KR100683194B1 - Jumbo type al-si-zn ingot for plating and manufacturing method of the same - Google Patents

Abstract

An Al-Si-Zn based(55%Al-1.6%Si-Zn) alloy ingot having uniform quality and a method for manufacturing the ingot economically and stably are provided. A manufacturing method of a jumbo type Al-Si-Zn based ingot for plating comprises the steps of: injecting Al into a melting furnace(10) and heating the Al to a temperature of 700Œ20 deg.C to melt the Al; manufacturing an Al-Si alloy melt by adding Si to the Al melt(50) while temperature of the Al melt is maintained to 750Œ20 deg.C, locally heating a floating Si(30) on an upper layer part of the Al melt by a burner(20), and stirring the Si added Al melt by an electromagnetic stirrer(45), thereby inducing prompt diffusion melting of Si into the Al melt; manufacturing an Al-Si-Zn based alloy melt by stopping heating of the Al-Si alloy melt and injecting Zn into the Al-Si alloy melt at a temperature of 750 to 620Œ20 deg.C; and casting the Al-Si-Zn based alloy melt at a temperature of 620Œ20 deg.C in an ingot mold to manufacture an Al-Si-Zn based alloy ingot.

Description

Azo-Si-Zn-based ingot for jumbo plating and its manufacturing method {Jumbo type Al-Si-Zn ingot for plating and manufacturing method of the same}

1 is a conceptual diagram showing a method of alternately charging and melting a conventional 3% Si-Al ingot and Zn ingot;

2 is a conceptual diagram illustrating a method of simultaneously loading a conventional 3% Si-Al ingot and a Zn ingot into a plating port;

3 is a conceptual diagram illustrating a method of simultaneously loading a conventional 3% Si-Al ingot and a Zn ingot into a melting pot;

4 is a graph showing the amount of oxide generated according to Al dissolution temperature;

5 is a graph showing the content of hydrogen gas according to the temperature of Al,

6 is a conceptual diagram showing a method of using a burner and agitator in Si alloy according to the present invention;

7 is a conceptual diagram showing a method for separating and stirring the Al melt and the Zn melt due to the specific gravity difference;

8 is a conceptual diagram illustrating a design and cooling method of an Al-Si-Zn-based ingot-only mold according to the present invention;

9 is a conceptual diagram illustrating a phenomenon in which Zn penetrates into a mold furnace gap;

10 is a conceptual diagram showing an example of the case of sequentially pouring the Al-Si-Zn-based ingot-only mold according to the present invention with the bent amorphous refractory,

11 is a conceptual diagram showing an example of the case of constructing an Al-Si-Zn-based ingot-only mold according to the present invention with an amorphous refractory having a recessed portion;

12 is a perspective view showing a production example of an Al-Si-Zn-based ingot having no holes formed therein;

13 is a perspective view showing a production example of an Al-Si-Zn-based ingot according to the present invention;

14 is a conceptual diagram of a method for manufacturing Al-Si-Zn-based plated steel sheet using an Al-Si-Zn-based ingot according to the present invention.

<Description of Symbols for Main Parts of Drawings>

10: melting furnace 20: burner

30: suspended Si 40: jig for stirring only

45: electronic stirrer 50: Al molten metal

60: Zn molten metal 70: Al-Si-Zn type ingot mold

80: ingot 90: large tank

The present invention relates to an Al-Si-Zn-based ingot for jumbo type plating and a method for manufacturing the same, and more particularly, an Al-Si characterized in that a hole is formed through the upper and lower surfaces of an ingot made of an Al-Si-Zn-based alloy. Preparing Al-Si alloy molten metal by adding Al to a Zn-based ingot and a melting furnace and heating it at 700 ± 20 ° C. to dissolve Al, and adding Si while maintaining the Al melt at 750 ± 20 ° C. And discontinuing the heating of the Al-Si alloy molten metal and starting Zn at a temperature of 750 ° C. or lower to lower the temperature to 620 ± 20 ° C. to prepare an Al-Si-Zn alloy molten metal. And it relates to an Al-Si-Zn-based ingot manufacturing method comprising the steps of casting the Al-Si-Zn-based alloy molten metal in an ingot mold.

As shown in Table 1, since the melting point of Si is relatively higher than that of Al and Zn, it is difficult to dissolve Al and Zn in a normal reaction due to a rapid reaction when raising the temperature to Si melting point. Due to the rapid oxidation and evaporation, the loss occurs, and due to the specific gravity difference between Al and Zn, the melting furnace melts into two layers at the time of melting, making it difficult to manage the plating layer having a uniform chemical composition, and solidification of the Al-Si-Zn alloy Due to the wide range (temperature range), component segregation of 55% Al-1.6% Si-Zn alloy ingot occurs during solidification, and when casting with a jumbo mold, Separation occurs and mechanical properties of casting molds made of gray cast iron are limited, and due to the Zn penetration into refractory bricks due to increased fluidity due to the high temperatures involved in Zn alloys in melting furnace operations Due to manufacturing process problems such as shortening of life, conventionally, 55% Al-1.6% Si-Zn alloy ingots used in Al-Si-Zn-based galvanized steel sheets could not be manufactured directly. .

Al-Si-Zn type Solidification start temperature (℃) 590 ℃ Solidification end temperature (℃) 500 ℃ Al Melting Point (℃) 660 ℃ Boiling Point (℃) 2447 ℃ importance 2.7 Zn Melting Point (℃) 420 ℃ Boiling Point (℃) 907 ℃ importance 7.14 Si Melting Point (℃) 1415 ℃ Boiling Point (℃) 2680 ℃ importance 2.33

Therefore, despite the deterioration of quality and the increase in cost, the dissimilar material (3% Si-Al + Zn) is used by melting after alloying in the plating port or by alloying after melting in alloying port and plating it by plating Was done.

Referring to FIG. 1, a conceptual diagram of a method of alternately charging and dissolving a conventional 3% Si-Al ingot and a Zn ingot is shown.

As shown, the method according to FIG. 1 uses a conventional 3% Si-Al ingot (primary melt) and a Zn ingot (secondary melt) to Al-Si-Zn based (55% Al-1.6% Si-Zn). The levels of the pots are controlled by discharging them into the alloy pots alternately according to the ingredients and then melting them into the plating pots.

However, in this method, two kinds of alloys are alternately charged and dissolved in an alloy port, so that variations of components occur depending on the material to be loaded, so that it is difficult to manage a plating layer having a uniform chemical composition. By performing at a high temperature above the melting temperature, there is a problem in that the gas content and oxide in the molten metal are excessively generated by reacting with moisture and oxygen in the air, thereby deteriorating the integrity of the molten metal. In addition, the time is increased when the melting temperature is re-heated during the first melting after the second melting, additional power is consumed, and the power is inefficiently managed according to the operation of the two ports. As a result of rapid oxidation and evaporation, the amount of dross and evaporation increases, and the management items such as separate management of two kinds of materials, separate management of plating and alloy ports, and increase of management personnel are increased. have.

Referring to FIG. 2, a conceptual diagram of a method of simultaneously loading a 3% Si-Al ingot and a Zn ingot into a plating port is shown.

As shown in the drawing, the conventional 3% Si-Al ingot and Zn ingot are simultaneously charged into the plating port to match the Al-Si-Zn-based (55% Al-1.6% Si-Zn) component, but the melting point is low and the dissolution rate The pot level is controlled by adjusting the charging rate so that the fast loading of the Zn ingot is faster than the 3% Si-Al ingot so that it can dissolve at the same time if possible.

However, in this method, if the capacity of the port is not secured enough, the temperature of the port temporarily decreases when the plating ingot is charged. Therefore, uniform plating layer management is difficult due to the unevenness of the port temperature. Loading at the same time allows a relatively uniform component management than the method shown in FIG. 1, but it is not possible to accurately manage the plating layer of the component.

In addition, excessive power is consumed for the management of the port capacity more than necessary for the temperature management of the port, and if the port capacity is large, the surface area in contact with the air is large. There is a problem that the maintenance cost increases.

Referring to FIG. 3, a conceptual diagram of a method of simultaneously loading 3% Si-Al ingots and Zn ingots into a dissolution pot is shown.

As shown, the conventional 3% Si-Al ingot and Zn ingot are simultaneously charged to the dissolution pot in accordance with the Al-Si-Zn-based (55% Al-1.6% Si-Zn) component, but the melting point is low and the dissolution rate is low. It manages the pot level by adjusting the charging speed so that the fast Zn ingot charge rate is slower than 3% Si-Al ingot so that it can be dissolved simultaneously if possible.

However, this method is relatively uniform component management than the method shown in Figures 1 and 2, it is difficult to manage the plating layer of the correct component. In addition, the power is inefficiently managed according to the temperature management of the two port operation and melting ports, and the recovery rate decreases due to the increase in the dross generation due to the oxidation temperature higher than the plating temperature. And an increase in management items such as separate management of the melting port and the number of management personnel.

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SUMMARY OF THE INVENTION The present invention is to overcome the above-mentioned conventional problems, and an object of the present invention is to provide a stable and economical ingot of an Al-Si-Zn-based (55% Al-1.6% Si-Zn) alloy ingot having a uniform quality. It is to provide a manufacturing method.

The present invention is to achieve the above object, in the ingot made of a known Al-Si-Zn-based alloy, a hole 81 penetrating through the upper and lower surfaces of the ingot is formed to be able to charge the chain do.

In addition, the present invention is to achieve the above object, the step of dissolving Al by injecting Al into the melting furnace 10 and heating to 700 ± 20 ℃, while maintaining the temperature of the Al molten metal at 750 ± 20 ℃ After the addition of the above, locally floating Si floating in the upper portion of the molten metal using a burner and stirred by a stirrer to induce rapid diffusion dissolution of Si to produce an Al-Si alloy molten metal, and After the heating is stopped, Zn is added at a temperature of 750 to 620 ± 20 ° C. to prepare Al-Si-Zn alloy molten metal, and the Al-Si-Zn alloy is molten at a temperature of 620 ± 20 ° C. It is characterized by consisting of a step of casting in a mold to produce an ingot.

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In addition, the molten metal heating in the Al-Si alloy molten metal manufacturing step is heated in a reflection furnace, characterized in that the heating by the burner crater installed in a variable type.

In addition, the alloy composition of the ingot in the step of producing the ingot is characterized in that consisting of Al; 55, Si; 1.6%, Zn: residue and other unavoidable impurities.

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In addition, in order to remove impurities present in the molten metal after manufacturing the Al-Si-Zn-based alloy molten metal, 2% of flux and an inert gas were added to the molten metal while maintaining a temperature of 620 ± 20 ° C., and 20 ± 5 minutes Degassing for a time is characterized in that it further comprises.

In addition, the melting furnace is characterized in that the shaft is in contact with each other in the form of the refractory material of the bent form 13 or the recessed portion (14) is formed so as to minimize the infiltration of the Zn into the gap between the furnace and infiltrate the furnace.

In addition, the ingot mold is characterized in that it is made of a rolled steel for general structure.

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Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

First, Al is added to a melting furnace and heated to 700 ± 20 ° C. to dissolve Al, and then Si is added while maintaining the Al melt at 750 ± 20 ° C. to prepare an Al-Si alloy melt.

Referring to FIG. 4, a graph of oxide generation amount according to Al dissolution temperature is shown, and referring to FIG. 5, a graph of content of hydrogen gas according to Al temperature is shown.

When dissolving Al, the burner is indirectly heated horizontally without directly injecting it into the molten metal.Since melting point is 1415 ℃, it is not possible to directly dissolve the Si floating in the upper part of the molten metal directly by using a burner. Stirring leads to rapid diffusion dissolution. At the melting temperature of Al (700 ± 20 ° C.), an alloy is formed by diffusion dissolution of Si into Al, not an alloy due to melting of Si, but the rate is very slow. As shown in FIG. 5, the alloying process is performed in an area of 750 ± 20 ° C. in which gas content and oxide generation in the Al molten metal 50 can be suppressed. At this time, the chemical composition of Si inspected by the luminescence spectroscopy should be 2.8 ± 0.3%.

When the alloying process is performed at a temperature above 750 ± 20 ℃, oxides are formed, and silicon is not diffused and dissolved at a temperature below 750 ± 20 ℃, so the temperature range is 750 ± 20 ℃.

At this time, available melting furnaces include burner-type crucibles and large-capacity reflection furnaces, but burner-type crucibles have less dissolution per charge than in large-capacity reflection furnaces, and are induction heating type. As the increase is not suitable for the mass production method, the Al-Si-Zn-based ingot mold is suitable for the large-capacity reflection furnace.

Referring to FIG. 6, a conceptual diagram of a method of using a burner and an agitator in Si alloy is shown.

As shown, the burner 20 crater of the melting furnace 10 is installed in a variable manner, not fixed, and is locally heated directly upon melting the suspended Si 30, and a stirring jig 40 (Jig) or an electronic stirrer ( 45) to cause diffusion dissolution of Si to occur rapidly.

Next, after the heating of the Al-Si alloy molten metal is stopped, Zn is started to be introduced at a temperature of 750 ° C. or lower to lower the temperature to 620 ± 20 ° C. to prepare an Al-Si-Zn alloy molten metal. . At the temperature below 590 ℃, the molten Al-Si-Zn alloy may be solidified, so the temperature should not be lowered below 600 ℃. At this time, the amount of Zn in the solid lump state is usually about 1 ton, so the temperature of the molten metal is drastically lowered. Therefore, the temperature of the molten metal does not rise.

Oxidation and evaporation increases rapidly when Zn is dissolved above 750 ° C. After dissolving Si, turn off burner 20 at a temperature below 750 ° C and start charging Zn to start flux injection at 620 ± 20 ° C. Dissolve in At this time, the chemical composition of Zn inspected by the luminescence spectroscopy is 43.4 ± 2.0%.

After manufacturing the Al-Si-Zn-based alloy molten metal, in order to remove impurities present in the molten metal by adding an inert gas such as flux and nitrogen or argon, bubbling the impurities and reacting with the flux to remove the suspended solids. At the same time, the impurity gas mixed in the molten metal is also degassed. The injection temperature is maintained at 620 ± 20 ℃ to prevent the Al-Si-Zn alloy molten metal to solidify, the input amount is 2% compared to the molten metal, the injection time is 20 ± 5 minutes. If the input time is 20 ± 5 minutes or less, the reaction time is insufficient and the reaction does not occur evenly. Therefore, in order for sufficient reaction to occur, the input time is 20 ± 5 minutes.

Finally, the Al-Si-Zn-based alloy molten metal is cast at a temperature of 620 ± 20 ° C. to prepare an ingot. Al-Si-Zn-based alloys are usually solidified at a temperature of 590 ° C., so they may be cast at 590 ° C., but near the start of solidification, solid and liquid phases may coexist, resulting in uneven quality of the ingot. Casting at the temperature of

Referring to Figure 7, a conceptual diagram of the separation and stirring method of Al and Zn by the specific gravity difference is shown.

As shown, since the separation phenomenon occurs due to the specific gravity difference between the Al melt 50 and the Zn melt 60 before casting after the alloy of the Al-Si-Zn-based ingot, Al-Si-Zn-based high Zn component during casting As the ingot starts tapping into the tapping hole 15, the Al component becomes higher as time passes and it becomes difficult to obtain an Al-Si-Zn-based ingot of a uniform component.

Therefore, casting is carried out while stirring using the electromagnetic stirrer 45 or the jig 40 dedicated to stirring to obtain an Al-Si-Zn-based ingot of a uniform component.

Referring to FIG. 8, a conceptual diagram of a design and cooling method of an Al-Si-Zn-based ingot-only mold 70 is shown.

The solidification characteristics of the Al-Si-Zn-based (55% Al-1.6% Si-Zn) alloy are shown in Table 1, because the solidification section is wide, the solidified Al-Si-Zn-based ingot 80 is composed of the components. Segregation occurs severely, and Al-Si-Zn-based ingots are mostly jumbo-type molds, so when the cooling rate is slow, separation of upper and lower ingots is shown as shown in FIG. 7 due to the specific gravity difference between Al and Zn. It can also occur.

Therefore, the mold 70 is provided with a heat sink 72 as shown in FIG. 8 so that the cooling rate of the ingot 80 is maximized, so that heat is generated well, and the most common SS400 among the general structural rolled steels is the structural steel sheet 71. It should be designed to be quenched by being immersed in the cooling water 91 circulated in the cooling tank 90 by using.

In addition, the material of the non-ferrous jumbo mold is generally used as a casting (FC (GC) 200 ~ 300), but the mechanical properties are not better than SS400, mold (mould) is required when casting the mold, and the shape change is not easy have. In addition, Al-Si-Zn-based ingot 80 has a higher specific gravity than Al ingot and has a higher casting temperature than Zn, so the fatigue life due to thermal impact on the casting mold is very high and the life is very short. It was used as this outstanding general structural rolled steel 71 (SS400) (GC400 tensile strength 300N / mm <2>, elongation 1% SS400 tensile strength 400N / mm <2>, 20% elongation). That is, SS400 has better mechanical properties than FC (GC) series, and designs, cuts, and welds mold shapes, thus eliminating the need for molds (moulds) and making it easy to change shapes. In addition, the life of the mold is extremely long, and it is easy to adjust the mold size to the capacity of the plating port.

Referring to FIG. 9, there is shown a conceptual diagram illustrating a phenomenon in which Zn 12 penetrates into a waste material gap.

As shown in the drawing, when the reverberation furnace is regenerated with a standardized refractory brick 11, Zn penetrates into the cracks of the furnace due to the fluidity at a high temperature of Zn, thereby leaving the furnace material and leaking to the outside of the furnace. Significantly shortened and soaked Zn makes it difficult to control the components accurately during the next operation, which leads to quality problems.

Therefore, as shown in FIGS. 10 and 11, an amorphous refractory material is manufactured and used using formwork. That is, it is arbitrarily manufactured in the form of the bent form (13), the form (14) in which the concave portion is formed, or the form in which the concave-convex portion is formed, and structurally strengthens the binding force of the refractory material. Sufficient effect can be seen. In addition, in the prior art, refractories were cast using mortar of other materials and the refractory material, but in the present invention, by using the refractory material of the same material as the mortar 15, the binding force was further strengthened. Therefore, the gap which Zn can penetrate than the conventional shaft furnace method is reduced, and even if it penetrates, it is possible to prevent the displacement of the old material.

Hereinafter, the present invention will be described in more detail with reference to Examples.

Referring to FIG. 12, an example of manufacturing an Al-Si-Zn-based ingot without a hole is shown.

When manufactured in the form of no hole as shown in (a), as shown in (b), the crane 82 and the jig 83 catch the projection 85 of the ingot and load it into the port. However, there is a problem that can not be lifted if the jig is abnormal.

Referring to Figure 13, there is shown an example of manufacturing a jumbo Al-Si-Zn-based ingot according to the present invention.

As shown, the jumbo type Al—Si—Zn based ingot 80 according to the present invention is manufactured in the form shown in (a), (b). At this time, the weight is 1000 ~ 1650kg is heavy and heavy, but as shown in (c) when processing the hole 81 can be loaded into the port using a chain 84 or the like in the event of a jig or crane failure.

14, there is shown a conceptual diagram of a method for manufacturing Al-Si-Zn-based plated steel sheet using a jumbo Al-Si-Zn-based ingot manufactured according to the present invention.

As shown, the pot management temperature is 610 ± 10 ℃, the Al-Si-Zn-based ingot is charged according to the port level, heated by the induction heating type method, the alloy ingot weight is sized according to the capacity of the pot As a result of controlling the amount of metal, a uniform Al-Si-Zn-based ingot having a certain component at a constant temperature was always loaded to obtain a uniform coating layer of a certain component, and reduced the processing time, energy consumption, and the recovery rate of the plating material. It could increase costs.

As described above, the Al-Si-Zn-based ingot for jumbo type plating according to the present invention and a method of manufacturing the same can be manufactured of Al-Si-Zn-based ingot of uniform quality, and can reduce the process time and energy It is possible to increase the recovery rate of plating materials, to provide stable supply through mass production of Al-Si-Zn-based ingots, and to freely change the shape and weight of Al-Si-Zn-based ingots, Cost can be reduced by manufacturing high quality Al-Si-Zn based ingots.

Claims (10)

In the ingot of a known Al-Si-Zn-based alloy, Jumbo plating Al-Si-Zn-based ingot, characterized in that the hole 81 is formed through the upper and lower surfaces of the ingot so that the chain can be charged. Injecting Al into the melting furnace 10 and heating to 700 ± 20 ° C. to dissolve Al; After adding Si while maintaining the temperature of the Al molten metal at 750 ± 20 ° C., the Si floating in the upper portion of the molten metal was locally heated using a burner and stirred by an agitator to induce rapid diffusion dissolution of Si to form an Al-Si alloy. Preparing a molten metal; Preparing an Al-Si-Zn alloy melt by injecting Zn at a temperature of 750-620 ± 20 ° C. after stopping heating of the Al-Si alloy melt; The Al-Si-Zn-based alloy molten metal cast ingot ingot at a temperature of 620 ± 20 ℃ to produce an ingot, Jumbo-type Al-Si-Zn-based ingot manufacturing method comprising the steps. delete The method of claim 2, Melting heating in the Al-Si alloy molten metal manufacturing step is heated in a reflection furnace, jumbo type Al-Si-Zn-based ingot manufacturing method characterized in that it is heated by a burner crater installed in a variable type. The method of claim 2, Alloy composition composition of the ingot in the step of producing the ingot is Al; 55, Si; 1.6%, Zn: remainder and other unavoidable impurities, Jumbo plating Al-Si-Zn-based ingot manufacturing method. delete The method of claim 2, After manufacturing the Al-Si-Zn-based alloy melt, 2% of flux and an inert gas were added thereto while maintaining a temperature of 620 ± 20 ° C. to remove impurities present in the melt, and a time of 20 ± 5 minutes was used. Jumbo-type Al-Si-Zn-based ingot manufacturing method characterized in that it further comprises the step of degassing. The method of claim 2, The melting furnace is jumbo-type plating, characterized in that the axis is interlocked with each other in the form of a refractory in the form (13) or the bent shape (14) is bent so that even the infiltration of the Zn is not to escape even if the infiltrate into the crack of the furnace. Al-Si-Zn based ingot manufacturing method The method of claim 2, The ingot mold Al-Si-Zn-based ingot manufacturing method for jumbo type plating, characterized in that made of rolled steel for general structure. delete

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