JPS60162555A - Continuous casting device for thin plate - Google Patents

Abstract

PURPOSE:To eliminate penetration of a molten metal between stationary gates and the end faces of water-cooling rolls and to enable stable continuous casting with a casting device of a twin drum type by disposing the bottom ends of the stationary gates pressed to the end faces of the rolls in a prescribed position. CONSTITUTION:The bottom ends of stationary gates 2, 2' to be pressed to the end faces of water-cooling rolls 1, 1' are disposed in the position satisfying h=Rsintheta [where h: the distance (mm.) from the neutral point P of the rolls 1, 1' to the bottom ends of the gates 2, 2', R: the radius (mm.) of the rolls 1, 1' the angle theta between lines connecting the center of the rolls 1, 1' and the center at the bottom end of the gates 2, 2'; 1-10 deg.], thereby constituting the titled device of a twin drum type. The above-described twin drum type method is a method for obtaining a thin plate by pouring a molten metal 4 into the space formed of the rolls 1, 1' and the gates 2, 2' and a thin plate 3 is stably and continuously cart by the above-mentioned device.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a continuous thin plate casting apparatus, particularly a twin drum type continuous thin plate casting apparatus.

[Disadvantages of the conventional twin-drum continuous casting machine] The conventional twin-drum continuous casting machine pours molten metal into the space formed by two internal water-cooled drums and two fixed weirs pressed against the drum end faces, and continuously casts thin plates. In a drum-type continuous casting machine, the molten metal solidifies on the fixed weir wall surface, and this solidified material is rolled near the neutral point of the drum, creating medium waves and pushing and spreading the fixed weir, thereby forming a gap between the drum end surface and the fixed weir. clearance occurs. This has the disadvantage that molten metal gets inserted into this clearance, making stable casting impossible.

[Object of the present invention]

SUMMARY OF THE INVENTION An object of the present invention is to provide a continuous thin plate casting apparatus that eliminates the above-mentioned drawbacks. In other words, an object of the present invention is to provide a thin plate continuous casting apparatus that can stably perform continuous casting without impairing the properties of slabs.

[Configuration of the present invention]

In the present invention, as a means for achieving the above object, a fixed weir is provided above the neutral point of the water-cooled roll to press against the end face of the water-cooled roll, and the location of the fixed weir is specified.

That is, the present invention has a structure in which (2) a fixed weir is not provided at a portion where the coagulated material generated on the constant weir wall surface is rolled and the width is expanded. More specifically, the invention includes:
Two water-cooled rolls arranged horizontally in parallel with a gap corresponding to the thickness of the metal strip to be manufactured, and rotated in mutually rotating directions 'kA', and two fixed rollers pressed against the end faces of the water-cooled rolls. A continuous casting device for producing thin plates by pouring molten metal into a space formed by a weir, characterized in that the lower end of the fixed weir that presses against the end face of the water-cooled roll is disposed at a position that satisfies the following formula: It is a device.

h=Rsinθ [The formula is the distance (mm) from the neutral point of the water-cooled roll to the lower end of the fixed weir, and R is the radius of the water-cooled roll (mm)
and θ is the angle formed by the center line of the water-cooled roll and a line connecting the center of the water-cooled roll and the center of the lower end of the fixed weir,
This θ is 1 to 10 degrees. ] In the present invention, the fixed weir is 17o.

Preferably, the fixed weir is made of a refractory material with a melting point above °C, such as alumina graphite, alumina, poron nitride, zirconia oxide, silicon nitride. It is preferable to make it possible.

Further, this fixing plate is pressed against the end face of the water-cooled roll with a constant surface pressure to prevent leakage and insertion of the molten metal.

By the way, the present invention has a structure in which a fixing bolt is not provided in the part where the width of the slab is widened by the solidified shell on the surface of the water-cooled roll. The inventor conducted various experiments regarding the location of this fixed weir, and as a result, h=Rsin
It has been found that the range of θ (where θ is 1 to 10 degrees) is appropriate when the slab thickness is 2 to 5 degrees. That is, in the present invention, if the entire arrangement is fixed so that θ is 10 degrees or more, solidification at the end of one slab will cause leakage of the molten metal, and if θ is 1 degree or less, When a fixed weir is placed in the fixed weir, a coagulum is generated on the lower wall surface of the fixed weir, and the rolling of this coagulated material causes the width to expand, forcing the fixed weir to widen, and causing the connection between the water-cooled roll and the fixed weir to increase. A clearance occurs in between. Then, the molten metal is inserted into this clearance, and as a result, stable casting becomes impossible and the object of the present invention cannot be achieved.

Hereinafter, the present invention will be explained in detail based on FIGS. 1 and 2. FIG. 1 is a longitudinal cross-sectional view of a continuous thin plate casting apparatus according to an embodiment of the present invention, and FIG. 2 is a cross-sectional view taken along the line A-A' in FIG. 1, mainly showing the structure of the fixed weir. be. The apparatus shown in Fig. 1 includes a water-cooled casting roll 1゜1' for casting a thin plate slab 3, a fixing mechanism @ 2.2' for preventing leakage of molten metal 4 between the water-cooled casting rolls 1 and 1', and a molten metal such as molten steel. All major components include the tundish 5, which supplies a constant amount of 4 tons.

To explain this apparatus in detail, as shown in FIG. 1, water-cooled casting rolls 1 and 1' are installed horizontally and are driven to rotate (in the direction of the arrow) by a drive device (not shown). This water-cooled casting roll 1.1' is made of copper, copper alloy, or steel, for example, and has a built-in water cooling mechanism, and has a fairly large diameter drum in order to obtain a large contact area with the molten metal 4. . In addition, water-cooled casting roll 1.1'
Fixtures @ 2.2' made of a fire-resistant material are pressed against both ends of the rolls to seal the sides, and two water-cooled casting rolls 1.1' and two fixations @ 2.2 are pressed. Molten metal 4 is poured into the space formed by '. The poured molten metal 4 is cooled by contacting the surface of the water-cooled casting roll 1.1', and the resulting solidified shell is integrated into a slab 3. This slab 3 is pulled out by a vinyl roll 6 and a guide roll 7.

Next, the structure of the fixed weir will be explained based on FIG. The fixture @2 is made of a refractory material having a melting point of 1700° C. or higher, and is preheated from the back side by a heater 9 so that it can be heated even during casting.

The fixed plate 2 and the heater 9 are housed in the heating box 8 with the surface of the fixed plate 2 exposed.
The entire drum is pressed against the end surface of the drum by a hydraulic (air) cylinder 10 with a constant surface pressure. In FIG. 2, reference numeral 11 denotes a refractory castable, which is generally made of a common material used in electric furnaces, casting, etc., such as alumina. Further, this direction addition '@2 is not located near the neutral point P of the water-cooled casting roll 1, but is disposed above the neutral point P at a predetermined distance h'6. And this distance h ij , Re1nθ [However, R is the radius (key) of the water-cooled casting roll 1, and 0 is the radius (key) of the water-cooled casting roll 1.
The center line of roll 1, the center of water-cooled casting roll 1 and the solid foot weir 2
The angle formed by the line connecting the center of the lower end of the
within the range of ] is within the range.

In the present invention, as described above, the fixing plate 2 is not located near the neutral point P of the water-cooled casting roll 1, but is disposed above it.The reason for this is as follows. Fixed @2
is placed near the neutral point P, a solidified material is formed on the lower wall surface of this fixed weir, and the rolling of this solidified material causes the width to expand, forcing the fixed weir to widen and connecting it to the water-cooled casting roll 1. A clearance is created between S and @2. This is because the molten metal will be inserted into this clearance, and as a result, stable casting will not be possible. In addition,
Even if there is no fixed weir 2 near the neutral point P of the water-cooled casting roll 1, solidified material is generated in this area and there is no molten metal, so it is necessary to cool the molten metal using the fixed weir in this area. It's something that doesn't exist.

Although the present invention has been described in detail above, the present invention will be explained in more detail by giving specific examples of the present invention.

〔Concrete example〕

The dimensions and conditions of the component parts when cast steel are as follows.

(1) Water-cooled casting roll The water-cooling casting roll is made of steel and has an internal water cooling system, and has a roll diameter of 2000φ and a roll width of 1200mm. The dimensions of the slab are l 5 mmt x 1200 mm 11,
The a-le rotation speed (casting speed) at this time is approximately 24 m/
It is min.

(2) Fixed weir The lower end of the fixed weir is located at a position that satisfies h==RsiHθ. That is, when θ is 5 degrees, h is 52.5 mm. Boron nitride ('
B) t, ), silicon nitride (Si3N<), etc. were used for extensive experiments. Further, the fixing plate was preheated to about 1280° C. and was energized during casting. In addition, the fixed weir was pressed against the end face of the drum with a pressure of 6 to 7 cm. Casting was performed under the above conditions, and there were no operational troubles such as breakouts, and beautiful slabs could be stably obtained. Ta.

[Effects of the present invention]

As described in detail above, even if the solidified material on the fixed weir wall (2) becomes excessive and the solidified material is rolled to cause medium corrugation, there is no fixed weir in the part where medium corrugation occurs. Therefore, the fixed weir is not fully expanded, and therefore there is no insertion of molten metal between the fixed weir and the end face of the water-cooled roll, resulting in the effect that stable casting is possible.

[Brief explanation of the drawing]

・Figure 1 is a longitudinal cross-sectional view of a thin plate continuous casting apparatus according to an embodiment of the present invention, and Figure 2 is a cross-sectional view taken along line A+AI in Figure 1, mainly showing the structure of the fixed weir. I'll go. 1.1'... Water-cooled casting roll 42'... Fixed weir 5... Slab 4... Molten metal 5---Tundish 6... Pinch roll 7・■ Guide roll 8...
・・・Heating box 9・・・Heater 100・Hydraulic pressure (Air cylinder 111I・・Fireproof castable h・Distance (III+1) θ・Angle P・Water cooling roll neutral point R・・・Water-cooled roll beef diameter (m) Sub-agent 1) Meifuku agent Ryo Hagiwara - Figure 1

Claims (1)

[Scope of Claims] Two water-cooled rolls arranged horizontally in parallel with a gap corresponding to the thickness of the metal strip to be manufactured and whose rotating directions are different from each other, and two water-cooled rolls pressed against the end faces of the water-cooled rolls. In a continuous casting device for pouring molten metal into a space formed by individual fixed weirs to obtain a thin plate, the lower end of the fixed weir that presses against the end face of the water-cooled roll is located at a position that satisfies the following formula. Continuous thin plate casting equipment. h=Rsinθ [where hH is the distance from the neutral point of the water-cooled roll to the lower end of the fixed weir (tJnn) and I! D and R are the radius of the water-cooled roll (a
t), where θ is the angle formed by the center line of the water-cooled roll and a line connecting the center of the water-cooled roll and the center of the lower end of the fixed weir, and this θ is 1 to 10 degrees. ]