KR100419266B1 - Consumable electrode type vacumn arc melt-casting apparatus for titanium - Google Patents

Abstract

The present invention uses the specimen and the crucible as an electrode for arc generation while moving the specimen fixing means up and down the specimen fixed above the crucible furnace to dissolve the specimen and inject the molten metal into the mold of the centrifugal rotating plate located below The present invention relates to a vacuum electrode melting apparatus for consumption electrode type titanium melting casting, comprising: a chamber having an internal space; Shanghai transport means is fixed to the upper portion of the chamber; Specimen fixing means which is moved by the operation of the shanghai conveying apparatus and fixes the specimen; A vacuum means connected to the chamber to make the interior into a vacuum state; A crucible furnace having a double cooling structure provided with a skull installed below the specimen fixing device; Current supply means for supplying current to the specimen and the crucible furnace; A crucible furnace is connected to the rotating shaft rotated by the driving force of the motor, and a crucible rotating control means configured with a reduction device installed between the motor and the rotating shaft; A mold for casting a part having a shape that holds a molten metal; A guide member fixed to the bracket of the chamber to easily inject the molten metal into the mold when pouring the molten metal into the mold; A centrifugal rotating plate for rotating the mold; Power generating means for providing a power source for rotating the centrifugal rotating plate; Cooling means for preventing heat generated by high temperature arc heat from being transferred to the crucible furnace; It is characterized by consisting of control means for controlling each of the devices.

Description

Consumable electrode type vacumn arc melt-casting apparatus for titanium}

The present invention uses the specimen and the crucible as an electrode for arc generation while moving the specimen fixing means up and down the specimen fixed above the crucible furnace to dissolve the specimen and inject the molten metal into the mold of the centrifugal rotating plate located below A consumption electrode type vacuum arc melting apparatus for titanium melt casting.

Titanium and titanium alloys have been used mainly in the aerospace, aerospace, and marine fields because of their lightness, specific strength, inelasticity, and excellent corrosion resistance, and their use is increasing with the development of the aviation and aerospace industries.

Titanium alloys, which account for 50% of the world's titanium production, are not only used for light weight, but also for extreme durability and corrosion resistance. Used as medium and large titanium alloy parts in automotive, food, oil refining, chemical and petrochemical plant, power generation equipment, pharmaceutical, food, pulp and paper, plating plant, medical field, sports leisure, dairy processing and environmental industry. Is expanding.

Titanium is a metal that is much more active at high temperatures than other metals such as aluminum and copper, so that gases or impurities generated during melting can lead to defects in titanium castings. Titanium reacts with them, resulting in severe surface defects in the final product, such as extremely poor machinability even in hot and cold.

In order to overcome these disadvantages, the US and Japan have developed and applied processing methods using superplastic properties at specific temperatures, but they are suitable for the manufacture of small parts with simple shapes, but in the case of medium and large parts, the molding presses and molds are enlarged. Due to the increase in manufacturing cost due to the increase in processing losses and the manufacturing cost has a problem that rises sharply. In addition, fabrication is not possible for medium to large parts with complex dimensions.

In order to overcome these problems, the US and Japan have established vacuum arc melting technology using non-consumable electrodes and mold technology that does not react with titanium, and have developed medium and large titanium parts using these methods. It is used in commercial parts such as turbine blades and compressor disks in industrial gas turbines. However, the vacuum arc dissolving method using the non-consumable electrode has disadvantages of contamination of molten titanium by the non-consumable electrode and difficulty in manufacturing a large cast product.

The object of the present invention devised in view of the above-described conventional problems is to produce titanium casting parts requiring medium and large size and precise dimensions at a low cost, and to consume the electrode for titanium melt casting to prevent contamination in the melting and casting process To provide a vacuum arc melting apparatus.

1 is an exemplary view schematically showing a configuration of a vacuum arc melting furnace according to the present invention.

Figure 2 is a side cross-sectional view of the crucible furnace and the guide member which is the main part of the present invention.

<Description of the symbols for the main parts of the drawings>

10: chamber 20: Shanghai transport vehicle

25 cooling means 30 specimen fixing means

40: vacuum means 41: rotary pump

50: crucible 51: skull

52: outer wall 60: crucible rotation control means

61: motor 62: rotating shaft

63: reduction gear 70: power supply

80: mold 85: centrifugal rotating plate

90: power transmission device 95: guide member

100: control means S: specimen

In order to achieve the above object, the present invention provides a vacuum arc dissolving apparatus, comprising: a chamber having a see-through portion capable of forming an inner space and observing its interior, and a safety valve for adjusting the pressure therein; Shanghai transport means is fixed to the upper portion of the chamber; Specimen fixing means for fixing the specimen while being installed in the chamber while being moved by the operation of the shanghai transport device; A vacuum means connected to the chamber to make the interior into a vacuum state; A crucible furnace having a double cooling structure provided with a skull having an outer wall of stainless steel and an inside of copper alloy when installed below the specimen fixing device; Current supply means for supplying current to the specimen and to the crucible furnace located below the specimen; A crucible furnace connected to a rotating shaft which is supported by a bearing and a bearing installed in the chamber and is rotated by a driving force of the motor, and a crucible furnace rotation control means configured to have a reduction device installed between the motor and the rotating shaft; A mold for casting a part having a shape trough molten titanium; A guide member fixed to the bracket of the chamber so that the specimen in the molten state into the crucible is easily injected into the mold; A centrifugal rotating plate for rotating the mold; Power generating means for providing a power source for rotating the centrifugal rotating plate; Cooling means for preventing heat generated by high temperature arc heat from being transferred to the crucible furnace; It is achieved by a vacuum arc melting apparatus for titanium melt casting using a skull, characterized in that the control means for controlling the respective devices.

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

1 is a schematic view showing the configuration of a vacuum arc melting furnace according to the present invention according to the present invention, the electrode electrode vacuum arc melting apparatus (1) for titanium melt casting according to the present invention to form an inner space and observe the inside Perspective part 11 which can be provided on the outside and the other side thereof is provided with a specimen fixing means 30 for fixing the specimen inside the chamber 10 is provided with a safety valve 12 for adjusting the pressure inside. At this time, the specimen fixing means 30 for fixing the specimen (S) is connected to the shanghai conveying means 20 installed on the outer upper side of the chamber 10 is installed to be movable.

Meanwhile, a vacuum means 40 connected to the chamber 10 to make the interior into a vacuum state and releasing gas generated during melting of the specimen S to the outside is installed, and the vacuum means 40 is a rotary pump. (Rotary pump) 41 and booster pump (Booster pump) (42).

Further, a crucible furnace 50 having a double cooling structure in which the outer wall 52 is made of stainless steel and a skull 51 in which the inside is made of copper alloy is installed below the specimen fixing device 30. ) Is supported by a bearing 14 installed in the chamber 10 and a bearing 15 installed in the bracket 16 and connected to a rotating shaft 62 which is rotated by a driving force of the motor 61, and the motor 61. And a crucible composed of a reduction device 63 installed between the rotary shaft 62 and the rotation control means 60 is rotatably installed.

The crucible furnace (50) located below the specimen (S) and the specimen (S) is connected to the current supply means for supplying a current, the shape of the trough molten titanium below the crucible furnace (50) A mold 80 for casting a part of the mold and a centrifugal rotating plate 85 for rotating the mold are installed, and molten titanium is easily formed in the mold 80 between the crucible furnace 50 and the mold 80. The inside is made of graphite and the outside is made of graphite, the guide member 95 made of stainless steel is fixed to the bracket 15 of the chamber.

On the other hand, the centrifugal rotating plate 85 is installed to rotate in connection with the power generating means 90 is installed in the lower outer side of the chamber 10, the crucible furnace 50 is the heat generated by the high-temperature arc heat is transmitted Cooling means 25 for preventing the connection is configured and each means is configured to be controlled by the control means (100).

Referring to the operation of the present invention having the structure as described above in detail, the alloy to be cast in the first to make a specimen (S) by making a cylindrical rod (max. Ψ 200mm) and the specimen by welding to the specimen fixing device 30 After the installation, it is installed in the chamber 10, and when the installation of the specimen S is completed, the vacuum means 40 is operated by using the control means 100 so that the inside of the chamber 10 has a constant vacuum degree (10 ^-2 torr- 10 ^-3 torr) is maintained.

As described above, when the initial operating conditions of the device is completed, the current is supplied to the specimen fixing means 30 and the crucible furnace 50 to fix the consumed electrode, that is, to fix the specimen S, through the bus bar in the power supply device 70. At the same time as the supply (max. 10KA), the specimen fixing means 30 is conveyed downward by the operation of the shanghai conveying means 20.

Between the specimen (S) of the conveying specimen fixing means 30 and the crucible furnace 50 installed in the downward direction is conveyed downward until a predetermined gap, and when the trough gap is formed, the specimen (S) and AC or DC voltage is applied between the crucible furnace 50 to generate an arc that generates heat at about 6000 ° C. to make the specimen (the melting point of titanium is 1668 ° C.) melted.

When the gas caused by the arc generation remains in the chamber 10, the gas affects the molten metal, so that the arc is formed by using the vacuum means 40 formed of the rotary pump 41 and the booster pump 42 to prevent this. When generated, the gas is discharged to the outside.

At this time, observe the molten state of the specimen (S) and the inside of the chamber (S) during casting through the observation port 20, when the excessive pressure is generated in the chamber (10) equal to the optimum operating conditions by the safety valve 25 To adjust the pressure.

On the other hand, the present invention titanium melting, casting electrode vacuum arc melting device (1) is titanium is melted, the contamination from the crucible during the casting process is a skull (51) that is inserted into the crucible furnace 50 is installed Is prevented by.

As described above, when the arc is generated by the current supply of the power supply device 70 and the specimen S is melted, a gap is generated between the crucible furnace 50 and the specimen S by the volume of the molten specimen, that is, the height thereof. This is a problem in the generation of arc, so as to descend by the molten height of the specimen (S) in the shanghai transport apparatus 20 to maintain a constant gap between the crucible furnace 50 and the specimen (S).

When the specimen 2 is melted and filled in the crucible 50, the rotation control means 60 supported by the bearing 14 and the bearing 16 in the chamber 10 as shown in FIG. 2. The motor 61 is operated to rotate the rotation shaft 62. At this time, the rotating shaft 62 rotates by the rotational force of the motor 61 is gradually rotated in a state in which the rotation speed is significantly reduced by the reduction device (63).

On the other hand, the specimen of the molten state in the crucible furnace 50 rotated by the motor 61 of the rotation control means 60 is injected into the mold 80 installed at the same time as the rotation.

More specifically, as shown in FIG. 2, the crucible furnace 50 is initially located at a point “A” in the initial state, but when the crucible furnace 50 is rotated, the melting furnace is filled therein according to its rotation angle. The specimen in the state falls to the bottom, when the rotated distance is the largest angle when the crucible furnace 50 is rotated 90 ° came to the point "B".

However, at this time, since one side of the crucible is horizontal, the molten state of the crucible furnace 50 cannot be completely discharged, and therefore, at least the portion of the crucible must be moved to the lower part rather than the point 'B'. Up to the point "C", the molten specimen in the crucible is completely supplied downward and fed to the mold 80.

As described above, when the crucible furnace 50 is moved from the point "A" to the point "C", the moving distance of the vertical center line is changed. This means that when rotating toward the point “B”, which is the movement distance when the rotation radius is the largest, the distance to the center of the vertical center increases, and when it is located at the point “B”, the radius r is equal to the size of the point “B”. If you move to the position of point 'C', the distance from the center of the center to the center will be reduced. If the distance from the center of the point of "C" is L, the distance through the "B" will be reduced by the distance of rL if you are at the point "C" Should be.

The specimen in the molten state falling downward by the crucible furnace 50 rotated as described above is fixedly installed on the bracket 15 of the chamber 10 between the crucible furnace 50 and the mold 80 to be a crucible furnace. It is connected to the support shaft (95a) is the same as the movement distance according to the rotation angle of.

On the other hand, the mold 80 for casting molten molten metal is installed on the centrifugal rotating plate 85 rotated at about 400 rpm by the power transmission device 90 to obtain a casting trough by the vertical centrifugal casting method. .

Control and control of the various devices described above using the control panel 100, in order to prevent the transfer of heat generated by the high-temperature arc to use the cooling means 25 to cool each device.

The effect of vacuum arc melting (VAR) device using skull and the development of melting casting technology can be reduced about 40 ~ 50% compared to forging products. It is possible to produce large and medium sized titanium castings that are impossible. In addition, since the molten metal does not come into direct contact with the crucible furnace by using a skull, it is possible to completely prevent contamination, thereby producing a quality casting. Other effects include the import substitution effect of medium and large titanium parts by the development of vacuum arc melting device and melting casting technology of titanium alloy, establishment of manufacturing technology of industrial titanium casting parts, and securing vacuum arc casting technology for medium and large titanium parts. It is expected to improve the casting technology of difficult casting metals, prevent industrial accidents and environmental pollution by developing low pollution mold materials, apply titanium materials to sports leisure industry, and establish the basic technology of relatively weak titanium precision casting industry. It is expected to be applied to the development of steam turbine impeller, acid pump body and oil refinery valve product using titanium alloy and manufacturing technology of dental materials.

Claims (6)

In the vacuum arc melting apparatus, A chamber having a see-through portion for forming an inner space and observing the inside and a safety valve for adjusting the pressure therein; Shanghai transport means is fixed to the upper portion of the chamber; Specimen fixing means for fixing the specimen while being installed in the chamber while being moved by the operation of the shanghai transport device; A vacuum means connected to the chamber to make the interior into a vacuum state; A crucible furnace having a double cooling structure provided with a skull having an outer wall of stainless steel and an inside of copper alloy when installed below the specimen fixing device; Current supply means for supplying current to the specimen and to the crucible furnace located below the specimen; Crucible rotation control means is provided on the rotating shaft is supported by a bearing and a bearing installed in the chamber to rotate by a driving force of the motor is provided with a reduction device; A mold for casting a part having a shape trough molten titanium; A guide member fixed to the bracket of the chamber so that the specimen in the molten state into the crucible is easily injected into the mold; A centrifugal rotating plate for rotating the mold; Power generating means for providing a power source for rotating the centrifugal rotating plate; Cooling means for preventing transfer of heat generated by high-temperature arc heat; Consumable electrode type vacuum arc melting apparatus for titanium melt casting, characterized in that the control means for controlling each device. The apparatus of claim 1, wherein the crucible furnace is rotated at a predetermined angle by the crucible furnace rotation control means. The apparatus of claim 1, wherein the crucible furnace comprises a skull installed inside. The method of claim 1, wherein the gap is maintained by the shanghai conveying means when the arc is dissolved between the specimen and the crucible furnace of the specimen fixing device moved by the operation of the shanghai conveying apparatus for titanium melt casting Consumable electrode vacuum arc melting device. The apparatus of claim 1, wherein the guide member is made of graphite and the outside is made of stainless steel. The method of claim 1, wherein the guide member is fixed to the bracket of the chamber is connected to the support shaft which is linked to the same as the moving distance according to the rotation angle of the crucible, the electrode melting vacuum arc melting for titanium melting casting Device.