JPH067900A - Equipment and method for continuous casting of slab - Google Patents

Abstract

PURPOSE:To provide an equipment and method for continuous casting which can manufacture thick slab without tubular or porous casting structure inside. CONSTITUTION:A metallic belt 1 which travels in the transverse direction and a secondary cooling zone 3 on the outlet side of the metallic belt 1 are arranged. An edge heater 13 to heat the upper part of both side surfaces of the cast slab is arranged on the outlet side of the secondary cooling zone 3. A roll to execute slight reduction of the cast slab is arranged on the outlet side of the edge heater 13. A pair of side weirs 8a, 8b which travel between the metallic belt 1 and the secondary cooling zone are provided, and a rear weir is provided between the side weirs 8a, 8b on the metallic belt 1. For the cast slab where the external solidification is completed, the upper part of both side surfaces of the cast slab is heated to the temperature of 1200 deg.C or higher temperature by the edge heater 13, and slight reduction is executed by horizontal rolls 14a, 14b.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a continuous casting machine and a continuous casting method capable of producing thick slab slabs having a thickness of 50 mm or more, particularly 300 mm or more.

[0002]

2. Description of the Related Art As a method for producing a thick slab having a thickness of 300 mm or more, for example, an ordinary ingot making method can be considered. However, the steel ingot produced by the ingot making method has a problem that a slab rolling process for forming a desired slab is required and the yield is low.

Japanese Patent Publication No. 53-19290, Japanese Patent Laid-Open No. Sho 6
The invention of 1-14067 relates to the production of an extremely thick slab-shaped slab. However, since these methods are methods of assembling a flat mold corresponding to the extra-thick slab-shaped slab to be manufactured each time, the assembly of the mold is complicated, and water cooling or other forced cooling is not performed. , The solidification rate is slow and the productivity is low.

Thick slab slabs with a thickness of 300 mm or more are
It takes a long time to complete the solidification of the central part. For this reason, in a normal vertical continuous casting machine in which the central portion vertically supports the solidified shell with the unsolidified portion, the secondary cooling zone is a large-scale facility, and bulging is likely to occur due to the static pressure of the molten metal.

[0005]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a simple continuous casting machine for producing thick slab cast pieces and a continuous casting method for producing thick slab cast pieces using this continuous casting machine. There is.

[0006]

FIG. 1 is an explanatory view of the present invention, (A) is a front explanatory view, and (B) is a plan explanatory view. The continuous casting machine according to the present invention has a metal belt 1 whose side surface is cooled and runs sideways. This metal belt 1
Is a pulley 2 with an endless metal belt at the same height.
It is obtained by spanning a and 2b and rotating the pulleys 2a and 2b in the direction of the arrow. Reference numeral 5 in the figure is a cooling device for cooling the back surface of the metal belt 1.

A secondary cooling zone 3 is arranged on the exit side of the metal belt 1. The secondary cooling zone has a large number of rollers 4 and injection nozzles 6 arranged between the rollers 4. Each injection nozzle 6 injects a cooling medium, such as water, upward. Also many rollers 4
Are arranged so as to extend in the running direction of the metal belt so that the upper end thereof is at the same height as the metal belt 1.

The continuous casting machine of the present invention is also provided with metal belts 1 and 2 with a space corresponding to the width W of the cast slab 7 to be manufactured.
A pair of side wall weirs 8a extending over the next cooling zone 3
And 8b. The side wall weirs 8a and 8b run in the same direction as the arrow 9 of the metal belt 1 at the same speed.

Two or more side wall blocks, for example, 8-1, 8-2, 8-3, and 8-4 in FIG. 1 (B) are detachably connected in the longitudinal direction to form a side wall, and an arrow 9 is formed. Bearing the slab that has come off the secondary cooling zone 3 or has completed solidification as a result of traveling in the direction, for example, the side wall block 8-4 is separated from the side wall 8a, and When it is transferred to the position and sequentially connected to the tail end of the side wall block 8-1, the four side wall blocks 8-1, 8-2, 8-
The side wall 8a can be formed by 3, 8-4.

The continuous casting machine of the present invention also includes a secondary cooling zone 3
The edge heater 13 is arranged on the output side of the. The edge heater 13 heats the upper portions of both side surfaces of the cast slab 7. For heating the edge heater, various general-purpose heating means such as heating with a gas, heating with a plasma torch, or heating with an induction current can be used.

The continuous casting machine of the present invention also has a pair of horizontal rolls 14a and 14b on the outlet side of the edge heater 13. This horizontal roll is arranged to apply a light reduction to the slab 7 whose side surface has been heated by the edge heater 13.

The continuous casting machine of the present invention also includes a metal belt 1
Between the upper side weirs 8a and 8b, there is a metal belt 1 and a rear side weir 10 arranged in close contact with the side weirs 8a and 8b. The rear weir 10 does not run in the direction of the arrow 9 but is provided at a fixed position. Therefore, the inner wall surfaces of the metal belt 1 and the side weirs 8a and 8b rub against the rear weir 10 to run.

At the time of continuous casting, the molten metal 11 is poured into the space formed by the metal belt 1, the side surface dams 8a and 8b, and the rear surface dam 10. The poured molten metal 11 is cooled by the metal belt 1 to form a solidified shell 12 on the metal belt 1. While this solidified shell grows, it runs in the direction of arrow 9 following the running of the metal belt 1.

After reaching the exit side of the metal belt, the solidified shell is supported by the roller 4. When the end of the metal belt in the running direction is reached, the unsolidified molten metal 11 remains above the solidified shell 12, but the solidified shell has grown and is already thick and has sufficient strength. Even if the support by the belt 1 is changed to the support by the rollers 4, breakage or other trouble does not occur. Since the unsolidified molten metal 11 exists above the solidified shell 12, the side walls are continuously supported by the side wall weirs 8a and 8b even in the secondary cooling zone 3 to prevent the molten metal 11 from flowing out from the side surface.

Even in the secondary cooling zone 3, the solidification shell 12
The bottom surface is continuously cooled by a cooling medium, such as water, which is sprayed upward from the spray nozzle 6, and the slab 7 becomes a solidified outer surface while traveling in the direction of arrow 9.

FIG. 2 is an explanatory view of the cast piece 7 whose outer surface is solidified.
(A) is an explanatory view of the progress of coagulation, and (B) and (C) are FIG. 2 (A).
2B is an explanatory view of a vertical cross section, (B) shows a case with a side weir, and (C) shows a case without a side weir. At the end of solidification, the solidification shell 12 grows and becomes thicker, but
The surface coagulation layer 15 is also formed on the first bath surface. The solidified shell 12 and the surface solidified layer 15 are united to form a cast piece 7 whose outer surface is completely solidified. At the time of this coalescence, a part of the molten metal 11 may be caught in the solidification shell 12 and the surface solidification layer 15 and may be trapped in the slab.

The molten metal confined in the slab finally solidifies, and the confined molten metal solidifies into a pipe-shaped or porous casting structure 16. In addition, at this time, side solidified shells 17 that have been grown by being cooled by the side surface weirs 8a and 8b are formed on both sides of the pave-shaped or porous casting structure 16.

Pipe-shaped or porous cast structure 16
Is an unhealthy steel material if the inside is oxidized during heating in the hot rolling in the next step. Therefore, immediately after casting, it is desirable to subject the slab to a light reduction to bring the pipe-shaped or porous casting structure 16 into close contact. At the time of this light reduction, the side surface solidified shell 17 also needs to be plastically deformed. However, since the side solidified shell 17 is dense, it is hard to be plastically deformed, so that the pipe-shaped or porous cast structure 16 tends to be insufficiently adhered.

In the present invention, the side heater 17 is heated by the edge heater 13. Using the edge heater 13, the upper parts of both side surfaces of the slab whose solidification on the outer periphery is completed are
When heated to 0 ° C. or higher, the side solidified shell 17 is softened, and therefore plastically deforms when lightly pressed. Therefore, with a small rolling force, a pipe-shaped or porous casting structure 16
Can be closely attached. In FIG. 1, 14a and 14b are
It is a horizontal roll that applies this light reduction.

Japanese Examined Patent Publication No. 19290/53, JP-A-6
In the invention of 1-14067, as described above, the work of assembling the flat mold each time is complicated, but in the present invention, the length of the slab is desired by a cutting machine (not shown) arranged on the exit side of the horizontal roll. It can be adjusted like. Further, in the present invention, when changing the plate width W of the slab to be manufactured, the side surface dams 8a and 8b are arranged at intervals corresponding to the plate width of the slab to be manufactured.
To move. The side wall weirs 8a and 8b normally run along a guide (not shown) arranged over the metal belt 1 and the secondary cooling zone 3, but the side wall weirs 8a and 8b are moved by, for example, a pusher (not shown) or the like. 8a and 8
The traveling path of b also moves, and the distance between the side dams 8a and 8b is easily changed and set as desired.

Japanese Patent Publication No. 53-19290, JP-A-6
The invention of 1-14067 has a low solidification rate and low productivity because it does not use a cooling medium such as water, but in the present invention, since the slab is directly cooled by the cooling water injected from the injection nozzle 6, High solidification rate and high productivity.

In a normal vertical continuous casting machine, since the central portion vertically supports the solidified shell that is not solidified, in order to manufacture a thick slab slab, the large static pressure of the unsolidified molten metal in the central portion is endured. A secondary cooling zone with a strong and large-scale structure is required, and the equipment becomes large-scale. In the present invention, the static pressure of the unsolidified molten metal is small because the upper part horizontally supports the solidified solidified shell, and the secondary cooling zone can have a simple structure. There is no bulging.

[0023]

According to the present invention, a thick plate slab cast piece can be manufactured by a simple continuous casting machine. Further, according to the present invention, it is possible to manufacture a thick plate slab slab having no pipe-shaped or porous cast structure.

[Brief description of drawings]

FIG. 1 is an explanatory view of a continuous casting machine of the present invention, and FIG. 2 is an explanatory view of generation of a pipe-shaped or porous casting structure of a slab and means for improving it.

[Explanation of symbols]

1: metal belt, 2a (2b): pulley, 3: secondary cooling zone, 4: roller, 5: cooling device, 6: injection nozzle, 7: cast slab, 8a (8b): side wall, 9: metal belt , Solidified shell, running direction of side weir, 10: rear weir, 11: molten metal, 12: solidified shell, 13: edge heater, 14a (14b): horizontal roll, 15:
Surface solidified layer, 16: Pipe-shaped or porous cast structure, 17: Side solidified shell.

Claims (2)

[Claims] 1. A metal belt having a back surface cooled and running laterally, a large number of rollers each having an upper end arranged at the same height as the metal belt, and an injection nozzle arranged between the rollers to inject a cooling medium upward. Then, the secondary cooling zone arranged on the outlet side of the metal belt and the metal belt and the secondary cooling zone are extended at intervals corresponding to the strip width of the slab to be produced and synchronized with the metal belt. A pair of side wall dams that run, and an edge heater that is arranged on the outlet side of the secondary cooling zone and heats the upper portions of both side surfaces of the slab,
Having a pair of horizontal rolls arranged on the outlet side of the edge heater to apply a light reduction to the slab, and a non-running rear weir arranged closely between the metal belt and the side weir between the side weirs on the metal belt. A continuous casting machine for slabs. 2. The continuous casting machine according to claim 1 is used to inject molten metal into a pool formed by a metal belt, a side weir, and a rear weir to form a solidified shell on the metal belt. The solidified shell is cooled from the bottom surface by the belt and the secondary cooling zone, and is made to follow the metal belt while growing the solidified shell to form a slab with the solidification of the outer surface completed, and both sides of the slab with the solidification of the outer surface completed. A continuous casting method for slabs, characterized in that the upper part of the surface is heated to 1200 ° C or higher by an edge heater and lightly reduced by a horizontal roll.