JPH02112854A - Metal strip continuous casting apparatus - Google Patents

Abstract

PURPOSE:To improve the productivity of a metal strip having only a little surface defect by arranging exciting devices for giving fine vibration to endless belts running as sloping and mutually facing and forming long side wall of an upper widening mold. CONSTITUTION:The long side faces of the upper widening mold inner wall are formed with the endless belt 1 running as sloping between an upper roll 2 and a lower roll 3 and the endless belt 1' arranged as facing with the belt 1 and running as sloping between an upper roll 2' and a lower roll 3'. Molten metal 6 is poured into the mold and as the endless belts 1, 1' are cooled with cooling pads 4, 4' at back faces, solidified shells 10, 10' are formed in the mold. Then, the exciting devices 12, 12' give the fine vibration so that the solidified shells 10, 10' smoothly slide on the endless belts 1, 1'. Successively, the lower rolls 3, 3' pressurize the solidified shells 10, 10' through the endless belts 1, 1' to form the metal strip 11.

Description

[Detailed Description of the Invention] [Industrial Field of Application] The present invention is directed to the continuous production of metal ribbons directly from molten metal.
This invention relates to continuous metal ribbon casting equipment.

[Prior Art] It is preferable that a metal ribbon can be directly produced from molten metal because the rolling process can be greatly simplified.

FIG. 4 shows an example of a twin-drum continuous thin metal plate casting machine described in Japanese Patent Application Laid-Open No. 61-27675. The molten metal 6 is transferred to two rotating drums 18-1 and 18-2 that rotate in the direction of the arrow.
The water is injected into the pool formed by the water. The molten metal in contact with the rotating drum is cooled from point m to point n to form a solidified shell, but the solidified shells formed on 18-1 and 18-2 respectively coalesce at point n and form the metal. The thin plate 9 is taken out. In order to increase productivity (tons/hour) with this method, the rotating drum must be rotated quickly,
Since the distance between the m point and the n point is short, if the spindle is rotated too quickly, the thickness of the solidified shell will be insufficient, making it impossible to produce a metal ribbon with a predetermined thickness. Furthermore, increasing the diameter of the rotating drum results in extremely large-scale equipment.

FIG. 5 shows an example of a twin-belt type continuous metal sheet hammer making machine described in Japanese Patent Application Laid-Open No. 59-47047. The molten metal 6 is transferred to a pulley 19-1.19-2.19- rotating in the direction of the arrow.
The water is injected into a pool formed by the endless belt 1, which is stretched across the belt 3, and the endless belt 1', which is stretched in the same way. Since the back surfaces of the endless belts 1 and 1' are cooled by the cooling device 20, the molten metal in contact with the endless belts forms a solidified shell, and is taken out as a metal plate 21 that has completely solidified.

In order to produce a thin metal plate using this method, the distance t between the endless belts 1 and 1' must be narrowed, but if t is made too small using this method, the injection flow 22 of the molten metal will become endless. This is not preferable because it will damage the endless belt and damage the surface of the metal plate 21 if it hits the belt. As stated above,
A twin-drum continuous thin metal sheet casting machine can produce thin metal sheets, but it is not easy to achieve high productivity.
Although high productivity can be obtained by increasing the distance between -1 and 19-2, it is not easy to manufacture thin metal plates.

[Problems to be Solved by the Invention] The present invention discloses a metal thin strip continuous casting apparatus that can manufacture inexpensive metal strips with high productivity and can precisely control the thickness distribution of the metal strips.

[Means for Solving the Problems] FIG. 1 is an overall view of an example of the continuous metal ribbon casting apparatus of the present invention, in which (A') is an explanatory side view, (B) is a sectional view taken along line X-x, (
C) is a YY cross-sectional view.

The continuous ribbon casting apparatus of the present invention has an upper roll 2 and a lower roll 3.
An endless belt 1 that is inclined and runs in the direction of arrow 5, for example, and an endless belt 1 that is inclined and runs in the direction of arrow 5, for example, between an upper roll 2'' and a lower roll 3' that are disposed facing the belt. 1' running along the upper side of the mold form the long side surface of the inner wall of the upper wide mold. In the present invention, the endless belts 1 and 1' are stretched under tension by, for example, tension rolls 8 and 8'. 7 and 7' are side weirs 1, for example, endless belts 1 and 1'
It is a wide type that runs along the running direction of the belt, and is sandwiched between endless belts.
Forms the short side of the inner wall of the upper wide mold. The molten metal 6 is injected into the mold, but since the back side of the endless belt is cooled by the cooling pads 4, 4', the solidified shell 10.
10" and solidified shell 10°10' at the lower end of the mold.
are combined to form a metal ribbon 11.

The continuous thin strip casting apparatus of the present invention differs from the twin-drum type continuous thin plate casting machine described above, in that the upper roll 2 (2') and the lower roll 3 (3') are provided with a sufficient distance between them. Therefore, even when casting at a high speed, a sufficiently thick solidified shell 10,10' can be obtained to produce a metal ribbon of a predetermined thickness. Furthermore, unlike the previously mentioned twin-belt type continuous thin plate casting machine, the continuous thin strip casting apparatus of the present invention injects the molten metal into a mold with a wide top, so it is easy to cast even when casting thin metal strips. , the injection stream of molten metal hits the endless belt,
There is no possibility of damaging the endless belt or damaging the surface of the thin metal strip 11.

In the ribbon continuous casting apparatus of the present invention, an endless belt 1 (1')
It has a vibrating device 12 (12') that gives minute vibrations to the.

The vibration device 12 (12') vibrates the portion (between 2 (2') and 3 (3')) where the endless belt forms the mold wall. As the minute vibrations, for example, low frequency vibrations of about 10) 1z to ultrasonic vibrations of about 20 KHz can be used. The vibration device may be a vibration device that applies pulsations to the cooling water that the cooling pad 4 (4') supplies to the endless belt 1 (1'). For example, by immersing an ultrasonic transducer in the cooling water of a cooling pad, it is possible to give pulsations to the cooling water.

Further, the vibration device may be a vibration device using an electromagnet. If the endless belt is made of a ferromagnetic material such as steel, and a high-frequency electromagnet is used, minute vibrations can be applied to the endless belt.

This minute vibration causes the solidified shell 10 (1
0') is added so that it slides smoothly on the endless belt 1 (1').

When the solidified shells 10 (10') are combined, the lower rolls 3 and 3' press the solidified shells via the endless belts 1 and 1'. The metal ribbon 11 is formed by this pressurization.

[Operation] In the present invention, minute vibrations are applied to the endless belt, and the reason thereof will be explained.

Figure 2 shows that the solidified shells 10 and 10' are combined to form the metal ribbon 1.
FIG. The solidified shells 10 and 10' meet at P-P' and have a thickness of T. The solidified shells having a thickness of tl are pressed against the lower rolls 3 and 3', and
The metal ribbon has a thickness of t2. During this pressurization, the approximate trapezoid PP'Q'Q whose upper side is t and whose lower side is t2 is rolled to a thickness of t2. Because of this rolling, between PQ and P'
Between Q', a difference occurs between the running speed of the rolled material PP'Q'Q and the running speed of the endless belt. In other words, similar to the backward movement phenomenon in normal rolling, behind the neutral point (above in Figure 2),
The running speed of the rolled material PP'Q"Q becomes slower than the running speed of the endless belt. Due to this backward movement phenomenon, the solidified shell 10 above PP' is pushed back upwards in FIG. 2 with respect to the endless belt 1. If the solidified shell 10 and the endless belt l are non-uniformly fixed, the solidified shell 10 will buckle and deform due to this push back, causing a gap between the solidified shell 10 and the endless belt 1, for example, as shown in FIG. However, when the air gap G is formed,
The solidification rate decreases, resulting in a solidified shell with non-uniform thickness, which causes surface cracks in the metal ribbon 11.

As already mentioned, in the present invention, minute vibrations are applied to the endless belt forming the mold wall. This minute vibration causes
The solidified shell 10 and the endless belt 1 do not adhere unevenly, and the solidified shell 10 slides smoothly on the endless belt 1 to prevent buckling, thereby preventing the occurrence of surface cracks, etc. of the metal ribbon 11. can be prevented.

In addition, in Fig. 2, if the pressing force between the lower rolls 3 and 3' is small,
Disadvantageously, the solidified shells 10 and 10' are not sufficiently crimped and break-out occurs.

Therefore, the lower rolls 3 and 3' press the solidified shells with a force sufficient to withstand the static pressure of the unsolidified molten metal 6 and press the solidified shells 10 and 10' together, and this force causes the solidified shells to be rolled. It turns out.

[Example 1] It has a structure as shown in Figure 1, and the belt thickness is 1mm.

Belt width 800i++m, diameter 300cm roll 3.3
Using a casting machine equipped with a cooling pad of 800mm long, molten steel of 5US304 stainless steel composition at a temperature of 1490°C was poured into a mold with a wall thickness of 2mm and a plate width of 70mm.
A metal ribbon of 0m+a was manufactured.

As shown in Fig. 1, this casting device has a belt vibration device 1.
2.12'', but when it was initially cast without using a vibrating device, many horizontal cracks occurred almost perpendicular to the casting direction.In response to this, the vibrating device was operated at 12°12'. When the belt was subjected to vibrations of about 100 Hz, slabs without surface defects such as cracks were obtained.

[Example 2] As shown in Fig. 3, the minimum gap between belts 1 and 1' is formed by the cooling pads on both sides, the belt thickness is 1 mm, and the curvature near the minimum gap of the cooling pad is Using a casting device with a radius of 600 mm+, pour molten steel at a temperature of 1490°C with a stainless steel composition of SO8304,
A metal ribbon with a wall thickness of 2 mm and a plate width of 700 mm was manufactured.

As shown in Fig. 3, this casting device has a belt vibrating device 1.
2.12', but when it was initially cast without using a vibration device, many transverse cracks occurred almost perpendicular to the casting direction. In response to this, the vibration devices 12 and 12' were operated to apply vibrations of about 1 () OHz to the belt, and a slab without surface defects such as cracks was obtained.

[Effects of the Invention] By using the continuous metal ribbon casting apparatus of the present invention, thin metal strips can be manufactured with high productivity. The metal ribbon obtained by the method of the present invention is lightly rolled and uniform. Since the metal strip is cooled to a temperature of 100%, the structure is dense and there are few surface defects such as cracks, making it a metal strip suitable for the next rolling process.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing the entire example of the device of the present invention, FIG. 2 is a schematic diagram illustrating the combination of solidified shells, FIG. 3 is a diagram showing another example of the device of the present invention, and FIG. FIG. 5 is a diagram showing a twin-drum type continuous metal sheet casting machine. FIG. 5 is a view showing a known twin-drum type continuous metal sheet casting machine. 1.1': Endless belt, 2.2': Upper roll,
3.3': Lower roll, 4.4': Cooling pad,
5.5': Endless belt running direction, 6: Molten metal, 7.
7': Side weir, 8.8': Tension roll,
9: Metal thin plate, 10.10': Solidified shell, 11
: Metal thin plate. 12.12': Vibration device, 18 (18-1, 18
-2): Rotating drum, 19 (19-1, 19-2,
19-3, 19'-1, 19'-2゜19'-3):
Pulley 20 = cooling device. Patent applicant Nippon Steel Corporation

Claims (3)

[Claims] (1) The feature is that it has endless belts 1 and 1' that run while forming the long side walls of the upper wide mold, and is equipped with an excitation device that gives minute vibrations to the endless belt 1 (1'). Continuous metal ribbon casting equipment (2) The vibration device is a vibration device in which the cooling pad 4 (4') that cools the endless belt 1 (1') from the back side gives pulsations to the cooling water supplied to the endless belt 1 (1'); Metal ribbon continuous casting apparatus according to claim (1) (3) The vibration device is a vibration device that applies minute vibrations to the belt 1 (1') using an electromagnet placed near the cooling pad 4 (4') that cools the endless belt 1 (1') from the back side. , a metal ribbon continuous casting apparatus according to claim (1).