KR101082946B1 - Method for producing an ingot using an electric furnace - Google Patents

Abstract

The present invention relates to a method for producing an alloy ingot, and in particular, to produce an alloy plating ingot of uniform quality by using an electric induction in an economical manner and to suppress the reaction explosion of flammable magnesium with a minimum of inert gas stability and Provided is a method of manufacturing an ingot for plating an alloy using an improved electric induction to improve a real error rate.

In the manufacturing method of the alloy plating ingot of the present invention for this purpose, the zinc in the solid state is introduced into the electric induction, and the zinc is heated by heating the electric induction under low power conditions of 50KW or more, 150KW or less and 100Hz or more, 150Hz or less. Melting to prepare a zinc base molten metal; After grinding the magnesium to make the particle size of the magnesium smaller than the particle size of the zinc in the solid state, when the temperature of the molten metal is 650 ℃ or more, the magnesium is melted through the inlet pipe immersed in the molten metal is installed at the top of the electric induction Putting in; And injecting an inert gas into the inlet tube to maintain the inside of the inlet tube as an inert gas, thereby maintaining a temperature of the molten metal at 650 ° C. or more and 700 ° C. or less to produce a molten ingot. It is done.

Ingot, electric furnace, zinc, aluminum, magnesium

Description

Method for producing alloy ingot using electric induction {Method for producing an ingot using an electric furnace}

The present invention relates to a method for producing an alloy ingot, and in particular, to produce an alloy plating ingot of uniform quality by using an electric induction in an economical manner and to suppress the reaction explosion of flammable magnesium with a minimum of inert gas stability and It relates to a method for producing alloy ingot using the improved electric induction to improve the error rate.

In general, a process of manufacturing an alloy ingot is a burner-type crucible, which is performed by dissolving zinc (Zn), aluminum (Al), or silicon (Si) in a melting furnace such as a large-capacity reflection furnace. .

Table 1 below shows the melting point, boiling point, and specific gravity of zinc, aluminum, and magnesium. As shown in Table 1, Zn has a relatively low melting point and boiling point, so it can boil even at low temperatures, and Al and Zn have a large difference in specific gravity. In the furnace melting, the molten metal may be separated into two layers, thereby making it difficult to manufacture an alloy ingot having a uniform composition.

TABLE 1

division Melting point (캜) Boiling Point (℃) importance Zn 419.6 907 7.14 Al 660 2060 2.7 Mg 650 1100 1.74

Therefore, in order to stably maintain the molten state of Zn, it is necessary to properly control the temperature of the melting furnace to maintain the molten metal within an appropriate range, but the conventional melting furnace is insufficient to precisely control and maintain the temperature of the melting furnace. In addition, in order to uniformly melt Zn and Al, it is necessary to stir with vigorous stirring force, but in the case of a large-scale reflection furnace, it was difficult to actively stir Zn and Al, and in the case of burner-type crucible, per charge Due to the small amount of melt and the induction heating type, there is a problem that the cost increases due to the high power ratio.

In addition, in the case of preparing a Zn-Al-Mg alloy ingot by dissolving magnesium, as shown in Scheme 1 below, magnesium is easily combined with oxygen and oxidized combustion.

[Scheme 1] 2Mg + O _2- > 2MgO

Accordingly, in the magnesium dissolution process, there is a risk of explosion due to oxidative combustion, so that the stability is low, and a problem in which a mistake rate for magnesium input is lowered due to oxidation of magnesium also occurs.

In particular, as shown in Table 1, since magnesium has a lower specific gravity than zinc, when magnesium is melted in the zinc base (Zn base), magnesium rises to the surface of the molten metal, which causes magnesium to form oxygen or water vapor. The problem of explosion in reaction can be increased.

In addition, the ignition temperature of magnesium is 490 ~ 550 ℃, the melting point of magnesium is less than 650 ℃ requires considerable care when operating the furnace, but the existing melting furnace is difficult to precisely control and maintain the temperature of the molten metal Was.

The present invention has been made to solve all the problems of the prior art as described above, by producing an ingot for the alloy plating of uniform quality in an economical manner by active stirring and maintaining the cleanliness of the electric induction in an economical manner and minimal inert gas It is an object of the present invention to provide an ingot manufacturing method for alloy plating using an improved electric induction to suppress reaction explosion of furnace combustible magnesium to improve stability and real error rate.

Ingot manufacturing method for alloy plating of the present invention for solving the above problems is to put the zinc in the solid state in the electric induction, heating the electric induction under 50KW or more, 150KW or less low power and 100Hz or more, 150Hz or less low frequency conditions Melting the zinc to prepare a zinc base molten metal;
After grinding the magnesium to make the particle size of the magnesium smaller than the particle size of the zinc in the solid state, when the temperature of the molten metal is 650 ℃ or more, the magnesium is melted through the inlet pipe immersed in the molten metal is installed at the top of the electric induction Putting in; And
Preparing an ingot in a molten state by injecting an inert gas into the inlet tube and maintaining the inside of the inlet tube as an inert gas;
Characterized in that comprises a.

delete

In addition, argon gas is suitable as the inert gas, and argon gas is particularly preferably injected into the input pipe at 2 (Nm ³ / h) or more and 30 (Nm ³ / h) or less.

The alloy plating ingot manufacturing method includes the steps of moving the ingot in the molten state to a heating furnace; Maintaining the temperature of the heat-retaining furnace to more than 470 ℃ 500 ℃; may be further included.

According to the method for producing an alloy plating ingot using the electric induction of the present invention,

First, since Zn-Al-Mg alloy plating ingot is manufactured by using an electric induction path, segregation with other metals generated during alloy plating ingot production is not generated through active stirring and maintaining the cleanliness of the molten metal. In addition, melting can be performed at low power and low frequency to precisely and easily control and maintain the melt temperature. Therefore, as well as manufacturing ingots for Zn-Al-Mg alloy plating of uniform quality, it is possible to obtain the effect of maximizing productivity by minimizing the consumption of process time and energy.

Secondly, the magnesium is introduced into the molten metal through the inlet pipe immersed in the molten metal, and the molten ingot is manufactured by sealing the inside of the inlet tube with argon gas, thereby blocking oxygen or water vapor in the air, By suppressing the reaction explosion, it is possible to improve the stability as well as to improve the error rate of the magnesium input. In addition, the argon gas serves to suppress the magnesium injury by acting as a step-down of the input pipe, thereby isolating the magnesium from the atmosphere can promote magnesium melting as well as suppress the reactivity of magnesium. In addition, since argon (Ar) having a low warming index is used as an inert gas, it is environmentally friendly and overcomes limitations in use.

Third, magnesium is introduced into the molten metal through an inlet pipe immersed in the molten metal and installed in the upper part of the electrical induction furnace, and argon is only partially inside the upper magnesium inlet tube without filling the entire air contacting the entire surface of the molten metal with inert gas. Since the gas is injected, the amount of inert gas required for suppressing the reactivity of magnesium can be greatly reduced.

Fourth, since magnesium is added to the molten metal in a state where the particle size of magnesium is smaller than zinc, magnesium can be melted quickly, and thus magnesium can rise to a solid state to suppress reaction explosion with oxygen in the atmosphere.

Hereinafter, with reference to the accompanying drawings will be described in detail a preferred embodiment of the alloy plating ingot manufacturing method of the present invention.

1 is a flow chart showing a method for manufacturing an alloy ingot according to the present invention, Figure 2 is a view schematically showing an electric induction for performing the method for producing an ingot according to the present invention.

Referring to FIG. 2, the electric induction path 10 is generally known, and the side wall part 11 and the bottom part 12 which comprise a cylindrical container, and the furnace cover provided in the upper side of the furnace are shown. (13, Top CAP), the inner surface of the side wall portion 11 is constructed with a built-in refractory (16, Working Lining), the grout (15, Grout) is formed. The electric induction path 10 supplies a proper arc to an electrode (not shown) to dissolve the solid charged therein, and allows molten steel to be pushed out through a spout 14 formed on one side of the side wall part 11. . In the structure of such a general electric induction path 10, in the present invention, through the furnace cover 13 to the upper portion of the electric induction path 10 to install an injection tube 17 made of aluminum A1050, it is used Ingot production is to be performed economically and stably. The inlet tube 17 is inserted into the electric induction furnace to be immersed in the zinc molten metal 20, and the magnesium 40 is introduced into the zinc molten metal 20 through the inlet tube 17.

Hereinafter, with reference to Figure 1 will be described ingot manufacturing method for alloy plating of the present invention carried out by the above-described electrical induction (10). As shown in Figure 1, the alloy plating ingot manufacturing method according to the present invention is a molten zinc manufacturing step (S1), magnesium injection step (S3), argon injection step (S4) and molten ingot production step (S5) It is made to include. The present inventors have repeatedly performed experiments to prepare ingots for Zn-Al-Mg alloy plating of various compositions by the above method for producing ingots for alloy plating, and as a result 74-82% Zn, 15-23% Al, 3% It was confirmed that the ingot for plating Zn-Al-Mg alloy of uniform quality in the range of Mg composition can be manufactured economically and stably.

In detail step by step, in order to manufacture a zinc base (Zn Base) ingot, first, zinc (Zn) is added to the electric induction, and the electric induction is heated to melt the Zn in the solid state to produce a zinc-based molten metal (S1). In order to manufacture a Zn-Al-Mg alloy plating ingot, it is possible to charge the solid Al (30) to the bottom of the electric induction in advance before Zn input.

The molten Zn molten metal 20 is heated with sufficient stirring to increase the temperature, and when the molten metal temperature is 650 ° C. or more, the magnesium 40 is introduced into the molten metal through an inlet tube immersed in the molten metal installed at an upper portion of the electric induction furnace. (S3).

Magnesium has a lower specific gravity than zinc, so there is a high risk of floating on the surface of the molten metal. In addition, the melting point is higher than zinc and may not be melted before injury. Therefore, when magnesium is melted quickly by increasing the surface area by making the particle size of magnesium smaller than zinc, it is possible to reduce the rise of magnesium into a solid state. For this purpose, as a step before performing step S3 of injecting magnesium into the molten metal, it is preferable to perform step S2 of grinding the magnesium so that the particle size of magnesium is smaller than that of zinc.

On the other hand, when magnesium is added to the molten metal at a temperature of less than 650 ° C., the magnesium may react with oxygen or water vapor while heating the molten metal to a temperature of 650 ° C. or higher necessary for melting the magnesium, resulting in low stability and recovery rate. Can be. Therefore, when the molten metal temperature is 650 ℃ or more in the magnesium input step (S3), the magnesium is added to the molten metal so that the magnesium can be melted at the same time as the molten metal.

Argon gas is injected into the injection tube to maintain the inside of the injection tube as an inert gas (S4). Solid magnesium is injected into the molten zinc through an input tube, and the specific gravity of magnesium (1.74) is lower than the specific gravity of zinc (7.14) so that it does not sink down, but rises from the molten metal in the input tube and is in contact with the molten metal. There is a risk of reacting with oxygen or water vapor. Therefore, the inside of the inlet tube should be kept inert gas to block the flammable magnesium from the atmosphere, for this purpose argon gas is injected into the inlet tube (S4). Argon gas injected into the input tube not only blocks the reaction between magnesium and oxygen in the atmosphere, but also serves to promote magnesium melting by suppressing the rise of magnesium.

The use of argon (Ar) as an inert gas is environmentally friendly and less constrained due to its lower warming index than other inert gases such as sulfur hexafluoride (SF6).

In this case, it is preferred that the amount of argon gas is added 2 (Nm ³ / h) or less than 30 (Nm ³ / h). This is because when the amount of argon gas injected is less than 2 (Nm ³ / h), it does not suppress magnesium injury, does not completely prevent magnesium from reacting with oxygen or water vapor in the atmosphere, and the error rate of magnesium input is reduced. This is because when it exceeds (Nm ³ / h), the effect of blocking oxygen and suppressing injury due to the additional input of argon gas cannot be expected, resulting in low economic efficiency. Therefore, the amount of argon gas to be introduced is preferably 2 to 30 (Nm ³ / h), more preferably 5 to 20 (Nm ³ / h), particularly 10 (Nm ³ / h) to reduce the argon gas (强壓It is desirable in terms of cost-effectiveness (oxygen blocking and injury suppression).

The inlet tube may be made of an aluminum alloy material such as Al1050 having a higher melting point than zinc or magnesium.

As described above, in the method of manufacturing an alloy ingot for plating according to the present invention, after injecting magnesium into the molten metal through an inlet tube, argon gas may be injected only into the inner tube of the upper side of magnesium, so the amount of inert gas necessary for suppressing the reactivity of magnesium is used. This can greatly reduce the cost.

Meanwhile, in FIG. 1, although the argon injection step S4 is performed after the magnesium injection step S3 is performed, this is merely an example, and unlike the illustration, the magnesium injection step S3 is performed. It is also possible to perform the argon injection step (S4) before performing. That is, argon is injected into the input tube at 2 (Nm ³ / h) or more and 30 (Nm ³ / h) or less, and then magnesium is introduced into the molten metal through the input tube, and then the inside of the input tube is filled with argon gas. It is also to be considered to belong to the scope of the present invention to maintain the temperature of the melt in the maintained state at 650 ~ 700 ℃ to produce an ingot in the molten state.

In this way, while maintaining the inside of the inlet tube with an inert gas, magnesium is melted to prepare an ingot for plating Zn-Al-Mg alloy in a molten state (S5). At this time, since the melting point of Zn is extremely low and the boiling point is also low, the temperature of the melting ingot should be maintained at 700 ° C. or lower. In order to melt magnesium in the zinc-based melt, the molten metal must be heated to a temperature of 650 ° C. or higher. It is preferable to keep temperature at 650 degreeC or more and 700 degrees C or less. Since the temperature of the molten metal is carried out by controlling the heating temperature of the electric induction furnace, it is easy to maintain the temperature of the molten metal at 650 ° C or more and 700 ° C or less, and also actively stirring the electric induction and the cleanliness of the molten metal. It is possible to produce an ingot of uniform quality without segregation with other metals generated during the production of ingots for alloy plating through the holding.

At this time, the heating and stirring by the electric induction is preferably performed at a low power of 50KW or more, 150KW or less, and low frequency of 100Hz or more and 150Hz or less. This is because when the work is performed at a low power of less than 150KW and a low frequency of less than 150Hz, the temperature of the molten metal can be kept constant by precisely controlling the heating temperature of the electric induction furnace. In addition, since the power is less than 50KW, the frequency less than 100Hz takes a long time to heat the electric induction and the scale is formed, it is preferable in terms of economic efficiency and efficiency to perform the work at 50KW or more, 100Hz or more.

When the manufacture of the molten ingot is completed, the step of moving the ingot in the molten state from the electric induction path 10 to the thermal furnace 50 shown in FIG. do. The insulation 50 is preferably maintained in an ingot of 80% or more of its capacity to minimize heat loss. When the heating furnace moving step S6 is performed, the step S7 of maintaining the heating furnace at a temperature of 470 ° C. or more and 500 ° C. or less is performed. The molten ingot in the heating furnace is continuously cast through the Orbit Type Casting Machine (60) (S8), and finally the ingot 70 of uniform quality is finished through the cooling process (S9).

[Example]

Zn was added to an electric induction furnace filled with solid Al, followed by heating to melt, to prepare a zinc-based molten metal. After stirring and heating the molten metal, the magnesium was introduced into the molten metal through an inlet tube as soon as the molten metal temperature reached 660 ° C. It was. As the input tube, an aluminum alloy tube having a diameter of 250 mm, a thickness of 5 mm, and a length of 1000 mm was used. After injecting magnesium into the inlet tube and injecting only argon gas at 10 (Nm ³ / h), the molten state was manufactured by maintaining the temperature of the melt at 670 ° C. for 10 minutes. Electric induction was performed at low power of 50 ~ 150KW and low frequency of 50 ~ 150Hz. The ingot in the molten state was transferred to a thermal furnace, and the temperature of the thermal furnace was maintained at 480 ° C. Subsequently, the molten ingot in the thermal furnace was subjected to continuous casting and cooling of Orbit Type to finally manufacture 74-82% Zn, 15-23% Al, 3% Mg of Zn-Al-Mg alloy plating ingot. . As a result, the ingot for plating Zn-Al-Mg alloy of uniform quality could be manufactured, and no explosion occurred due to the magnesium reaction in the ingot manufacturing process.

1 is a flow chart of the method for producing an alloy ingot for plating using electric induction in accordance with the present invention.

Figure 2 is a schematic diagram of the electrical induction used in the ingot manufacturing method for alloy plating according to the present invention.

Figure 3 is a view for explaining the process of manufacturing an ingot through a heating furnace and orbit type casting machine.

♧ description of symbols for the main parts of the drawing

10: electric induction road 11: side wall part 12: bottom part

13: Furnace 14: Spout 15: Grout

16: internal refractories 17: inlet tube 20: zinc (Zn) molten metal

30: aluminum (Al) 40: magnesium (Mg)

Claims (5)

Preparing a zinc-based molten metal by injecting zinc in a solid state into the electric induction furnace and heating the electric induction furnace at a low power of 50KW or more, 150KW or less, and low frequency conditions of 100Hz or more and 150Hz or less to melt zinc; After grinding the magnesium to make the particle size of the magnesium smaller than the particle size of the zinc in the solid state, when the temperature of the molten metal is 650 ℃ or more, the magnesium is melted through the inlet pipe immersed in the molten metal is installed at the top of the electric induction Putting in; And Preparing an ingot in a molten state by injecting an inert gas into the inlet tube and maintaining the inside of the inlet tube as an inert gas; Ingot production method for alloy plating using an electric induction, characterized in that comprises a. delete The method according to claim 1, wherein the inert gas Ingot production method for alloy plating using an electric induction, characterized in that the argon gas. The method of claim 3, wherein the argon gas is 2 (Nm ³ / h) or more 30 (Nm ³ / h) less than 30 (Nm ³ / h) ingot manufacturing method for alloy plating using an electric induction, characterized in that the injection pipe. The method of claim 1, wherein the alloy ingot manufacturing method Moving the ingot in the molten state to a heating furnace; Maintaining the temperature of the heating furnace at 470 ° C. or higher and 500 ° C. or lower; Ingot production method for alloy plating using an electric induction further comprising a.

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