JP2001294906A - Metallic wire composed of super hard metal difficult to work and having flexibility and resiliency and its producing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a metallic wire without fluctuation of the physical properties of the build-up weld parts using the wire for welding, even though the raw material metal in a superhard metal difficult to work and has lens flexibility and resiliency, and to provide a wire capable of continuous automatic welding. SOLUTION: This metallic wire is composed of a superhard metal difficult to work and hardly having flexibility and resiliency, by forming its structure the porous one, however the flexibility and resiliency of the wire are imparted. In the method for producing the metallic wire, at least the fine powder of the superhard metal a polymer binder with water or an organic solvent are kneaded to form slurry, and extruded into a wire rod, and sintered the wire rod to increase its strength. In step, the metallic wire rod is porously sintered, and flexibility and resiliency are imparted to the metallic wire after the sintering.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a long metal wire having flexibility and elasticity even though it is made of hard-to-work hard metal having little flexibility and elasticity, and its production. More particularly, the present invention relates to a welding wire suitable as a filler metal for overlay welding.

[0002]

2. Description of the Related Art Conventionally, as one of filler metals made of hard-to-work hard metal having little flexibility and elasticity as a raw material,
A welding rod made of a stellite alloy which is a cobalt-based alloy is known. The stellite alloy is available from Deloro Stellit of the United States.
This is a Co-Cr-W alloy developed by e Company, Inc. This stellite alloy is an alloy having excellent wear resistance, heat resistance, and corrosion resistance, and is often used as a filler metal for performing overlay welding on a part of a machine component. Conventionally, the stellite alloy welding rod has been manufactured by casting a molten stellite alloy into a sand mold. Using this stellite alloy welding rod, overlaying is performed by electric welding or the like.

However, this technique has the following problems. (1) When one welding rod is used up, it takes time to set the next welding rod, and the welding operation must be temporarily interrupted. At that time, the temperature of the previously welded portion decreases. After a short period of time to change the welding rod, further build-up welding is continued, but there is a difference between the temperatures of the old and new welds. This non-uniform temperature lowers the strength of the welded surface, and when used later as a product, the welded surface is more likely to peel off. (2) Further, when one welding rod is used up, the welding operation is interrupted until the next welding rod is set, so that it is difficult to automate the welding operation and productivity does not increase.

[0004] In order to solve the above-mentioned problems, an overlay MIG is used for the purpose of automation and continuity of the welding operation.
(Metal Inert Gas) It became necessary to develop a stellite alloy continuous wire for welding. For the MIG welding, a continuous welding robot having a mechanism for continuously supplying a welding line is used. It became necessary to develop a stellite alloy continuous wire to be set on this continuous welding robot.

[0005] In response to this request, the aforementioned Deloro Ste
llite Company, Inc. has developed stellite wire. This stellite wire is prepared by mixing powders of materials other than cobalt, such as chromium, nickel, and carbon, among stellite alloy materials. It is wrapped into a stellite wire (hereinafter referred to as Metal Cored Wire). The winding method is different, but it is a product like cigarette. The stellite wire is wound around a bobbin and supplied to a welding robot during MIG welding to contribute to continuous welding. The stellite wire is alloyed into a stellite alloy during welding.

[0006]

However, this technique is not perfect, but has the following problems. (1) Since the joining of thin cobalt sheets to form a tube is performed only by caulking, the joints of the cobalt sheets are easily broken with a little force and the powder inside jumps . In addition, the cobalt sheet itself is easily broken by a small force, and the powder in the sheet is scattered. (2) Since it is composed of a mixed powder, the composition of the material is likely to be non-uniform. (3) The ratio of cobalt to powder is easily changed. (4) Since Metal Cored Wire is a mixture of the constituent materials, it must be alloyed at the time of welding in order to become a stellite alloy, but the alloy composition tends to be non-uniform. (5) Due to the above reasons (1) to (4), there is a large variation in the physical properties of the overlay weld.

The present invention has been made in view of the above problems, and has as its object to provide a metal wire made of a hard-to-work hard metal having little flexibility and elasticity. Nevertheless, an object of the present invention is to provide a metal wire capable of performing continuous automatic welding without causing a variation in physical properties of a build-up welded portion when used as a welding wire, and a method of manufacturing the same.

[0008]

In order to achieve the above object, the present invention provides a porous metal wire which is made of a hard-working hard metal having little flexibility and elasticity. In spite of the fact, it has flexibility and elasticity. "

The metal wire according to the present invention described in claim 1 is a metal wire made of a hard-working hard metal having little flexibility and elasticity, and having a porous structure. Is a metal wire to which flexibility and elasticity are imparted.
Since the metal wire is provided with flexibility and elasticity, when the wire is finally wound around a bobbin as a welding wire to produce a product, the metal wire is not broken and damaged. Therefore, winding and rewinding to and from the bobbin can be easily performed. MI
G It is the most suitable metal wire for continuous long welding work with a welding machine.

[0010] The method for producing a metal wire from a hard-to-work hard metal according to the present invention according to claim 2 comprises: a fine powder of a hard-to-work hard metal having little flexibility and elasticity; Using a polymer binder and a solution of water or an organic solvent as at least raw materials, kneading the raw materials to form a slurry, and extruding the slurry in a string shape to form a metal wire, And a sintering step of sintering the metal wire in order to increase the strength. The sintering step includes sintering the metal wire in a porous manner, and forming the sintered metal wire with flexibility and elasticity. Is provided. The sintering step is a step of sintering the metal wire extruded in a string shape in a porous manner and imparting flexibility and elasticity to the sintered metal wire. And has elasticity.

According to a third aspect of the present invention, in addition to the feature of the second aspect, the method of manufacturing a metal wire using a hard-to-work hard metal as a raw material further comprises the step of: The sintering temperature and the sintering time are determined so that the metal density of the simple metal wire is in the range of 85.0% to 97.0%. Further, preferably, the metal density of the metal wire is 90.0% to 9%.
The sintering temperature and the sintering time are preferably determined so as to be within the range of 6.0%. More preferably, the metal density of the porous metal wire is in the range of 85.0% to 97.0%.
When it is within the range of 90.0% to 96.0%, a metal wire having flexibility and elasticity suitable for winding and unwinding onto a bobbin when finally wound around a bobbin as a welding wire to produce a product is obtained. Can be

According to a fourth aspect of the present invention, there is provided a method of manufacturing a metal wire using a hard-to-work hard metal as a raw material according to the second aspect of the present invention. Raw material of hard-to-work hard metal with almost no hardness is Co-C such as stellite
a sintering temperature of 1200 ° C. to 1300 ° C. and a sintering time of 2 hours so that the metal density of the porous metal wire is within a desired range in the sintering step. ~ 8 hours. When the raw material of hard-to-work hard metal is Co-Cr-W alloy such as stellite, set the sintering temperature in the range of 1200 to 1300 ° C and the sintering time in the range of 2 to 8 hours. When it is determined, a metal wire having flexibility and elasticity suitable for winding and unwinding onto a bobbin when finally wound around a bobbin as a welding wire and commercialized is obtained.

According to a fifth aspect of the present invention, in addition to the features of the second aspect, the method of manufacturing a metal wire using a hard-to-work hard metal as a raw material according to the present invention further comprises: It has a winding step (hereinafter referred to as a flower winding step) that enables the metal wire to be shrunk after winding by winding in a spiral shape on one plane like a mosquito coil, and in the sintering step, the metal wire is It is characterized by being carried out in a state of being wound in a spiral shape.

[0014] The method for producing a metal wire from a hard-to-work hard metal according to the present invention according to claim 6 comprises a fine powder of hard-to-work hard metal having little flexibility and elasticity; Using a polymer binder and a solution of water or an organic solvent as at least raw materials, kneading the raw materials to form a slurry, and extruding the slurry in a string shape to form a metal wire, A winding step (hereinafter referred to as a flower winding step) for winding the metal wire rod immediately after the extrusion step into a spiral shape on a plane such as a mosquito coil to allow the metal wire rod to contract after winding; And at least a sintering step of sintering in a state of being spirally wound to increase the strength.

In the flower winding step according to the fifth and sixth aspects, the metal wire is wound in a spiral shape, so that the metal wire can be long wound. In addition, in the sintering step, the metal wire is shrunk by sintering, but the metal wire is sintered in a state of being spirally wound on one plane like a mosquito coil, so that distortion occurs. Can be shrunk freely. Furthermore, since it is not necessary to rewind the metal wire rod once wound in the flower winding process in the sintering process,
Even if the metal wire before sintering is weak, there is no risk of damage. As a result, a longer metal wire can be manufactured than the manufacturing method in which the metal wire is sintered in a straight state. It is possible to provide the optimal metal wire for continuous long-time welding work with a MIG welding machine.

[0016]

Embodiments of the present invention will be described below. The embodiment of the present invention has a slurry forming step, an extrusion step, a flower winding step, a sintering step, and an outer surface swaging step as basic steps in this order. If necessary, slurry deaeration step, drying step after extrusion, degreasing step after drying,
It has a continuous wire manufacturing step after sintering and a bobbin winding step after swaging as appropriate.

[Slurry Forming Step] The slurry forming step is a step of preparing the following materials and kneading those materials with a kneading machine to form a slurry. A solution of a hard-to-work hard metal powder, a polymer binder, water or an organic solvent is prepared. Further, an additive such as a substance that is insufficient when bonding as an alloy, for example, a carbon fine powder corresponding to the amount of insufficient carbon is prepared as necessary. Examples of the fine powder of the hard-to-work hard metal include Co-Cr-W alloys represented by stellite alloys, WC-Co alloys, and WC alloys.
TiC-Co alloy, TiC-Mo2 C-Ni alloy, TiC-Mo2
Fine powders of hard-to-work hard metal such as C-WC-Co-Ni alloys may be used.

The polymer material of the polymer binder acts as a binder until sintering, regardless of nature or synthesis, and can be eliminated by thermal decomposition by heating for degreasing and sintering. There are no restrictions on the type of object. Also, without specifying the polymer substance that the polymer substance dissolves in water or dissolves in various organic solvents, for example, starch, gelatin, casein, agar, gum arabic, alginic acid, etc. Natural polymer materials or synthetic polymer materials such as polyvinyl alcohol, polyacryl, polyvinyl acetate, methylcellulose, polyvinyl ether, and polyvinylpyrrolidone are appropriately selected and used. Examples of the organic solvent other than water include alcohols, ketones, aromatic hydrocarbons, and lower hydrocarbon halides.

When the slurry is extruded into a string by an extruder described later, it is necessary to optimize the material viscosity in order to maintain the stability of the extruding behavior. Also, the amount of the binder is preferably small so that the metal powder density is increased from the time of slurry molding and the degreasing operation therefor can be facilitated. In addition, it is preferable that the amount of the solution be small so that the metal powder density can be increased from the time of slurry molding. Therefore, regarding the weight of the binder and the solution, the average particle size formed by the atomization method is 80 μm.
The binder is based on 2 to 15 parts, preferably 3
Up to 8 copies. The lysis solution is basically 5 to 40 parts, preferably 6 to 15 parts.

The above-prepared materials are kneaded using a double bowl open type kneader to form a slurry. For example, as the slurry performance, when the shear rate is 1 to 100 sec ^-1 , the viscosity is 10 ⁴ to
10 ⁵ poise. At the time of kneading, it is necessary to pay attention to disperse each material uniformly and not to raise the temperature abnormally. In the extrusion step described below, it is important to make the physical properties of the entire slurry uniform in order to keep the shape of the circular cross section of the extrudate when the slurry is extruded in a string shape. Therefore, the powder such as metal, the binder, and the solution are each uniformly dispersed, and in particular, the binder is kneaded with care so that the binder is completely dissolved in the solution so that there is no undispersed aggregate of the metal powder. .

In addition, in the flower winding process described later, the above-mentioned material viscosity is such that the metal wire 4 immediately after the extrusion shown in FIG. In order to maintain such a catenary curve and not to cause damage to the metal wire 4 immediately after extrusion, it is selected to maintain a predetermined melt tension. The reason for using an open type kneader without using a pressurized kneader or a rotor kneader is that if high kneading is performed under high pressure or with a high-speed rotating rotor, the material temperature will rise in a short time,
This is because negative factors such as insufficient dispersion and the tendency of water or organic solvent to evaporate to change the composition arise.

[Degassing Step] In order to prevent voids from being formed in the metal wire as the final product, the latter stage of kneading for forming the slurry, or immediately after the slurry is injected into an extruder used in the next step, Alternatively, during extrusion, the slurry is subjected to reduced pressure to remove any gas present in the slurry.
Here, exposure to a high degree of vacuum or exposure to a vacuum for a long time promotes evaporation of water and organic solvents, and thus must be avoided.

[Extrusion Step] The slurry is continuously extruded in a string form from a die having a circular cross section by a screw type extruder or a plunger pump to form a metal wire before sintering. The slurry is extruded long in a string shape by using the constant force and the constant discharge property as the action of the screw or the plunger. At this time, in order to keep the shape of the circular cross section of the string-shaped extrudate uniform, it is noted that the pressure before the nozzle during extrusion is kept constant. For example, as the slurry performance, the viscosity is 10 ⁴ to 10 ⁵ poi when the shear rate is 1 to 100 sec ^-1.
When se (10 ³ -10 ⁴ Ns / m ² ) is constant, the pressure before the nozzle is
The value is almost constant between 20 and 100 kgf / cm ² (1.96 to 9.8 MPa). Since the slurry containing powder is extruded, the extrusion pressure does not fluctuate slightly, but the limit of the fluctuation is ±
20 kgf / cm ² (1.96 MPa) or less, preferably ± 10 kg / cm
² (0.98MPa) or less. The final product diameter after sintering is smaller than the wire diameter at the time of extrusion, and generally, the wire diameter at the time of extrusion is smaller than the diameter of the die nozzle. Therefore, the die nozzle diameter is determined by a prior experiment so as to obtain a desired final product diameter.

[Hana winding process] The slurry 4 long extruded in a string shape on a winding plate 2 by the winding device 1 shown in FIG.
That is, the metal wire 4 immediately after the extrusion is wound in a spiral shape like a Katori incense. This is called a Hanamaki. Then, the drying, degreasing, sintering, and other subsequent steps are performed while the metal wire 4 wound with flowers is placed on the winding plate 2.
This is because the metal wire 4 immediately after extrusion is weak, and if the wound wire is once rewound, damage may occur. Furthermore, since the metal wire 4 immediately after the extrusion is shrunk in the sintering step, the metal wire 4 can be freely shrunk on the winding plate 2 and the metal wire 4 immediately after the extrusion is as long as possible. It is wound in a spiral like a Katori incense so that it can be wound. as a result,
A super hard metal wire longer than the manufacturing method of sintering the sintering front 4 in a straight state can be manufactured.

The flower winding device 1 will be described with reference to FIG. Fig. 1 (a) is a top view, Fig. 1 (b) is a front view, Fig. 1 (c)
Is a side view. The flower winding device 1 has a winding plate 2 and a support shaft 3. In FIG. 1, reference numeral 4 denotes a sintering front, 5 denotes a die nozzle of an extruder, and 6 denotes an extrusion head of the extruder.
The winding plate 2 is a flat thin plate. The material of the winding plate 2 may be a degreasing furnace, a sintering furnace, or the like so that a drying process, a degreasing process, a sintering process, and other subsequent processes can be performed while the sintering front 4 is placed on the winding plate 2. A material that does not cause a chemical change or damage due to high temperature even if it is disposed in the area is selected. For example, ceramics and the like can be mentioned.

The support shaft 3 is moved in a certain direction (the direction of the arrow b).
While rotating horizontally, the center of rotation O is
(a direction), and is fixed to the lower surface of the winding plate 2 to support the winding plate 2 from below. Accordingly, when the rotation center O moves in the direction of arrow a while the support shaft 3 rotates in the direction of arrow b, the winding plate 2 also rotates in the direction of arrow B while rotating in the direction of arrow b.
Moves in the direction of arrow a. The support shaft 3 and the winding plate 2
Is the metal wire 4 extruded from the die nozzle 5 of the extruder.
Is located at a position where it falls vertically, and the support shaft
3 is installed such that the rotation center O moves in a direction away from the die nozzle 5.

Next, a winding method using the flower winding device 1 shown in FIG. 1 will be described. The metal wire 4 extruded from the die nozzle 5 of the extruder falls vertically. The metal wire 4 separated from the extrusion point Q of the die nozzle 5 comes into contact with the winding plate 2 at the contact point P with the winding plate 2. On the other hand, the winding plate
2 is rotating horizontally, so the contact point P
The metal wire 4 up to draws a catenary curve 4a. As viewed from the external stationary point, the positional relationship between the points Q and P should be kept constant during extrusion. As the metal wire 4 is wound, the rotation center O is moved in the direction of the arrow a so that the distance between the rotation center O and the contact point P increases. At this time, the peripheral speed V of the contact point P is kept constant, and the rotation speed of the winding plate 2 by the support shaft 3 is controlled so that the behavior of the metal wire 4 at the contact point P becomes constant. The moving speed and the peripheral speed are controlled so as to maintain the positional relationship between the points Q and P.

For example, the distance between the rotation center O and the contact point P is d
, Where n is the rotation speed, V = π dn, and n = V / (π
d). The distance d between the points OP changes, and the peripheral speed V of the contact P
Is made constant, the rotation speed of the winding plate 2 is changed in inverse proportion to the value of d. As a result, the metal wire immediately after extrusion
4 is not sufficiently dried and is sufficiently soft.
Is wound in a spiral shape with uniform winding performance in accordance with the rotation of and the movement of the rotation center O 2.

[Drying Step] In the drying step, the solution contained in the metal wire is dried and discharged. When the dissolving solution is water, the gas to be discharged is steam, so that it can be easily dried. When the solution is an organic solvent, drying itself is easy, but since the gas discharged is an organic solvent, it may not be easily discharged outside the drying furnace. May be required. However, it is desirable to dry naturally without performing forced drying as much as possible. This is because, when the forced drying is performed, a phenomenon such as surface cracking may occur. In practice, it takes half a day to a day to dry naturally. There is no special concern about rust of the metal powder during this time. This is because in the subsequent sintering process, the rust, that is, the oxidation phenomenon, is reduced and disappears. In the drying step, there is almost no shrinkage of the metal wire.

In the drying step, since the solution has completely disappeared, the metal wire after drying is porous without performing degreasing as the next step. For example, final wire diameter 1.6mm
The target is 100: 4 weight ratio of metal powder weight: binder weight: solution. 3: 7. In the case of the metal wire extruded using the slurry of 1, the space volume occupied by the metal powder and the binder is about 70.0%, which is porous.

[Degreasing Step] In general, when directly sintering a solid compact made of only metal powder and a binder, the compact may be ruptured due to the gas pressure of the binder decomposition gas. In such a case, degreasing is required. It is. Also, in general,
When sintering a wire, vacuum sintering is often performed using a vacuum furnace. Whether the porous metal wire before sintering supplied from the previous process needs to be degreased or not depends on the amount of decomposition gas generated from the binder during sintering. Is determined based on whether or not the amount is to reduce the amount. If the metal wire before sintering is sintered as it is, the amount of decomposition gas generated from the binder at the time of sintering is large, and there is a possibility that the sintering furnace may be damaged or the vacuum property may be reduced.

In the case of a thick wire, if sintering is performed without performing the degreasing step, a large amount of decomposition gas of the polymer binder is generated during sintering, and the degree of vacuum is reduced. Further, the polymer decomposed substance of the polymer binder adheres to the wall surface of the vacuum furnace, which causes a problem that the degree of vacuum does not increase even after cleaning. Therefore, in the case of a thick wire having a wire diameter of the metal wire before sintering or a wire diameter of the final product larger than 1.0 mm, a degreasing step is required. If the wire diameter is small, the amount of decomposition gas generated from the binder at the time of sintering is small, so that degreasing is not necessary. If the wire diameter of the metal wire before sintering or the wire diameter of the final product is as thin as 1.0 mm or less, the vacuum furnace will not be damaged without degreasing.

In the degreasing step, in order to prevent the sintering furnace from being damaged, the polymer binder before the sintering is melted to such an extent that the metal powder constituting the metal wire before sintering loses its adhesive strength and does not collapse. This is the step of removing from the wire. Degreasing, degreasing rate 30
%, Preferably in the range of 30% to 70%. Aiming at a final wire diameter of 1.6 mm, the weight ratio of metal powder: binder: solution is 100: 4.3: 7. In the case of the metal wire before sintering extruded using the slurry of 1, the space volume occupied by the metal powder and the binder is about 64.4% at a degreasing rate of 30%.
With a 70% degreasing rate, it becomes porous at about 57.2%. In addition, even in the degreasing step, there is almost no shrinkage of the metal wire before sintering.

[Sintering Step] This is a step of sintering each of the metal powders in order to make the metal wire into a wire having high strength. Here, the metal wire, the sintering temperature and the sintering time are controlled so that the metal wire before sintering becomes a porous metal wire after sintering, and is sintered in a flower winding state. The metal wire after sintering is hereinafter referred to as a sintered wire. The reason why the sintered wire has a porous structure is to impart flexibility and elasticity to a metal wire made of a hard-to-work hard metal based on the following findings of the present inventors. Inventor's knowledge: When a metal wire made of hard-to-work hard metal is used as a porous structure, the metal wire has flexibility and elasticity despite the use of hard-to-work hard metal. It will have the nature.

When the degree of porosity is defined by the metal density, the hard-worked hard metal is used as a raw material so that the metal density is in the range of 85 to 97.0%, preferably in the range of 90.0 to 96.0%. Is finished as a porous structure. As a result, appropriate bending and elasticity can be obtained as a welding line used for welding. The sintering temperature range differs for each material, but for stellite, the sintering temperature is 1200
Specified in the range of ℃ ~ 1300 ℃. Preferably 1240 ° C to 1280 ° C
Determined in the range. If the temperature is lower than 1200 ° C., the diffusion between the metal particles is insufficient, and the strength of the wire is reduced, so that it cannot be used. On the other hand, when the temperature exceeds 1300 ° C., the shape as a wire cannot be maintained. The sintering time is determined in the range of 2 hours to 8 hours. Preferably 2. Set within the range of 5 hours to 4 hours. Two
If the time is shorter than the above, the solid phase sintering does not proceed and the product strength cannot be maintained. If the time is longer than 8 hours, the metal density becomes too large and the flexibility as a wire is insufficient.

[Continuous Wire Manufacturing Process] This is a continuous wire manufacturing process in which a plurality of sintered wires batch-sintered in units of a certain length are connected by welding to form a continuous wire. Since the longer the welding line to be supplied to the welding robot, the better, the ends of each of the plurality of sintered wires are joined by an electric welding machine, and the length of the hardened metal which is difficult to process is used as a raw material. Manufactures continuous metal wires of length. After welding, the welded portion, which is the joining surface, becomes nonporous at the end face, but does not affect the property of bending the continuous metal wire.

[Outer surface swaging step] In order to use a continuous metal wire elongated from a hard metal as a welding wire, the purpose is to make the wire diameter constant to obtain a uniform circular cross section, For the purpose of smoothing, the outer surface of the elongated continuous metal wire is swaged by a swaging machine. When supplying a welding line to a welding portion using a robot, in order to continuously and stably supply a wire, in addition to having the above-described flexibility, elasticity, and uniform strength, It is necessary that the line cross section is substantially a perfect circle and that the diameter of the circle is constant in the longitudinal direction. Furthermore,
The surface of the weld line must be smooth. for that reason,
The wire diameter and the wire surface of the elongated continuous metal wire made of the cemented carbide are used.

In this swaging step, the wire diameter becomes slightly smaller. At this time, the wire diameter before swaging is 1.01 to 1.27 times the final product wire diameter in order to maintain the flexibility and elasticity of the continuous metal wire made of a cemented carbide metal as a raw material.
This swaging increases the metal density on the wire surface, but does not increase the metal density on the entire wire, but does not change the metal density at the central portion that maintains flexibility and elasticity.

[Bobbin Winding Step] The bobbin winder installed subsequent to the swaging machine winds the metal continuous wire made of the hard metal after swaging as a raw material onto a bobbin. The bobbin is wound around the product with a predetermined weight as a unit. The diameter of the bobbin is not limited, but the bobbin winding diameter of the continuous metal wire made of a hard metal is 200 mm to 10 mm.
It is common to wind up to a range of 00 mm. When the bobbin winding diameter is smaller than 200 mm, a large load is applied to the metal continuous wire made of a hard metal,
If the bobbin winding diameter is larger than 1000 mm, it will be difficult to mount the product on the robot, or it will be difficult to mount it on the robot.

The method of the present invention for producing a metal wire using a cemented carbide as a raw material has a sintering step even when an alloy powder is used as a raw material or a powder of each metal alone is used as a raw material. The manufactured metal wire is a product having an alloy composition, and has a uniform composition without an uneven composition portion. For this reason, the physical properties of the welded portion differ between the portions, and do not vary. Therefore, stable physical properties of the welded portion can be always obtained. Furthermore, according to the manufacturing method of the present invention, the sintering process is performed so that the sintered metal wire has flexibility and elasticity. Nothing to do. As a result, winding and rewinding to and from the bobbin can be easily performed, and a long continuous metal wire can be obtained.

In addition, according to the production method of the present invention,
Since it has an outer surface swaging process, the cross section of the manufactured continuous hard metal wire is substantially circular and there is no change, and since the surface of the wire is smooth, there is no delay from the bobbin built in the robot. Supplied to the weld. Therefore, continuous long-time welding work is possible with a MIG welding machine. As a result, a continuous welding operation becomes possible, a discontinuous welding surface is eliminated in the welded portion, and the strength of the welded portion becomes uniform.

[0042]

Next, an embodiment of the present invention will be described. [Slurry forming step] The following raw materials were prepared. Stellite
No. 6 Atomized powder of alloy, Serander (Methylcellulose binder manufactured by Yuken Industries Co., Ltd.), and water as a solution. Weight ratio: (metal powder: binder: solution) = (10
0: 4.3: 7.1). As a standard for preparing a slurry, the properties of the resulting slurry are based on a shear rate of 1 to 10
The viscosity was adjusted to 10 ⁴ to 10 ⁵ poise (10 ³ to 10 ⁴ Ns / m ² ) at ⁰ sec ⁻¹ . In this formulation, the spatial volume of the slurry composition is as follows. Metal powder space volume (Volume Fraction) 51.8% Binder space volume (same as above) 18.2% Solvent solution space volume (same as above) 30.0%

The above raw materials were kneaded. In general, kneading is performed for 15 to 40 minutes using a double bowl open type kneader as a kneading machine. Although it is effective to cool the kneading chamber of the kneading machine, the temperature of the slurry is adjusted so as not to rise to 250 ° C. or more without cooling. As an example, in one batch, 6 kg of the above mixed material, kneading time was 20 minutes, and the temperature of the material was increased by +5.
Kneaded at a temperature within ° C.

[Degassing Step] The slurry mixed in one batch was put into a hobber of an extruder at once as a lump. At this time, the pressure was reduced around the entire hopper of the extruder.
The degree of pressure reduction is preferably in the range of 300 to 600 mmHg (39.9 to 79.8 kPa), and in the embodiment, the degree of vacuum is 600 mmHg (79.8 kP
The conditions of a) were used. In this case, leaving the screw for 30 seconds before rotating prevented the occurrence of voids in the extrudate. When the degree of vacuum was reduced, more than 30 seconds were required depending on the degree of reduction. With the rotation of the screw of the extruder, the contained gas was discharged, facilitating the extrusion, and did not form voids in the cord-like extrudate.

[Extrusion Step] The extrusion step was performed under the following conditions. The die nozzle diameter is 1.6 mm for the final product wire diameter after sintering.
Was determined by experimentation.・ Extruder diameter 80mm ・ Die nozzle diameter 1.94mm (in case of final product wire diameter 1.6mm) ・ Extrusion rate 2kg / hr ・ Nozzle front pressure 35 kgf / cm ² (3.43MPa) ・ Nozzle front pressure fluctuation ± 5 kgf / cm ² (0.49 MPa) ・ Extruded wire diameter 1.91 mm Die nozzle diameter is 1.94 mm, while extruded wire diameter is 1.91 mm and swell ratio is 1.0 or less. This is a phenomenon called Drow down,
The line is in a stretched state. As discussed below, the sintering stage suggests that the longitudinal shrinkage is greater than the radial shrinkage.

[Hanamaki Step] The unsintered wire rod extruded in the above step was wound up by a Hanamaki device. The size of the winding plate made of alumina ceramics was 400 mm × 400 mm in area and 10 mm in thickness. [Drying step] The flower-wound wire before sintering was naturally dried. After drying, the space volume of metal powder and binder is 7
The volume of the space where the lysis solution disappeared was 30.0%.
It became a porous structure and exhibited very brittle properties.

[Degreasing Step] The wire after drying and before sintering was degreased under the following conditions. -Degreasing temperature 200 ° C-Degreasing time 4 hours-Degreasing rate 62%-Space volume of metal powder and residual binder 58.6% (including metal powder space volume 51.8%)

[Sintering Step] The wire before sintering was sintered.・ Vacuum furnace vacuum degree 1 Torr (133.3224N / m ² ) ・ Maximum sintering temperature 1250 ℃ ・ Effective sintering time 3 hours ・ Wire diameter before sintering 1.91mm ・ Wire diameter after sintering 1.61mm ・ Metal density after sintering 94.0 % Metal powder space volume of 51.8% became 97% of metal density after sintering. The wire shrank by 15.7% (1 / 1.186) in the radial direction and 22.5% (1 / 1.29) in the longitudinal direction of the wire, and a sintered wire of about 10 m was completed. As described above, the longitudinal shrinkage of the wire was greater than the radial shrinkage. By repeating the above steps, a plurality of sintered wires of about 10 m in length were manufactured.

[Continuous Wire Manufacturing Process] Each end face of the plurality of sintered wires was joined by an electric welding machine to manufacture a long continuous metal wire using a hard metal as a raw material. BMS-1 manufactured by Tokyo Shindenki Co., Ltd. was used as a welding machine. End faces of two sintered wires to be welded were inserted from right and left sides of a welding point of the electric welding machine to perform face matching, and electricity was applied to perform welding.

[External Swaging Step] The long continuous metal wire was swaged. As a swaging machine, SD-2000 manufactured by Yoshida Kinen Co., Ltd. was used. The wire diameter before swaging was 1.01 times the swaging machine die diameter (final product wire diameter). Before treatment-Diameter of continuous metal wire 1.61mm-Metal density of continuous metal wire 94.0%-Swaging machine die diameter 1.60mm

[Bobbin Winding Step] The swaged metal continuous wire was wound around a bobbin by a bobbin winding machine installed subsequent to the swaging machine. The bobbin was wound around the product with a predetermined weight as a unit.

[0052]

According to the method for producing a continuous wire made of hard metal of the present invention, alloy powder is used as a raw material, or
Since the sintering step is performed using the powder of each metal alone as a raw material, the metal wire using the manufactured hard metal as a raw material is a product having an alloy composition, and has a uniform composition without an uneven composition portion. For this reason, the physical properties of the welded portion differ between the portions, and do not vary.

According to the metal wire of the present invention described in claim 1, the metal wire is made of a hard-working hard metal having little flexibility and elasticity as a raw material. By doing so, the metal wire is provided with flexibility and elasticity. Therefore, when finally wound around a bobbin as a welding wire to produce a product, the metal wire is not broken and damaged. Therefore, winding and rewinding to and from the bobbin can be easily performed. This is the most suitable metal wire for continuous long-time welding with a MIG welding machine.

According to the method of the present invention for producing a metal wire using a hard-to-work hard metal as a raw material, the sintering step comprises sintering the metal wire extruded in a string shape into a porous material. Then, since this is a step of imparting flexibility and elasticity to the metal wire after sintering, the resulting metal wire has flexibility and elasticity. Therefore, when the metal wire manufactured according to the present invention is finally wound around a bobbin as a welding wire and commercialized, the metal wire does not break and is damaged, and can be easily wound and unwound onto the bobbin. Can operate. MIG
It is possible to obtain an optimal metal wire for performing a welding operation continuously for a long time with a welding machine.

According to the method for producing a metal wire using a hard-to-work hard metal as a raw material according to the present invention as set forth in claim 3, in addition to the effect as set forth in claim 2, in the sintering step, When the sintering temperature and the sintering time are determined so that the metal density of the porous metal wire is in the range of 85.0% to 97.0%,
Preferably, when the sintering temperature and the sintering time are determined so that the metal density of the metal wire is in the range of 90.0% to 96.0%, the wire to the bobbin when finally wound around the bobbin as a welding wire and commercialized is manufactured. A metal wire having flexibility and elasticity suitable for winding and rewinding can be obtained.

According to the method for producing a metal wire using a hard-to-work hard metal as a raw material according to the present invention described in claim 4, in addition to the effects described in claim 2 or 3, in addition to the effects described in claim 2, The raw material of cemented carbide is a Co-Cr-W alloy such as stellite, and the sintering temperature
1200 ° C ~ 1300 ° C and sintering time 2 hours ~ 8
When the time is determined within the range of the time, a metal wire having flexibility and elasticity suitable for winding and rewinding the bobbin when the wire is finally wound around the bobbin as a welding wire to produce a product is reliably obtained.

According to the method for producing a metal wire from hard-to-work hard metal according to the present invention as set forth in claim 5, in addition to the effect as set forth in claim 2, the metal wire immediately after the extrusion step is added. In a spiral shape on a plane like a mosquito coil,
Since there is a flower winding step that enables the metal wire to be contracted after winding, the metal wire can be wound long. Furthermore, since the metal wire has a sintering step in which the metal wire is sintered while being spirally wound on one plane like a mosquito coil, the metal wire shrinks due to sintering, Can be freely shrunk without occurrence of cracks. Further, since the metal wire once wound in the flower winding process does not need to be unwound in the sintering process, there is no risk of damage even if the metal wire before sintering is weak. as a result,
A longer metal wire can be manufactured than a manufacturing method in which a metal wire is sintered in a straight state. It is possible to provide the optimal metal wire for continuous long-time welding work with a MIG welding machine.

According to the method of the present invention for producing a metal wire from a hard-to-work hard metal according to the present invention, the metal wire immediately after the extrusion step is formed into a spiral shape on a plane such as a mosquito coil. A flower winding step of allowing the metal wire to contract after winding, and a sintering step of sintering to increase the strength while the metal wire is wound in a spiral shape. Since the metal wire has at least the metal wire, the metal wire can be wound up for a long time, and can be freely shrunk without distortion even in the sintering process. Further, since the metal wire once wound in the flower winding process does not need to be unwound in the sintering process, there is no risk of damage even if the metal wire before sintering is weak. As a result, a longer metal wire can be manufactured than a manufacturing method in which a metal wire is sintered in a straight state. MI
G We can provide the most suitable metal wire for continuous long-time welding work with a welding machine.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating a flower winding device according to an embodiment of the present invention.

[Explanation of symbols]

 1 Hanamaki device 2 Winding plate 3 Support shaft 4 Wire rod before sintering 5 Die nozzle of extruder 6 Extrusion head

Claims (6)

[Claims] 1. A metal wire made of a hard-to-work hard metal having little flexibility and elasticity, wherein the metal wire has a porous structure and is provided with flexibility and elasticity. line. 2. A fine powder of hard-to-work hard metal having little flexibility and elasticity, a polymer binder, and a solution of water or an organic solvent are used as at least raw materials, and the raw materials are kneaded. A step of forming a slurry, an extruding step of extruding the slurry in a string shape to form a metal wire, and a sintering step of sintering the metal wire to increase strength. Is porous sintering the metal wire,
A method for producing a metal wire from a hard-to-work hard metal which is a step of imparting flexibility and elasticity to a sintered metal wire. 3. The sintering step, wherein a sintering temperature and a sintering time are determined so that a metal density of the porous metal wire is in a range of 85.0% to 97.0%. 3. The method for producing a metal wire from a hard-to-work hard metal as described in 2 above. 4. The raw material of the hard-to-work hard metal having little flexibility and elasticity is a Co—Cr—W alloy, and in the sintering step, the metal density of the porous metal wire is a desired value. The sintering temperature is between 1200 ° C and 13
The production of a metal wire using a hard-to-work hard metal as a raw material according to claim 2 or 3, wherein the sintering time is determined in a range of 00 ° C and a sintering time in a range of 2 hours to 8 hours. Method. 5. The method according to claim 1, further comprising: winding the metal wire immediately after the extruding step in a spiral shape on a plane like a mosquito coil, so that the metal wire after the winding can be contracted. 3. The method according to claim 2, wherein the bonding step is performed while the metal wire is wound in a spiral shape. 6. A hard powder of hard-to-work hard metal having little flexibility and elasticity, a polymer binder, and a solution of water or an organic solvent are used as at least raw materials, and the raw materials are kneaded. A step of forming a slurry, an extrusion step of extruding the slurry in a string shape to form a metal wire, and after winding the metal wire immediately after the extrusion step in a spiral shape on a plane such as a mosquito coil. Winding process that allows the metal wire to shrink, and at least a sintering process in which the metal wire is sintered to increase its strength while being wound in a spiral shape. A method of manufacturing a metal wire using a hard metal as a raw material.