JPH06122080A - Resistance welding method of aluminum material and insert member - Google Patents

Abstract

PURPOSE:To execute the high efficiency of the resistance welding of aluminum material and provide a stably welded product by effectively preventing generation of galvanic corrosion or the like. CONSTITUTION:An insert member to be interposed at the joining surface is made of the powder 23 where at least one kind of the substance to be selected from Ti, Cr and Mo is mixed in at least one kind of substance to be selected from Fe, Ni and Co. Interposition of this insert member allows oxide films 22, 24 on the surface of aluminum plates 21, 25 to be removed during electrification, and to be composited or alloyed after electrification.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resistance welding method for aluminum-based materials such as aluminum and aluminum alloys (hereinafter referred to as aluminum-based materials) and an insert member used for the resistance welding.

[0002]

2. Description of the Related Art As one of conventional methods for joining aluminum plate materials (aluminum-containing alloy plate materials), there is a method disclosed in Japanese Patent Application Laid-Open No. 58-47576. In this method, an anodic oxide film or a chemical oxide film is formed in advance on the overlapping parts of aluminum plate materials and welded.For example, the work is subjected to margin coating and then immersed in a sulfuric acid bath or the like to form the anodic oxide film. Then, the part is welded.

However, in this method, not only the number of steps until welding is large, but also a processing bath is required, so that there is a disadvantage that the cost becomes high.

Further, in general, when performing resistance welding of an aluminum plate material, since the aluminum material has high electric conductivity, it tends to be necessary to increase a pressing force and a welding current. Moreover, an oxide film is formed on the surface of the aluminum plate material, which becomes a resistor and is sandwiched between the electrode tip and the work contact surface, so that heat is also generated in this part, resulting in dust, welding, etc. There were problems such as deterioration of the appearance quality. In addition, the occurrence of dust, welding, etc. also affects the life of the electrode tip and has the drawback of shortening the life.

Further, as another prior art, Japanese Patent Laid-Open No. 63-
The ones disclosed in JP-A-278679 and JP-A-55-100882 are known.

[0006] In Japanese Patent Laid-Open No. 63-278679, the insert material (plate material) is provided in advance at the welding location, so that there is a drawback that it is wasteful and costly. On the other hand, in the above-mentioned JP-A-55-100882, since the insert material is a plate-like solid material such as a disk shape or a plate shape, it is necessary to set the insert material at each welding point. Therefore, this is good when the work is a single work (one welding is completed with one spot), but there is a drawback that the work becomes difficult when the work welded portion is continuous. In addition, since a plate-shaped solid material is used as the insert material, there is a drawback that the cost is increased.

Further, as a technique for interposing a substance which increases the inter-plate resistance between the plates to be welded, JP-A-64-62284 and JP-A-63-1 are disclosed.
There are Japanese Patent Laid-Open No. 19988 and Japanese Patent Laid-Open No. 1-254388. All of these plate materials are galvanized steel plates, and inclusions are Al ₂ O ₃ (particle size 50 to 500 μm), mending tape (thickness 0.1 mm), and salt particles (particle size 25).
0 μm) and MnSi ₂ (particle size 100 μm).

[0008] These methods increase the resistance of the site by inserting inclusions, thereby reducing the current and shortening the energization time, reducing the loss of zinc from the two, and improving the corrosion resistance. It is intended to improve and prolong the life of the electrode. In addition, the strength is improved by forming a nugget between the welded plates.

However, if the above inclusions are used for the aluminum-based material to be welded according to the present invention, the welding characteristics are rather deteriorated, and such inclusions cannot be applied to the present invention. The reason is as follows.

The surface of the aluminum plate material is easily oxidized and is usually covered with Al ₂ O ₃ which is an oxide film thereof.
The affinity between aluminum and oxygen is about 100 times greater than the affinity between Zn and O ₂ . Therefore, the film thickness of Al ₂ O _{3 on} the surface of the aluminum plate material is much thicker than the oxide film on the surface of the galvanized steel sheet. Moreover, further the use of for Al ₂ O ₃ inclusions from the resistivity of the Al ₂ O ₃ [rho large as ^{1 × 10 16 Ω · cm (} 14 ℃), becomes too large the resistance between the welding electrodes, We can no longer weld. In this case, JP-A-64-62284
If a particle size as large as 50 μm to 500 μm is used, as in Japanese Patent Publication No. JP-A-2003-96, the resistance becomes even higher and welding becomes even more impossible.

Moreover, regarding the welding strength after welding, since the inclusions are used, it is only expected that the strength will be improved due to the reduction of the thermal effect on the base material. That is, when using Al ₂ O ₃ as inclusions, since the Al ₂ O ₃ is inclusion weld members not be alloyed or combined by welding, welding by the complexing or alloying This is because the strength cannot be improved.
Rather, when the plate material to be welded is an aluminum plate material, if Al ₂ O ₃ grains having a grain size of 50 to 500 μm are interposed, the strength rather deteriorates, and under stress, the Al ₂ O ₃ grains also become a fracture source. In addition, when a mending tape is used as an inclusion, the mending tape itself is too thick, so that electricity cannot be passed between the welded plate materials as in the case where Al ₂ O ₃ is used. Cannot be done.

Further, if salt grains are used as inclusions, the welding strength between the aluminum plate materials will be reduced.

Furthermore, the plate material to be welded is aluminum-based.
Material, MnSi as an inclusion ₂When using
In addition, Mn and Si cause a needle-like phenomenon, which causes
Weld strength is reduced.

The present invention has been made by paying attention to the above-mentioned problems. By interposing a metal insert member between the aluminum plate materials to be welded, the efficiency of resistance welding is improved, and the occurrence of electrolytic corrosion or the like occurs. It is an object of the present invention to provide a resistance welding method for an aluminum-based material and an insert member capable of effectively suppressing the above-mentioned problem and obtaining a stable welded product.

[0015]

According to the present invention, in the resistance welding method for an aluminum-based material in which an insert member is interposed when the aluminum-based material is resistance-welded, the insert member is made of Fe, Ni and Co. Ti, Cr and Mo as at least one substance selected from
Is a powder in which at least one substance selected from the above is mixed, the insert member is interposed in the joining surface, the oxide film on the surface of the aluminum-based material is removed at the time of energization, and it is compounded or alloyed after energization. A resistance welding method for an aluminum-based material is obtained.

Further, according to the present invention, when the aluminum-based material is resistance-welded, the insert member is interposed on the joint surface, and the insert member is 62% by weight ≦ Fe + N.
At least one substance selected from Fe, Ni and Co having a composition range of i + Co ≦ 96% by weight, 4% by weight ≦ Cr + Ti + Mo + W + Nb + Al ≦ 38% by weight
An insert member is obtained which is composed of a mixture of at least one substance selected from Cr, Ti, Mo, W, Nb and Al having the composition range of.

Aluminum material has a high electric conductivity, and when performing resistance welding, compared with SP steel sheet and galvanized steel sheet, a large current,
Requires high pressure. Therefore, in order to maintain sufficient heat generation and enable welding, increase the current-carrying area by increasing the current-carrying area (increasing the electrode tip diameter), or increase the resistance of the weld between aluminum materials. Need to let.

Now, as shown in FIG.
Insert member 1 for increasing the work resistance between 12
When 5 is inserted, a preferential heat generation portion is provided in that portion, so that it becomes possible to increase the Joule heat generation efficiency and limit the generation portion. At this time, if the conditions such as the amount, type, particle size, and particle size of the insert member 15 are appropriately determined, it is expected that a great effect can be obtained by a simple method of interposing a substance between the works.

If the insert member 15 to be interposed between the works is made of powder, flash should occur for a very short time at the beginning of energization. This is because the powder has a small contact grain area and a large current concentrates there.

On the other hand, the surface of the aluminum material is generally covered with Al ₂ O ₃ which is an oxide film. Therefore, during resistance welding, the oxide film having high electric resistance is sandwiched between the aluminum-based material and the aluminum-based material. Therefore, it is considered that this portion is first melted by energization, but it is well known that the aluminum material has high thermal conductivity and the nugget moves to the upper or lower part of the oxide film. Especially in the case of direct current, this phenomenon is remarkable, and the nugget is biased to the + side. This is a phenomenon that is often seen in TIG welding, but eliminating the effect of such an oxide film,
It is thought that bringing the nugget to the center will improve weldability. In order to eliminate the influence of the oxide film, it is preferable to destroy this oxide film, but in this case as well, a powder having a high resistance, at least as compared with an aluminum-based material that is a base material or the like, is interposed between the oxide films. It is considered appropriate to let

Now, in consideration of the above, when the powder is interposed between the aluminum plate materials to be welded, as shown in FIG. 2, the aluminum plate materials 21 and 25 face each other through the powder 23, and a large current outlet is formed. Since it will be limited, it can be easily estimated that the arc will fly. This is a plasma state and has sufficient energy to destroy the oxide films 22 and 24. When the current value is about several KA (direct current) or several hundreds A, the energy obtained by this flash is several tens generated on the aluminum plate materials 21 and 25.
It has the ability to destroy the μm-thick oxide films 22 and 24. Therefore, the oxide films 22 and 24 are removed by flashing, a clean metal surface appears, and this is welded.

Electrode 1 after energization and flashing
Considering the resistance between 3 and 14, as shown in FIG. 1, the internal resistance 31 of the electrode 13, the contact resistance 32 between the electrode 13 and the work 11, the resistance 33 in the work 11, the work 11-the insert member (powder). 15-Workpiece 12 (contact) resistance 3
4, a series resistance of the resistance 35 in the work 12, the contact resistance 36 between the work 12 and the electrode 14, and the internal resistance 37 in the electrode 14. Among them, in resistance welding, as is well known, when the resistance 34 is overwhelmingly larger than other resistances, welding with high efficiency and high welding strength can be performed. An insert member (powder) 15 sandwiched between clean metal surfaces created by the flash is arranged to raise and control this resistance 34.

Therefore, after flashing, the temperature rise of the metal on the clean metal surface, so-called Joule heat generation, selectively occurs here. As the temperature rises, the electric resistance further exponentially rises, so that this portion is melted in time and is compounded or alloyed with the interposed insert member (powder) 15.

In the latter stage of welding, the energization is stopped, and heat conduction causes the heat of the melted portion to diffuse to the base material and the electrode. At this time, the insert member (powder) 15 used is included in the nugget and solidifies as the contact portion melts. Since the thermal conductivity of the insert member (powder) 15 is usually about 1/1000 of that of the base material aluminum, the cooling rate is moderated.

In the conventional resistance welding of aluminum materials, the cooling rate at this time is extremely fast, so that
Cracks were likely to occur at the interface between the peripheral structure and the weld, and even if a post-heat current was passed, the thermal conductivity was too good and a large effect could not be expected.However, according to this method, the post-heat current is sound enough to be unnecessary A different organization was obtained.

FIG. 3 shows these welding models. It is easy to think that there will be a time lag due to the flash area, but after the flash, a clean metal surface will be welded, so the current rises sharply after that, and in fact, it becomes faster than the delay. Of.

Further, the interposed insert member (powder) 15 must be selected so as to be composited or alloyed with the material of the work and not to deteriorate the strength of the material. It is preferable to select so as to increase the strength and rigidity of the (material) weld zone by compounding or alloying.

As described above, in the case of aluminum-based material, Al ₂ O ₃ which is an oxide film is formed on the surface (see FIG. 2). Therefore, the aluminum plates 21, 2
In addition to the particle size of the powder 23, the oxide film 22
And 24 film thicknesses will be added. The specific resistance of Al ₂ O ₃ which is the oxide films 22 and 24 is about 1 × 1.
Since it is as high as 0 ¹⁶ Ω · cm, aluminum plate materials 21, 25
In order to pass a large current that enables welding between them, it is necessary that the resistivity of the powder 23 to be interposed is not too large.

For example, when a powder made of Al ₂ O ₃ is used as the powder 23, the specific resistance of Al ₂ O ₃ is large, so if the resistance value of the powder 23 is reduced, the particle size thereof is reduced. Will have to be reduced. On the other hand, since the surface of the aluminum plate materials 21 and 25 originally has irregularities, the particle diameter of the powder 23 becomes small, and if the degree of irregularity is equal to or less than this, the oxide films 22 and 24 come into contact with each other. As a result, the significance of interposing the powder 23 is lost. Therefore, the material of the powder 23 to be interposed is required to have a small specific resistance. A metal is considered as a material satisfying this requirement.

Further, since the aluminum material is melted during welding of the aluminum material, the aluminum material is powder 2
The powder 23 is taken in by being compounded or alloyed with the material of No. 3. Since aluminum materials are generally brittle, it is necessary to prevent impact failure when an object is hit. Therefore, the substance used for the powder 23 is preferably a substance that strengthens the aluminum material when incorporated into the aluminum material. Examples of such materials include Ni and C among metals.
o and Fe are preferable. In addition, although these materials can be used alone, a plurality of materials can be used at the same time.

The grain size of Ni, Co and Fe is 2
It is preferably in the range of 00 μm or less, and more preferably in the range of 5 to 100 μm. If the particle size is larger than this,
The resistance value of the powder 23 becomes too large, and it becomes difficult for the current necessary for welding to flow.

When the particle size and particle size are small, the powder coating layer may be composed of many particles. That is, when using a particle size smaller than this, it becomes possible if the powder is overlaid on the powder and the thickness of the overlaid layer falls within the specified range.

As the material of the powder 23, Fe, Ni, Co
In the case of using, the large current concentrates on the portion where the powder 23 is in contact with the oxide films 22 and 24, so that flash occurs at the initial stage of energization. The oxide films 22 and 24 are removed by this flash, the clean metal surfaces of the aluminum plate 21 and the aluminum plate 25 are exposed, and welding is performed from this portion. As a result, these metals have lower thermal conductivity than Al, so this metal part is preferentially heated, and when heated, the electrical resistance becomes higher, and this metal part is heated more and more to the end. To melt.

While these metals have the function of increasing the welding strength when incorporated in an aluminum material, they may cause electrolytic corrosion. Therefore, in the above metals,
By mixing at least one selected from Ti, Cr, Mo, etc., the corrosion resistance including weather resistance can be improved, and a stable molten product can be obtained.

The present invention can be applied not only to aluminum plate materials, but also to aluminum-based materials such as aluminum alloys.

The powder 23 is applied to the joint surface by applying a solution in which the powder 23 is mixed. This solution is preferably vinyl acetate, nitrocellulose, polystyrene, polyacrylic resin, binder such as melamine resin, acetone, alcohol, thinner system,
It is prepared by using a solvent such as triene or hexane, a developing agent such as (ethyl) cellosolve, ethyl phthalate or butyl phthalate, and a drying control agent such as butyric acid. The combination of these is optional.

Further, a tape member may be used instead of the above solution in order to interpose the powder 23 on the joint surface. That is, a metal tape in which powder 23 is vapor-deposited on a thin tape member having a thickness of about 5 μm is prepared, and the metal tape is attached to the joint surface.

Further, the powder 23 is temporarily attached to the tape member, and the tape member is once attached to the joint surface.
The powder 23 can be left on this joint surface by removing the tape member.

Furthermore, by substituting the powder 23 for use, vacuum melting this powder, forming a foil plate-like body of about several tens of μ, and adhering this foil plate-like body to one joint surface. It is also possible to interpose an insert member on the joint surface.

[0040]

EXAMPLES Example 1 The member to be welded has a plate thickness of JIS A5052P equivalent 2.
The aluminum material was 0 mm, and two aluminum materials were superposed and welded. Welding is performed using a DC resistance welding machine, and the welding conditions are welding current of about 8 KA.
-40 KA, energization time was 15 cycles. The electrodes used were chromium copper φ16 × 190 mm (water cooling). The powder to be interposed between aluminum materials has an average particle size of 1
A powder having a particle size of about 0 μ or less and a compositional substance and a compounding ratio thereof are as shown in FIGS.
6, No. 29 and No. 34). This powder is 10g / 100m in a mixed solution of melamine, acetone, alcohol, ethyl cellosolve and butyl phthalate.
It was dispersed for about 1 l, and was interposed on the joint surface by drying after dipping.

Therefore, the welding current value and the tensile shear strength at which the nugget diameter corresponding to the Class B guaranteed value 5√t (t is the plate thickness) is obtained are measured, and the powder sandwiched between the members to be welded is measured. An experiment was conducted to detect what kind of change the welding current shows. Further, the nugget diameter generated by spot welding is about 1.15 times the Class B guaranteed value 5√t in the conventional method, that is, the welding method in which no insert member is interposed on the joint surface. A continuous dotability test was conducted by multiplying the current value at which each class B guaranteed value of 5√t was obtained by 1.15. In FIG. 4 to FIG. 8, the continuous hitting number column, the left side shows the number of hitting points satisfying the tensile shear strength, and the parentheses on the right side of this column () indicate the same at the level judged as 15 points by the conventional method. This is a comparison and shows the number of continuous dots having a quality that can be distributed as a product in appearance.

The result was judged as a nugget satisfying the class B guaranteed value 5√t and the tensile shear strength of class A 7
The test was carried out on the basis of satisfying 50 kgf, and having no external appearance deformation, surface irregularities and dust. As a result,
Compared with the conventional method, the current value at which the nugget diameter of Class B guaranteed value 5√t was obtained was reduced to about 1/2 or less in all of FIGS. 4 to 8. In addition, the values in parentheses of the number of continuous dots are the same comparison at the level judged as 15 dots in the conventional method, and in this example, the continuous dot property that can be achieved as a product is remarkably improved and the electrode life is improved. The effect of being improved all at once was obtained.

Further, according to the conventional method, when a member to be welded having a plate thickness of 2.0 mm was welded, blow holes having a maximum of about 1.5 mm and an average of about 1.0 mm were confirmed in the generated nugget. In this embodiment, almost no blowholes of this kind have occurred. This is because the blowholes are generated by the H ₂ gas contained in the aluminum material, and when the powder is interposed between the members to be welded as in this embodiment, the powder has a higher thermal conductivity than the aluminum material. Low,
Compared with the conventional method, it is possible to suppress the local concentration of blowholes due to the delay in solidification, and the surface oxygen and adsorbed oxygen present on the surface of the powder and the carbon of the organic matter used as a binder act effectively. It is thought that there is. That is, hydrogen, which causes blowholes in the aluminum material, is consumed by the reaction shown in FIG. The generated H ₂ O and CH ₄ molecules are larger than H ₂ and are removed to the outside at the time of melting before forming the nugget, so that not only blowholes but also grain boundary cracks are prevented as much as possible. be able to.

Next, a corrosion acceleration test was performed on the welded welded product using various powders having the composition ratios shown in FIGS. 4 to 8. That is, as shown in FIG. 10, only the nugget portions of the works A and B are brought into contact with each other, and a potential difference is given from the outside to promote corrosion, and the work is immersed in the ion-exchanged water C. Then, after a certain time has elapsed, it is broken,
The strength and corrosion conditions were checked. As a result, it was found that the breaking strength was excellent and the corrosion was small as compared with the conventional method. Particularly, in the conventional method, the tensile shear strength is reduced by 10 to 15%, which is considered to be because the cracks generated in the welded portion grew during the corrosion test.

In this case, in the present embodiment, at least one substance selected from Fi, Ni and Co is added to Ti and C.
By interposing a powder in which at least one substance selected from r and Mo is mixed in the joint surface, a current value that can obtain a desired nugget diameter is about 1/2 of that obtained when no powder of this type is used. It is possible to obtain an effect that the welding quality can be improved and the corrosion resistance can be improved in addition to the decrease below. At that time, No. 1 in FIG. As shown in 3, when Cr + Ti + Mo + Nb + W is 2% by weight,
The tensile shear strength does not satisfy Class A (750 kgf), and the continuous dot property is not so much improved. On the other hand, N in FIG.
o. As shown in 34, Cr + Ti + Mo + W + Nb +
If Al is 38.5% by weight, the same problem will occur. Therefore, 4% by weight ≦ Cr + Ti + Mo + W +
By setting the composition range of Nb + Al ≦ 38% by weight, it becomes possible to easily improve the continuous hitting property.

Further, by mixing at least one substance selected from Cu, Zn, Mg and Si in the powder, it is possible to stabilize the member itself of the welded portion of the work and to prevent electrical corrosion and aging. Various effects are obtained (see FIG. 7).

Incidentally, in FIG. 29 ☆ (See Fig. 7)
The relationship between the welding current and the nugget diameter when the powder of No. 3 is used is shown. The desired nugget diameter, which could not be obtained with a welding current of 30 KA or more in the conventional welding method, is obtained in the vicinity of 11.5 KA in the present embodiment, and the welding current is reduced all at once. Example 2 As an insert member, No. 2 shown in FIG. The composition of 16 * is selected, the composition is vacuum melted, then thinly cut, and further pressed to form a foil plate-like body of several tens of μm.
Then, in the same manner as in Example 1, as a member to be welded, A505
2P equivalent product, plate thickness 2.0 mm, 2 sheets stacked, with foil plate-like body stuck to one welded member, energization time 15 cycles, water cooled chrome copper φ16 × 190 mm as electrode, Welding tests were performed at welding currents of 8 KA to 40 KA.

As a result, the relationship between the welding current and the nugget diameter and the relationship between the welding current and the tensile shear strength are shown in FIG.
2 and FIG. 13. As a result, a slight increase in welding current is seen compared to the one using powder,
It is stable enough in strength. In addition, blowholes and cracks due to rapid heating and cooling were hardly generated, and good welded products were obtained.

[0049]

As described above, according to the present invention, by using the insert member, the welding current can be easily reduced and the energization time can be shortened. Furthermore, as the insert member, a powder based on at least one substance selected from Fe, Ni and Co is used, and Ti is contained in the powder.
At least one substance selected from Cr and Mo is mixed. Therefore, corrosion resistance including electrolytic corrosion resistance is improved, and stable welding quality can be secured. Moreover, Cr, Ti, Mo, W,
By selectively mixing Nb and Al, the continuous spotting property is further improved, and it becomes possible to effectively prevent the reduction of the electrode life.

[Brief description of drawings]

FIG. 1 is a diagram for explaining a resistance welding method of an aluminum-based material in which an insert member is interposed on a joint surface.

FIG. 2 is a diagram for explaining a method of resistance welding by interposing powder between aluminum plate materials.

FIG. 3 is a diagram for explaining a welding model of the present invention and a conventional method.

FIG. 4 is an explanatory diagram of a composition ratio of powder and a determination result.

FIG. 5 is an explanatory diagram of a composition ratio of powder and a determination result.

FIG. 6 is an explanatory diagram of a composition ratio of powder and a determination result.

FIG. 7 is an explanatory diagram of a composition ratio of powder and a determination result.

FIG. 8 is an explanatory diagram of a composition ratio of powder and a determination result.

FIG. 9 is an explanatory diagram showing a reaction of H ₂ in Al.

FIG. 10 is a schematic explanatory diagram of a corrosion acceleration test.

FIG. 11 is a diagram showing the relationship between welding current and nugget diameter in the second embodiment.

FIG. 12 is a relationship diagram between a welding current and a nugget diameter when using powder and a foil plate.

FIG. 13 is a graph showing the relationship between the welding current and the tensile shear strength when using powder and a foil plate.

[Explanation of symbols]

 11, 12 ... Work to be welded 15 ... Insert member 21, 25 ... Aluminum plate material 22, 24 ... Oxide film 23 ... Powder

Claims (5)

[Claims] 1. A resistance welding method for an aluminum-based material, wherein an insert member is interposed during resistance welding of the aluminum-based material, wherein the insert member is made of Fe, Ni and C.
a powder in which at least one substance selected from Ti, Cr and Mo is mixed with at least one substance selected from o, the insert member is interposed in the joint surface, and the aluminum-based material surface A resistance welding method for an aluminum-based material, comprising removing an oxide film and compounding or alloying after energization. 2. The method according to claim 1, wherein a solution obtained by mixing a powder that is an insert member is applied to the joining surface of the aluminum-based material, the oxide film on the surface of the aluminum-based material is removed during energization, and after energization, A resistance welding method for an aluminum-based material, which is characterized by compounding or alloying. 3. The method according to claim 1, wherein the powder that is the insert member is melted to form a foil plate-like body, and the foil plate-like body is interposed between the joining surfaces of the aluminum-based material, and the aluminum plate is energized. A resistance welding method for an aluminum-based material, which comprises removing an oxide film on the surface of the material and forming a composite or an alloy after energization. 4. An insert member to be interposed in a joint surface during resistance welding of an aluminum-based material, the insert member comprising Fe, Ni and Co having a composition range of 62% by weight ≦ Fe + Ni + Co ≦ 96% by weight. 4% by weight ≤ Cr + Ti + Mo in at least one selected material
C having a composition range of + W + Nb + Al ≦ 38% by weight
An insert member comprising a mixture of at least one substance selected from r, Ti, Mo, W, Nb and Al. 5. The insert member according to claim 4, wherein
An insert member comprising at least one substance selected from Cu, Zn, Mg and Si having 0.2 wt% ≤ Cu + Zn + Mg + Si ≤ 10.0 wt%.