WO2018159844A1

WO2018159844A1 - Arc welding method

Info

Publication number: WO2018159844A1
Application number: PCT/JP2018/008165
Authority: WO
Inventors: 光木梨; 悠梅原; 佐藤　浩二
Original assignee: 株式会社神戸製鋼所
Priority date: 2017-03-02
Filing date: 2018-03-02
Publication date: 2018-09-07
Also published as: CN110402177B; CN110402177A

Abstract

The purpose of the present invention is to provide an arc welding method with which the generation of spatter can be reduced, and which provides good slug agglomeration even at high welding rate. An embodiment of the present invention relates to an arc welding method for welding a steel sheet while a weld wire is feed-controlled in forward and backward directions. The arc welding method includes performing the welding using: a weld wire which contains C and, by mass%, not less than 0.2% and not more than 1.3% of Si, not less than 0.2% and not more than 1.5% of Mn, and not less than 0.01% and not more than 0.05% of S, with the remainder comprising Fe and unavoidable impurities; and a gas including Ar. The frequency of the weld wire in the forward and backward directions is not less than 35 Hz and not more than 160 Hz.

Description

Arc welding method

The present invention relates to an arc welding method.

As an arc welding method capable of reducing the occurrence of spatter during welding of a thin steel plate, an arc welding method in which welding is performed while controlling feeding in the forward and backward directions of the wire and a pulse control type arc welding method are known.

For example, in Patent Document 1, as an arc welding method for suppressing the generation of pores such as blow holes and the generation of spatter, a short-circuit and an arc are repeatedly arced using a welding wire for a surface-treated member. A welding method for performing welding is disclosed. This welding method includes a step of transferring a droplet formed from a wire to the member side, and pressing the molten pool in a direction opposite to the welding progress direction to weld the member so that gas generated from the member escapes from the generation point. And steps. Then, by retracting the wire, the distance between the wire and the molten pool is set within a predetermined range, a predetermined welding current for generating an arc force for pushing the molten pool is supplied, and the welding current is supplied for a predetermined period. In the meantime, it is constant or gradually increases or decreases.

In addition, for example, in Patent Document 2, a welding wire having a predetermined chemical composition is used as a welding method that generates less spatter during welding and has excellent welding workability, and a mixture of an inert gas and carbon dioxide gas is used. A gas shielded arc welding method is disclosed in which pulse mag welding is performed by a pulse arc method using a gas as a shielding gas. Here, in the gas shielded arc welding method described in Patent Document 1, the pulse frequency is preferably controlled to 60 to 120 Hz from the viewpoint of suppressing spatter generation and preventing welding defects. Further, from the viewpoint of suppressing the amount of spatter generated and the stability of penetration, the pulse width is preferably controlled to 1.0 to 1.3 msec.

Japanese Patent No. 6044369 Japanese Patent No. 3523917

By the way, an electrodeposition coating process may be carried out after arc welding on steel plates used in automobiles, building materials, electrical equipment, and the like. In such a case, if the slag does not sufficiently aggregate in the welded part during arc welding, the slag remains in the welded part. And when slag remains in a welding part, there exists a problem that adhesiveness of the coating film formed by subsequent electrodeposition coating cannot fully be ensured. Therefore, in such a use, it is calculated | required that the slag aggregation property at the time of welding is favorable.

However, in the arc welding methods described in Patent Documents 1 and 2, the cohesiveness of the slag has not been sufficiently studied and there is room for improvement. That is, if the slag does not sufficiently aggregate at the time of welding, the slag may remain in the welded portion, resulting in the above-described problem. In particular, in thin plate welding, it is also required that the welding speed is high, and it is also required that the slag cohesiveness is good while increasing the welding speed.

The present invention has been made paying attention to the above-mentioned circumstances, and the object thereof is to provide an arc welding method capable of reducing the occurrence of spatter and improving the slag cohesiveness while increasing the welding speed. There is to do.

The first embodiment of the present invention is an arc welding method for welding a steel sheet while controlling the feeding of the welding wire in the forward and backward direction,
Containing C,
% By mass
Si: 0.2% to 1.3%,
Mn: 0.2% or more and 1.5% or less, and S: 0.01% or more and 0.05% or less,
A welding wire with the balance being Fe and inevitable impurities;
Using a gas containing Ar,
The present invention relates to an arc welding method in which welding is performed with a frequency in the advancing and retreating direction of the welding wire being 35 Hz to 160 Hz.

In a preferred aspect of the first embodiment of the present invention, the welding wire is in mass%, further Al: 0.1% to 0.5%, Mo: 0.1% to 2.0%, Ti : 0.3% or less, Cu: 0.4% or less may be contained.

Further, in a preferable aspect of the first embodiment of the present invention, the contents of S and Al in the welding wire may satisfy 0.3 ≦ S × 10 + Al ≦ 0.7.

Further, in a preferred aspect of the first embodiment of the present invention, the plate thickness of the steel plate may be not less than 0.6 mm and not more than 5 mm.

Also, in a preferred aspect of the first embodiment of the present invention, welding may be performed with the frequency in the advancing / retreating direction of the welding wire being 45 Hz to 130 Hz, more preferably 70 Hz to 110 Hz.

Further, in a preferred aspect of the first embodiment of the present invention, welding may be performed with an average value of welding current of 80 A or more and 350 A or less and a welding speed of 60 cm / min or more.

The second embodiment of the present invention is an arc welding method for arc welding a steel plate by a pulse control method,
Containing C,
% By mass
Si: 0.2% to 1.1%,
Mn: 0.2% or more and 1.4% or less, and S: 0.010% or more and 0.050% or less,
A welding wire with the balance being Fe and inevitable impurities;
Using a gas containing Ar,
The present invention relates to an arc welding method in which welding is performed with a voltage pulse frequency of 50 Hz to 200 Hz and a voltage pulse width of 1.5 ms to 10 ms.

In a preferred aspect of the second embodiment of the present invention, the welding wire is in mass%, further Al: 0.1% to 0.5%, Mo: 0.1% to 2.0%, Cu : 0.4% or less may be contained.

Further, in a preferred aspect of the second embodiment of the present invention, welding may be performed with a peak current of 380 A or more and 490 A or less.

Further, in a preferred aspect of the second embodiment of the present invention, welding may be performed with the base current set to 80 A or more and 180 A or less.

Further, in a preferred aspect of the second embodiment of the present invention, welding may be performed with the duty ratio of the pulse current set to 0.2 or more and 0.6 or less.

Moreover, in a preferable aspect of the second embodiment of the present invention, the plate thickness of the steel plate may be not less than 0.6 mm and not more than 5 mm.

According to the arc welding method of the present invention, the generation of spatter can be reduced, and the slag cohesiveness can be improved while increasing the welding speed.

Hereinafter, embodiments for carrying out the present invention will be described in detail. Note that the present invention is not limited to the embodiments described below.

[First Embodiment]
An arc welding method according to the first embodiment of the present invention (hereinafter also referred to as a welding method according to the first embodiment) is an arc welding method in which a steel wire is welded while feeding control of a welding wire in the forward / backward direction is performed. In addition to containing C, by mass, Si: 0.2% to 1.3%, Mn: 0.2% to 1.5%, and S: 0.01% to 0.05 An arc welding method in which welding is performed with a welding wire frequency of 35 Hz or more and 160 Hz or less using a welding wire containing Fe or less and the balance consisting of Fe and inevitable impurities and a gas containing Ar. .

In the welding method according to the first embodiment, arc welding is performed while controlling feeding in the advance and retreat direction of the wire. More specifically, while controlling the feeding of the wire in the forward and backward direction, the wire is advanced (forward feeding) while generating an arc, and the molten metal at the tip of the molten wire is brought into contact with the molten pool to extinguish the arc. Thereafter, the wire is moved backward (reversely fed) to transfer the molten metal. By performing welding in this way, it is possible to reduce the occurrence of spatter during welding. Note that the frequency in the wire advance / retreat direction in the welding method according to the first embodiment is defined as one forward (forward feed) and backward (reverse feed) of the wire as one cycle. The welding method according to the first embodiment includes, for example, Cold Metal Transfer welding.

<Welding wire>
Subsequently, in the following, the reason for limiting the content of each element of the welding wire (hereinafter also referred to as the wire according to the first embodiment or simply the wire) used in the welding method according to the first embodiment. Will be described. In addition, content of these each element is content with respect to the wire total mass. Moreover, in this specification, the percentage (mass%) based on mass is synonymous with the percentage (weight%) based on weight.

(C)
C is an element that improves the strength. In the wire according to the first embodiment, it is sufficient that C is contained, that is, the content of C should be more than 0%. However, in order to achieve the above effect better, 0.02 mass. % Or more is preferable, and 0.04% by mass or more is more preferable.
The upper limit of the C content is not particularly limited, but from the viewpoint of suppressing spatter reduction and high-temperature cracking, the C content is preferably 0.15% by mass or less, more preferably 0.10% by mass or less. preferable.

(Si)
Si is an effective deoxidizer and is an indispensable element in deoxidation of weld metal. When the Si content is less than 0.2% by mass, the deoxidation effect is impaired, the surface tension is lowered, and pore defects such as pits and blowholes are likely to occur. Moreover, slag cohesiveness falls. Accordingly, the Si content is 0.2% by mass or more, preferably 0.3% by mass or more, and more preferably 0.5% by mass or more.
On the other hand, Si has a feature that the electrical resistance of the wire decreases as the content decreases, and the wire is less likely to melt as the electrical resistance of the wire decreases (the electrical resistance heat decreases). As a result, the arc force is increased, so that pore defects such as pits and blowholes can be suppressed. On the other hand, if the Si content exceeds 1.3% by mass, the amount of slag generated on the bead surface increases, and the slag cohesiveness also decreases. Therefore, the Si content is 1.3% by mass or less, preferably 1.2% by mass or less, more preferably 1.0% by mass or less.

(Mn)
Mn is an effective deoxidizer similar to Si, and is an element that easily binds to S. When the Mn content is less than 0.2% by mass, the deoxidation and desulfurization effects are impaired, the surface tension is lowered, and pore defects such as pits and blowholes are likely to occur. Moreover, slag cohesiveness falls. Therefore, the Mn content is 0.2% by mass or more, preferably 0.3% by mass or more, and more preferably 0.5% by mass or more.
On the other hand, if the Mn content exceeds 1.5% by mass, a thin oxide film that hardly peels off is generated on the bead surface. Moreover, slag cohesiveness falls. Therefore, the Mn content is 1.5% by mass or less, preferably 1.3% by mass or less, more preferably 1.1% by mass or less.

(S)
S is an element that contributes to the aggregation of slag, but if it is less than 0.01% by mass, the effect cannot be obtained, so the S content is 0.01% by mass or more, preferably 0.02% by mass. That's it.
On the other hand, when the S content exceeds 0.05 mass%, the flow on the surface of the molten pool is greatly changed, and as a result of the slag coming close to the vicinity of the arc and greatly vibrating, the agglomeration effect is lowered. Therefore, the S content is 0.05% by mass or less, preferably 0.04% by mass or less.

The remainder of the wire according to the first embodiment is made of Fe and unavoidable impurities. Examples of the unavoidable impurities include P, Cr, Ni, N, O, and the like, as long as the effects of the present invention are not hindered. It is allowed to contain.

Moreover, in addition to the above-described chemical components, at least one of the following components may be added to the wire according to the first embodiment.

(Al)
Al is an element that contributes to slag aggregation. In the wire according to the first embodiment, the addition of Al is not essential, but when the Al content is less than 0.1% by mass, it is difficult to obtain a coagulation effect of slag. The content is preferably 0.1% by mass or more, and more preferably 0.2% by mass or more.
On the other hand, if the Al content exceeds 0.5% by mass, droplet detachment becomes unstable, vibration of the molten pool is disturbed, and as a result of frequent spattering, the slag aggregation effect may be reduced. Therefore, when adding Al, it is preferable to make the content into 0.5 mass% or less, and it is more preferable to set it as 0.4 mass% or less.

(Mo)
Mo is an element that contributes to improvement in strength. In the wire according to the first embodiment, the addition of Mo is not essential, but in order to exert such an effect well, when adding Mo, the content may be 0.1% by mass or more. Preferably, it is more preferably 0.3% by mass or more.
On the other hand, when Mo exceeds 2.0 mass%, the effect is saturated because Fe and an intermetallic compound are formed at a high temperature. Therefore, when adding Mo, it is preferable to make the content into 2.0 mass% or less, and it is more preferable to set it as 1.5 mass% or less.

(Ti)
Ti is a strong deoxidizing element and can reduce the amount of oxygen in the molten metal and reduce the surface tension. Therefore, it is effective when the amount of oxygen in the wire is high. However, if added over 0.3 mass%, a large amount of slag is generated. Therefore, when adding Ti, the content is preferably 0.3% by mass or less, and more preferably 0.2% by mass or less.

(Cu)
Cu is an element that is effective in improving the electrical conductivity and rust resistance. When Cu is contained, the lower limit value of the content is not particularly limited, but is preferably 0.1% by mass or more in order to obtain this effect more favorably. Moreover, it is preferable that content of Cu is 0.4 mass% or less from a viewpoint of suppressing generation | occurrence | production of a hot crack. The wire of the first embodiment may be subjected to Cu plating if desired. Here, Cu is a value obtained by adding up the amount contained in the base material of the wire and the amount of Cu plating.

(0.3 ≦ S × 10 + Al ≦ 0.7)
In the wire according to the first embodiment, the S and Al contents preferably satisfy the following relational expression. In this case, the slag cohesiveness can be further improved by adjusting the S and Al contents so as to satisfy the relational expression.
0.3 ≦ S × 10 + Al ≦ 0.7

(Wire diameter)
In the first embodiment, the diameter of the wire is not particularly limited, and may be appropriately selected from a range that is usually applied. The diameter of the wire is, for example, 0.8 mm to 1.4 mm. The same applies to a second embodiment described later.

(Wire production method)
As a method for manufacturing the wire, for example, a steel wire having a predetermined composition may be drawn to a predetermined diameter. The wire drawing process may be either a method using a hole die or a method using a roller die. Moreover, when performing Cu plating, you may wire-draw after Cu plating. The same applies to a second embodiment described later.

<Shield gas>
The shield gas used in the welding method according to the first embodiment only needs to contain Ar, and may consist only of Ar. Alternatively, in addition to Ar, CO ₂ , O _2, or the like may be contained. For example, about 5 to 30% by volume of CO ₂ to O ₂ and the balance of Ar may be used. The shield gas can also contain N ₂ , H _2, etc. as inevitable impurities.
Here, since the amount of slag decreases as the content ratio of Ar in the shield gas is higher, it is desirable that the content ratio of Ar in the shield gas is higher. From this viewpoint, the content ratio of Ar is preferably 70% by volume or more, and more preferably 80% by volume or more. On the other hand, as described above, the shielding gas may be composed only of Ar (that is, the Ar content may be 100% by volume). For example, the Ar content may be 70% by volume or less. . The same applies to a second embodiment described later.

<Frequency of wire advance / retreat direction>
In the welding method according to the first embodiment, when controlling the feeding of the wire in the forward / backward direction, the frequency in the forward / backward direction of the wire is controlled to be 35 Hz or more and 160 Hz or less.
As a result of intensive studies, the present inventors have found that the natural frequency of the molten metal is about several tens of Hz, and by controlling the frequency in the advancing and retreating direction of the wire to an appropriate range so as to match the natural frequency of the molten pool, It has been found that the vibration of the molten pool surface becomes optimal, the hot water flow on the molten pool surface changes so as to involve slag, and the slag cohesiveness can be improved. If the frequency in the wire advance / retreat direction is less than 35 Hz, short circuit occurs frequently in the peak current period, regular droplet transfer cannot be performed, the molten pool vibration is disturbed, and good slag cohesiveness cannot be obtained. The frequency in the advancing / retreating direction of the wire is 35 Hz or more, preferably 45 Hz or more, more preferably 70 Hz or more. On the other hand, if the frequency in the wire advance / retreat direction exceeds 160 Hz, the effect of depressing the molten pool by the arc in the peak period is reduced, and sufficient molten pool amplitude cannot be obtained, and good slag cohesiveness is obtained. Therefore, the frequency in the advancing / retreating direction of the wire is 160 Hz or less, preferably 150 Hz or less, more preferably 130 Hz or less, and further preferably 110 Hz or less.

<Base material>
In the welding method according to the first embodiment, the base material to be welded may be a steel plate, and the composition and thickness of the steel plate are not particularly limited. For example, the thickness is 0.6 mm or more and 5.0 mm or less. It can also be applied to thin steel sheets. In addition, the steel type may be, for example, mild steel or high-tensile steel up to 590 MPa class. The surface of the base material may be subjected to various plating treatments such as galvanization and aluminum plating. The same applies to a second embodiment described later.

<Welding conditions>
Moreover, each welding condition in the welding method according to the first embodiment, such as a welding current, a welding voltage, a welding speed, and a welding posture, is not particularly limited, and may be appropriately adjusted within a range applicable in the arc welding method.
Here, the average value of the welding current is, for example, 80 A or more and 350 A or less, and preferably 100 A or more and 300 A or less. Moreover, as a welding speed, it is 60 cm / min or more, for example. According to the welding method according to the first embodiment, welding can be performed with good slag cohesion even under these welding conditions.

[Second Embodiment]
An arc welding method according to a second embodiment of the present invention (hereinafter also referred to as a welding method according to the second embodiment) is an arc welding method in which a steel plate is arc-welded by a pulse control method, and contains C. In addition, by mass%, Si: 0.2% to 1.1%, Mn: 0.2% to 1.4%, and S: 0.010% to 0.050%, the balance An arc welding method in which welding is performed using a welding wire made of Fe and inevitable impurities and a gas containing Ar, with a voltage pulse frequency of 50 Hz to 200 Hz and a voltage pulse width of 1.5 ms to 10 ms. is there.

<Welding wire>
About the content of each element of the welding wire used for the welding method which concerns on 2nd Embodiment, and its suitable range, it is as follows. The reason for the numerical limitation is the same as in the first embodiment.
(C)
Lower limit: more than 0%, preferably 0.02% by mass or more, more preferably 0.04% by mass or more Upper limit: preferably 0.15% by mass or less, more preferably 0.10% by mass or less (Si)
Lower limit: 0.2% by mass or more, preferably 0.3% by mass or more, more preferably 0.5% by mass or more, upper limit: 1.1% by mass or less, preferably 1.0% by mass or less, more preferably 0.8% by mass. 9% by mass or less (Mn)
Lower limit: 0.2% by mass or more, preferably 0.3% by mass or more, more preferably 0.5% by mass or more, and upper limit: 1.4% by mass or less, preferably 1.3% by mass or less, more preferably 1. 1% by mass or less (S)
Lower limit: 0.010 mass% or more, preferably 0.020 mass% or more Upper limit: 0.050 mass% or less, preferably 0.040 mass% or less

The remainder of the wire according to the second embodiment is made of Fe and unavoidable impurities, and examples of the unavoidable impurities include Ti, P, Cr, Ni, N, O, and the like, and do not hinder the effects of the present invention. It is allowed to contain in a range.
Moreover, in addition to the above-described chemical components, at least one of Al, Mo, and Cu may be added to the wire according to the second embodiment. Is the same as in the first embodiment.

<Pulse control conditions>
Next, pulse control conditions in the welding method according to the second embodiment will be described.

(Voltage pulse frequency: 50Hz to 200Hz)
(Voltage pulse width: 1.5 ms to 10 ms)
In the welding method according to the second embodiment, when performing arc welding by the pulse control method, the voltage pulse frequency (hereinafter, also simply referred to as pulse frequency) is 50 Hz to 200 Hz, and the voltage pulse width (hereinafter simply referred to as pulse). The pulse is controlled so that the width is also 1.5 ms to 10 ms.
As a result of intensive studies, the inventors have found that the natural frequency of the molten metal is about several tens of Hz, and by controlling the frequency and width of the pulse within an appropriate range so as to match the natural frequency of the droplet, It has been found that the vibration of the molten pool becomes optimal, the hot water flow on the surface of the molten pool changes so as to involve slag, and the slag cohesiveness can be improved.
When the pulse frequency exceeds 200 Hz and / or the pulse width is less than 1.5 ms, the effect of depressing the molten pool by the arc in the peak period is reduced, and sufficient molten pool amplitude cannot be obtained. It will be difficult to obtain good slag cohesiveness. Therefore, the pulse frequency is 200 Hz or less and the pulse width is 1.5 ms or more. The pulse frequency is preferably 180 Hz or less, more preferably 150 Hz or less. The pulse width is preferably 3 ms or more, more preferably 5 ms or more.
On the other hand, if the pulse frequency is less than 50 Hz and / or the pulse width exceeds 10 ms, the peak period becomes longer and the formation of droplets becomes excessive, so that the droplet transfer becomes unstable. This disturbs the vibration of the slag and makes it difficult to obtain good slag cohesion. Furthermore, spattering is likely to occur and the bead appearance is deteriorated. Therefore, the pulse frequency is 50 Hz or more and the pulse width is 10 ms or less. The pulse frequency is preferably 55 Hz or more, more preferably 60 Hz or more. The pulse width is preferably 9 ms or less, more preferably 8 ms or less.

Also, in the welding method according to the second embodiment, it is preferable to control the pulse current during welding as follows.

(Peak current: 380A to 490A)
In the peak current period, droplets are formed and at the same time the molten pool is pushed down by the arc force. Here, in the welding method according to the second embodiment, the peak current is not particularly limited, but is preferably 380 A or more and 490 A or less from the following viewpoints. That is, if the peak current is less than 380 A, there is a possibility that an arc force sufficient to push down the molten pool cannot be obtained. Therefore, the peak current is preferably 380 A or more, more preferably 400 A or more, and further preferably 410 A or more.
On the other hand, when the peak current exceeds 490 A, the formation of droplets becomes excessive, and the molten pool is irregularly short-circuited, and the molten pool may not be vibrated regularly. Further, the arc force becomes excessive, and the convection flow that pushes the slag backward with respect to the welding progress direction may be too strong. As a result, slag aggregation may be hindered. Therefore, the peak current is preferably 490 A or less, more preferably 480 A or less, and even more preferably 460 A or less.

(Base current: 80A to 180A)
During the base current period, the arc force is lowered to facilitate the detachment of droplets formed at the peak current. Here, in the welding method according to the second embodiment, the base current is not particularly limited, but is preferably 80 A or more and 180 A or less from the following viewpoints. That is, if the base current is less than 80 A, the range of the execution current may be greatly limited. Therefore, the base current is preferably 80 A or more, more preferably 90 A or more, and further preferably 100 A or more.
On the other hand, when the base current exceeds 180 A, the amount of heat input becomes excessive, and there is a possibility that the burnout is likely to occur when the thin plate is welded. Accordingly, the base current is preferably 180 A or less, more preferably 160 A or less, and even more preferably 150 A or less.

(Duty ratio: 0.2-0.6)
In the welding method according to the second embodiment, the duty ratio of the pulse current is not particularly limited, but is preferably 0.2 to 0.6 from the following viewpoints. That is, when the duty ratio is less than 0.2, the peak current period becomes too short compared with the base current period, and the effect of pushing down the molten pool by the arc cannot be sufficiently obtained, and the molten pool can be sufficiently vibrated. As a result, the slag aggregation effect may be reduced. Therefore, the duty ratio of the pulse current is preferably 0.2 or more, and more preferably 0.3 or more.
On the other hand, when the duty ratio exceeds 0.6, short-circuits frequently occur during the peak current period, spattering frequently occurs, and the vibration of the molten pool tends to be irregular, which may reduce the slag aggregation effect. Therefore, the duty ratio of the pulse current is preferably 0.6 or less, more preferably 0.5 or less.

Note that, in the welding method according to the second embodiment, the average current of the pulse current is not particularly limited, and is appropriately determined according to the respective preferable ranges of the peak current, the base current, and the duty ratio described above. It only has to be decided. The average current of the pulse current is, for example, 250 A or more and 350 A or less.

<Welding conditions>
Further, the welding conditions such as the welding speed and the welding posture in the welding method according to the second embodiment are not particularly limited, and may be appropriately adjusted within a range applicable in the arc welding method.
As a welding speed, it is 70 cm / min or more, for example. According to the welding method according to the second embodiment, welding can be performed with good slag cohesion even if the welding speed is increased.

Hereinafter, the present invention will be described in more detail with reference to examples. However, the present invention is not limited to these examples, and may be implemented with modifications within a range that can be adapted to the gist of the present invention. All of which are within the scope of the present invention.

In the following, the first embodiment will be described with reference to examples and comparative examples.
Using a wire with a diameter of 1.2 mm having the composition shown in Tables 1 and 2, welding was performed under the conditions shown below while controlling the frequency of the wire in the forward / backward direction to the frequency shown in Tables 1 and 2. Carried out.
(1) Steel plate A steel plate having a length of 200 mm, a width of 60 mm, and a thickness of 3.2 mm was used. The steel type of the steel plate is SPHC590.
(2) Welding posture Horizontal overlap fillet welding was performed.
(3) Shielding Gas In Examples 1 to 28 in Table 1 and Examples 30 to 59 in Table 2, Ar + 20 vol% CO ₂ was used as the shielding gas.
Further, in the example 29 and example 60 in Table 2 of Table 1, it was used 100 vol% CO ₂ as a shielding gas.
(4) Welding current and welding voltage Welding was carried out at a welding current of 240 A and a welding voltage of 18 V.
(5) Welding speed and welding length The welding speed was 100 cm / min. Further, welding was performed up to a welding length of 150 mm.

In Tables 1 and 2 and Table 3 described later, “wire component (mass%)” represents each component amount (mass%) per total mass of the wire. “-” Means that the content is less than the detection limit. Further, the Cu content shown in Tables 2 and 3 includes a Cu plating content. The balance is Fe and inevitable impurities.

(Evaluation of slag cohesiveness)
With a weld length of 150 mm, the slag on the bead surface was visually observed, and the slag on the surface was collected and evaluated according to the following criteria. In addition, (double-circle) and (circle) are set as pass, and x is set as disqualified.
A: 90% by weight or more of slag out of the total amount of slag is present (aggregated) in the vicinity of the crater portion.
○: 50% by weight or more and less than 90% by weight of slag is present (aggregated) in the vicinity of the crater part.
X: Only slag of less than 50% by weight of the total amount of slag is present (aggregated) in the vicinity of the crater portion.

Of Examples 1 to 60, Examples 1 to 20 and Examples 30 to 51 are examples, and Examples 21 to 29 and Examples 52 to 60 are comparative examples. As shown in Tables 1 and 2, in Examples 1 to 20 and Examples 30 to 51, good slag cohesion was obtained.

In Examples 21 and 52, the S content in the wire was too low, and in Examples 22 and 53, the S content in the wire was too high, so the slag cohesiveness deteriorated.
In Example 23 and Example 54, the frequency in the wire advance / retreat direction was too large, and in Example 24 and Example 55, the frequency in the wire advance / retreat direction was too small, so the slag cohesiveness deteriorated.
In Examples 25 and 56, the Si content in the wire was too low, and in Examples 26 and 57, the Si content in the wire was too high, so the slag cohesiveness deteriorated.
In Examples 27 and 58, the Mn content in the wire was too low, and in Examples 28 and 59, the Mn content in the wire was too high, so the slag cohesiveness deteriorated.
In Example 29 and Example 60, 100% CO ₂ gas containing no Ar was used as the shielding gas, so the slag cohesiveness deteriorated.

Next, the second embodiment will be described below with reference to examples and comparative examples.
Using a wire having a diameter of 1.2 mm having the composition shown in Table 3, arc welding was performed under pulse control under the following conditions.
(1) Steel plate A steel plate having a length of 200 mm, a width of 60 mm, and a thickness of 3.2 mm was used. The steel type of the steel plate is SPHC590.
(2) Welding posture Horizontal overlap fillet welding was performed.
(3) Shielding Gas In Examples 61 to 90 and 92 to 93 in Table 3, Ar + 20 vol% CO ₂ was used as the shielding gas.
Further, in the example 91 in Table 3, it was used 100 vol% CO ₂ as a shielding gas.
(4) Pulse control conditions Welding was performed while controlling the pulse frequency (Hz), pulse width (ms), peak current (A), base current (A), and duty ratio to the conditions shown in Table 3.
(5) Welding speed and welding length The welding speed was 100 cm / min. Further, welding was performed up to a welding length of 150 mm.

(Evaluation of slag cohesiveness)
With a weld length of 150 mm, the slag on the bead surface was visually observed, the slag on the surface was collected, and the ratio (weight%) of slag existing (aggregated) in the vicinity of the crater portion out of the total amount of slag was obtained. In the column of “Slag aggregation ratio (% by weight)”. Here, if the ratio of slag existing (aggregated) in the vicinity of the crater portion is 60% by weight or more, it can be evaluated that the slag agglomeration is good. In addition, the column of “slag aggregation ratio (% by weight)” in Table 3 shows an example in which the ratio of slag existing (aggregated) in the vicinity of the crater portion was less than 60% by weight and the slag aggregation was poor. The result is described as “x” and the ratio is omitted.

(Evaluation of bead appearance)
Moreover, the external appearance of the weld bead obtained in each example was evaluated according to the following criteria.
◎: Smooth bead appearance with few surface irregularities ○: Sound bead appearance without undercuts, etc. ×: Irregularities at the bead and surface irregularities occur, resulting in poor bead appearance is there

Among Examples 61 to 93, Examples 61 to 82 are examples, and Examples 83 to 93 are comparative examples. As shown in Table 3, in Examples 61 to 82, good slag cohesion was obtained. The bead appearance was also good.

In Example 83, the S content in the wire was too low, and in Example 84, the S content in the wire was too high, so the slag cohesiveness deteriorated.
In Example 85, the slag cohesiveness deteriorated because the pulse frequency was too large. In Example 86, since the pulse frequency was too small, the slag cohesiveness deteriorated and the bead appearance was poor.
In Example 87, since the Si content in the wire was too small, the slag cohesiveness deteriorated and the bead appearance was poor. Moreover, in Example 88, since there was too much Si content in a wire, slag cohesiveness deteriorated.
In Example 89, the Mn content in the wire was too low, and in Example 90, the Mn content in the wire was too high, so the slag cohesiveness deteriorated.
In Example 91, since using 100% CO ₂ gas not containing Ar as the shield gas, slag cohesiveness is deteriorated.
In Example 92, since the pulse width was too small, the slag aggregation was deteriorated. In Example 93, the pulse width was too large, and the Mn content in the wire was too large, so the slag cohesiveness deteriorated and the bead appearance was poor.

Although the present invention has been described in detail with reference to specific embodiments, it will be apparent to those skilled in the art that various changes and modifications can be made without departing from the spirit and scope of the invention. The present application includes a Japanese patent application filed on March 2, 2017 (Japanese Patent Application No. 2017-039845), a Japanese patent application filed on March 28, 2017 (Japanese Patent Application No. 2017-063694), Based on a Japanese patent application filed on March 30, 2017 (Japanese Patent Application No. 2017-069238), which is incorporated by reference in its entirety. Also, all references cited herein are incorporated as a whole.

Claims

An arc welding method for welding a steel plate while controlling the feeding of the welding wire in the forward and backward direction,
Containing C,
% By mass
Si: 0.2% to 1.3%,
Mn: 0.2% or more and 1.5% or less, and S: 0.01% or more and 0.05% or less,
A welding wire with the balance being Fe and inevitable impurities;
Using a gas containing Ar,
An arc welding method in which welding is performed with a frequency in the advancing / retreating direction of the welding wire being set to 35 Hz to 160 Hz.
The welding wire is mass%, and Al: 0.1% or more and 0.5% or less,
Mo: 0.1% or more and 2.0% or less,
Ti: 0.3% or less,
Cu: 0.4% or less,
The arc welding method according to claim 1, wherein at least one of them is contained.
S and Al content in the welding wire,
0.3 ≦ S × 10 + Al ≦ 0.7
The arc welding method according to claim 2, wherein:
The arc welding method according to claim 1, wherein the steel plate has a thickness of 0.6 mm or more and 5 mm or less.
The arc welding method according to claim 1, wherein welding is performed with a frequency in the advancing / retreating direction of the welding wire being 45 Hz or more and 130 Hz or less.
The arc welding method according to claim 5, wherein welding is performed with a frequency in the advancing / retreating direction of the welding wire set to 70 Hz to 110 Hz.
The arc welding method according to any one of claims 1 to 6, wherein welding is performed with an average value of a welding current of 80 A to 350 A and a welding speed of 60 cm / min or more.
An arc welding method in which a steel plate is arc-welded by a pulse control method,
Containing C,
% By mass
Si: 0.2% to 1.1%,
Mn: 0.2% or more and 1.4% or less, and S: 0.010% or more and 0.050% or less,
A welding wire with the balance being Fe and inevitable impurities;
Using a gas containing Ar,
An arc welding method in which welding is performed with a voltage pulse frequency of 50 Hz to 200 Hz and a voltage pulse width of 1.5 ms to 10 ms.
The welding wire is mass%, and Al: 0.1% or more and 0.5% or less,
Mo: 0.1% or more and 2.0% or less,
Cu: 0.4% or less,
The arc welding method according to claim 8, comprising at least one of them.
The arc welding method according to claim 8, wherein welding is performed at a peak current of 380A or more and 490A or less.
The arc welding method according to claim 8, wherein welding is performed with a base current of 80A or more and 180A or less.
The arc welding method according to claim 8, wherein welding is performed with a duty ratio of the pulse current set to 0.2 or more and 0.6 or less.
The arc welding method according to any one of claims 8 to 12, wherein a thickness of the steel sheet is 0.6 mm or more and 5 mm or less.