JP2509125B2 - Welding repair method, welding method and welding apparatus for metal member - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to various metal products including synthetic resin molding dies, rubber molding dies, die casting dies and glass dies (hereinafter referred to as metal members). Welding repair method performed for repair (including correction, the same applies hereinafter) such as relatively fine crushing, scratches, and dimension correction of the welding, the welding method performed for the repair method, and the method used for performing the method. Related to welding equipment.

[0002]

2. Description of the Related Art Conventionally, in the process of newly manufacturing a mold in a mold factory, the following problems have routinely occurred. a) Input error during cutting by NC processing machine such as milling machine, or biting of end mill or drill (overcutting) due to careless mistake due to manual feeding.

B) Biting (overcutting) due to an input error in machining by an electric discharge machine. c) Damage due to secondary discharge (arc discharge) of electric discharge machine,
Bite. d) Too much shaving by hand such as a file. e) Scratch marks caused by dropping or hitting a hammer, tool, etc. due to carelessness, busyness and immaturity of work,
Dents, scratches.

F) The need for padding to change the resin thickness or to prevent burrs during product identification by test molding. g) A padding that corrects the inner corner angle into an R shape by modification or design change. h) Dimension change due to modification or design change. The following problems often occur in molding sites and casting sites using the synthetic resin molding dies, rubber molding dies, die casting dies, and glass dies.

A) The resin enters the parting line, and a dent is formed in the parting line during molding 10 times or hundreds of times. b) Scratches and wear occur on the cavity, core, core pin, bite, etc. during molding. In addition, careless tool hits may occur. In short, there are many needs for relatively fine repairs and corrections of the following metal members in the field.

A) Repair of wear, sagging and crushing of the parting line of the mold. b) Repair of abrasion, sagging, and crushing at the corners of the three vertices. c) Repair of edge sagging and crushing. d) Repair of scratches on the slide part. e) Repairing pinholes.

F) Repairing secondary shrinkage, undercuts, cracks, blowholes and pits after argon welding. g) Repair when the internal angle (corner angle) becomes R due to design change. h) Repair of core pin scoring, chipping of tip, and additional dimension. i) Raising the bottom of the ejector pin and repairing the size addition of the tip.

J) Cutting of rubber mold, cutting of blow mold, and repair of scratches on driving pin. k) Cutting, pushing and repairing butt joints. l) Repair of chipping of rising core with thin plate thickness. m) Repair of a blade-shaped mold part with a sharp tip. BACKGROUND ART Synthetic resin molding dies, rubber molding dies, die casting dies, glass dies, etc. play a central role in mass production, quality improvement, homogenization and cost reduction of industrial products in their respective fields. On the other hand, the production of these molds requires expensive machine tools and specialized operators, and the final finishing process involves the hand-polishing process of skilled workers, which requires a lot of manpower and requires a large amount of cost and production days. And the mold price is 1 million yen at a cheap price, 500 for large molds and precision molds.
There are many things that cost 0,000 yen. For example, a car production line that uses a molded product of a mold must be operated as planned, and if the production line is stopped, a huge penalty must be prepared. Therefore, due to the above-mentioned causes, the mold that has been made is ruined,
The fact that the mold cannot be used due to the above causes is a great blow to the industry in terms of economy and production, and the importance of reusing by repairing the mold is extremely large for many years. Has been a request for. As a conventional die repair method, argon welding (argon TIG welding overlay) is adopted for relatively large repairs. As other methods, a repair method using a build-up with silver brazing, a repair method using a plated build-up, a method of tapping, and a method of nesting are variously implemented. However, each method has merits and demerits, and especially fine repairs are in the state of being a hand.

[0009]

[Problems to be Solved by the Invention] (1) Conventionally, a relatively large bite (overcut), remodeling or design change is
Repair is generally performed by argon welding. But,
After this argon welding, the following troublesome problems occur. First of all, the arc temperature of argon welding is 600
Since the temperature is as high as 0 ° C. to 8000 ° C., when the weld metal in the molten pool contracts, the boundary between the heat-affected zone and the weld metal, that is, the periphery of the bond becomes a concave state, which is a so-called “shrink” problem. The size of the "shrink" varies, but it is usually 1 mm to 4 mm in width and 1/100 mm to 5/100 mm in depth. Further, gas is generated from the mold material itself in the molten pool, and argon gas, air, etc. are confined, so that broholes and pits are easily formed in the weld metal. There is also a problem that the mold is deformed and discolored when residual heat is applied to the mold. In addition, undercut often occurs and becomes a problem. Furthermore, the argon torch interferes with the welding of the narrow portion, making it extremely difficult to perform build-up welding, especially at the inner corner (inner corner). When welding the tip and scratches of the core pin, the entire core pin bends due to the effect of heat, and the nearby mold part, core, which is not related to build-up welding,
Core pins also bend and discolor. Even if a polishing process is performed after the discoloration, the plastic product has a pattern of metal structure change, and the deterioration of the product value due to the poor appearance of the molded product is a drawback. In addition, argon welding is difficult to perform unless you are a skilled welding engineer, small mold parts such as core pins, fine ridges such as parting lines are melted due to high heat, and because of high temperature. In fine welding, there are many problems such as the heat-affected zone and No. 2 becoming brittle and the finishing being difficult due to the large welding surplus. (2) The method of repairing with the build-up with silver brazing is relatively simple and can be done by anyone, and has the characteristic of good weldability.
However, because the mold material cannot be welded, the silver solder is soft, it can be scratched immediately, there is no durability, the mold is deformed and discolored because it heats the whole mold, and there is a problem of re-welding. Sometimes there is a problem that the whole brazing melts. (3) The repair method by plating plating is suitable for repairing a large area. However, there are problems that the plating time is extremely long and unrealistic, the mold material cannot be plated, the welding force is weak and peels off quickly, the mold is corroded by the plating solution, and it poses a danger to the human body. is there. (4) The repair method by hammering out is a method of correcting the parting line by hammering out the mold with chisel, which has been performed for a long time. This method is effective at an early stage. However, it cannot be tapped again, it is not possible to process hard or hardened materials, the place where it can be processed is limited, it is extremely dependent on craftsmanship, the place where the chisel hits is thin and it is not durable, etc. Is a problem. (5) The repair method using the insert has the features that the insert itself is reliable because it is a mold material, and the material can be changed when strength is required. However, there are problems that it takes a long time to repair, and when the cavity (and thus the surface of the product) is scratched, the boundary line of the nest is exposed on the surface, so that it cannot be used.

Therefore, the objects of the present invention are as follows.
(EN) A method for repairing a metal member satisfying the condition (1), and a welding method and welding apparatus used for carrying out the method. B) Welding is strong and durable, and welding repairs that do not cause peeling can be performed. B) Welding repair can be performed with durability equal to or close to that of metal members. C) No adverse effects due to heat will occur near the welded parts of metal members. D) No blowholes, pits, undercuts, shrinkage, or discoloration occur at the weld repair area. E) There is no corrosion or discoloration of metal parts and it is safe for the human body. F) Welding can be started in a relatively short time. G) Does not melt metal parts. H) There is little extra weld metal (extra thickness) and the finish is easy, and hand finishing is also possible. Re) Welding setup is easy and welding work can be done immediately. Nu) Anyone can easily weld without requiring any skill in welding. Le) There is no need for know-how that only an expert can do, such as the residual heat process. Wo) Welding can be repaired on the cavity (surface of the product) without leaving any marks.

[0011]

As a means for solving the problems in the conventional technology. [Means for Solving the Problems], weld repair method for a metal member according to a first aspect of the invention, connects the secondary electrode 2 to metals member 1 , placed an appropriate amount of fine powder welding powder 4 onto the repair portion 3 of the metal member 1, 300 to 1,500 amperes of <br/> large current against the primary electrode 5 locally to the welding powder 4 1 / 1000-4 / 1000 seconds in a short time with energized in pulses to form the metal member 1 two-dot-shaped nugget 6, the extent necessary to repair portions 3 by continuous number of the nugget 6 It is characterized in that the build-up welding of a spot-like, linear, or plane-like shape having a required thickness is performed over the entire length, and then the build-up welding portion 6 is polished and finished.

Further, the invention of claim 2 to 5, a welding method for carrying out welding repair method described above, the first,
The secondary electrode 2 is connected to the metal member 1 and an appropriate amount of fine-grained powdered welding powder 4 is placed on the metal member 1 to locally press the primary electrode 5 onto the welding powder 4 for 300 to 15
00 amps high current of A 1 / 1000-4 / 1000 seconds
Within a short time to form a pulse-shaped nugget 6 on the metal member 1 by energizing it in a pulsed manner. Secondly, a large number of the nuggets 6 on the metal member 1 are continuous or overlapped to cover a necessary range. Performing spot-shaped or linear-shaped or surface-shaped build-up welding with a required thickness. Thirdly, using the magnet piece 7, the welding powder 4 on the metal member 1 is drawn along the line of magnetic force that is narrowed down. rise allowed to the <br/> this welding the welding powder 4 in this rising state locally pressed at the primary electrode 5 and the feature.

Furthermore, the invention of claim 6-7, a welding apparatus used in the practice of the repair and welding method, and the secondary electrode 2 is electrically connected to the metal member 1, the metal member The primary electrode 5 having a strength and shape capable of being locally pressed against the welding powder 4 in the form of fine particles placed on the repairing point 3 of No. 1 and 300 between the primary and secondary electrodes.
A large current of 1500 amps 1 / 1000-4 / 10
It is characterized in that it comprises a power supply device that energizes in a pulse shape within a short time of 00 seconds , and that the magnet piece 7 is used.

[0014]

When a large amount of electric current flows for a moment while the primary electrode 5 locally press-welds the welded powder 4 placed on the metal member 1 (raised), it is said that a large point-like conducting path flows. Microscopic fine sparks are generated by the high-density electric shock of the electric current, and at the same time, due to the Joule heat that is instantaneously generated, among the metals of the welding powder 4 and the metal member 1,
The nugget 6 (melting and solidifying portion = small build-up welding) is melted only at the portion where the next electrode 5 abuts (microscopically minute guide path) and strongly adhered to the metal member 1 with interatomic bonding of metal. Part) is considered to be formed. In other words, when the resistance heat is generated in the metal member 1 and the welding powder 4 in an instant and the metal of the welding powder 4 reaches the melting point, the nugget 6 of the interatomic bond in the form of fusion pressure welding is added because the discharge phenomenon is added. Is also considered to be formed. The fact that welding between dissimilar metals is possible is hard to explain. In any case 1/1
A minute dot-like (about 0.6 to 1.0 mm in diameter) nugget 6 is generated by energizing one pulse for a short time of about 000 to 4/1000 seconds, but the heat generated at this time is locally generated. is intended also for a moment a very high temperature, and the heat <br/> capacity of the metal member 1 is you compared to infinity and large enough it can be said also for fine enough heating of the weld point is negligible, the peripheral portion No heat effect occurs, and discoloration of the metal member 1 does not occur.

Thus, a weld metal (nugget 6) having a diameter of 0.6 mm to 1.0 mm and a thickness of 0.1 mm to 0.2 mm is formed under the pressure melting point of the primary electrode 5. By overlaying the small nuggets 6 (welding metal) continuously or overlapping them in a plurality of layers, overlay welding with a desired thickness in a desired range can be performed. Therefore, after welding, if the surplus of the welded portion 6 is scraped off and polished to finish, the scratches and the like of the metal member 1 are restored to the original state.

By the way, when the metal member 1 is a magnetic material and the welding powder 4 placed on the repaired portion 3 is also a magnetic material, when the magnet piece 7 is brought close to these, the metal member 1 and the welding powder 4 are provided. Is magnetized by magnetic induction,
The welding powder 4 in the form of fine particles exhibits a phenomenon in which it is concentrated and rises along the lines of magnetic force from the surface of the metal member 1 to the magnet piece 7. Therefore, especially for such repair of sagging or ridge of the three vertices of the square, the closer is sharpened one pole of the magnet piece 7 (N pole or S pole) in <br/> destination fine shape, the corner portion Or , the welding powder 4 can be extremely concentrated and risen along the ridge (corner), and the rise of the welding powder 4 can be locally suppressed by the primary electrode 5. Efficient welding and formation of the nugget 6 or continuity or overlap of the nugget 6 is achieved.

[0017]

EXAMPLE An example of the present invention shown in the drawings will be described below.
First, FIGS. 1A to 1C show the wear of the three corners of the metal member 1,
It shows the process of repairing the repaired part 3 (FIG. 1A) due to sagging or crushing, and as shown in FIG. 1B, build-up welding that forms a dumpling shape of a necessary and sufficient size over the range necessary for repairing the repaired part 3 is shown. After that, the surplus of the above-mentioned build-up welded portion 6 is scraped off by using a tool such as scraping and finished by polishing with a grinder or a file to restore the corner 11 of the three vertices (Fig. 1C) to the original. To be repaired.

FIG. 2 is a bird's-eye view showing the procedure of the build-up welding of the above three corners, and FIGS. 3A to 3D show the movement and usage of the primary electrode 5 in the build-up welding in the order of steps. For repairing the corners of the three vertices, the illustrated round bar primary electrode 5 is suitable for use. The welding powder 4 in the form of fine particles is shown in FIG.
Put an appropriate amount on top of the repaired part 3 as shown in (fill).
About 45 to the corner of the welding powder 4 and the metal member 1.
The one pole (S pole) of the magnet piece 7 which is sharpened in a taper shape is brought closer to the direction of °. Then, since the welding powder 4 concentrates on the corners of the welding member 1 along the lines of magnetic force , the primary electrode 5 is attached to the magnet piece 7 and the metal member 1 as shown in FIGS.
Inserted between and moving up and down, left and right while pressing the welding powder 4 locally (dotted) and repeating the dot welding, a large number of point nuggets 6 are continuously and multi-layered. By doing so, overlay welding is performed. When the thickness of the build-up welding is insufficient, an appropriate amount of welding powder 4 is added and placed, and the magnet piece 7 is used to raise the welding powder 4 and press the primary electrode 5 against the welding powder 4 as described above. , Welding is continued by overlapping the nugget 6 in multiple layers.

The principle diagram of the overlay welding is shown in FIGS. 4 and 5 . FIG. 4 shows a case where overlaying welding is performed on the plane of the metal member 1 using the tapered primary electrode 5. Since the tip of the primary electrode 5 increases the current density and locally presses the welding powder 4 placed on the metal member 1 to form a finely restricted current guide path, the tip has a radius of 0.2 to
It is formed in a thin round shape of about 0.5 mm (about the tip of a ballpoint pen). The primary electrode 5 is made of, for example, a silver-tungsten alloy (or brass may be used) in a round bar shape having a diameter of about 3 mm or 5 mm and a length of about 50 mm. As a material of the primary electrode 5, copper is not preferable because it has a property of adhering to and welding to the metal member 1. Since the primary electrode 5 is also alloyed with the nugget 6, a material that is inferior to the alloy cannot be used. The illustrated primary electrode 5 is for manual use . As shown in FIG. 6 , this is inserted into the tip of an electrode holder 8 made of an insulating material such as hard rubber, and a set screw 9
It is fixed in and used. The above-mentioned tip shape of the primary electrode 5 is used by grinding it with a grinder, a filer or the like before or during use to make a shape easy to use.
The primary side of the power supply device is connected to the primary electrode 5 via an electrode holder 8 in the form of a cord 10 as shown in FIG. 6 , for example. The secondary electrode 2 wired from the secondary side of the power supply device is attached to the metal member 1 or laid under the metal member 1 to be electrically connected to the metal member 1. The material of the welding powder 4 changes depending on the material of the metal member 1,
When the metal member 1 is a steel material, iron-nickel alloy powder is preferably used because it has good weldability. When the metal member 1 is steel or stainless steel, the welding powder 4 made of stainless steel can be preferably used. However, since the stainless steel has no magnetism, the magnet piece 7 cannot be used. The materials for these metal powders 4 are commercially available at low cost. The welding powder 4 is used after being processed into particles having a particle size of about 150 to 320 mesh by granulating and powdering the above materials. Welding powder 4
The smaller the particle size, the lower the current value, and the better the weldability. However, there is also a problem that it is difficult to obtain the thickness of the nugget 6, and a grain size of about 200 mesh is considered to be practically appropriate from the viewpoint of current value and weldability. The use of the metal member 1 does not matter. Even if the material of the metal member 1 is conductive,
Copper and aluminum cannot be welded. Berium, copper alloys, aluminum alloys, steel and stainless steel are good base materials. Of course, when the metal member 1 is non-magnetic stainless steel, the magnet piece 7 cannot be used. It has also been confirmed that welding powder of cemented carbide can be welded to a steel material whose surface is nitrided, or cemented carbide. The welded portion of the metal member 1 is pre-treated to remove metal oil, impurities and the like in advance.

As shown in FIG. 4, the power supply device for energizing the above-mentioned primary and secondary electrodes 5, 2 is a household AC10.
When 0 V is used as the power source and the power switch 13 is turned on, welding is possible. Each time the welding operator steps on the foot switch 12, welding of one energization (one pulse) is performed. The magnitude of the welding voltage is AC by the voltage regulator (SL-1) 14.
Adjustment is performed in the range of 0V to 10V. When the foot switch 12 is stepped on (switched on) once, the capacitors C ₁ , C ₂ , C ₃ and C ₄ are charged by the operation of the solid state relay (SSR) 15.
Subsequently, discharge is performed by the thyristor (SCR) 16, and a low voltage, large current (300A to 1500A) flows to the secondary side of the transformer (T ₁ ) 17, which is instantaneously transferred from the primary electrode 5 to the secondary electrode 2. It flows and welding is performed. At this time, the current waveform that instantaneously flows in a pulse shape to the primary electrode 5 is
As shown in FIG. 4, the energization time (1/1000 to
4/1000) and the current value (300A to 1500A) are in inverse proportion. When the foot switch 12 is continuously depressed, the above-mentioned charging and discharging operations are intermittently performed, and continuous welding can be performed. Period of the intermittent operation, the timer -1 8
Is adjusted in the range of 0.3 seconds to 1.5 seconds. Reference numeral 19 in FIG. 4 is a control / display unit of this power supply device. This power supply is manufactured as a lightweight, compact and portable type. When the metal member 1 is repaired by welding, the primary electrode 5 is mounted on the electrode holder 8 as shown in FIG. 6, and the cord 10 thereof is connected to the power supply device by the socket 20. An appropriate amount of welding powder 4 is placed on the repaired portion 3 of the metal member 1 and the electrode holder 8
Grasp the tip of the primary electrode 5 against the welding powder 4 with your hand and switch on the foot switch 12 of the power supply 7 to energize a large current of 300 A to 1000 A in a pulsed manner to form a dot-shaped nugget. It is formed on the member 1. Alternatively, by advancing the primary electrode 5 by a pitch corresponding to the diameter of the nugget so that a large number of nuggets are continuous or overlapped in multiple layers, a dot-shaped, linear-shaped or planar-shaped region having a required thickness over a range required for a repair location is formed. Overlay welding can be performed. When mechanizing the welding work, the primary electrode 5 is attached to a robot hand or the like, and an auto switch attached to the power supply device is used. FIG. 5 shows a case where a round bar electrode having a flat tip is used as the primary electrode 5, and the corner portion of the tip is pressed pointwise onto the welding powder 4 to perform welding. This one
The tip corner portion of the secondary electrode 5 is formed into a rounded corner with a radius of about 0.2 to 0.5 mm.

FIG. 7 shows a case where the ridgeline of the metal member 1 is repaired by welding. The welding powder 4 in the form of fine particles is placed in an appropriate amount along the ridgeline to be repaired of the metal member 1, and welding work is carried out while rolling the primary electrode 5 with a round bar in the ridgeline direction. 8B to 8D show the operation state and angle of the movement of the primary electrode 5 at this time as viewed from the side (side surface direction) and the arrangement of the magnet pieces 7. Welding powder 4, ing and shape which rises centralized on the edge line of the metal member 1 by the magnet piece 7. The primary electrode 5 is pressed against the welding powder 4 having the rising shape in this manner, and is moved as shown in FIGS. 8B to 8D to perform linear build-up welding along the ridge. After that, the surplus of the build-up welded portion 6 is scraped off, and the ridge line of the metal member 1 is repaired to the original state by polishing and finishing.

FIG . 9 shows a procedure for welding and repairing a small repair portion 3 such as a V scratch or a pinhole generated in the metal member 1. That is, welding powder 4 onto a small pinhole.
The primary electrode 5 is strongly pressed onto it and the current is applied to perform welding. When the thickness of the fill is insufficient in one welding, the welding powder 4 is further added and several overlapping weldings are performed. . Finally, the nugget dumpling is hit with a hammer to make the metal structure dense, and the surplus is scraped off, polished, and finished as in the above-mentioned embodiment, and the mirror surface can be repaired.

FIG. 10 shows the procedure of welding repair for R machining of the inner corner of the metal member 1. The appropriate amount of welding powder 4 is placed on the inner corner. The primary electrode 5 has a sharpened tip and is strongly pressed against the welding powder 4 to perform welding. FIG. 11 shows a case where the metal member 1 is repaired by adding the dimensions of a narrow rising portion which is often generated. Place an appropriate amount of welding powder 4 on the upper surface of the rising edge and centralize this by using the magnet piece 7 .
Then , the log electrode 5 is rolled and welded. It is the same as each of the above-described embodiments that the excess thickness is scraped off after welding and the repair is completed by polishing and finishing.

[0024]

EFFECTS OF THE INVENTION The welding repair method, welding method and welding apparatus for metal members according to the present invention have the following effects.
Since the welding powder 4 is free of impurities, the welding repair metal has a strong welding force, is durable, and does not peel off. Further, since a durable alloy (nugget) close to the metal member 1 can be welded, the repaired state of the metal member is perfect.

Since the welding is performed in the form of fine dots, all the heat is absorbed by the metal member 1 and no adverse effects due to the heat occur near the welded portion. Similarly, blowholes, pits,
No undercut or shrinkage, no discoloration. Since the repair method does not use chemicals, the metal member 1 is free from corrosion and discoloration, and is safe for the human body. Further, since the welded portion is small, welding can be performed in a relatively short time.

Since the weld metal has a small amount of extra weld metal (excessive thickness) and is small in size, the subsequent polishing and finishing operations are easy, and hand finishing can be easily performed. Since welding powder without impurities is used, the workability of welding is good, the setup of welding is easy, the welding work can be started immediately, and no welding skill is required, and anyone can easily weld. For example, know-how that only an expert can perform, such as the step of preheating the metal member 1, is not required.

As a result of the above, since it is possible to promptly repair fine defects caused by various causes which are generated in various metal members 1 which are expensive or indispensable in the production process, and to reuse the metal member 1. It greatly contributes to the improvement of economic efficiency of the industrial world and the smooth execution of daily business.

[Brief description of drawings]

1A to 1C are perspective views showing a procedure for repairing a corner sag.

FIG. 2 is a perspective view showing a welding procedure for a corner sag.

3A to 3D are plan views showing a welding process of corner sag.

FIG. 4 is a principle view of a welding device.

FIG. 5 is a principle view of a welding device.

FIG. 6 is a front view of a primary electrode.

FIG. 7 is a perspective view showing how to weld a ridgeline of a metal member.
It

8A to 8D are front views showing a ridge line welding process.
It

FIG. 9 shows a method for welding a pinhole generated in a metal member .
FIG.

FIG. 10 is a front view showing a method for welding and repairing an inner corner.

FIG. 11 In front view showing the welding repair method of the rising part
is there.

[Explanation of symbols]

 1 Metal Member 2 Secondary Electrode 3 Repair Area 4 Welding Powder 5 Primary Electrode 6 Nugget 7 Magnet Piece

 ─────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP 62-134193 (JP, A) JP 62-40987 (JP, A) Tomihiko Teramoto et al. 7-10) Industry newsletter P. 120-125, 131 type technology, 6 ~ 13! (1991) Nikkan Kogyo Shinbun Co., Ltd. The first advertisement page and advertisement page from the back cover (Material request number 65) Mold Shimbun, (Head 3-6-10) Stock Company Mold Newspaper P. 29

Claims (7)

(57) [Claims] 1. A secondary electrode is connected to a metal member, and an appropriate amount of fine-grained powdered welding powder is placed on the repaired portion of the metal member, and the primary electrode is locally pressed against the welding powder to 300 to 1500. a large current of Amp 1 / 1000-4
/ 1000 sec. In the short time of 1000 seconds , a pulse-like current is applied to form a dot-shaped nugget on the metal member, and a large number of these nuggets are made continuous or overlapped to form a dot-shaped nugget with a necessary thickness over the range required for repair. Alternatively, a method for welding and repairing a metal member is characterized in that linear or planar build-up welding is performed, and then the build-up welded portion is polished and finished. 2. A secondary electrode is connected to a metal member, a proper amount of fine-grained powdered welding powder is placed on the metal member, and the primary electrode is locally pressed against the welding powder to form 300-1.
A large current of 500 amps 1 / 1000-4 / 1000
A method for welding a metal member, comprising forming a dot-shaped nugget on the metal member by energizing in a pulse shape within a short time of seconds . 3. A secondary electrode is connected to a metal member, a proper amount of fine powder powder of welding powder is placed on the metal member, and one pole of a tapered magnet is placed on the welding powder of the metal member. The welding powder is made to approach the part and rises along the line of magnetic force that is narrowed down, and the primary electrode is locally pressed toward the welding powder in the standing state.
A large current of 0 to 1500 Amps 1 / 1000-4 / 1
A method for welding a metal member, comprising forming a dot-shaped nugget on the metal member by energizing in a pulse shape within a short time of 000 seconds . 4. A secondary electrode is connected to a metal member, and an appropriate amount of fine-powdered welding powder is placed on the metal member, and the primary electrode is locally pressed against the welding powder to form 300-1.
A large current of 500 amps extent 1 / 1000-4 / 10
A point-like nugget is formed on the metal member by energizing it in a pulsed manner within a short time of 00 seconds, and a large number of these nuggets are continuous or overlapped to form a dot-like or linear shape having a necessary thickness over a necessary range. Alternatively, a welding method is characterized by performing surface build-up welding. 5. A secondary electrode is connected to a metal member, a proper amount of fine powdered welding powder is placed on the metal member, and one pole of a tapered magnet is placed on the welding powder of the metal member. The welding powder is made to approach the part and rises along the line of magnetic force that is narrowed down, and the primary electrode is locally pressed toward the welding powder in the standing state.
A large current of 0 to 1500 Amps 1 / 1000-4 / 1
A point-like nugget is formed on a metal member by energizing it in a pulsed manner within a short time of 000 seconds, and a plurality of these nuggets are made continuous or overlapped to form a dot-like or linear shape having a necessary thickness over a necessary range. Alternatively, a welding method is characterized by performing surface build-up welding. With a secondary electrode 6. is electrically connected to the metal member, the fine powder locally can be pressed strength and shape to the welding powder which is placed on the repaired portion of the metallic member 3 between the primary electrode and the primary and secondary electrodes
A large current of 00 to 1,500 amps 1 / 1000-4 /
A welding device comprising a power supply device which energizes in a pulse shape within a short time of 1000 seconds . With a secondary electrode 7. is electrically connected to the metal member, the fine powder locally can be pressed strength and shape to the welding powder which is placed on the repaired portion of the metallic member A primary electrode, a magnet piece that approaches the metal member and a welding powder in the form of fine-grained powder placed on the metal member in an appropriate amount to magnetize the welding powder and raise the welding powder along a line of magnetic force that is narrowed down; 30 between secondary electrodes
A large current of 0 to 1500 Amps 1 / 1000-4 / 1
A welding device comprising a power supply device for energizing in a pulse shape within a short time of 000 seconds .