JPS5945059A - Method and device for charging molten metal in producing quickly cooled light-gage metallic strip - Google Patents

Abstract

PURPOSE:To control exactly the flow rate of molten metal and to obtain a quickly cooled light-gate metallic strip having good accuracy in width by allowing the molten metal to standby at the melt level lower than the height of a gate for adjusting the rate of charging and raising the melt level in the stage of starting the charging. CONSTITUTION:A gate 2 for adjusting the rate of charging is projected on the inside of a charging nozzle 1 along the opening edge thereof. Molten metal is allowed to standby at the melt level (a) slightly lower than the height of the gate 2 before starting charging the molten metal. The melt level is raised up to a charging level (b) in the stage of starting the charging so as to flow over the gate 2, and the molten metal is thus charged. The control of the flow rate of the molten metal is made easy by the above-mentioned method irrespectively of the length of runners, whereby the generation of the non-stationary flow in the stage of starting and stopping the charging is reduced and the quickly cooled light-gage metallic strip having good accuracy is obtd.

Description

[Detailed Description of the Invention] The present invention relates to a metal molten metal method and a metal pouring machine that are useful when applied to the production of quenched metal ribbons, and in particular to a metal pouring machine that can be used under accurate flow control even when a large amount of metal is poured. This paper attempts to propose a pouring method capable of supplying molten metal, along with a suitable pouring machine for carrying out the method.

In recent years, a manufacturing method has been developed in which a molten metal is directly obtained from the molten metal by continuously supplying the molten metal onto a cooling body whose cooling surface is updated and moving at high speed, and rapidly solidifying the molten metal.

In this method of manufacturing thin metal strips, a pouring machine is required to hold the molten metal and supply it to the cooling body. Since accuracy depends on the flow rate of the molten metal, it is required to be able to delicately control the flow rate and maintain appropriate humidity.

By the way, recently, the industrialization of the above-mentioned quenched metal ribbon is being planned, but conventionally, a pouring machine has a capacity of several tens of kg at most.
There are only small-capacity pouring machines, and in order to implement it in an industrial scale, a large-capacity pouring machine of at least several tons is essential. In a conventional small-scale pouring machine, the flow rate control and temperature control described above could be performed relatively easily, but when the capacity became large, it was extremely difficult to implement them.

In other words, in the conventional pouring method, the molten metal is held by surface tension at the nozzle opening before pouring, and when pouring starts, the gas pressure inside the nozzle is controlled and the pouring spout is controlled by a stopper. The flow rate was controlled by opening and closing operations, but with this method of applying molten metal pressure to the tip of the pouring nozzle, the amount of molten metal that can be processed is up to several tens of kilograms, and as the amount processed exceeds that amount, the molten metal pressure increases. Therefore, it was impossible to accurately control the flow rate of molten metal by adjusting the gas pressure.

As a solution to the above problem, a bottom pouring method using a pressurized push-up method was proposed in Japanese Patent Application Laid-Open No. 56-165542. However, such a bottom pouring method has problems in workability and maintenance, and is also disadvantageous in that it generates relatively large vibrations due to the short distance from the floor surface, and is particularly disadvantageous compared to the twin roll method. However, there was a problem that it was difficult to access the roll kissing part of the pouring nozzle, and there was a high risk of being covered with molten metal, making it unusable.

In this respect, top-pouring teapot-type pouring machines do not have the above-mentioned problems. However, especially when applied to the twin roll method, the following problems remain.

(1) In order to arrange the tip of the pouring nozzle in the center of the cooling roll, it is necessary to have a good runner, but if the runner is long, the temperature of the molten metal will drop significantly.

(2) When starting and stopping molten metal pouring, it is necessary to reduce the occurrence of unsteady flow as much as possible, but unsteady flow must be reduced when the runner is long and especially in a large-capacity pourer. It becomes difficult to control the flow rate.

The present invention advantageously solves the above-mentioned problems, and is suitable for use in a method for pouring molten metal that can accurately control the flow rate under appropriate temperature control even in large volumes, and for its implementation. We also propose a hot water pouring machine.

That is, the present invention provides a method for producing a rapidly cooled metal ribbon, in which molten metal is continuously poured from a pouring nozzle onto a cooling body whose cooling surface is updated and moved at high speed, and is rapidly solidified into a metal ribbon. , for the molten metal poured from the pouring nozzle, prior to the start of pouring, the molten metal level is lower than the weir height of the pouring amount adjustment weir that is protruded inward along the opening edge of the pouring nozzle. This is a method for pouring molten metal in the production of rapidly cooled metal ribbon, characterized by keeping the metal on standby at a temperature of 100 mL, starting pouring, and raising the level of the molten metal so that it exceeds the regulating weir.

The present invention also includes a sump for storing molten metal, and an inclined runner that protrudes from the bottom of the side wall of the sump and has a pouring port provided at its tip located above the level of the molten metal in the sump. In a teapot type molten metal pouring machine that continuously pours the molten metal onto a cooling body whose cooling surface is updated and moved at high speed, a long horizontal runner is connected to the inclined runner. This horizontal runner is provided with a pouring nozzle whose upper part projects into the runner as a pouring amount adjustment weir and a heating means extending over the entire runner, and a heating means extending over the entire runner. The quenched metal ribbon is characterized in that it is equipped with a molten metal receiving port, a circulation heating device for the stored molten metal, and a feeding means for pushing up the molten metal contained in the sump into a horizontal runner. This is a pouring machine for pouring molten metal for manufacturing.

In the pouring machine of the present invention, an electromagnetic pump provided in the inclined runner is suitable as the feeding means for pushing up the molten metal contained in the sump into the horizontal runner.

The pouring method of the present invention will be specifically explained below.

Now, in this invention, the molten metal is allowed to fall freely from the pouring nozzle and poured onto the cooling body.
Instead of simply dropping the metal through the pouring nozzle 1 that opens downward as in the conventional example shown in the figure, the metal is protruded inward along the opening edge of the pouring nozzle 1 as shown in Figure 2. The molten metal is allowed to climb over the pouring amount adjustment weir 2 and fall.

That is, before starting pouring of molten metal, the molten metal is kept on standby at a level that is slightly lower than the weir height of the pouring amount adjustment weir as shown in a in Figure 2, and when pouring starts, the molten metal level is The molten metal is poured by raising the molten metal level to the pouring level shown by b in the figure and making the molten metal go over the regulating weir.

By always keeping the molten metal on standby near the pouring nozzle, it becomes easy to control the flow rate of the molten metal regardless of the length of the runner, and the transition to a steady flow occurs quickly. The occurrence of unsteady flow, which was a concern when starting and stopping pouring, can be significantly reduced. In this regard, in the conventional example shown in Figure 1, the molten steel was kept waiting in the inclined runner before pouring, so if the horizontal runner was short, the horizontal runner became longer, although not by much. In some cases, it took time for the molten metal flow to stabilize.

Next, a preferred embodiment of the pouring machine of the present invention will be described.

FIG. 3 shows a longitudinal section of a preferred embodiment of the present invention applied to a twin-roll type quenched ribbon manufacturing apparatus, and FIG. 4 shows a plane taken along line A--A. In the figure, number 3 is the hot water reservoir of the pouring machine, 4 is the inclined runner that protrudes obliquely upward from the bottom of the side wall, and 5 is
is a horizontal runner that communicates with the inclined runner 4 and extends horizontally.

Now, the hot water reservoir part 3 has a hot water receiving port 6 on its side, and when receiving hot water from the hot water receiving port 6, as shown in FIG. By receiving the molten metal through the tap nozzle 9, oxidation of the molten metal can be prevented. Further, the sump 3 has a heating device 10 which can be composed of a channel heater and which appropriately circulates and heats the molten metal received therein, so that the molten metal can be maintained at a desired constant temperature.

In this example, an electromagnetic pump 11 is installed in the inclined runner 4 as a feeding means for pushing up the molten metal contained in the sump 3 to the horizontal runner 5.
is installed so that the molten metal can be fed to the horizontal runner 5 under accurate flow control.

Further, in the horizontal runner 5, as a heating means for the entire runner 5, as shown in the cross section of the runner 5 in FIG. It is surrounded by a dielectric heating coil 14, and the graphite 13 is heated by the coil 14 as necessary to compensate for the temperature drop when the molten metal passes through the long horizontal runner 5.

Further, at the tip of the horizontal runner 5, as shown in detail in FIG. 7, a molten metal volume regulating weir 2 of a constant height is installed inside along the opening edge of the pouring nozzle 1 that opens downward. Prevents leakage unless the molten metal level exceeds a certain value. As shown in the same figure and Figure 2 above, before pouring the molten metal, it is kept on standby at level a, which is lower than the weir height. The molten metal level is raised to pouring level b, which exceeds the molten metal level.

As described above, in the pouring machine according to the present invention, the molten metal can be held in the vicinity of the pouring nozzle 1, so that the time during which unsteady flow occurs when pouring starts and stops can be significantly shortened.

Furthermore, in this pouring machine, as shown in FIG. The hot water nozzle 1 can be easily moved toward or away from the roll kissing part in the center area of the roll.

For reference, FIG. 8 shows a case in which the pouring machine according to the present invention is applied to the production of rapidly solidified metal ribbon by a single roll method.

Examples of the present invention will be described below.

For the experiment, a molten metal pool with a capacity of about 5 tons was used, and a channel heater was used as a circulating heating device for the molten metal in the trough.
A pouring machine equipped with an electromagnetic pump was used as a means for feeding the molten metal, and the procedure was as follows.

First, the pouring machine is moved to the specified position using a trolley, and then
The interior of the water reservoir and runner was filled with Ar gas to maintain a non-oxidizing atmosphere, and the horizontal runner was previously heated with an induction heating coil. The molten steel at 1580℃ is then passed through the ladle through the inlet, which is isolated from the outside air by a seal duct.
A ton was charged into the sump. Continuing to operate the electromagnetic pump, the molten steel in the pool is pushed up into the horizontal runner, and the level of the molten metal reaches level 3.
It was kept on standby at 0 mm. The height of the pouring amount control weir is 35m.
The molten copper in the pouring machine was maintained at a constant temperature of 1550°C by a channel heater and a dielectric heating coil. Then, the electromagnetic pump was operated again to raise the molten steel surface to a height of 35 mm or more at the pouring amount control weir, thereby continuously pouring the molten steel toward the roll kiss portion of the twin rolls rotating at high speed.

In this way, a quenched ribbon having a constant thickness of 0.2 mm and a constant width of 100 mm and good surface properties was obtained.

From the shape of the obtained quenched ribbon, we investigated the occurrence of unsteady flow at the start and stop of pouring, and found that the total length for both was approximately 5 m, and that for the conventional method it was approximately 1 m.
Compared to the previous case of about 5 m, the period during which unsteady flow occurs has been significantly shortened.

In the above embodiments, an electromagnetic pump is used as a flow rate control means for feeding molten steel from the molten metal pool to the horizontal runner, but in other cases, the flow rate can also be controlled by adjusting the atmospheric gas pressure in the molten metal pool. You can also do that.

As mentioned above, according to the pouring method of the present invention, the molten metal can always be kept waiting in the vicinity of the pouring nozzle, so even if the horizontal runner is long, the molten metal can start pouring and The period during which unsteady flow occurs during stoppage can be significantly reduced, and according to the pouring machine of the present invention, accurate flow control can be achieved under appropriate temperature control even when the molten metal capacity is increased. In this way, it is possible to manufacture rapidly cooled metal grooves with high accuracy in terms of thickness and plate width while greatly reducing defective parts caused by unsteady flow, which is advantageous.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view of a conventional pouring nozzle, FIG. 2 is a cross-sectional view of a pouring nozzle according to the present invention, FIG. 3 is a cross-sectional view of essential parts of a pouring machine according to the present invention, and FIG. The A-A arrow view of Figure 5 and Figure 6 are B-B and C of Figure 4, respectively.
-C arrow view, FIG. 7 is a sectional view of the pouring nozzle, and FIG. 8 is a front view of the pouring machine according to the present invention applied to a single roll method. 1...Pouring nozzle, 2...Pouring amount adjustment weir, 3...
Hot water pool part, 4... Inclined runner, 5... Horizontal runner, 6.
...Inlet, 7...Seal duct, 8...Ladle, 9
...Tap water nozzle, 10...Circulation heating device, 11...
- Electromagnetic pump, 12... Fireproof wall, 13... Graphite, 14... Dielectric heating coil, 15... Elevator,
16, 17... Trolley.

Claims (3)

[Claims] 1. In the method of manufacturing quenched metal ribbon, in which molten metal is continuously poured from the pouring nozzle onto a cooling body whose cooling surface is updated and moves at high speed, the metal is rapidly solidified into a metal ribbon. Prior to the start of pouring, the molten metal to be poured is made to stand by at a level lower than the weir height of the pouring amount adjustment weir that protrudes inward along the opening edge of the pouring nozzle. . A method for pouring molten metal in the production of rapidly cooled metal ribbon, characterized by starting pouring and raising the level of the molten metal so that it exceeds the regulating weir. 2. The molten metal is provided with a sump for storing molten metal, and an inclined runner that protrudes from the bottom of the side wall of the sump and has a spout provided at its tip located above the level of the molten metal in the sump,
In teapot-shaped molten metal pouring where the molten metal is continuously poured onto a cooling body whose cooling surface is updated and moved at high speed, a long horizontal runner is extended in communication with the inclined runner. This horizontal runner is provided with a pouring nozzle whose upper part serves as a pouring amount adjustment weir and which protrudes into the runner, and a heating means extending over the entire runner, and a molten metal in the pool. Metal for rapidly cooling metal ribbon production, characterized in that it is equipped with a molten metal receiving port and a circulation heating device for the molten metal contained therein, and further provided with a feeding means for pushing up the molten metal contained in the sump into a horizontal runner. Molten metal pouring machine. 3. The hot water pouring machine according to claim 2, wherein the feeding means is an electromagnetic pump installed in the inclined runner.