JP4257646B2 - Method and apparatus for manufacturing magnesium strip - Google Patents

Description

  The present invention relates to a continuous casting and rolling of a magnesium alloy, and more particularly to a manufacturing method and a manufacturing apparatus for manufacturing a high-quality magnesium strip continuously and stably.

As a method for continuously producing a magnesium strip, a method is known in which a molten magnesium alloy obtained in a melting furnace is continuously cast and rolled with a rolling roll. In order to produce a continuously stable magnesium alloy sheet by continuous casting and rolling, the molten metal level in the tundish is temporarily controlled by supplying the magnesium alloy molten metal from the melting furnace to the rolling roll. It is necessary to always keep the level within a certain range. Conventionally, the amount of hot water supplied to the tundish from the melting furnace by controlling the tilt angle of the melting furnace by measuring the level of the hot water in the tundish with a sensor and controlling the tilt angle of the melting furnace with the electrical signal from the sensor. There is known a manufacturing method for controlling the hot water level of a tundish by adjusting the temperature (for example, see Patent Document 1).
Japanese Patent Laid-Open No. 11-47892 (second page, FIG. 1)

  However, in the former prior art, when the molten metal is supplied into the tundish from the tilted melting furnace, the molten metal level in the tundish fluctuates, and the signal from the sensor that measures the molten metal level fluctuates. It was difficult to measure the hot water level. In addition, with the means for controlling the tilt angle of the melting furnace, it is difficult to control the amount of hot water supplied in a very small amount. As a result, it is difficult to control the molten metal surface level within a certain range, and the supply pressure of the molten metal to the rolling roll fluctuates, making it difficult to produce a continuous and stable high quality strip. It was.

  The present invention has been made to solve the conventional problems as described above, and the level of the molten metal in the tundish is maintained at a set level by an easy means, and the molten metal to the rolling roll is maintained. An object of the present invention is to provide a manufacturing method and a manufacturing apparatus for manufacturing a magnesium strip having a high quality continuously and stably by making the supply pressure constant.

  According to a first aspect of the present invention, there is provided a method for producing a magnesium strip, wherein a magnesium alloy melt obtained in a melting furnace is supplied to a tundish, and the magnesium alloy melt supplied from the tundish is continuously cast and rolled by a rolling roll. In the method for manufacturing a magnesium strip plate, the amount of molten magnesium alloy supplied from the melting furnace to the tundish is larger than the amount of molten magnesium alloy supplied from the tundish to the rolling roll, and the tundish is excessive. By returning the molten metal to the melting furnace, the magnesium alloy molten metal is circulated between the melting furnace and the tundish while producing a magnesium strip with the rolling roll.

  The method for producing a magnesium strip according to a second aspect of the present invention is the method for manufacturing a magnesium strip according to the first aspect, wherein the molten magnesium alloy is in the melting furnace and the tundish, and the molten magnesium alloy is circulated between the melting furnace and the tundish. In an inert gas atmosphere.

  Furthermore, in the first or second invention, the method for manufacturing a magnesium strip according to the third aspect of the present invention supplies a magnesium alloy ingot of an equivalent amount to the melting furnace based on the mass of the manufactured magnesium strip. It is characterized by that.

  Furthermore, the magnesium strip production apparatus of the fourth invention comprises a melting furnace for melting the magnesium alloy, and a rolling roll for continuously producing and rolling the magnesium alloy molten metal obtained in the melting furnace to produce the magnesium strip. In the magnesium strip manufacturing apparatus, a magnesium alloy molten metal obtained in the melting furnace is accommodated and supplied to the rolling roll, and a molten magnesium alloy is discharged from the supplying section to the rolling roll together with the molten metal. A tundish having a molten metal discharge section, a supply path for supplying molten magnesium alloy from the melting furnace to the tundish, and a return path for returning the molten magnesium alloy discharged from the tundish to the melting furnace. The supply path is necessary to produce a magnesium alloy strip with the rolling roll. Wherein the magnesium alloy melt volume than can be supplied molten magnesium alloy of excessive in the tundish from the melting furnace molten metal Utsuriyu device is provided. Examples of the molten metal transfer device include a molten metal pump and a conventional tilting furnace.

  Furthermore, in the fourth invention, the manufacturing apparatus for a magnesium strip plate according to the fifth invention has a system including the melting furnace, the tundish, a supply path and a return path connecting them, and a magnesium alloy in the system. An inert gas supply means for placing the molten metal in an inert gas atmosphere is provided.

  Furthermore, the magnesium strip manufacturing apparatus of the sixth invention is characterized in that, in the fourth or fifth invention, a heater part for preventing solidification of the molten metal moving in the supply path and the return path is provided.

  Furthermore, the manufacturing apparatus of the magnesium strip plate of 7th invention is based on the mass of the magnesium strip plate manufactured in any one of the 4th-6th invention. The ingot supply device to supply and the melting furnace are provided with an ingot insertion port through which magnesium alloy metal can be supplied.

  Furthermore, the magnesium strip manufacturing apparatus according to the eighth invention is characterized in that, in any of the fourth to seventh inventions, the tundish is provided with a molten metal discharge section that is movable in the height direction.

  Furthermore, the magnesium strip manufacturing apparatus of the ninth invention is characterized in that, in any of the fourth to eighth inventions, a movable weir movable in the height direction is provided in the molten metal discharge part.

  Furthermore, the magnesium strip manufacturing apparatus of the tenth invention is characterized in that, in any of the fourth to seventh inventions, the molten metal discharge part is composed of an overflow discharge port.

According to the present invention, the magnesium alloy ingot supplied to the melting furnace is melted in the melting furnace, and the magnesium alloy molten metal has an amount larger than the amount of molten metal required for manufacturing the magnesium strip by the molten metal transfer device. It is supplied to the tundish from the supply path, and the required amount is sent to the rolling roll from the supply unit and continuously cast and rolled to produce a magnesium strip.
On the other hand, the excess molten metal in the tundish is returned to the melting furnace through the return path from the molten metal discharge part. The surplus magnesium alloy molten metal is constantly circulated with the melting furnace, the molten metal transfer device, the supply path, the tundish, the return path, and the melting furnace. As a result, the surface level of the molten magnesium alloy in the tundish is kept constant at the height of the molten metal discharge part, the supply pressure of the molten magnesium alloy to the rolling roll is constant, and the stable and high quality. A magnesium strip is produced.

Moreover, by making the molten metal discharge part movable in the height direction, the level of the molten metal in the tundish can be made variable, and the supply pressure of the molten metal to the rolling roll can be adjusted.
Furthermore, by providing a movable weir movable in the height direction in the molten metal discharge section, the molten metal level in the tundish can be varied, and the supply pressure of the molten metal to the rolling roll can be adjusted. The movable weir may be provided in the fixed molten metal discharge part, but may be provided in the movable molten metal discharge part. In this case, the rough molten metal surface level is set by the movable molten metal discharge part, The hot water level can also be set with a movable weir.

  Furthermore, the molten metal discharge part is used as an overflow discharge port, and the molten metal level in the tundish can be kept constant by allowing excess molten metal to overflow.

  As described above, according to the present invention, the surface level of the molten metal in the tundish can be stably maintained at a set level without using a special molten metal transfer means. The supply pressure can be made constant, and a stable and high quality magnesium strip can be manufactured.

Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings.
FIG. 1 shows one embodiment of the magnesium strip manufacturing apparatus of the present invention, and FIG. 2 shows the structure of a movable weir installed in the molten metal discharge portion according to one embodiment of the present invention.

The apparatus for producing a magnesium strip of the present invention includes a pair of rolling rolls 6 for producing a magnesium strip 16 by continuously casting and rolling a magnesium alloy melt M, and obtaining a magnesium alloy melt M used above by melting the magnesium alloy. A melting furnace 1 and a tundish 2 that temporarily stores molten magnesium M obtained in the melting furnace 1 and supplies the molten magnesium M to the rolling roll 6 are provided.
The melting furnace 1 is sealed with a lid 1a except for a part, and an ingot insertion port 10 for supplying a magnesium alloy ingot 11 as a raw material is formed in the lid 1a. With this insertion port 10, it becomes possible to supply the magnesium alloy ingot 11 into the melting furnace 1 without opening the melting furnace 1. The magnesium alloy ingot 11 is attached to the ingot supply means 20, and is configured so that the ingot can be supplied into the melting furnace 1 at a desired speed and quantity by the operation of the ingot supply means 20.
Further, the melting furnace 1 is provided with a molten metal transfer device 3 for transferring the magnesium alloy molten metal M obtained by melting the ingot in the furnace. The molten metal transfer device 3 can be constituted by an appropriate pump or the like.

A supply pipe 4 that is a supply path of the present invention is connected between the molten metal transfer device 3 and the tundish 2. Further, the tundish 2 is provided with a supply unit 5 for supplying the molten metal to the rolling roll 6 and a discharge port 7 (molten discharge unit) for discharging the molten metal in the tundish 2 to overflow. A return pipe 8 serving as a return path of the present invention is connected between the melting furnace 1 and the melting furnace 1. Around the supply pipe 4 and the return pipe 8, a heater portion 12 for preventing solidification of the magnesium alloy molten metal moving in the pipe is disposed at an appropriate position. The heater unit 12 is desirably temperature-controllable.
Further, as shown in FIG. 2, a movable weir 9 that can move up and down is disposed at the discharge port 7, and the lower limit height of the discharge port 7 can be adjusted. In the example shown in FIG. 2, the opening of the discharge port 7 is circular and the opening of the movable weir 9 is rectangular. However, this does not specify the shape, and any shape may be used. .

  Further, in order to create an inert gas atmosphere in the system including the melting furnace 1 and the tundish 2 and the supply pipe 4 and the return pipe 8 connecting them, these systems have a sealed structure, and the melting furnace 1 and the tundish 2 are connected to each other. An inert gas supply unit 13 is provided. The inert gas supply unit 13 is connected to an inert gas supply pipe 14 and an inert gas supply device (not shown). The inert gas supply means of the present invention is constituted by the inert gas supply unit 13, the inert gas supply pipe 14, and the inert gas supply device (not shown). By sealing the inert gas supplied from the inert gas supply device into the sealed space through the inert gas supply pipe 14 and the inert gas supply unit 13, the molten magnesium alloy in the system is made atmospheric and oxidized. To prevent it.

Next, the manufacturing method using the manufacturing apparatus of the magnesium strip | belt-shaped board of this invention is demonstrated.
The magnesium alloy ingot 11 supplied from the ingot insertion port 10 provided in the melting furnace 1 is melted in the melting furnace 1 to become a magnesium alloy molten metal M, and supplied from the supply pipe 4 to the tundish 2 by the molten metal transfer device 3. Is done. At this time, an excessive amount of molten metal necessary for manufacturing the magnesium strip 16 is supplied from the molten metal transfer device 3 by the rolling roll 6. In the tundish 2, the required amount is supplied from the supply unit 5 to the rolling roll 6 and continuously cast and rolled to produce the magnesium strip 16. On the other hand, the excess magnesium alloy melt M in the tundish 2 overflows from the discharge port 7 and returns to the melting furnace 1 through the return pipe 8. The excess magnesium alloy molten metal M thus circulated constantly with the melting furnace 1, the molten metal transfer device 3, the supply pipe 4, the tundish 2, the return pipe 8, and the melting furnace 1.

  The molten metal level of the magnesium alloy molten metal M in the tundish 2 is set by the height of the discharge port 7, but in the case of further comprising the movable weir 9, it is set by the adjusted height of the movable weir 9 and kept constant. Is done. Thereby, the supply pressure of the magnesium alloy molten metal M to the rolling roll 6 becomes constant, and a continuously stable high quality magnesium strip 16 is manufactured. In the molten metal transfer device 3, the amount of hot water required for the rolling roll and the amount of hot water to be returned can be determined in advance, and the sum of these can be operated as the amount of transferred water.

  Further, the production amount of the magnesium strip plate 16 produced by the rolling roll 6 is detected by a strip production sensor 21 or the like, and the ingot amount supplied by the ingot supply means 20 is set from the ingot required amount obtained by the detected amount. Thus, it is possible to control the production amount and the supply amount to be equal. In the strip plate production amount sensor 21, for example, the thickness of the magnesium strip plate 16 is grasped. Therefore, the production amount may be calculated from the production length to determine the ingot supply amount.

It is explanatory drawing of one Embodiment of the manufacturing apparatus of this invention. It is explanatory drawing of the movable weir similarly installed in the molten metal discharge port.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Melting furnace 2 Tundish 3 Molten metal transfer apparatus 4 Supply path 6 Rolling roll 7 Molten metal discharge part 8 Return path 9 Movable weir 10 Ingot insertion port 12 Heater part 13 Inert gas supply part 16 Magnesium strip plate 20 Ingot supply means 21 Strip shape Plate manufacturing quantity sensor M Magnesium alloy molten metal

Claims (10)

In the method for producing a magnesium strip, the molten magnesium alloy obtained in the melting furnace is supplied to a tundish, and the magnesium alloy melt supplied from the tundish is continuously cast and rolled with a rolling roll to produce a magnesium strip. The amount of magnesium alloy molten metal supplied from the furnace to the tundish is larger than the amount of magnesium alloy molten metal supplied from the tundish to the rolling roll, and returning the molten metal surplus in the tundish to the melting furnace, A method for producing a magnesium strip, wherein the magnesium alloy melt is circulated between the melting furnace and the tundish while producing the magnesium strip with a rolling roll. The magnesium strip according to claim 1, wherein the molten magnesium alloy in the melting furnace and the tundish and the molten magnesium alloy circulated between the melting furnace and the tundish are placed in an inert gas atmosphere. A manufacturing method of a board. 3. The method for producing a magnesium strip according to claim 1, wherein an equivalent amount of magnesium alloy metal is supplied to the melting furnace based on the mass of the produced magnesium strip. 4. Magnesium obtained in the melting furnace in a magnesium strip production apparatus comprising a melting furnace for melting a magnesium alloy and a rolling roll for continuously casting and rolling a molten magnesium alloy obtained in the melting furnace to produce a magnesium strip A tundish having a supply portion for containing molten alloy and supplying the rolling roll to the rolling roll, and a molten metal discharge portion for discharging a part of the magnesium alloy molten metal from the supply portion to the rolling roll; A supply path for supplying the magnesium alloy melt to the tundish; and a return path for returning the magnesium alloy melt discharged from the tundish to the melting furnace. Magnesium alloy molten metal in excess of the amount of magnesium alloy molten metal required to produce Apparatus for manufacturing a magnesium strip-shaped plate, wherein the melting furnace from a supply capable melt Utsuriyu device to the tundish is provided. A system including the melting furnace, the tundish, a supply path connecting them and a return path is made in a sealed structure, and an inert gas supply means for placing the molten magnesium alloy in the system in an inert gas atmosphere is provided. The manufacturing apparatus of the magnesium strip | belt board of Claim 4 characterized by these. The apparatus for producing a magnesium strip according to claim 4 or 5, further comprising a heater portion for preventing solidification of the molten metal moving through the supply path and the return path. Based on the mass of the produced magnesium strip, an ingot supply device that supplies a magnesium alloy ingot of the same amount to the melting furnace and an ingot insertion port that can supply the magnesium alloy ingot to the melting furnace are provided. The manufacturing apparatus of the magnesium strip | belt-shaped board in any one of Claims 4-6 characterized by the above-mentioned. The manufacturing apparatus of the magnesium strip | belt-shaped board in any one of Claims 4-7 provided with the molten metal discharge | emission part which can move to the said tundish in a height direction. The apparatus for producing a magnesium strip according to any one of claims 4 to 8, wherein a movable weir movable in the height direction is provided in the molten metal discharge portion. The apparatus for producing a magnesium strip according to any one of claims 4 to 7, wherein the molten metal discharge portion is composed of an overflow discharge port.

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