body 27 .

Inside the cover 26, a rod-shaped heater 25 formed in a U-shape is installed on a support 27, on the outer surface 2 in the width direction of the movable mold 2.
b, and is disposed and attached at a position close to the outer surface 2b.

28 is an insulator attached to the inner wall of the cover 26; 29
is a reinforcing metal fitting for supporting the heater 25 on the insulator 28.

The heater 25 is a tube 3 made of 5US304 alloy.
0. Spiral iron built into tube 30-
A heating element 31 made of nichrome wire and a tube 30
An insulator 3 made of MgO is filled between the heating element 31 and the
It is composed of 2.

A plurality of heaters 25 are installed at predetermined intervals in the moving direction of the movable mold 2.

Since this embodiment uses a heater that uses electrical energy, the surface of the movable mold 2 is not contaminated.

Similar to the first embodiment, this embodiment also has the function of removing moisture and oil adhering to the surface of the movable mold 2 before starting continuous casting, and controlling the temperature of the movable mold 2 to a temperature determined by the casting conditions. have

[Effects of the Invention] As explained above, according to the present invention, the temperature of the movable mold can be controlled to a temperature suitable for the casting conditions, so good slabs can be reliably cast and high-speed casting can be performed effectively. . Furthermore, since it is possible to remove moisture and oil adhering to the surface of the moving mold at the start of casting, the pressure increase in the mold space due to gas generation is eliminated, and the slight gap between the injection nozzle and the moving mold is eliminated. This prevents molten metal from spewing out from the mold and from the joint between the upper and lower movable molds, eliminating surface defects on slabs such as nozzle breakage and vertical cracks due to cracking. Many industrially useful effects are brought about, such as the ability to

[Brief explanation of the drawing]

FIG. 1 is a schematic explanatory diagram showing a first embodiment of this invention, FIG. 2 is a schematic explanatory diagram showing a second embodiment of this invention, and FIG.
The figure is a sectional view taken along line A-A in Figure 2 showing the structure of the heater.
Figure 4 is a cross-sectional view of the heater, Figure 5 is a vertical cross-sectional view of the same,
Figure 6 is a schematic diagram showing an example of a conventional moving mold type continuous casting machine, Figure 7 (a) is a schematic diagram showing an example of a closed type continuous casting method, and Figure 7 (b) is an open type continuous casting machine. FIG. 2 is a schematic explanatory diagram showing an example of a continuous casting method according to the method. In the drawings, 1... Radiation heater, 2... Moving mold, 2a.
...Inlet, 2b...Outer surface, 2c...Side wall, 3
．． 4... Moving mold type continuous casting machine, 5... Block, 6... Support body, 7...
Mold space, 8... Molten metal, 9... Slab,
10... Molten metal injection nozzle, 10a... Tip part,
DESCRIPTION OF SYMBOLS 11... Tandish, 11a... Side wall lower part, 12.12a, 12b, 12c, 12d-Sprocket, 13... Pinch roll, 14... Cavity. 15... Bow-shaped support body, 16... First heater pan 17... Second heater bank, ri. 18...Third heater bank, 19...Fourth heater bank 20...Specular reflector, Nk, 21.22,
23.24... Temperature sensor', 25... Heater, 26... Cover, 27... Support body,
28... Insulator, 29... Reinforcement fittings,
30...tube, 31...heating element, 32...
·Insulator.

Claims (1)

[Scope of Claims] At least a pair of upper and lower endless track-shaped movable molds disposed at a predetermined interval so that opposing surfaces move in the same direction at the same speed, and a mold formed by the movable molds. a molten metal injection nozzle for injecting the molten metal in the tundish into the mold space, the base end of which is attached to the tundish, and the tip of which is inserted into the entrance of the mold space; In a moving mold type continuous casting machine that cools and solidifies molten metal injected by a moving mold and thus casts a slab, the movable mold is placed close to the movable mold in a position where the mold space is not formed. A moving mold type continuous casting machine, characterized in that a heater is provided for heating the outer surface and raising the temperature of the moving mold.