JP3345883B2 - Arc welding apparatus and arc welding method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to an arc welding method in which a welding wire is fed while welding is performed at a high speed. And an arc welding method.

[0002]

2. Description of the Related Art When performing arc welding while feeding a welding wire, for example, an arc welding apparatus as shown in FIG. 11 is used.

An arc welding apparatus 11 shown in FIG. 11 has a power supply tip 12 supported by a support mechanism (not shown), and has a welding wire passage hole 12H formed at the center thereof so that the welding wire 13 can be fed. It has a structure in which a shield gas nozzle 14 for supplying a shield gas is provided therearound.

In arc welding to the base material 15 to be welded, a power source (not shown) is connected to apply a voltage between the power supply tip 12 and the base material 15 to be welded, and the gas nozzle 14 for supplying the shield gas is used for the welding. Supply shielding gas,
A welding wire supply roll (not shown) is driven to feed the welding wire 13.

At this time, as a shielding gas, a mixed gas mainly composed of carbon dioxide gas or argon gas and added with carbon dioxide gas or oxygen gas is used.

[0006] The welding current is adjusted to perform arc welding in an arc form such as transition of short-circuit, transition of granularity, transition of spray, and transition of droplet controlled by pulse control.

[0007] In the arc form according droplet transfer pulse control Of these, I ² · in a state in which the welding wire 13 is held between the welded preform 15 without short-circuited with the welding base material 15 a predetermined distance After resistance heating by R, small droplets formed by arc heating are transferred to the base material 15 to be welded, so that a considerably good weld bead is formed.

In this pulse control transfer type arc welding,
The droplet is forcibly transferred by spraying by instantaneously increasing the current while the average current is small,
Although it is suitable as a welding method without spatter generation, when the welding speed is increased, the width of the arc becomes wider than the width of the weld bead, and both ends of the weld bead are exposed to the arc. In the conventional method having a small number, problems such as undercut, breakage of bead, generation of humping bead, and the like are liable to occur, and there is a problem that welding quality may be deteriorated.

In order to solve such a problem, an arc welding apparatus as shown in FIG. 12 has been developed.

The arc welding apparatus 21 is provided with a welding wire 2
The power supply tip 23 having the welding wire passage hole 23H through which the welding wire 2 passes, and the insulating tip 24 also having the welding wire passage hole 24H formed therein are joined to form the welding wire passage hole 24H.
And a wire guide chip 25 also formed with a welding wire passage hole 25H.

In such an arc welding apparatus 21,
A power supply (not shown) is connected to apply a voltage between the power supply tip 23 and the base material 26 to be welded, and a shield gas is supplied from a shield gas nozzle (not shown), and a welding wire supply roll (not shown) is driven to drive the welding wire 22. Send.

At this time, the connection of the power source to the welding wire 22 is performed via the power supply tip 23,
When the tip of the wire comes into contact with the base material 26 to be welded, the temperature of the welding wire 22 rises due to electric heating, and the welding wire 22 melts.
An arc between the welding base material 26 is formed, droplets from the tip of the welding wire 22 is welded bead by moving toward a welding base material 26 is formed, during which the welding wire 22 is I ² The temperature is increased in advance by resistance heating by R.

In such an arc welding apparatus 21, the distance from the tip of the power supply tip 23 to the tip of the arc is longer than that of the conventional one, so that the welding wire can be sufficiently heated. The welding current can be increased even when welding is performed, the welding current decreases when the wire feed speed is constant, and the arc force is almost proportional to the welding current, so the arc force can be suppressed, resulting in undercutting No defect occurs, and a high-quality weld bead is formed.

[0014]

As described above, by increasing the distance from the tip of the power supply tip 23 to the tip of the welding wire 22, power supply heating (I ² R heating) of the welding wire 22 can be performed well. Therefore, even when high-speed arc welding is performed, there is no problem such as undercut or the like, and since the heated welding wire 22 is guided by the wire passage hole 25H of the wire guide chip 25, no bending occurs. In addition, the welding line is not displaced, so that good welding can be performed. However, there is a problem that it may take time to adjust the protrusion length of the welding wire. Since three parts of the guide chip 25 are to be fastened, two fastening parts are formed, and the adhesion at the fastening parts is not good. In the case where the relationship between the diameter and the size of the welding wire passage hole formed in the three parts and the characteristics (especially, thermal conductivity, etc.) of the insulating tip 24 provided in the middle are not appropriate, the gas shield arc welding is necessary. There has been a problem that the wire feedability and the arc stability may not be improved.

[0015]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned conventional problems, and can improve wire feedability and arc stability required for gas shielded arc welding. It is an object of the present invention to enable high-speed welding without problems such as undercut and the like, and at the same time, to form a good weld bead by reducing generation of spatter.

[0016]

According to a first aspect of the present invention, there is provided an arc welding apparatus for supplying a welding wire while continuously supplying power to a welding wire via a power supply tip provided on a torch body. In an arc welding apparatus, an insulating guide is screw-connected to a side of a base material to be welded of the power supply tip, and
The depth h of the thread is formed on the feed tip
Make the height smaller than the height H of the
Angle of the concave surface at the end face of the thread
The inclination of the convex surface at the end face of the external thread formed on the power supply tip
Make the angle smaller than the angle
To form the welding wire passing hole opening peripheral end at the threaded part
Welding wire passing through the external thread formed on the feed tip
A special feature is that the peripheral edge of the hole opening is always in close contact.
It is a sign. Also, as described in claim 2,
Similarly, in the arc welding equipment,
The insulation guide was screwed to the material side to form the insulation guide
The depth h of the female thread is determined by the height of the male thread formed on the feed tip.
To be smaller than H and to be formed on the insulation guide
The radius of curvature R of the concave surface at the end face of the screw
From the radius of curvature r of the convex surface at the end face of the formed male thread portion
And at least make it into the insulation guide
Edge of the welding wire passage hole opening and the power supply tip at the joint
Of the opening of the welding wire passage hole in the external thread formed in the hole
It is characterized in that the part is always in close contact .

Further, in the arc welding apparatus according to the present invention, as described in claim 3 , as a material of the insulating guide, a bending strength at room temperature of 300 MPa or more,
Thermal expansion coefficient is 8.0 × 10 ⁻⁶ / ° C or less, thermal conductivity is 1
A material having a temperature of at least 00 W / (m · K), a thermal shock temperature of at least 300 ° C., and an electric resistance of at least 10 ¹ Ω · cm can be used.

[0018]

Similarly, in the arc welding apparatus according to the present invention, as described in claim 4 , the diameter a (mm) of the welding wire passing through the power supply tip and the diameter b (mm) of the welding wire passing through the insulating guide. A ≦ b a = d × (1.03 to 1.18) b = d × (1.18 to 1.70) in relation to the diameter d of the welding wire, and in some cases, b =
d × (1.20 to 1.70).

[0020] Also, in the arc welding apparatus according to the present invention, as set forth in claim 5, with respect to the power feed tip of the welding wire passage hole diameter a (mm), the axis of the welding wire passage bore of the insulating guide Exceed a * 0% to a * 20%
The eccentricity can be set in the following range.

The arc welding method according to the present invention is characterized in that
As described in 6 , the relationship between the amount of Nb and the amount of Al in steel using the arc welding apparatus according to any one of claims 1 to 5 is expressed as follows: Nb (%) ≧ −2.5 × Al (%) + 0.10 is used, for example, as described in claim 7 , the weight%
And C: 0.01-0.15%, Si: 0.15-1.
35%, Mn: 0.50 to 1.80%, P: 0.025
%, S: 0.025% or less, Cu: 0.50% or less, Cr: 0.50% or less, Ni: 0.50% or less, M
o: 1.00% or less, Al: 0.30% or less, Ti:
A welding wire consisting of 0.30% or less, Nb: 1.20% or less, the balance being Fe and impurities, and having Nb (%) ≧ −2.5 × Al (%) + 0.10 can be used.

Similarly, in the arc welding method according to the present invention, as described in claim 8 , a welding wire having a volume resistivity ρ of 32 μΩ · cm or less can be used.

Similarly, in the arc welding method according to the present invention, as described in claim 9 , the arc welding apparatus according to any one of claims 1 to 5 is used, and the insulation guide is used. Apparent length L (m
m) is in the range of 10 to 25 mm, and is characterized in that arc welding is performed.

Similarly, in the arc welding method according to the present invention, as set forth in claim 10 , claim 1 is provided.
The present invention is characterized in that the arc welding apparatus according to any one of ( 5 ) to ( 5 ) is used to perform arc welding by applying to the consumable electrode type arc welding.

Similarly, in the arc welding method according to the present invention, as described in claim 11 , claim 1
The present invention is characterized in that the arc welding apparatus according to any one of ( 5 ) to ( 5 ) is applied to non-consumable electrode type arc welding to perform arc welding.

Similarly, in the arc welding method according to the present invention, as described in claim 12 , claim 1
The distance E from the tip of the power supply tip to the base metal to be welded is set to 14 to 4 using the arc welding apparatus according to any one of (1) to ( 5 ).
It is characterized in that arc welding is performed within a range of 8 mm.

[0027]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An arc welding apparatus and an arc welding method according to the present invention have the above-described configuration, and an arc welding apparatus as shown in FIG. 1 can be used.

The arc welding apparatus 1 includes a torch body 2
A power supply tip 4 made of a conductive material and having a welding wire passing hole 4H through which the welding wire 3 passes and an insulating guide 5 made of an electrically insulating material also having a welding wire passing hole 5H. It has a structure in which an insulating guide 5 is attached to the power supply chip 4 on the side of the base material 6 to be welded.

The material of the power supply chip 4 is as follows.
Copper or a copper alloy is preferably used, and as a material of the insulating guide, a bending strength at room temperature of 300 MPa or more,
A ceramic material having a thermal expansion coefficient of 8.0 × 10 ⁻⁶ / ° C. or less, a thermal conductivity of 100 W / (m · K) or more, a thermal shock temperature of 300 ° C. or more, and an electric resistance of 10 ¹ Ω · cm or more is used. It is preferably used.

In addition, it is preferable that the insulating guide 5 is attached to the power supply tip at a position where the insulating guide 5 is always in close contact so that the continuous feedability of the welding wire 3 is not impaired.
For example, as shown in FIG. 2, the insulating chip 4 and the insulating guide 5 are screwed together and formed on the insulating guide 5 by a screw 5A.
Is smaller than the height H of the external thread portion 4A formed on the power supply tip 4 and the inclination angle θ of the concave surface at the end face of the screw portion 5A is formed on the power supply tip 4 to be formed on the insulating guide 5. It is possible to use the arc welding apparatus 1 in which the inclination angle の of the convex surface at the end face of the external thread 4A is smaller than that of the arc welding apparatus 1. End 5
E and the peripheral end 4E of the opening of the welding wire passage hole in the external thread 4A formed on the power supply tip 4 can be always in close contact with each other, so that the feeding stability of the welding wire 3 is further improved. Become.

Alternatively, as shown in FIG. 3, the power supply tip 4 and the insulating guide 5 are screwed together, and the depth h of the screw portion 5A is formed on the power supply tip 4 to form the insulating guide 5 with the male thread 4A. Is smaller than the height H, and the radius of curvature R of the concave surface at the end surface of the screw portion 5A formed on the insulating guide 5 is larger than the radius of curvature r of the convex surface at the end surface of the male screw portion 4A formed on the feed tip 4. The arc welding apparatus 1 can also be used. In this case, the welding wire passing hole opening peripheral end 5E in the screw portion 5A and the male screw portion 4A formed in the feeding tip 4 are also formed on the insulating guide 5. Peripheral end 4E of welding wire passage hole opening
Can always be brought into close contact with each other, and the feeding stability of the welding wire 3 is further improved.

More preferably, the hole diameter a (mm) of the welding wire passage hole 4H formed in the power supply tip 4 and the hole diameter b of the welding wire passage hole 5H formed in the insulating guide 5
(Mm) and the relationship with the wire diameter d (mm) of the welding wire 3 is a = d × (1.03 to 1.18) b = d × (1.18 to 1.70) or b = d ×
(1.20 to 1.70) can be used, whereby the continuous welding wire passage holes 4H and 5H can be used.
H allows the welding wire 3 to pass more stably and satisfactorily, and also makes it possible to supply power to the welding wire 3 satisfactorily.
, And the prevention of bending can be satisfactorily performed while maintaining the good feeding property.

As described above, the hole diameter a is set to 1.03 × d (m
m) or more, good feedability of the welding wire 3 at the power supply tip 4 is maintained, and the hole diameter a is set to 1.
The power supply chip 4 can be set to 18 × d (mm) or less.
In this way, good power supply characteristics can be secured. Further, the hole diameter b is 1.18 × d (mm) or more or 1.20 × d
(Mm) or more, good feedability of the welding wire 3 in the insulating guide 5 is maintained, and by setting the hole diameter b to 1.70 × d (mm) or less, the rise in the insulating guide 5 is increased. Bending deformation of the heated welding wire 2 is prevented.

Further, with respect to the hole diameter a (mm) of the welding wire passage hole 4H formed in the power supply tip 4, the axis of the welding wire passage hole 5H formed in the insulating guide 5 is a × 20.
%, It is desirable in some cases that the eccentricity is within the range of not more than%. When the welding wire 3 sent out from the power supply tip 4 shifts and melts by arc heat, the welding wire 3 has a bend in most of it. Therefore, the power supply tip 4 may not be able to supply power satisfactorily depending on the bending of the welding wire 3. On the other hand, the welding wire 3 having the eccentricity as described above has a bending. 3 comes in contact with almost the tip of the power supply tip 4, and as shown in FIG.
V, welding current: 200 A, shielding gas: CO ₂ , welding wire diameter: 1.2 mm, effective protrusion length: 33 mm As shown in the welding example, the power to the welding wire 3 can be stably and favorably supplied. become. However, if the degree of the eccentricity is too large, the feedability of the welding wire 3 is reduced, and the instantaneous arc start rate is deteriorated.

Next, the welding wire 3 used in the present invention has a relationship between the amount of Nb and the amount of Al in steel such that Nb (%) ≧ −2.5 × Al (%) + 0.10. It is sometimes desirable to use it.

That is, the Nb content and A in the welding wire
When the effect of the amount of l on sputter generation was examined, the results shown in FIG. 5 were obtained (○: small amount of spatter generated, Δ: slightly large amount of spatter generated, ×: large amount of spatter generated), in order to reduce the generation of spatter. It was found that Nb (%) ≧ −2.5 × Al (%) + 0.10.

More desirably, such a welding wire is C: 0.01 to 0.15% by weight, S:
i: 0.15 to 1.35%, Mn: 0.50 to 1.80
%, P: 0.025% or less, S: 0.025% or less, C
u: 0.50% or less, Cr: 0.50% or less, Ni:
0.50% or less, Mo: 1.00% or less, Al: 0.3
0% or less, Ti: 0.30% or less, Nb: 1.20% or less, the balance consisting of Fe and impurities: Nb (%) ≧ −2.5 × Al (%) + 0.10, and more preferably Volume resistivity ρ is 32μ
It was recognized that it was better to be Ω · cm or less.

Here, the reasons for the above-mentioned component composition are preferably as follows. C: 0.01 to 0.15% C is the basic composition of the steel-based welding wire, and the volume resistivity ρ
(ΜΩ · cm) is not so large. Therefore, the upper limit is preferably set to 0.15% and the lower limit is set to 0.01% from the viewpoint of welding workability and manufacturability of the welding wire.

As for the viscosity of the welding wire immediately before the droplet, the higher the C content, the lower the viscosity.
There is no significant decrease in melting point up to the upper limit of 0.15%. Si: 0.15 to 1.35% Si is an element that has a great effect on the increase and decrease of the volume resistivity ρ. To make the volume resistivity ρ 32.0 μΩ · cm or less, the upper limit is set to 1.00%. The lower limit is preferably set to 0.15% in consideration of the action as a deoxidizing element. Mn: 0.50 to 1.80% Mn acts as a deoxidizing element together with Si.
Since the volume resistivity ρ has little effect, the upper limit is 1.80.
%, And the lower limit is preferably 0.50%. P: 0.025% or less P is an impurity element and has little effect on the increase or decrease of the volume resistivity ρ. Therefore, the upper limit is preferably set to 0.025% as a range that does not adversely affect the cracks of the weld metal. S: 0.025% or less S is an impurity element and has little effect on the increase or decrease of the volume resistivity ρ. Therefore, the upper limit is preferably set to 0.025% as a range that does not adversely affect cracks in the weld metal. Cu: 0.50% or less Cu is an element that decreases the volume resistivity ρ, but has a large effect on the crack susceptibility of the steel-based weld metal, and the upper limit is 0.50 in consideration of the amount of Cu plating on the surface of the welding wire. % Is good. Cr: 0.50% or less Since Cr is an element that increases the volume resistivity ρ, it is better to limit the upper limit to 0.50. Ni: 0.50% or less Ni does not significantly affect the increase or decrease of the volume resistivity ρ, but the upper limit is preferably limited to 0.50% in consideration of the adverse effect on the weld metal. Mo: 1.00% or less Mo does not greatly affect the change in the volume resistivity ρ, but the upper limit thereof is preferably set to 1.00% within a range that does not adversely affect the weld metal. Al: 0.30% or less Al is an element that decreases the volume resistivity ρ,
Above 5%, spatter generation generally decreases. However, by firmly covering the welding wire immediately above the droplet of the welding wire heated by the I ² R method with the alumina oxide film on the surface, it is possible to maintain the stability of droplet transfer without agglomeration with the droplet directly below. Having. The upper limit of the addition of Al alone is preferably set to 0.30%. Ti: 0.30% or less Ti is an arc stabilizing element and a deoxidizing element, which is an effective element capable of controlling droplet transferability, but does not greatly affect the volume resistivity ρ. From this point, the upper limit is preferably set to 0.30% in consideration of an adverse effect on the toughness of the weld metal, although it may be increased. Nb: 1.20% or less Nb is effective as a denitrifying element, but has little effect on the volume resistivity ρ. Also, Nb, which is an active element, easily forms Nb carbon / nitride by reaction with the welding atmosphere gas,
These prevent agglomeration from the high-temperature welding wire immediately above the droplet, and promote the stabilization of the arc because the transfer of the droplet is regularized almost in the same manner as the effect of the addition of Al.

Therefore, the lower limit of adding Nb alone is 0.1
The upper limit is preferably set to 0% and the upper limit is set to 1,20%.

In order to reduce the occurrence of sputtering, it is preferable that the relationship between Nb and Al is Nb (%) ≧ −2.5 × Al (%) + 0.10.

Further, when the volume resistivity ρ of the welding wire is large, the expansion of the welding wire in the longitudinal direction of the wire due to self-heating is increased, and a short circuit is likely to occur. As a result, the stabilization of the arc is impaired. The molten metal that has been heated near or above the melting point due to the self-heating of the welding wire around the molten metal sphere at the wire tip falls in the direction of the molten metal sphere to form a larger molten metal sphere, which causes gravity and other It moves to the base metal side molten pool due to the action of arc force, etc., and once the large molten metal ball separates and moves, the arc elongates and the next molten metal ball is formed because the welding wire is fed at a constant speed. It takes a long time for the arc to evolve, and the arc becomes unstable as if the length of the arc becomes longer or shorter and the arc becomes unstable. Resistivity is preferably set to those some extent, specifically it is more preferable to use a material having a component composition comprising less 32μΩ · cm.

More desirably, the diameter b (mm) of the welding wire passage hole 5H formed in the insulating guide 5 is determined by the diameter d (mm) of the welding wire 3 and the welding current Y (A).
For 500 ・ b-400 ・ d-20 ≧ Y ≧ 500 ・ b-40
The arc welding apparatus 1 having a relationship of 0 · d−220 can be used, thereby maintaining good feedability of the welding wire 3 and stabilizing the occurrence of welding of the welding wire 3. Will be prevented.

Further, the apparent protrusion length (including arc length) L of the welding wire 3 from the tip of the insulating guide 5
It is more desirable to use the arc welding apparatus 1 in which (mm) is in the range of 10 to 25 mm, so that the function of protecting the insulating guide 5 from thermal shock can be sufficiently improved.

The arc welding method using the welding wire according to the present invention can be applied to consumable electrode type arc welding to perform arc welding, or
It can be applied to non-consumable electrode type arc welding to perform arc welding. In any case, the welding wire 3 is made to generate resistance heat based on I ² R to sufficiently cope with higher-speed welding. It will be.

At the time of arc welding, the above-described arc welding apparatus 1 is used, and the distance from the tip of the power supply tip 4 to the base metal 6 to be welded (effective projection length of the welding wire).
It is more desirable to perform arc welding with E in the range of 14 to 48 mm. If the distance E is shorter than 14 mm, the heating effect by I ² R of the welding wire 3 becomes small, and the increase in the amount of melted wire tends to be insufficient. If it is longer than 48 mm, the heat generated by I ² R becomes excessive, and the droplet transfer is disturbed,
This tends to cause poor bead appearance and increase the amount of spatters generated.

[0047]

Hereinafter, embodiments of the present invention will be described.
It goes without saying that the present invention is not limited to only such an embodiment.

FIG. 1 shows an arc welding apparatus used for performing an arc welding method using a welding wire according to an embodiment of the present invention. The arc welding apparatus 1 shown in FIG.
Is a power supply tip 4 fixed to the torch body 2 and having a welding wire passage hole 4H through which the welding wire 3 passes.
A male screw part 4A formed at one end of the power supply tip 4 and an insulating guide 5 having a welding wire passage hole 5H and a wrench tool engaging part 5T.
The power supply chip 4 has a structure in which an insulating guide 5 is mounted on the side of the base material 6 to be welded by screw connection with a screw portion 5A to form the insulating guide 5 as shown in an enlarged view in FIG. In this embodiment, the depth h of the screw portion 5A is smaller than the height H of the male screw portion 4A formed on the power supply tip 4 (that is, in this embodiment, h = 6.5 mm and H = 7.5 mm, h <H), the inclination angle θ of the concave surface at the end face of the screw portion 5A formed on the insulating guide 5 is made smaller than the inclination angle 凸 of the convex surface at the end surface of the male screw portion 4A formed on the power supply tip 4 ( That is, θ = 30 °, Θ = 4
5 ° and θ <Θ), so that the insulation guide 5
In a state where the screw portion 5A and the male screw portion 4A formed on the power supply chip 4 are screwed together, the insulating guide 5
Therefore, the peripheral end 5E of the opening of the welding wire passage hole in the screw portion 5A and the peripheral end 4E of the opening of the welding wire passage hole in the male screw portion 4A formed in the power supply tip 4 are always in close contact with each other.

At this time, the power supply tip 4 is made of a conductive material (Cu metal in this embodiment) so that power can be supplied to the welding wire 3, and the insulating guide 5 is insulated from the welding wire 3. An insulating material (such as SiC or Al ₂ O _{3 in} this embodiment) is used as a body, and a wrench tool engaging portion 5T is provided on the outer peripheral portion of the insulating guide 5.
Is formed.

The arc welding apparatus 1 having such a structure
And, as the welding wire 3, C: 0.06%, S
i: 0.35%, Mn: 1.35%, P: 0.015
%, S: 0.012%, Cu: 0.22%, Cr: 0.
10%, Ni: 0.10%, Mo: 0.05%, Al:
0.03%, Ti: 0.01%, Nb: 0.10%, balance substantially consisting of Fe, volume resistivity ρ 23.8 μΩ
A wire diameter d having a component composition of cm and a volume resistivity =
A bead-on-plate welding was performed by a pulsed mag method with a 1.2 mmφ effective protrusion length E of 14 to 48 mm depending on the current used.

At this time, a material having different bending strength, thermal (linear) expansion coefficient, thermal conductivity, thermal shock temperature, and electrical resistance (volume resistivity) at room temperature is selected as the material of the insulating guide 5. Table 1 to Table 4
The results are shown in FIG.

[0052]

[Table 1]

[0053]

[Table 2]

[0054]

[Table 3]

[0055]

[Table 4]

As a result of Tables 1 to 4 and many other tests, when the insulating guide 5 was mounted on the power supply chip 4 on the side of the base material 6 to be welded, the bending strength at room temperature was 300 MPa as a material of the insulating guide 5. As described above, the thermal expansion coefficient is 8.0
× 10 ⁻⁶ / ° C or less, thermal conductivity 100 W / (m · K)
As described above, the thermal shock temperature is 300 ° C. or more, and the electric resistance is 10 ¹
It was confirmed that it is better to use one having Ω · cm or more.

Further, as the welding wire 3, a wire diameter d =
1.0mm (YGW12), wire diameter d = 1.2mm
(YGW16) and a wire diameter d = 1.6 mm (YGW11), the feedability of the welding wire 3 was evaluated by variously changing the hole diameter b of the welding wire passage hole 5H of the insulating guide 5. , FIG. 6, FIG. 7 and FIG.

Further, the results shown in FIGS.
The result shown in FIG. 9 was obtained by rearranging the wire diameter d.

Then, the wire diameter of the welding wire 3 is set to d (mm).
In the case where the hole diameter of the insulating guide 5 is b (mm) and the welding current is Y (A), from FIG. 6, when d = 1.0 mm, 500 · b-450 ≧ Y ≧ 500 · b-650 According to FIG. 7, when d = 1.2 mm, 500 · b−500 ≧ Y ≧ 500 · b−700. From FIG. 8, when d = 1.6 mm, 500 · b−650 ≧ Y ≧ 500 · b−850. In the relationship between the constant C and the wire diameter d of the welding wire 3, the welding current Y (A) is: 500-b-400.-400.d-220≤C≤-400.d-20 d-20 ≧ Y ≧ 500 · b-40
It was found that it was more preferable to set the value to 0 · d−220.

The welding wire 3 has a wire diameter d = 1.2.
mm (YGW16) and the effective protrusion length E
Is set to 28 mm and bead-on welding (200A-32V) is performed by the pulse mag method, and the effect on the wire feedability due to the hole diameter a of the welding wire passage hole 4H of the power supply tip 4 and the hole diameter b of the welding wire passage hole 5H of the insulating guide 5 is given. Upon examination, the results were as shown in FIG.

As a result, in the case of: a ≦ b, a = d × (1.03 to 1.18), and b = d × (1.20 to 1.70), the feedability of the welding wire 3 is more improved. A more stable and favorable state was obtained.

[0062]

According to the arc welding apparatus of the present invention, as described in claim 1, there is provided an arc welding apparatus for continuously feeding and feeding a welding wire via a feed tip provided on a torch body. An insulating guide was screw-connected to the welding base material side of the power supply tip to form an insulating guide.
The depth h of the female thread is determined by the height of the male thread formed on the feed tip.
To be smaller than H and to be formed on the insulation guide
The angle of inclination of the concave surface at the end face of the screw
The angle of inclination of the convex surface at the end face of the formed male thread is smaller than Θ
Drill, at least, to form the thread on the insulation guide
In the peripheral edge of the welding wire passage hole opening and the power supply tip
Around the opening of the welding wire passage hole
Because the structure is always in close contact, or
As described in claim 2, the power supply chip is similarly insulated from the power supply chip.
Screw the guide to form an insulating guide.
The depth h is greater than the height H of the external thread formed on the feed tip.
In order to make it smaller and to form it on the insulation guide,
The radius of curvature R of the concave surface on the
The radius of curvature of the convex surface at the end face of the threaded portion should be larger than r.
At least in the threaded section to form the insulation guide.
Formed on the peripheral edge of the welding wire passage hole opening and the feed tip
Always keep the peripheral end of the welding wire passage hole opening
Since the connection state is adopted, it takes less time to adjust the protruding length of the welding wire, and there is only one fastening part between the power supply tip and the insulating guide. A remarkably excellent effect is obtained that the properties can be further improved.

And, as described in claim 3 ,
300M bending strength at room temperature as insulation guide material
Pa or more, coefficient of thermal expansion of 8.0 × 10 ⁻⁶ / ° C. or less, thermal conductivity of 100 W / (m · K) or more, and thermal shock resistance of 3
By using a material having an electric resistance of at least 00 ° C. and an electric resistance of at least 10 ¹ Ω · cm, it is possible to prevent the insulation guide from being overheated at the time of arc welding and to reduce damage due to thermal shock. Is significantly improved.

[0064]

[0065]

[0066]

Further, as described in claim 4 ,
In the relationship between the welding wire passing hole diameter a (mm) of the power supply tip, the welding wire passing hole diameter b (mm) of the insulating guide, and the welding wire diameter d, a ≦ ba = d × (1.03 to 1.18) b = D × (1.18 to 1.70), the welding wire can be more stably and satisfactorily passed through the continuous welding wire through hole, and the welding wire Power supply to the welding wire, and furthermore, it is possible to maintain the good feedability of the weld wire that has been thermally expanded by heating, and also it is possible to perform the bending prevention satisfactorily. The effect is brought.

Further, as set forth in claim 5 , the axis of the welding wire passage hole of the insulating guide exceeds a × 0% with respect to the welding wire passage hole diameter a (mm) of the power supply tip. By making the eccentricity within the range of × 20% or less, the bent welding wire comes into contact with almost the tip of the power supply tip, and the power supply to the welding wire can be performed stably and well. Is obtained.

Further, as described in claim 6 ,
The welding using the arc welding apparatus according to any one of claims 1 to 7, wherein the relationship between the amount of Nb and the amount of Al in the steel is Nb (%) ≧ −2.5 × Al (%) + 0.10. By using wires, it is possible to perform high-speed welding without problems such as undercuts, and in addition, it is possible to form good weld beads by reducing spatter generation. There is a very good effect that the arc welding can be performed as it is.

And, as described in claim 7 ,
C: 0.01-0.15%, Si: 0.15% by weight
To 1.35%, Mn: 0.50 to 1.80%, P: 0.
025% or less, S: 0.025% or less, Cu: 0.50
%, Cr: 0.50% or less, Ni: 0.50% or less, Mo: 1.00% or less, Al: 0.30% or less, T
i: 0.30% or less, Nb: 1.20% or less, balance Fe
By using a welding wire composed of Nb (%) ≧ −2.5 × Al (%) + 0.10 and made of impurities, it is possible to further reduce the generation of spatter during arc welding. Is obtained.

[0071] And also, as described in claim 8, by forming to use a welding wire volume resistivity ρ is less than 32μΩ · cm, more satisfactory arc stability during arc welding A remarkably excellent effect is obtained.

Further, as described in the ninth aspect , using the arc welding apparatus according to any one of the first to seventh aspects, the apparent protrusion length L (mm) of the welding wire from the tip of the insulating guide is used. ) Has a remarkably excellent effect that the function of protecting the insulating guide from thermal shock can be sufficiently improved.

Further, as described in the tenth aspect , by applying arc welding by applying to consumable electrode arc welding, it is possible to perform high-speed welding in consumable electrode arc welding. Significant effects are achieved.

Furthermore, by applying arc welding by applying to non-consumable electrode type arc welding as described in claim 11 , high-speed welding in non-consumable electrode type arc welding is enabled. Significantly improved effect.

Further, as set forth in claim 12 , the distance (effective protrusion length) E from the tip of the power supply tip to the base metal to be welded is set in the range of 14 to 48 mm so as to perform arc welding. By undercut,
An extremely excellent effect that arc welding by high-speed welding becomes possible without causing problems such as bead breakage and occurrence of humping beads is provided.

[Brief description of the drawings]

FIG. 1 is an explanatory sectional view of an arc welding apparatus used for performing an arc welding method according to an embodiment of the present invention.

FIG. 2 is a cross-sectional explanatory view ((A) of FIG. 2) showing an embodiment of a power supply tip and an insulating guide screw-coupled to the power feeding tip in the arc welding apparatus shown in FIG. (B)).

FIG. 3 is a cross-sectional explanatory view ((A) of FIG. 3) and a plan explanatory view of the insulating guide (FIG. 3A) showing another embodiment of the power supply tip and the insulating guide to be screw-coupled thereto with the arc welding apparatus shown in FIG. 3 (B)).

FIG. 4 is a graph illustrating the result of examining the effect of the eccentricity of the insulating guide hole on the power supply chip on the instantaneous arc start rate.

FIG. 5 is an explanatory diagram illustrating a result of examining the influence on spatter generation by the amounts of Nb and Al contained in a welding wire.

FIG. 6 is a graph illustrating the result of examining the effect of wire diameter b of a welding wire passage hole of an insulating guide on wire feedability when the wire diameter d of the welding wire is 1.0 mm.

FIG. 7 is a graph illustrating the result of examining the effect of wire diameter b of a welding wire passage hole of an insulating guide on wire feedability when the wire diameter d of the welding wire is 1.2 mm.

FIG. 8 is a graph illustrating the result of examining the effect of wire diameter b of a welding wire passage hole of an insulating guide on wire feedability when the wire diameter d of the welding wire is 1.6 mm.

FIG. 9 is a graph illustrating results obtained by rearranging the results of FIGS. 6 to 8 by the welding wire diameter d.

FIG. 10 shows the diameter a of the welding wire passage hole formed in the power supply tip and the diameter b of the welding wire passage hole formed in the insulation guide.
9 is a graph illustrating the result of examining the effect of wire on wire feedability.

FIG. 11 is an explanatory sectional view showing a conventional example of an arc welding apparatus using a welding wire.

FIG. 12 is an explanatory sectional view showing another conventional example of an arc welding apparatus using a welding wire.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Arc welding apparatus 2 Torch body 3 Welding wire 4 Power supply tip 4A Male thread part of power supply tip 4E Peripheral end of welding wire passage hole opening of male thread part of power supply tip 4H Welding wire passage hole of power supply tip 5 Insulation guide 5A Insulation guide Female thread part 5H Welding wire passage hole of insulation guide 5E Peripheral end of welding wire passage hole opening of female thread part of insulation guide 6 Base material to be welded

Continuation of the front page (56) References JP-A-63-80978 (JP, A) JP-A-56-973 (JP, A) JP-A-2-46994 (JP, A) JP-A-3-52795 (JP) , A) Japanese Utility Model Showa 58-107275 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) B23K 9/133 B23K 9/26

Claims (12)

(57) [Claims] 1. An arc welding apparatus for continuously feeding and feeding a welding wire via a power supply tip provided on a torch body, wherein an insulation guide is screw-connected to a base material side of the power supply tip to be welded. The depth h of the threaded portion formed in the guide is made smaller than the height H of the male threaded portion formed in the power supply tip, and the inclination angle θ of the concave surface at the end face of the threaded portion formed in the insulating guide is formed on the power supply tip. The welding wire at the peripheral end of the opening of the welding wire passage hole in the threaded portion and the male screw portion formed in the power supply tip at least smaller than the inclination angle 凸 of the convex surface at the end surface of the formed male thread portion. An arc welding apparatus, wherein a peripheral end of an opening of a through hole is always in close contact. 2. An arc welding apparatus for continuously feeding and feeding a welding wire via a feed tip provided on a torch body, wherein an insulating guide is screw-connected to a base material to be welded of the feed tip, and the insulation guide is insulated. The depth h of the threaded portion formed on the guide is made smaller than the height H of the male threaded portion formed on the power supply tip, and the radius of curvature R of the concave surface at the end face of the threaded portion formed on the insulating guide is formed on the power supply tip. The radius of curvature r of the convex surface at the end surface of the formed male screw portion is made larger than at least the peripheral end of the welding wire passage hole opening in the screw portion to be formed in the insulating guide and the welding wire in the male screw portion formed in the power supply tip. An arc welding apparatus, wherein a peripheral end of an opening of a through hole is always in close contact. 3. The material of the insulating guide has a bending strength at room temperature of 300 MPa or more and a thermal expansion coefficient of 8.0 × 10 −3.
6 / ° C. or less, thermal conductivity of 100 W / (m · K) or more, thermal shock temperature of 300 ° C. or more, and electric resistance of 101 Ω · c
The arc welding apparatus according to claim 1, wherein an arc welding apparatus having a length of at least m is used. 4. A welding wire passing hole diameter a (m) of a power supply tip.
m) and the relationship between the diameter b (mm) of the welding wire passage hole of the insulating guide and the diameter d of the welding wire, a ≦ ba = d × (1.03 to 1.18) b = d × (1.18 to 1) .70) The arc welding apparatus according to any one of claims 1 to 3, wherein 5. A diameter a (m) of a welding wire passing hole of a power supply tip.
5. The method according to claim 1, wherein, with respect to m), the axis of the welding wire passage hole of the insulation guide is eccentric in a range of more than a × 0% to a × 20% or less. An arc welding apparatus as described in the above. 6. The relationship between the amount of Nb and the amount of Al in steel using the arc welding apparatus according to claim 1 is as follows: Nb (%) ≧ −2.5 × Al (%) + 0 10. An arc welding method using a welding wire of 7. C: 0.01 to 0.15% by weight,
Si: 0.15 to 1.35%, Mn: 0.50 to 1.8
0%, P: 0.025% or less, S: 0.025% or less,
Cu: 0.50% or less, Cr: 0.50% or less, Ni:
0.50% or less, Mo: 1.00% or less, Al: 0.3
0% or less, Ti: 0.30% or less, Nb: 1.20% or less, using a welding wire composed of the balance of Fe and impurities, and Nb (%) ≧ −2.5 × Al (%) + 0.10 The arc welding method according to claim 6, wherein: 8. The arc welding method according to claim 6, wherein a welding wire having a volume resistivity ρ of 32 μΩ · cm or less is used. 9. An arc welding apparatus using the arc welding apparatus according to any one of claims 1 to 5, wherein an apparent protrusion length L (mm) of the welding wire from the tip of the insulating guide is in a range of 10 to 25 mm. An arc welding method characterized by the following. 10. An arc welding method using the arc welding apparatus according to any one of claims 1 to 5, wherein the arc welding is applied to a consumable electrode type arc welding. 11. An arc welding method using the arc welding apparatus according to any one of claims 1 to 5, wherein the arc welding is applied to non-consumable electrode type arc welding. 12. The arc welding apparatus according to claim 1, wherein the distance E from the tip of the power supply tip to the base material to be welded is in the range of 14 to 48 mm. Arc welding method.