JPH0754066A - Production of consumable electrode - Google Patents

Abstract

PURPOSE:To prevent the collapse and deviation of compacts according to the rotation thereof without tack welding the compact group outside a chamber by supporting the compact group by auxiliary rollers at the time of rotating the compact group on plural pieces of main rollers and welding the compact group in the chamber. CONSTITUTION:High melting active metals in powder, granular, flaky, spongy and other forms or a mixture formed by mixing desired alloy elements with these high melting active metals is compression molded to a plate body divided in a circular shape in a circumferential direction to form the compact group c. The compact group C formed by combining such compacts c to a circular columnar form is pressurized and held in its axial direction and is placed in this state on two pieces of the main rollers 7 juxtaposed on a truck body 6 of a roller truck 3 in the chamber 1. The compact group C is then rotated in a circumferential direction and is welded by a plasma torch 4. The outer peripheral surface of the compact group C of the largest outside diameter lowered by some angle from just the lateral side thereof as a central angle is supported from the lateral.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a consumable electrode used for arc melting of high melting point active metals such as titanium, zirconium, tantalum, molybdenum or alloys thereof.

[0002]

2. Description of the Related Art A consumable electrode type arc melting method is often used for melting high melting point active metals such as titanium, zirconium, tantalum and molybdenum or alloys thereof. This arc melting method, as is well known, is a method in which a cylindrical consumable electrode is housed in a vacuum melting furnace, an arc is generated between the tip of the consumable electrode and a counter electrode, and the consumable electrode is sequentially melted from the tip, The molten metal is cast into a water cooled copper crucible.

In the consumable electrode type arc melting method of high melting point active metal, compacts obtained by compression molding of high melting point active metal in the form of powder, particles, flakes, sponge, etc. are integrated by welding. A consumable electrode is manufactured. Further, as the water-cooled copper crucible, a cylindrical one is usually used. When a consumable electrode is melted in a cylindrical water-cooled copper crucible, the consumable electrode often has a circular cross section. If the outer diameter of the consumable electrode is small, a circular compact is also used,
When the outer diameter of the consumable electrode is large, a semicircular, 1/3 circular, or 1/4 circular compact obtained by dividing the circle into 2 to 4 in the circumferential direction is often used in view of the scale and capacity of the compression molding machine. .

These compacts are combined in a cylindrical shape, and the compact group is integrally fixed by welding to be a consumable electrode. As welding, in-chamber welding is often used to prevent contamination of high melting point active metals.
FIG. 1 shows a welding apparatus used for assembling a consumable electrode by in-chamber welding.

As an operation, first, the compact c is assembled into a cylindrical shape, and the compact group C is axially tightened and placed on the roller carriage 3 in the chamber 1. The roller carriage 3 includes a carriage body 6 that moves in the chamber 1 in the longitudinal direction, and two main rollers 7 arranged in parallel on the carriage body 6.
Have and. The main roller 7 rotates the cylindrical compact group C in the circumferential direction (see FIG. 2).

When the compact group C is housed in the chamber 1, the chamber 1 is evacuated and replaced with an Ar atmosphere. Then, while the roller carriage 3 is running, the compact group C is bead-welded in the longitudinal direction by the plasma torch 4 provided on the upper portion of the chamber. When the first bead welding is completed, the main roller 7 is driven to rotate the compact group C by a predetermined angle in the circumferential direction, and the second bead welding is performed. By repeating this, the compact group C undergoes bead welding in the longitudinal direction at equal intervals in the circumferential direction and is integrally fixed.

[0007]

In the assembly of the consumable electrode using beat welding as described above, the compact group C rotates on the main roller 7. Therefore, the compact group C must be sufficiently fixed to obtain the compact c. Depression or slippage occurs. Therefore, the compact group C on the main roller 7 is clamped in the axial direction. However, since the high melting point active metal forming the compact c is in the form of powder, particles, flakes, sponge or the like as described above, the coefficient of friction of the compact surface is large, and therefore the compact group C is simply added. In many cases, the tightening force is not sufficiently transmitted to the central portion of the compact group C in the axial direction only by tightening in the axial direction. In particular, as the length of the compact group is longer, the tightening is less likely to be transmitted to the central portion in the axial direction.

When the compact c has a circular shape, even if the tightening force is insufficient, there will be no collapse or deviation, but the compact c
Is ½ circle, ⅓ circle, ¼ circle, when performing rotation or transfer operation, as shown in FIG.
There is a risk of slippage and slippage.

As a countermeasure against this, the compact group C may be temporarily fixed outside the chamber 1 by spot welding before performing the welding inside the chamber. The spot welding used for temporary fixing is
In order to prevent contamination of the high melting point active metal, the welding heating part is made of Ar.
It is considered to be gas shield welding that shields with an inert gas such as. This method is not a problem as long as it completely shields the compact group from the atmosphere, but if it is not perfect, it is easily presumed that the quality is deteriorated.

As another measure, it is possible to strengthen the pressure holding of the compact group in the chamber.
However, such a measure requires a complicated frame such as an outer frame. Therefore, the work is complicated and the productivity is unavoidably reduced.

An object of the present invention is to prevent wear and tear of the compact group due to rotation of the compact group only by temporarily tack-welding the compact group outside the chamber and by simply pressurizing and holding the compact group in the chamber. It is to provide a manufacturing method of an electrode.

[0012]

The method for producing a consumable electrode according to the present invention is a powdery, granular, flaky, sponge-like high melting point active metal or a mixture of the high melting point active metal and a required alloying element. Is compacted by compressing a circle into a plate that is divided in the circumferential direction, and a state in which the compact group is pressed and held in the axial direction when the compact group in which the compacts are combined in a cylindrical shape is welded in the chamber. While being mounted on at least two main rollers for rotation or holding arranged in parallel in the chamber, and further supporting the compact group from the side by at least one auxiliary roller arranged above the main roller. It is characterized by rotating in the circumferential direction.

[0013]

In the method for manufacturing a consumable electrode according to the present invention, since the pressure is simply retained in the axial direction, the central portion of the compact group, which lacks holding force, collapses compactly as the compact group rotates. Directional force works. But,
Since the compact group is laterally supported by the auxiliary roll, it is possible to prevent the compact from collapsing or slipping. In addition, since the tack welding can be performed inside the chamber, it is possible to eliminate the risk of quality deterioration due to tack welding outside the chamber.

[0014]

Embodiments of the present invention will be described below with reference to the drawings.

In this manufacturing method, the consumable electrode is manufactured using the welding apparatus shown in FIG. The basic structure of this welding device is
It is the same as the conventional welding device shown in FIG.

That is, as shown in FIG. 1, the welding apparatus has a cylindrical chamber 1 whose central axis is oriented in the horizontal direction. Both ends of the chamber 1 are closed by removable end plates 2 and 2, and a roller carriage 3 is housed inside. A plurality of plasma torches 4 are provided above the chamber 1 at intervals in the longitudinal direction of the chamber 1. The plasma torch 4 faces downward and is vertically adjusted in accordance with the thickness of the compact group C housed in the chamber 1.

As shown in FIG. 3, the roller carriage 3 has a carriage main body 6 which is guided by a rail 5 laid under the chamber 1 and travels in the chamber 1 in the longitudinal direction.
A pair of left and right main rollers 7 are provided on the carriage body 6. The main roller 7 extends in the traveling direction of the carriage body 6,
The compact group C placed on it is supported over the entire length, and its rotation causes the compact group C to rotate in the circumferential direction.

A pair of left and right auxiliary rollers 8 are provided outside the main roller 7 on the carriage body 6.
The auxiliary roller 8 is located above the main roller 7 and laterally supports an outer peripheral surface of the compact group C having the maximum outer diameter, which is inclined by a certain angle from the side of the compact group C.

The auxiliary roller 8 is also attached to the head 9 via a spring 10. The head 9 moves back and forth on the base 12 by the rotation of the screw 11.

The compact group C is formed by arranging 1/4 circular compacts c in the circumferential direction and the axial direction to form a columnar shape, and has a through hole for passing the rod of the fastening metal fitting in the central portion.

In order to carry out the present manufacturing method, first, a large number of compacts c are assembled into a cylindrical compact group C, and a rod is passed through the through hole at the center thereof. Both ends of the rod are threaded parts, and after end plates are externally fitted to the both ends, nuts are screwed into the both ends, whereby the compact group C is axially tightened from both ends.

After the temporary assembly of the compact group C is completed, the compact group C is placed on the roller carriage 3 in the chamber 1 without temporary welding, and the auxiliary roller 8 comes into contact with the outer peripheral surface of the compact group C at a predetermined position. The position of the head 9 is adjusted according to the outer diameter of the compact group C.

Next, both ends of the chamber 1 are closed, and the inside of the chamber 1 is vacuum degassed and replaced with an Ar atmosphere. Then, the compact group C is temporarily welded by the plasma torch 4, and then bead welding is performed to form a consumable electrode.
These weldings are performed by moving the roller carriage 6 and rotating the compact group C by a predetermined angle in the circumferential direction by the main roller 7.

Since the compact group C on the roller carriage 6 is merely pressed and held in the axial direction, the compact group C becomes compact as the compact group C rotates at the central portion of the compact group where the holding force is insufficient. The force in the direction of collapse works. However, since the compact group C is laterally supported by the auxiliary roller 8, the compact c is prevented from being collapsed or displaced.

Although two sets of auxiliary rollers 8 are provided on both sides in the above embodiment, they may be provided only on the side where the compact c easily collapses in relation to the rotation direction of the compact group C,
Moreover, the compact c can be supported more reliably by providing three or more sets. The auxiliary rollers 8 of each set may support the entire length of the compact group C, or may support only the central portion where the tightening force in the axial direction is insufficient. Further, a roller extending in the axial direction or a combination of rollers supporting the compact group C at points in the longitudinal direction may be used.

Also for the main roller 7, the compact group C may be supported at three or more positions in the circumferential direction.

The compact c is not limited to the 1/4 circular shape, but may be a 1/3 circular shape or the like, and it is possible to target a shape having a risk of collapse or deviation.

[0028]

As is apparent from the above description, the method of manufacturing a consumable electrode according to the present invention uses the disc-divided compact, which is likely to be collapsed or displaced with the rotation of the compact group. It is possible to surely prevent the collapse and the deviation. Moreover, since the temporary welding outside the chamber is eliminated, the contamination of the high melting point active metal can be prevented, and a high quality consumable electrode can be manufactured. Further, for the compact group, it is possible to prevent the compact from collapsing or slipping simply by pressing and holding the compact group in the axial direction, so that a complicated frame such as an outer frame is not required, and workability and productivity are excellent. .

As described above, the effect of being able to prevent the compact from collapsing or slipping only by holding pressure in the axial direction without performing temporary welding outside the chamber is extremely large in the manufacture of the consumable electrode.

[Brief description of drawings]

FIG. 1 is a side view showing a schematic configuration of a welding apparatus used for manufacturing a consumable electrode.

FIG. 2 is a front view showing a supported state of the compact group in the chamber of the welding device.

FIG. 3 is a vertical sectional front view of a welding apparatus suitable for carrying out the method for manufacturing a consumable electrode according to the present invention.

[Explanation of symbols]

 1 Chamber 3 Roller Cart 4 Plasma Torch 6 Cart Main Body 7 Main Roller 8 Auxiliary Roller C Compact Group c Compact

Front page continuation (72) Inventor Yasuhiro Okuda 2-26-10 Yotsukijima, Konohana-ku, Osaka City, Osaka Prefecture Nisshin Metal Works Co., Ltd.

Claims (1)

[Claims] 1. A high melting point active metal in the form of powder, granules, flakes, sponge or the like, or a mixture of the high melting point active metal and a required alloying element, is compressed into a circular plate divided in the circumferential direction. When the compact group is formed into a compact shape and the compact group is assembled in a cylindrical shape and welded in the chamber, the compact group is pressurized and held in the axial direction, and at least two parallel arranged rotations in the chamber are performed. Alternatively, it is mounted on a main roller for holding, and further, the compact group is rotated in the circumferential direction while supporting the compact group from the side by at least one auxiliary roller provided above the main roller. Method.