KR0134561B1 - Low-fume flux-cored wire for use in gas-shielded arc welding - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flux filling wire for gas seal arc welding, and more particularly, to a flux filling wire for gas shield arc welding with a reduced amount of hum generated and applied to welding of mild steel, high tensile strength steel, and low alloy steel.

The present invention provides a flux filling wire for welding gas seal arc formed by filling a flux in a mild steel shell,

① Mild steel outer sheath, in proportion to the total weight of the outer shell,

C: 0.02%

Ti: 0.01 to 0.20%

Al: 0.01 to 0.15%

Containing, and

Ti / C 1.0

Al / C 1.5

Made of steel of composition to satisfy the

② flux is in proportion to wire total weight,

Mn (total amount of Mn in the skin): 0.50 to 3.60%

Si (total amount of Si in the shell): 0.10 to 1.80%

A flux filling wire for gas seal arc welding, and the like, which is a flux containing.

Description

Flux Filled Wire for Low Sea Gas Sealed Arc Welding

1 is a graph showing the relationship between the amount of hum generated and the amount of C, Ti, and Al in the mild steel shell,

2 is a graph showing the relationship between the amount of hum generated and the amount of Ti, C, and Al in the mild steel shell,

3 is a device equipped with a huum collecting box,

4 is a diagram showing the relationship between the amount of hum generated and the amount of C in the metal flux,

5 is a graph showing the relationship between the amount of generation of hum and the amount of Ti in the metal flux;

6 is a graph showing the relationship between the amount of generation of humus and the amount of Cs and Rb in the metal flux;

7 is a graph showing the relationship between the amount of hum generated and the amount of C in the titania flux,

8 is a graph showing the relationship between the amount of hum generated and the amount of Cs in the titania flux,

9 is a graph showing the relationship between the amount of hum generated and the TiO ₂ / Cs ratio in titania-based fluxes,

10 is a view showing an example of the cross-sectional shape of the flux filling wire,

11 is a graph showing the relationship between the amount of hum generated and the amount of C in the mild steel shell of the metal-based flux-filled wire,

12 is a graph showing the relationship between the amount of hum generated and the amount of Ti in the mild steel shell of the metal-based flux-filled wire,

FIG. 13 is a graph showing the relationship between the amount of hum generated and the amount of Cs and Rb in the flux of the metal flux filling wire. FIG.

Technical Field of the Invention

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flux filled wire for gas seal arc welding, and more particularly, to a flux filled wire for gas shielded arc welding with reduced amount of humming, and is suitable for welding mild steel, high tensile strength steel, low alloy steel and the like.

[Background of invention]

In recent years, there is a shortage of manpower in the entire industry, and in particular, the shortage of welding technicians is severe.In the industries of steel, industrial machinery, shipbuilding, etc., high efficiency, automation, and robotization are in progress. There is a rapid progress in research.

As a cause of the lack of welding function, the flux-filled wire for gas seal arc welding has been rapidly increasing in recent years in terms of (1) ease of welding and (2) high efficiency. Among them, metal-based flux-filled wires, in particular, have the characteristics that the amount of slag generation is small in addition to the advantages of (1) and (2). However, the greatest difficulty of this type of wire is that a large amount of hum is generated, thereby raising the question of its elongation in terms of welding working environment.

As a technique for reducing welding hum, Japanese Patent Nos. 1403569, 1515713, 1515727, and the like are known. In particular, it is known that it is effective to reduce the amount of C and oxygen in the shell. However, in the case of the metal-based flux charging wire, since a high current (for example, 300 to 500 A) is applied to obtain a solid solution deposition rate, the amount of welding hum is increased exponentially with the increase of the current, so that it cannot be sufficiently coped with in the prior art.

On the other hand, the titania flux filling wire has a particularly low spatter and a good bead appearance, and the demand for the welding is easily increased in the field of shipbuilding, bridges and industrial machinery due to the fact that welding is easy in the electronic world. But on the other hand, the shortage of welding technicians is getting worse. This is largely due to the fact that the welding environment is high temperature and the welding hum is poor compared to other industries.

[Overview of invention]

SUMMARY OF THE INVENTION An object of the present invention is to provide a flux filling wire for gas shielded arc welding with a low amount of hum generation.

Another object of the present invention is to provide a flux filling wire which can reduce the amount of hum generated by improving the composition of the shell, especially in the gas filled arc welding flux filling wire.

It is another object of the present invention to provide a flux filling wire which can reduce the amount of hum by improving the composition of the shell and the flux, particularly in the flux filling wire for gas seal arc welding.

Another object of the present invention is to improve the composition of the flux to provide a gas shielded arc-welded metal-based flux filling wire with a small amount of humus generation.

Another object of the present invention is to provide a gas shielded arc welded metal-based flux filling wire having a low amount of humming by improving flux and skin composition.

Another object of the present invention is to improve the flux composition to provide a gas shielded arc-welded titania-based flux filling wire having a low amount of hum generation.

Another object of the present invention is to provide a gas shielded arc welded Titania-based flux filling wire having a low amount of hum generation by improving flux and skin composition.

Therefore, the present inventors have made intensive studies on the outer sheath as a measure of reducing the amount of hum generated in the flux filling wire for gas seal arc welding. It was found that the adjustment of Ti and Al is effective. At that time, it was found that at least the amount of Mn and Si in the flux was adjusted to deoxidize, adjust the strength of the deposited metal, improve toughness, and improve bead shape.

Based on these findings, the present invention provides a flux filling wire for welding gas seal arc formed by filling a flux in a mild steel shell.

① Mild steel outer shell is the ratio of the outer weight of the outer shell,

C: 0.02%

Ti: 0.01 to 0.20%

Al: 0.01 to 0.15%

Containing, and

Ti / C 1.0

Al / C 1.5

Made of steel of composition to satisfy the

② the flux is the ratio of the total weight of the wire,

Mn (total amount of Mn in the skin): 0.50 to 3.60%

Si (total amount of Si in the shell): 0.10 to 1.80%

It is characterized by being a flux containing.

On the other hand, the present inventors have diligently studied to reduce the amount of low haze generated in the flux filling wire for gas seal arc welding, and as a result of reducing the amount of haze in terms of flux composition, the present inventors have found that in either of the metal flux and the titania flux, Even in the flux, it was found that low humming can be achieved by adding an appropriate amount of one or two of Cs and Rb.

Based on this knowledge, the gas-sealed arc-welded metal-based flux-filled wire formed by filling flux in the mild steel shell according to the present invention is a large flux total weight%,

Fe powder: 60 ~ 85%

C: 0.5% or less

Ti: 0.5 to 3.0%

One or two or more sums of the compounds of Cs and / or Rb

(Cs and / or Rb element conversion value): 0.01 to 0.3%

Flux containing 10 to 30% by weight of the total weight of the wire in the mild steel shell, and {C / (Cs + Rb)} + Ti = 3 or more (where Cs, and / or Rb is Cs and And / or the Cs and / or Rb element conversion value (vs. flux total weight%) in the compound of Rb.

In addition, the gas-sealed arc-welded titania-based flux-filled wire formed by filling a flux in a mild steel shell according to the present invention is a total flux% of flux,

TiO ₂ : 8 ~ 60%

Compound of Cs (Cs element conversion value): 0.01 to 1.0%

(However, the ratio of TiO ₂ / Cs compound (Cs element conversion value): 20 to 2000)

C: 0.5%

It is characterized in that the flux containing 5 to 30% by weight of the total weight% wire in the mild steel shell.

In addition, the present inventors have found that addition of one or two of Cs and Rb to the metal-based and titania-based fluxes together with the low C and the adjustment of Ti and Al in the soft steel outer shell achieves breakthrough lowering. .

Based on this knowledge, the gas-sealed arc-welded metal-based flux filling wire formed by filling flux in the mild steel shell according to the present invention,

① Mild steel outer shell is the ratio of the outer weight of the outer shell,

C: 0.02%

Ti: 0.01 to 0.20%

Al: 0.01 ~ 0.10%

Containing, and

Ti / C 1.0

Al / C 1.5

To satisfy the composition is made of steel,

② the flux is the ratio of the total weight of the wire,

One or more of oxides and fluorides of alkali metals excluding Cs and Rb

(Converted to alkali metal element): 0.01 to 0.30%

Fe powder: 5 ~ 28%

Metal powder: 94% (large flux total weight%)

Total of 1 or 2 types of Cs and Rb (converted value of Cs and Rb): 0.001 to 0.10%

Containing and

Mn (total amount of Mn in the skin): 0.50 to 3.60%

Si (total amount of Si in the shell): 0.10 to 1.80%

It is characterized by a flux containing.

In addition, a gas sealed arc welded titania-based flux filling wire formed by filling a flux in a mild steel shell according to the present invention,

① Mild steel outer shell is the ratio of the outer weight of the outer shell,

C: 0.02%

Ti: 0.01 to 0.20%

Al: 0.01 to 0.15%

Containing, and

Ti / C 1.0

Al / C 1.5

Made of steel of composition to satisfy the

② the flux is the ratio of the total weight of the wire,

TiO ₂ : 1.00 ~ 8.50%

Alkali metal oxides other than Cs (alkali metal element equivalent): 0.01 to 1.50%

Compound of Cs (Cs element conversion value): 0.0005 ~ 0.3%

(However, the ratio of TiO ₂ / Cs compound (Cs element conversion value): 20 to 2000)

C: 0.06%

Mn (total amount of Mn in the skin): 0.50 to 3.60%

Si (total amount of Si in the shell): 0.10 to 1.50%

It is characterized by being a flux containing.

Detailed description of the invention

(1) Low restraint mainly by adjusting the skin composition

The present invention mainly aimed at reducing the low humus by adjusting the soft steel outer shell composition will be described in detail.

First, various experiments are conducted in order to examine the means for reducing the welding hum from the outer skin formation surface, and an example of the experimental results showing the bones of the results obtained thereby will be described below.

In these experiments, the flux (metal flux of 15%) of No. 1 in Table 2 described later was used for mild steel shell (C: 0.003 to 0.03%, Mn: 0.20 to 0.30%, Si: 0.01) of various amounts of Ti and Al. ~ 0.03%, P: 0.008-0.011%, S: 0.005-0.007, N: 0.002-0.004%) to prepare a 1.4 mm diameter flux filled wire.

Next, downward bead-on-plate welding was performed using a test plate JIS G3106 SM490A (plate thickness 12 mm) under the constant welding conditions illustrated below, and the amount of welding hum generated therebetween was measured according to JIS Z3930. In this measurement, the apparatus provided with the huom collection box shown in FIG. 3 was used.

(Welding condition)

Welding current: 350A

Welding voltage: 36V

Welding speed: 30cm / min

Wire protrusion length: 25 mm

Polarity: DC (wire plus)

Sealed gas: CO ₂ , flow rate 25 liters / minute

1 and 2 show the relationship between the amount of weld humes and the amount of Ti, Al and C in the mild steel shell based on the data obtained by the experiment. As shown in FIG. 1 and FIG. 2, it was confirmed that in order to reduce the generation amount of welding hum, in addition to the low C% of the prior art, a compound addition of 0.01% or more of Ti and Al was effective. On the other hand, it turns out that Al has little effect alone, and a remarkable effect arises as a ratio by complex addition with Ti. In addition, the reduction effect of welding hum of Ti and Al is C 0.02%, Ti / C 1.0, Al / C It was also found to be obtained at 1.5.

The reason why the welding hum reduction effect is obtained by Ti and Al is that since Ti and Al have high affinity with oxygen and generate high solidification oxide, an oxide film is formed on the surface of the suspended volume of the wire tip during arc welding. It is thought that this is because it suppresses the explosive generation of CO and CO _{2 which} are the source of hum generated as a result of the reaction between C and oxygen.

In addition, the upper limit of Ti and Al amounts is Ti in order to avoid material deterioration such as ductility degradation and hardening resulting from recovery of the weld metal. 0.20%, Al It was clarified that it was necessary to make it 0.15%.

For the above reasons, as a mild steel shell suitable for reducing welding hum, as a ratio to the total weight of the shell,

C: 0.02%

Ti: 0.01 ~ 0.20%

Al: 0.01 ~ 0.15%

Containing, and

Ti / C 1.0, Al / C 1.5

It is steel of composition to satisfy.

To present a more desirable range,

C: 0.01%

Ti: 0.01 ~ 0.10%

Al: 0.01 ~ 0.05%

Containing,

Ti / C 3.0

Al / C 2.0

The composition is satisfied. In addition, considering the workability in the rolling or / and drawing process in wire manufacturing, Mn: 0.10 to 0.70%, Si A range of 0.35% is desired.

As the flux to be filled in the mild steel outer shell adjusted in this way, Mn and Si amount,

Mn (total amount of Mn in the skin): 0.50 to 3.60%

Si (total amount of Si in the shell): 0.10 to 1.80%

The flux of any component system may be used as long as the flux is adjusted as described above.

Here, Mn is added in consideration of the amount of Mn in the mild steel shell for the purpose of improving the toughness by improving the deoxidizer, strength or quenchability, and bead shape personality (particularly in the case of horizontal fillet) by increasing the viscosity of the molten metal slag. In that case, when Mn is less than 0.5%, sufficient strength is not obtained even for mild steel, and a bead shape is also not good. When Mn exceeds 3.6%, the weld metal strength becomes excessive and low temperature cracking is likely to occur. Moreover, Mn, Fe-Mn, Fe-Si-Mn etc. are mentioned as Mn source.

Si has the same effect as Mn. However, when Si is less than 0.1%, deoxidizer, toughness improvement and bead shape improvement effect are not obtained, and when Si exceeds 1.8%, the amount of Si in the weld metal becomes excessive and consequently, toughness and ductility fall, so it is in the above range. Moreover, as a Si source, alloys, such as Si, Fe-Si, Fe-Si-Mn, Fe-Si-Mg, are mentioned.

Moreover, as a preferable flux, in addition to said Mn and Si, with the wire total weight,

One or two or more sums of the compounds of Cs and / or Rb

(Elemental conversion amount of Cs and / or Rb): 0.0005 to 0.3%

It is a flux containing.

For example, in the case where the flux component system is a metal system, the preferable flux is a ratio with respect to the total weight of the wire,

Ti or Ti oxide (Ti equivalent): 0.03 to 1.0%

Alkali metal oxides or fluorides (alkaline metal element conversion): 0.01 to 0.15%

Fe powder: 5 ~ 28%

Metal powder: 94% (vs. flux total weight)

Containing, and

Mn (total amount of Mn in the skin): 0.5 to 3.6%

Si (total amount of Si in the shell): 0.1 to 1.8%

It is a flux of the composition containing it.

More preferably the flux is again, in proportion to the total weight of the wire,

Al or Al ₂ O ₃ (Al element equivalent): 1.0%

It is a flux containing.

Or again in proportion to the total weight of the wire,

C: 0.07%

(However, Ti / C 1.0)

Flux containing is also desirable.

Or again in proportion to the total weight of the wire,

Ti / C 3.0

Flux that satisfies is also preferable.

In the metal flux described above, Ti is effective in reducing the amount of weld break, penetration shape and arc stability, and is added in consideration of the amount of Ti in the mild steel shell.

That is, when Ti is 0.03% or more, it is effective in reducing the amount of weld rest, penetration depth and arc stability. However, if it exceeds 1.0%, in the case of the metal or alloy type Ti, the recovery to the deposited metal becomes large, the ductility is extremely low, and in the case of Ti oxide, the amount of slag becomes excessive and the slag is mixed during continuous multilayer welding. It is easy to produce defects.

The addition of alkali metal components such as Li, Na, K, Rb and Cs is intended to reduce arc stability and spatter amount. Since alkali metals have remarkable hygroscopicity, it is preferable to use one or more types of oxides and fluorides.

It is limited to the above range because the effect of improving arc stability and reducing spatter is not obtained at less than 0.01%, and if it exceeds 0.15%, these alkali metals have a high vapor pressure. This is because the welding hum reduction effect is not obtained.

In addition, feldspar, anhydrous sodium silicate, water glass, Li, Na, K, and the like are complex oxides, cryolite, potassium silicate, sodium silicate fluoride, and a small amount of alkali metal carbonate are also decomposed by arc heat to form an oxide. Effect is obtained.

The Fe powder is added in correspondence with the flux rate in order to obtain a solid solution rate. In the flux ratio (% of the total weight of the wire to the flux), the thickness of the shell metal is too thick at less than 10%, thereby increasing the spatter of the large particles. On the other hand, if it exceeds 30%, the wire becomes flexible due to the decrease in the thickness of the shell metal, so that the feedability is lowered, the arc is enlarged, and the penetration depth is likely to decrease or undercut. For this reason, as a flux ratio, 10 to 30% of range is preferable.

The Fe powder is added in accordance with the flux rate, but if it is less than 5%, a remarkable solid solution rate, which is a special feature of the metal-based flux filling wire, is not obtained. It is difficult to secure mechanical properties or prevent welding of pit, blowhole, and the like. Therefore, the Fe powder amount is in the range of 5 to 28%.

It is necessary to make the metal powder ratio in the flux to be 94% or more excluding nonmetallic materials such as oxides, fluorides, and carbonates in order to secure the high welding speed characteristics and the amount of slag capable of continuous multi-layer welding, which is a special feature of the metal-based flux-filled wire.

Al is not remarkable compared to Ti, but is added as necessary because it is effective in reducing the amount of welding rest. In that case, when Al exceeds 1.0%, in the case of Al, which is a metal or alloy, the recovery rate of Ti to the weld metal is excessively increased and the ductility is remarkably lowered. In the case of Al ₂ O ₃ , slag peelability is remarkably lowered. do. Further, Al as a circle, may be mentioned oxides such as Al, Fe-Al, Al-Li alloys, such as Al ₂ O _3.

C may be added to the flux in an appropriate amount in consideration of the amount of C in the mild steel shell as necessary to obtain toughness and penetration depth by improving the deoxidizer, strength or quenchability. In that case, when the amount of C exceeds 0.07%, the effect of reducing the amount of welding vacancies of Ti and Al is not obtained, and the amount of welding humes is significantly increased, so it is set to 0.07% or less. Moreover, as a C source, Fe-Mn, Fe-Si-Mn, graphite, iron powder (carbon steel, cast iron), carbonate, etc. are mentioned.

In order to reduce the amount of welding hum in the flux component, it is effective to reduce the amount of C in the flux and to add Ti to the amount of C. That is, a remarkable effect of reducing welding hum is obtained when the Ti / C ratio is 1.0 or more. Moreover, as Ti source, alloys, such as metal Ti and Fe-Ti, and oxides, such as rutile reduced aluminite, leucoxin, an illuminite, potassium titanate, are mentioned.

In addition, high temperature cracking does not occur in order to add oxides such as SiO ₂ , ZrO ₂ , CaO, FeO, or improve slag peelability in order to further improve the appearance and shape of beads within a range satisfying the proportion of the metal powder. Bismuth oxide (Bi ₂ O ₃ ) below 0.1% (total wire weight%) in the range may be added or MgO or Mg below 0.2% (total wire weight%) in which the bead shape does not deteriorate. have.

Next, the preferred flux when the component system of the flux is titania-based is a ratio with respect to the total weight of the wire,

TiO ₂ : 1.00 ~ 8.50%

Alkali Metal Oxides (Alkali Metal Element Reduction Value): 0.01 ~ 1.50%

Containing, and

Mn (total amount of Mn in the skin): 0.50 to 3.60%

Si (total amount of Si in the shell): 0.10 to 1.50%

It is a flux containing.

More preferably in proportion to the total weight of the wire,

Mg and / or MgO (Mg element conversion value): 0.01 to 1.00%

It is a flux containing.

Or again in proportion to the total weight of the wire,

C: 0.06% or less

It is a flux containing.

In the titania-based flux, TiO ₂ is expected to act as a slag release agent and an arc stabilizer. At least 1.00% or more is required in order to obtain a good bead appearance, shape, and arc stability improvement effect in the downward and horizontal posture of TiO ₂ . However, when TiO ₂ exceeds 8.50%, the solidification point of slag is high and the viscosity becomes excessive, and slag incorporation defects and pore bonds on the bead surface are likely to occur. Examples of the TiO ₂ source include oxides such as tutyl, reduced illuminite, rucoxin, illuminite and potassium titanate.

It is effective to add alkali metal components such as Li, Na, K, Rb, and Cs in order to improve arc stability and reduce spatter amount, but it is a significant source of welding hum. In particular, alkali metal fluorides, carbonates, and simple oxides such as Na ₂ O, K ₂ O, and Li ₂ O are a significant source of welding hum. However, when the alkali metal such as Li, Na, K, Rb, Cs, etc. is a composite oxide (x, y: integer) with at least one of oxides such as TixOy, AlxOy, FexOy, MnxOy, SixOy, ZrxOy, the amount of welding hum is generated. It is found that the increase is small, but decreases in the case of Cs and Rb. It is defined in the above range because the effect of improving arc stability and spatter is not obtained at less than 0.01%, and when it exceeds 1.50%, except for Rb and Cs, the effect of reducing hum due to limited skin composition is hardly expected. In addition, it is because slag peelability falls remarkably. Either one is added in the above range in terms of alkali metal element.

Examples of the composite oxide include LiFeO ₂ , Li ₂ SiO ₃ , Li ₂ , MnO ₃ , Li ₂ , ZrO ₃ , Li ₂ TiO ₃ , Na ₂ SiO ₃ , NaAlSi ₃ O ₈ , K ₂ TiO ₃ , KAlSi ₃ O _8, and CsAlSi ₁₂ O ₆ and the like.

As these composite oxides, natural materials such as feldspar may be used in addition to being manufactured by high temperature firing or melting.

Al-containing sheaths are used to reduce weld hum, and compounds of alkali metals are mixed in the flux to improve arc stability. In particular, when the improvement angle is small or the welding heat is large, the deterioration tendency of slag peelability becomes remarkable. Mg and / or MgO may be added as needed to improve slag peelability. The above range is limited because the effect of improving slag peelability is not obtained at less than 0.01%, and on the contrary, if it exceeds 1.00%, the amount of welding rest is increased and the object of the present invention is not achieved. In addition, since Mg and MgO have an oxygen reducing action in the weld metal, an effect of improving toughness and porosity is also obtained.

Examples of the Mg source include alloys such as Al-Mg, Li-Mg, Ni-Mg, and Si-Mg in addition to the metal Mg, and compounds such as krinka, magnesium silicate, and olivine side as the MgO source.

C can be added not only as a deoxidizer but also considering the amount of C in the shell as necessary to obtain penetration depth by securing toughness by adjusting strength or improving hardenability and promoting arc concentration. In this case, when the amount of C exceeds 0.06%, the effect of reducing the amount of welding hum of the outer shell to which low C, Ti, and Al are added is not obtained, and the amount of melting hum is significantly increased. The amount of spatter also increases.

In addition, the following components may be added to the filling flux and / or the shell metal in consideration of properties such as bead appearance, shape, weldability, and mechanical properties of the weld metal. In addition, all the addition amount is a ratio with respect to the wire total weight.

The addition of 0.1% or more of SiO ₂ is effective in improving weldability such as bead appearance, shape, slag peelability, etc., but when it exceeds 1.5%, the slag acidity or viscosity becomes excessive, and the cleanliness of the weld metal is reduced. Mixing and pore defects easily occur.

ZrO ₂ has the effect of increasing the solidification point of slag, and the improvement of bead shape in fillet welding, especially horizontal fillet welding, is observed at 0.05% or more, but when it exceeds 0.60%, slag peelability or bead appearance deteriorates.

Since Al ₂ O ₃ increases the solidification point and viscosity of the slag, there is an effect of improving the bead shape especially in a vertically upward or upward position. Al ₂ O ₃ is effective at 0.05% or more, but when it exceeds 1.0%, the slag viscosity becomes excessive and the appearance of slag in addition to deterioration of bead appearance, detective and workability in a vertically downward position, and deterioration of slag Becomes remarkable.

In addition to the shell metal, when Al is added in the flux, it acts as a deoxidizer and nitrogen fixative, and has the same effect as Al ₂ O ₃ . The preferred range of addition and limitation of Al are the same as in the case of Al ₂ O ₃ .

Alkali metals such as Na, K and Li Fluoride of alkaline earth metals such as Ca and Sr has a function of reducing the amount of hydrogen in the weld metal. The above-mentioned effect is obtained in the metal fluoride of 0.01% or more, but when it exceeds 0.20%, the amount of hum is remarkably increased, and the viscosity of the molten slag decreases, so that the deterioration of the bead shape in the vertical posture and the horizontal posture becomes significant.

Bismuth oxide (Bi ₂ O ₃ ) is present at the interface between the weld metal and the slag to significantly improve slag peelability. Bi ₂ O ₃ is found to be 0.005% or more of the above effect, but when it exceeds 0.050%, high temperature cracking is likely to occur.

In addition, to improve the cut toughness of the weld metal, it is effective to add Ti, B, which has a refining effect of crystal grains in addition to C, Mn and Si, to the metal. And / or in the flux. In addition, all the addition amount is a ratio with respect to the wire total weight.

As Ti, reduced Ti close to TiO ₂ and Ti in the metal shell are expected, but in order to enhance the deoxidation effect and to refine the crystal grains, it can be added in a maximum of 0.7% of the flux in addition to the shell metal powder. However, when Ti amount exceeds 0.7%, the recovery rate of Ti to the weld metal becomes high, the strength of the weld metal becomes excessive and ductility decreases.

B is usually added in combination with Ti or TiO ₂ to have an effect of miniaturizing the crystal grains of the weld metal and significantly increasing the toughness. B can be added to the metal shell or flux (alloy such as Fe-B or Bi ₂ O ₃ ), and the toughness improvement effect is obtained at 0.002% or more, but when it exceeds 0.025%, the yield in the weld metal becomes excessive. The weld metal hardens and, rather, deteriorates toughness and is susceptible to high temperature cracking.

Ni has a hardening ability to strengthen the matrix of the crystal structure of the weld metal to improve toughness. When the amount of Ni exceeds 4.0%, the hardening hardening of the weld metal becomes remarkable, and the crack resistance also falls remarkably.

In addition, Ni, Cu, Cr, and Ni, Cr, and Mo may be matched with a base material component in the use of weathering steel, respectively, and can be added by flux or a metal shell, and it can respond.

Moreover, the preferable range of the flux ratio (ratio of flux weight with respect to the wire total weight) in a wire is 5-30%.

In general, the flux ratio is determined by combining the wire cross-sectional shape in terms of uniformity and wire formability at the time of melting the wire, and the simple cross section is low flux rate for the fine diameter wire, and the high flux rate is complicated for the large diameter wire. Cross section is preferred.

(2) Low haum (metal-based) mainly by adjusting the flux composition:

Next, the present invention mainly aimed at lowering hues by adjusting the metal flux composition will be described in detail.

First, various experiments are carried out to examine the means for reducing the welding eruption from the flux composition surface, and an example of the experimental results showing the scores of the results obtained thereby will be described below.

In these experiments, flux filling wires having a diameter of 1.4 mm were prepared by combining various C-based, Ti-based, Cs- or Rb-based metal fluxes (flux rate 15%) with a mild steel sheath.

Next, downward bead on-plate welding was performed using test plate JIS G3106 SM490A (plate thickness 12 mm) under the constant welding conditions illustrated below, and the amount of welding hum generated therebetween was measured according to JIS Z3930.

In this measurement, the apparatus provided with the huum collection box shown in FIG. 3 was used.

(Welding condition)

Welding current: 350A

Welding voltage: proper (ark length: 1.5 mm from the base material surface)

Welding speed: 30cm / min

Polarity: DC (wire plus)

Tip and base material distance: 25 mm

The results of the welding test are the dominant factors for reducing the amount of hum generation of the metal-based flux-filled wires as shown in FIGS. 4, 5, and 6, and the amount of ① C, ② Ti, ③ Cs and / or Rb I knew this was important.

Therefore, in order to reduce the amount of hum generation of the metal-based flux-filled wires, (1) a decrease in the amount of C, (2) an increase in the amount of Ti, and (3) addition of Cs and / or Rb is essential and effective even in the absence of any of these conditions. It proved to be no means. In other words, by radically regulating all of the above three factors, breakthrough low breaks are achieved.

Based on the results of the above experiment, the metal-based flux filling wire which can achieve low restraint is a large flux total weight%,

Fe powder: 60 ~ 85%

C: 0.5% or less

Ti: 0.5 ~ 3.0%

One or two or more sums of the compounds of Cs and / or Rb

(Cs and / or Rb element conversion value): 0.01 to 0.3%

Flux containing 10% to 30% by weight of the total weight of the wire in the outer sheath of the steel, and {C / (Cs + Rb)} + Ti = 3 or more (where Cs and / or Rb is Cs and / Or a Cs and / or Rb conversion value (vs. total flux by weight) in the compound of Rb.

Here, when iron powder is less than 60%, the efficiency which is a characteristic of a metal type flux filling wire falls. However, if it exceeds 85%, other components (deoxidants, etc.) are insufficient, so that welding bonds such as pits and blow holes occur, and it is difficult to secure good weld metal.

C is regulated to 0.5% or less because the hum is increased (see Fig. 4), and the spatter is increased if it exceeds 0.5%.

Ti is less than 0.5% has no resting effect (see FIG. 5).

However, if it exceeds 3.0%, the amount of slag increases, which is not preferable in view of the toughness and crack resistance of the weld metal. In addition, Ti may be added in the form of an iron alloy, an oxide, or the like in addition to the metal alone.

If the sum of one or two of Cs and Rb is less than 0.001%, there is no resting effect (see Fig. 6).

However, if it exceeds 0.3%, the deterioration of the absorbing resistance decreases the porosity, the amount of diffusible hydrogen of the deposited metal increases, and the crack resistance deteriorates. In addition, Cs or Rb may be added in a suitable form, but in particular Cs may be added as Cs ₂ CO ₃ or in the form of a composite oxide with TiO ₂ , SiO ₂ , or the like.

However, the ratio between C and (Cs and Rb) and the relationship with Ti are regulated in view of weld defects.

That is, when the total amount of {C / (Cs + Rb)} + Ti is less than 3, the depth of penetration becomes shallow, and welding defects such as insufficient penetration and poor welding tend to occur particularly in welding in the improvement, so it is necessary to set it to 3 or more. There is. In addition, the first term of this equation is the indifference and the second term is%, and the sum of the values is 3 or more.

If the flux ratio (% of wire total weight) is less than 10%, the spatter of large particles increases.

On the other hand, if it exceeds 30%, the wire becomes soft due to the decrease in the thickness of the shell metal, so that the supplyability is lowered and defects such as undercut due to arc instability are likely to occur. Therefore, the flux ratio is in the range of 10 to 30%.

In addition, it goes without saying that components other than those normally added in the metal type flux filling wire can be added to the flux.

In addition, although a normal mild steel material may be sufficient as a cladding metal, especially when the cladding metal which contains C: 0.01% or less and Ti: 0.01-0.20% is used, it is effective for low humerization.

The more preferable composition of the mild steel shell,

C: 0.01%

Ti: 0.01 ~ 0.10%

Al: 0.01 ~ 0.05%

Containing, and

Ti / C 3.0

Al / C 2.0

If the composition satisfies, it is more effective to reduce hum.

(3) Low humility mainly by adjustment of flux composition (Titania):

Next, the present invention aimed at lowering holiday mainly by adjusting the Tinatia flux composition will be described in detail.

First, various experiments are carried out to examine the means for reducing the welding eruption from the flux composition surface, and an example of the experimental results showing the scores of the results obtained thereby will be described below.

These experiments consisted of a 1.2 mm diameter flux-filled wire by combining tin-based fluxes of various compositions with a soft steel sheath, and the effect of reducing the hum generation under the welding conditions and the reduction of the hum generation under the welding conditions in accordance with JIS Z3930. It examined by the test.

(Welding condition)

Welding method: downward bead-on plate welding

Welding current: 300A

Arc voltage: Proper (appropriate voltage for arc length of 1.5 to 2.0 mm)

Welding speed: 30cm / min

Wire protrusion length: 25 mm

Polarity: DCEP

Sealed gas: 100% CO ₂ (flow rate 25 liters / min)

Trial: JIS G3106 SM490A (plate thickness 12 mm)

As shown in Figs. 7 to 9, the welding test results show that the ratio of ①C amount, ②Cs amount, and ③TiO ₂ / Cs ratio on the flux surface is important as a controlling factor in the reduction of the amount of hum in the titania-based flux filling wire. It was recognized that ④ C amount and ⑤ Ti amount were important as the chemical composition surface of.

The present inventors also found that the reduction of the amount of hum generated in the titania-based flux-filled wire is effective only with one of the chemical components of the flux surface and the steel outer shell surface, but the effect is further enhanced by the combination of both.

Based on the above experimental effects, titania-based flux-filled wires capable of achieving low restraint have a large flux percent by weight.

TiO ₂ : 8 ~ 60%

Compound of Cs (Cs element conversion value): 0.01 to 1.0%,

(However, the ratio of TiO ₂ / Cs compound (Cs element conversion value): 20 to 2000)

C 0.5%

It is a titania-based flux filling wire, characterized in that the flux containing 5 to 30% by filling the total weight% of the wire in the steel shell.

Here, C is added as a deoxidizer, taking into consideration the amount of C in the shell as necessary for the purpose of securing toughness by improving strength and quenchability, and improving penetration depth by promoting arc concentration. In that case, when the amount exceeds 0.5%, the amount of generation of hum is remarkably increased and the amount of spatter is also increased (Fig. 7).

This is considered to be because the explosive generation of CO and CO ₂ as a source of humus generated as a result of the reaction between C and oxygen becomes remarkable at 0.5% or more. Therefore, the amount of C in the flux is regulated to 0.5% or less.

The mechanism by which Cs reduces the amount of hum is not clear in detail, but Cs is thought to be one of the reasons for decreasing the dislocation hardness of the arc and improving the stability of the arc. As shown in FIG. 8, the effect of reducing the hum generated by the addition of Cs is not shown. When the amount of Cs is less than 0.01%, the hum reduction effect is not recognized. Moisture absorption becomes remarkable, the amount of hydrogen in the weld metal increases, and the integrity and crack resistance deteriorate. Therefore, the amount of Cs in the flux is made 0.01 to 1.0%.

Further, the Cs source may be a mixed oxide with CsCO ₃ or SiO ₂ or the like and natural fluorite ore, and may be added in the form of simple salt or double salt by the synthesis thereof. However, when these Cs sources are added in excess of 1.0% in terms of Cs, the weldability is poor.

TiO ₂ is expected to act as a slag forming agent and an arc stabilizer. The amount of TiO ₂ should be at least 8% in order to obtain good bead appearance, shape, and arc stability improvement effect in the downward and horizontal postures. However, when TiO ₂ exceeds 60%, the slag solidification point is high, and the viscosity becomes excessive, whereby slag incorporation and gas defects on the bead surface tend to occur. Therefore, the amount of TiO ₂ in the flux is in the range of 8 to 60%.

Examples of the TiO ₂ source include oxides such as rutile, reduced illuminite, rucoxin, illuminite and potassium titanate.

The effects of addition of TiO ₂ and Cs alone were as described above, but it was found that the effects of both influenced each addition amount. In other words, the ratio of TiO ₂ / Cs also greatly affects the amount of humus generation, sag in welding in a vertically upward posture, and X-ray performance (welding defects, slag incorporation defects, etc.) of the weld metal (FIG. 9). .

In order to obtain good weldability in an electron field and to obtain a healthy weld metal, the ratio TiO ₂ / Cs needs to be at least 20 or more. However, if the ratio exceeds 2000, it is necessary to suppress it to 2000 or less because the effect of reducing the resting effect of Cs is reduced and the X-ray performance of the weld metal is deteriorated.

Moreover, the compound of alkali metals other than Cs, such as Li, Na, and K, can add a suitable amount as needed. Compounds of these alkali metals other than Cs are very effective in improving arc stability and reducing the amount of spatter generated, but become a significant source of humus. That is, fluorides, carbonates, and simple oxides such as Na ₂ O, K ₂ O, and Li ₂ O of these alkali metals are remarkable sources of hum, and even if they are complex oxides with other oxides, there is no doubt that they are sources of hum. none. Therefore, it is preferable to suppress the compound addition amount of alkali metals other than Cs to 7.0% or less in conversion of a metal element.

It is needless to say that the flux can be added with other components normally added as titania-based flux filling wire.

In addition, as the shell metal, a normal mild steel material is preferable, but in particular, when the shell metal containing C: 0.02% or less and Ti: 0.20% or less is used, it is effective for low-humidity.

The more preferable composition of the mild steel shell,

C: 0.01%

Ti: 0.01 ~ 0.10%

Al: 0.01 ~ 0.05%

Containing, and,

Ti / C 3.0

Al / C 2.0

If the composition satisfies, it is effective to reduce the rest.

For other components, Mn: 0.10 to 0.70%, Si in consideration of workability in the rolling and / or drawing process in wire manufacturing 0.35% range is preferred.

In general, the flux ratio is determined in combination with the wire cross-sectional shape in terms of uniformity at the time of wire melting, and a simple cross section at a low flux rate for a thin diameter wire, and a complex cross section at a high flux rate for a thick diameter wire is preferable. . However, in either case, when the flux ratio is less than 5%, a large particle spatter increases, and when the flux rate exceeds 30%, the outer skin becomes thin, resulting in a decrease in wire feedability. Therefore, the flux rate is defined as 5 to 30%.

(4) Low-humidity (metal-based) by adjusting the composition of both the shell metal and the flux:

Next, the present invention aimed at lowering the humidity by adjusting the components of both the shell metal and the metal flux will be described in detail.

The present inventors aimed at further lowering the rest, and by adding Cs and Rb as alkali metals in the metal-based fluxes filled with the mild steel shell which properly controlled the amount of C, Ti, and Al, a significant increase in the amount of rest was reduced. It was found that the effect was obtained. The test results that led to this finding are described below.

In these experiments, the flux (No. 15%) of the composition of No. 1 in Table 13, described later, was used for mild steel shells of various amounts of Ti and Al (C: 0.003 to 0.03%, Mbn: 0.20 to 0.30%, Si: 0.01 to 0.03). %, P: 0.008% to 0.011%, S: 0.005% to 0.007%, and N: 0.002% to 0.004%) to form a 1.4 mm diameter flux filled wire.

Next, downward bead-on plate welding was performed using a test plate JIS G3016 SM490A (plate thickness 12 mm) under the constant welding conditions illustrated below, and the amount of weld rest produced therebetween was measured in accordance with JIS Z3930.

In this measurement, the apparatus provided with the huum collection box shown in FIG. 3 was used.

(Welding condition)

Welding current: 350A

Welding voltage: 36V

Welding speed: 30cm / min

Wire protrusion length: 25 mm

Polarity: DC (wire plus)

Sealed gas: CO ₂ , flow rate 25 liters / minute

FIG. 11 and FIG. 12 show the relationship between the amount of weld break generation and the amount of Ti, Al and C in the mild steel shell based on the data obtained by the experiment. As shown in FIG. 11 and FIG. 12, in order to reduce the weld generation amount, it is a means that a compound addition of Ti and Al at 0.01% or more is effective in addition to the low C% of the prior art for the mild steel shell component Confirmed. Among them, it was found that Al alone had little effect, and a significant effect as a ratio was produced by the complex addition with Ti. In addition, the effect of reducing welding voids of Ti and Al is C 0.02%, Ti / C 1.0%, Al / C It was also found to be obtained at 1.5.

The reason why the welding rest reduction effect is obtained by Ti and Al is that since Ti and Al have high affinity with oxygen and produce high solidification oxide, an oxide film is formed on the surface of the suspended volume of the wire tip during arc welding. hyuum causes the resultant of the reaction of C with oxygen is considered as due to suppress the explosion in the generation of CO, CO _2.

In addition, the upper limit of Ti and Al amount is Ti in order to avoid material degradation such as ductility degradation and hardening resulting from recovery of weld metal. 0.20%, Al It was clarified that it was necessary to be 0.10%.

In addition, as shown in FIG. 13, it was also found that the effect of reducing welding hum becomes more remarkable by adding Cs and Rb to the flux.

For the above reasons, the mild steel shell suitable for reducing welding vacancy is a ratio to the total weight of the shell.

C: 0.02%

Ti: 0.01 ~ 0.20%

Al: 0.01 ~ 0.10%

Containing, and,

Ti / C 1.0

Al / C 1.5

It is steel of composition to satisfy.

To present a more desirable range,

C: 0.01%

Ti: 0.01 ~ 0.10%

Al: 0.01 ~ 0.05%

Containing, and,

Ti / C 3.0

Al / C 2.0

To satisfy the composition. In addition, considering the workability in the rolling or / and drawing process in wire manufacturing, Mn: 0.10 to 0.70%, Si 0.35% range is preferred.

In addition, the metal flux suitable for welding welding reduction is a ratio of the wire weight.

One or more of oxides and fluorides of alkali metals excluding Cs and Rb

(Converted to alkali metal element): 0.01 to 0.30%

Fe powder: 5 ~ 28%

Metal powder: 94% (vs. flux total weight)

The total of one or two kinds of Cs and Rb (calculated in terms of Cs and Rb): 0.001 to 0.10%, and

Mn (total amount of Mn in the skin): 0.5 to 3.6%

Si (total amount of Si in the shell): 0.1 to 1.8%

It is a flux of the composition containing it.

If the sum of one or two of Cs and Rb in the metal-based flux is less than 0.001%, there is no decrease in resting (see FIG. 13).

However, if it exceeds 0.10%, the porosity resistance decreases, the amount of diffusible hydrogen of the deposited metal increases and the crack resistance deteriorates with deterioration of hygroscopic resistance. Moreover, Cs and Rb are added in a suitable form, but in particular Cs can be added as CsCO ₃ or in the form of a composite oxide with TiO ₂ , SiO ₂ , or the like. In this invention, the value of Cs and / or Rb is the amount which converted Cs and / or Rb in these compounds into elements. More preferably, it is 0.001 to 0.010%.

Alkali metal components (except Cs and Rb), such as Li, Na, and K, are added in order to reduce arc stability and spatter amount. Since the hygroscopicity is remarkable, this alkali metal is preferably used in the form of an oxide or a fluoride. The above range is limited to less than 0.01% because the effect of improving arc stability and spatter reduction cannot be obtained, and if it exceeds 0.30%, since these alkali metals have a high vapor pressure, the spatter increases. In addition, the effect of reducing welding hum by Ti and Al cannot be obtained.

Furthermore, fluorides such as feldspar, anhydrous sodium silicate, water glass, composite oxides such as Li, Na, and K, cryolite, potassium silicate, and sodium silicate, and carbonates of small amounts of alkali metals are also decomposed by arc heat and oxides. Since the same effect is obtained. In this invention, the addition amount is the value converted into the alkali metal element. Preferably it is 0.01-0.10%.

The Fe powder amount is added according to the flux rate in order to obtain a high deposition rate. The flux ratio (flux-to-wire total weight) is less than 10%, so that the thickness of the shell metal is too thick, so that the spatter of large particles increases. On the other hand, if the content exceeds 30%, the wire becomes soft due to the decrease in the thickness of the shell metal, so that the supplyability is lowered, the arc spreads remarkably, and the penetration depth and the undercut are easily generated. For this reason, as a flux ratio, 10 to 30% of range is preferable.

Fe powder is added in accordance with the above-mentioned flux ratio, but if it is less than 5%, a remarkable solid solution rate which is a special feature of the metal-based flux-containing wire cannot be obtained, and if it exceeds 28%, other components such as a deoxidizer are insufficient, and a predetermined weld metal It is difficult to secure the mechanical properties and to prevent welding defects such as pits and blow holes. Therefore, the Fe powder amount is in the range of 5 to 28%. More preferably, it is 8-15%.

It is necessary to make the metal powder ratio in the flux to be 94% or more excluding non-metallic materials such as oxides, fluorides, and carbonates in order to secure the solid-solution speed characteristics and the amount of slag capable of continuous multi-layer welding of the metal-based flux-containing wire. .

Mn is added in consideration of the amount of Mn in the shell to improve the deoxidizer, toughness by improving strength or quenchability, and bead shape improvement (particularly in case of horizontal fillet) by increasing viscosity of molten metal slag. In this case, if Mn is less than 0.5%, sufficient strength cannot be obtained even for mild steel, and the bead improvement is not good. In addition, when Mn exceeds 3.6%, the weld metal strength becomes excessive and low temperature cracks are likely to occur. Moreover, Mn, Fe-Mn, Fe-Si-Mn, etc. are mentioned as Mn source. More preferably, it is 0.5 to 2.5%.

Si has the same effect as Mn. However, when Si is less than 0.1%, deoxidizer, toughness improvement and bead shape improvement effect cannot be obtained, and when Si exceeds 1.8%, the amount of Si in the weld metal becomes excessive, conversely, the toughness and ductility decrease. do. Moreover, as a Si source, alloys, such as Si, Fe-Si, Fe-Si-Mn, Fe-Si-Mg, are mentioned. More preferably, it is 0.3 to 1.2%.

In addition, within the range that satisfies the ratio of the metal powder described above, in order to further improve the appearance of the bead and the shape, oxides such as SiO 2, ZrO ₂ , CaO, FeO, etc. may be added or hot cracks may not be formed to improve slag peelability. Bismuth oxide (Bi ₂ O ₃ ) or less of 0.1% (total weight of wire) of MgO or Mg of 0.2% (total weight of weight of wire) or less of bead-like deterioration may be added. .

In addition, the applied base steels of the present invention are mainly mild steel and high tensile steel, but may be expanded to low alloy steel, high alloy steel, or the like by adding metals or alloys such as Ni, Cr, Mo, and Cu, depending on the application.

Further, in any of the above-described flux filling wires, the wire cross-sectional shape is not limited at all, and for example, those having various shapes illustrated in (A), (B), (C), and (D) in FIG. 10 can be used. Can be. Further, the surface of the wire may be plated with Cu, Al or the like, in which case the plating amount is appropriately 0.05 to 0.35%. In addition, a wire diameter can also be arbitrarily determined according to a use.

As the shield gas, an oxidizing, neutral, or reducing gas may be applied. Typical shield gases may be used as a mixed gas of two or more, such as CO ₂ gas, _{Ar, Co 2, O 2,} He.

(Description of the Preferred Aspect)

Next, the Example of this invention is shown.

(Example 1)

This example is mainly an example of low humming by the adjustment of the outer skin composition, and also an example in which the composition of a preferable eta flux is also investigated.

Filling fluxes for the composition of the compositions shown in Tables 2 and 3 were prepared using an outer sheath made of mild steel of the composition shown in Table 1, and the test wires (wire diameter 1.4 mm Φ in the cross-sectional shape of (A) in FIG. 10). ) Was produced. Next, welding was performed under the following conditions using each flux-containing wire, and the amount of hum generated, workability, and the like were examined.

(Welding condition)

Polarity: DC Wire (+)

Welding current: 350A

Voltage: 37 ± 3V

Speed: 30cm / min

Sealed gas: 100% CO ₂ , 25 liters / min

Base material spacing: 25 mm

Trial: JIS G3106, SM490A (12 mmt)

Welding method: downward bead-on plate welding

(Hypermetry)

According to JIS Z3930 "Method of Measuring Total Holum of Covered Arc Welding Rod", the weight (g / min) per unit time (average of repetition number = 3) was obtained by measuring the weight of the humm generated when welding for 1 minute. . Huum was recovered by the apparatus provided with the collection box shown in FIG.

(Workability)

Evaluation was made by sensory evaluation.

The test results are as shown in Table 4 and thus considered. In the tests Nos. 1 to 8, since the composition of the shell metal was appropriately adjusted, the amount of hum was extremely reduced in either case.

On the other hand, the test Nos. 9-16 are the examples in which either component of an outer skin metal is not suitable.

Specifically, in test No. 9, the amount of hum is increased because the amount of C in the shell metal is too large. Tests Nos. 10 to 11 are examples in which the Ti content of the shell metal is not appropriate. When the amount is too small, the amount of generation of humes increases, and when the amount is too high, the recovery to weld metal increases and the ductility decreases. Tests Nos. 12 to 13 are examples in which the amount of Al in the outer shell metal is not appropriate. If the amount is too small, the amount of humus is increased, and if the amount is too large, the ductility of the weld metal is lowered. In test No. 14, the amount of hum is increased as an example in which the Ti / C ratio of the shell metal and the Al / C ratio in No. 15 are not appropriate. Test No. 16 is an example where the C, Ti, Al, Ti / C ratio, and Al / C ratio of the shell metal are not all appropriate.

In addition, Test Nos. 17 to 30 are examples in which the adjustment of the composition of the shell metal is appropriate but the adjustment of the composition of the metal flux is not appropriate.

Specifically, in Test Nos. 17 to 18, examples in which Ti or Ti oxide (in terms of Ti) of the flux are not suitable are excessively small, the amount of hum is increased and the stability of the arc is deteriorated. When too much, the ductility of a weld metal will fall. Test No. 19 is an example in which the amount of Al in the flux is not appropriate, and the ductility of the weld metal is lowered. Test No. 20 is an example in which the Ti / C ratio of the flux is not appropriate, and the effect of reducing hum is not recognized. In test No. 21, the amount of hum is increased as an example in which the amount of flux C is outside the scope of the present invention. Test No. 22-23 is an example in which the alkali metal amount of a flux is not suitable, and when too small, arc stability will be bad and spatter will increase. If too much, spatter will increase and the hum reduction effect will be impaired. Test No.24-25 is an example in which the quantity of iron of a flux is not suitable, and when too small, the spatter of a large particle will increase. On the other hand, when too much, the thickness of the outer shell metal becomes thin, so that the feeding ability is weakened and the undercut or the like is easily formed. Test No. 26 is an example in which the metal powder ratio is not appropriate. The efficiency of the metal-based flux-containing wire is impaired, the amount of slag increases, and continuous multilayer welding becomes difficult. Test No. 27-28 is an example in which the amount of Mn is not suitable, when too small, sufficient strength will not be obtained and bead shape will also deteriorate. If too much, the strength is excessive, and low temperature cracks are likely to occur. In Test Nos. 29 to 30, examples in which the amount of Si is not appropriate, the bead shape deteriorates if the amount is too small, and the toughness or ductility of the weld metal decreases when the amount is too large.

In addition, the test No. 31 is not particularly suitable for all of the requirements (C, Ti, Al, Ti / C, Al / C for the clad metal, Ti, C, Ti / C for the flux) that contribute to the reduction of the amount of humus. As an example, the amount of hum is increasing.

(Example 2)

This example is mainly an example of low humming by adjustment of the outer skin composition, and also an example of investigating the composition of a preferable titania flux.

Combination flux of the mild steel shell metal which has the chemical component shown in Table 5, and the filling flux of the composition of the composition shown in Table 6, the cross-sectional shape of the cross-sectional shape of (A) in FIG. 15%). Subsequently, welding was carried out using the flux-containing wire under the following conditions, and the amount of hum generated, workability, and the like were examined.

(Welding condition)

Polarity: DC Wire (+)

Welding current: 280A

Welding voltage: 30V

Welding speed: 30cm / min

Sealed gas: 100% CO, 25 liters / min

Tip distance between tips: 25㎜

Trial: JIS G3106, SM490A (12 mmt)

Welding Method: Horizontal Fillet Welding

(Emergency Measurement)

According to JIS Z3930 "Method of Measuring Total Rest of Covered Arc Welding Rod", the weight per unit time (mg / min) (mean value of repetition number = 3) was obtained by measuring the weight of the rest produced when welding for 1 minute. Huum was recovered by the apparatus provided with the collection box shown in FIG.

(Workability)

Evaluation was made by sensory evaluation.

The test results are as shown in Table 7, and considered as follows.

In the tests Nos. 1 to 8, since the composition of the shell metal is appropriately adjusted, the amount of occurrence of hum is small, and the welding workability is also good.

On the other hand, test No. 9 is an unsuitable example of Ti / C of an outer skin metal, and the amount of a hum is increasing. In test No. 10, the occurrence rate of hum is remarkably increased as an example in which Al / C of the shell metal is not appropriate.

The experiments Nos. 11 to 15 are examples in which the component adjustment of the metal shell is appropriate, but the component adjustment of the titania flux is not appropriate.

Specifically, test No. 11 is an example in which the amount of TiO in the flux is too large, and the amount of the hum is small, but welding defects (slag incorporation) occur. Although test No. 12 shows that the amount of TiO in the flux is too small, the amount of hum is small, but the slag coatability of the bead surface is insufficient, and the bead appearance is inferior. Test No. 13 is an example in which the amount of alkali metal oxides (NaAlSiO) in the flux is excessively high, but the amount of hum is small, but the slag peelability is inferior. Test No. 14 is an example in which the amount of Mg in the flux is too large, and the amount of hum is increased.

In the test No. 15, the amount of C in the flux is too large, and the amount of hum is remarkably large, and the amount of spatter is also large.

(Example 3)

This example is an example regarding low humming by adjusting the metal flux composition.

Using the skin metal shown in Table 8, the filling flux of the composition shown in Table 9 was created, and the test wire (wire diameter 1.2mm (phi)) was created in the cross-sectional shape of FIG. 10 (A). Subsequently, welding was performed using the respective wires under the following conditions, and the amount of hum generated, workability, and the like were examined.

(Welding condition)

Polarity: DC wire (+), welding current: 300A, voltage: proper (ark length: 1.5 mm from the base material surface), speed: 30 cm / min, shield gas: 100% CO2, 25 l / min, tip base material distance: 25 mm, Test plate: JIS G3106, SM490A (12 mmt), Welding method: Downward bead-on plate welding

(Hypermetry)

In accordance with JIS Z3930 "Method of Measuring Total Rest of Covered Arc Welding Rod", the weight (g / min) (repeated number of times = average of 3 times) per unit time was obtained by measuring the weight of the rest produced when welding for 1 minute. Huum was recovered by the apparatus provided with the collection box shown in FIG.

(Workability)

Evaluation was made by sensory evaluation.

Although these experimental results are shown in Table 10, it can consider as follows. In Test Nos. 1 to 7, since the flux composition is appropriately adjusted, the amount of hum is extremely low (about 1/2 of conventional hum).

On the other hand, Test No. 8-19 is an example in which the component adjustment of a metal type flux is not appropriate.

Specifically, Test Nos. 17 and 18 are examples in which all three requirements (C amount, Ti amount, Cs and / or Rb amount) that are involved in the low hum are not satisfied, and the hum is generated very much. In test No. 8, since the amount of C is not appropriate, the amount of hum is increased. In Test Nos. 9 and 10, examples in which the Ti amount is not appropriate are excessively small, and the amount of hum is increased. Test Nos. 11 and 12 are examples in which the amount of Cs and / or Rb is not appropriate. If too small, the amount of hum is increased, and if too large, the hygroscopicity of the wire is deteriorated, and the porosity, crack resistance, and the like decrease. In experiments No. 13 and 14, examples in which the flux ratio is not appropriate are too small to increase the spatter of large particles, and too large to deteriorate the feedability. Test Nos. 15 and 19 are examples in which the amount of iron powder is not appropriate. If too small, the yield is deteriorated. If too large, other components (such as deoxidizer) will be insufficient, and defects such as pits and blow holes will occur. In test No. 17, the amount of {C / (Cs + Rb)} + Ti is not appropriate, penetration is shallow, and defects tend to occur in welding in the improvement.

(Example 4)

This example is an example of low humming by adjusting the titania flux composition.

Using a mild steel shell containing the components shown in Table 11, a flux-containing wire (1.2 mm Φ) filled with a flux containing the components shown in this table at a predetermined flux rate was produced. Subsequently, a welding test was carried out using the flux-containing wire under the following welding conditions.

(Welding condition)

Welding method: downward bead-on plate welding

Welding current: 300A

Arc voltage: Proper voltage with arc length of 1.5 to 2.0 mm

Welding speed: 30cm / min

Wire Extrusion Length: 25㎜

Polarity: DCEP

Sealed gas: 100% CO (flow rate 25 liters / min)

Trial: JIS G3106 SM490A (plate thickness 12 mm)

(Hypermetry)

According to JIS Z3930 "Method of Measuring Total Rest of Covered Arc Welding Rod", the weight per unit time (g / min) (mean value of repetition number = 3) was obtained by measuring the weight of the rest produced when welding for 1 minute. . Huum was recovered by the apparatus provided with the collection box shown in FIG.

(Workability)

Evaluation was made by sensory evaluation.

The test results are shown in Table 1.

Test Nos. 2 to 5, 8 to 10, 15 to 16, and 19 to 20 are suitable for adjusting titania-based fluxes, so any amount of hum is significantly reduced, and welding workability (spatter generation, bead deflection, X Wire performance, bead appearance, etc.) are also excellent.

On the other hand, other test examples are examples in which the adjustment of the composition of the flux is not appropriate, and there are many examples in which a large amount of hum is generated and problems in weldability.

Further, Test Nos. 1 to 6 were influenced by the amount of TiO in the flux, Test Nos. 7 to 11 were influenced by the amount of Cs in the flux, and Test Nos. 12 to 13 were C amounts in the flux. Effect, Test Nos. 14-17 are the effects of TiO content in the flux, Test Nos. 18-21 are the influences of the flux rate, Test Nos. 22-23 are the amount of C in the steel sheath and The effects of the amount of Ti are mainly investigated.

(Example 5)

This example is an example of low humming by adjusting the components of the shell metal and the metal flux.

Using a shell metal made of mild steel of the composition shown in Table 12, a filling flux for the composition of the composition shown in Table 13 was prepared, and the test wire (wire diameter 1.4 mm Φ in the cross-sectional shape of (A) in FIG. 10). ). Subsequently, each flux-containing wire was welded under the following conditions, and the amount of hum generated, workability, and the like were examined.

(Welding condition)

Polarity: DC Wire (+)

Welding current: 350A

Voltage: 37 ± 3V

Speed: 30cm / min

Sealed gas: 100% CO, 25 liters / min

Distance between tip materials: 25 mm

Trial: JIS G3106 SM490A (12 mmt)

Welding method: downward bead-on plate welding

(Hypermetry)

According to JIS Z3930 "Method of Measuring Total Rest of Covered Arc Welding Rod", the weight per unit time (g / min) (mean value of repetition number = 3) was obtained by measuring the weight of the rest produced when welding for 1 minute. Huum was collected by an apparatus equipped with a collecting box shown in FIG.

(Workability)

Evaluation was made by sensory evaluation.

The test results are as shown in Table 14 and considered as follows.

In Test Nos. 2, 3, 6, 7, 15, and 18, since the adjustment of the components of the shell metal and the flux was appropriate, the amount of hum was extremely low.

On the other hand, the example of the other test No. shows that since at least one of the components of the shell metal or the components of the flux is not appropriate, the amount of humming is large or the performance of weldability is inferior.

Specifically, tests No. 1 and No. 4 are examples where Cs and Rb are not appropriate, and when the amount is too small, the amount of hum is increased. When the amount is too large, the hygroscopicity of the wire is deteriorated, and the porosity and the crack resistance are deteriorated. Tests No. 5 and No. 8 are examples in which the amount of alkali metals is not appropriate. If the amount is too small, the arc stability is poor, the spatter increases, and if the amount is too large, the spatter increases, and the effect of reducing the occurrence of hum is impaired. .

Test Nos. 9 to 10 are examples where the iron powder amount is not appropriate, and if too small, the efficiency of welding decreases, but spatter increases. If the amount is too high, it is difficult to secure the mechanical properties of the weld metal and to prevent welding bonds such as pits and blow holes. . In Test Nos. 11 to 12, examples in which the amount of Mn is not appropriate are sufficient. If the amount is too small, sufficient strength cannot be obtained. The bead shape is also degraded. If the amount is too large, the strength is excessive, and low-temperature cracking properties are likely to occur.

In Test Nos. 13 to 14, if the amount of Si is too small, the bead shape deteriorates. If too large, the toughness and ductility of the weld metal decreases. In test No. 16, since the amount of C in the clad metal is not appropriate, the amount of hum is increased. Test Nos. 17 and 21 are examples in which the amount of Al in the shell metal is not appropriate. If the amount is too small, the amount of hum is increased and if the amount is too high, the ductility of the weld metal is decreased. Tests Nos. 19 to 20 are examples in which the Ti content of the shell metal was not appropriate. When the amount was too small, the amount of humus is increased, and when the amount is too high, the yield to the weld metal is increased and the ductility is decreased.

(Example 6)

This example is an example of low humming by adjusting the composition of the shell metal and the titania-based flux.

Using the soft steel outer shell containing the component shown in Table 5, the flux-containing wire (1.2 mmΦ) in which the flux containing the component shown in Table 15 was also filled with the predetermined flux rate was produced. Subsequently, a welding test was conducted using the flux-containing wire under the following welding conditions.

(Welding condition)

Welding method: downward bead-on plate welding

Welding current: 300A

Arc voltage: Appropriate voltage having arc length 1.5 to 2.0 mm

Welding speed: 30cm / min

Wire protrusion length: 25 mm

Polarity: DCEP

Sealed gas: 100% CO2 (flow rate 25 liters / min)

Trial: JIS G3106 SM490A (plate thickness 12 mm)

(Hypermetry)

According to JIS Z3930 "Method of Measuring Total Rest of Covered Arc Welding Rod", the weight per unit time (g / min) (mean value of repetition number = 3) was obtained by measuring the weight of the rest produced when welding for 1 minute. .

Huum was recovered by the apparatus provided with the collection box shown in FIG.

(Workability)

Evaluation was made by sensory evaluation.

The test results are shown in Table 16.

In Test Nos. 2, 3, 6, 7, 10, 11, 17, 18, 21, and 22, since the mild steel composition and the titania-based fluxes are appropriately adjusted, any amount of hum is significantly reduced, and welding workability is further reduced. (Bead appearance and shape, bead sagging, spatter generation amount, slag peelability, X-ray performance) is also excellent.

On the other hand, other test examples are examples in which the adjustment of the composition of the flux is not appropriate, and there are many cases in which a large amount of hum is generated and a problem in welding workability.

Further, Test Nos. 1 to 4 were influenced by the amount of TiO in the flux, Test Nos. 5 to 8 were affected by alkali metal oxides in the flux, and Nos. 9 to 12 were Cs in the flux. Amount and TiO / Cs ratio, No.13 affects the amount of C in the flux, Nos. 14 and No.16 to No.19 affect the amount of Mn in the flux, and Nos. 20 to 23 show the flux. It mainly examines the influence of the amount of Si in it.

Claims (22)

In the flux filling wire for gas seal arc welding formed by filling a flux in a mild steel shell, ① Mild steel outer sheath, in proportion to the total weight of the outer shell, C: 0.02% Ti: 0.01 to 0.20% Al: 0.01 to 0.15% Containing, and Ti / C 1.0 Al / C 1.5 Made of steel of composition to satisfy the ② flux is in proportion to wire total weight, Mn (total amount of Mn in the skin): 0.50 to 3.60% Si (total amount of Si in the shell): 0.10 to 1.80% Flux-filled wire for gas seal arc welding, characterized in that the flux containing a, The method according to claim 1, wherein the soft steel outer sheath, in proportion to the total weight of the sheath, C: 0.01% Ti: 0.01 to 0.10% Al: 0.01 to 0.05% Containing, and Ti / C 3.0 Al / C 2.0 Flux filling wire for gas seal arc welding, characterized in that the steel of the composition satisfying the. The flux according to claim 1 or 2, wherein as flux, in a ratio to the total weight of the wire, Ti or Ti oxide (Ti equivalent): 0.03 to 1.0% Oxides of alkali metals and at least one fluoride (alkali metal element equivalent): 0.01% to 0.15% Fe powder: 5 ~ 28% Metal powder: 94% (vs. flux total weight) Containing, and Mn (total amount of Mn in the skin): 0.50 to 3.60% Si (total amount of Si in the shell): 0.10 to 1.80% A gas sealed arc welded metal-based flux filling wire, characterized in that the metal-based flux containing. The method of claim 3, wherein the flux is further, in proportion to the total weight of the wire, Al or Al ₂ O ₃ (Al element equivalent): 1.0% A gas-sealed arc-welded metal flux-filled wire, comprising: The method of claim 3, wherein the flux is further, in proportion to the total weight of the wire, C: 0.07% (However, Ti / C 1.0) A gas-sealed arc-welded metal flux-filled wire, comprising: The method of claim 5 wherein the flux is Ti / C 3.0 Gas shielded arc welded metal-based flux filling wire, characterized in that to satisfy. The method of claim 1 or 2, wherein the flux is a ratio of the total weight of the wire, TiO ₂ : 1.00 ~ 8.50% Oxide of alkali metal (alkali metal element conversion value): 0.01 to 1.50% Containing, and Mn (total amount of Mn in the skin): 0.50 to 3.60% Si (total amount of Si in the shell): 0.10 to 1.50% A gas sealed arc-welded titania-based flux filling wire, characterized in that it is a titania-based flux containing. 8. The method of claim 7, wherein the flux is further proportional to the total weight of the wire, Mg and MgO or either (Mg element conversion value): 0.01 to 1.00% A gas sealed arc-welded titania-based flux filled wire, characterized in that it contains a. 8. The method of claim 7, wherein the flux is further, in proportion to the total weight of the wire, C: 0.06% or less A gas sealed arc-welded titania-based flux filled wire, characterized in that it contains a. In the gas-sealed arc-welded metal-based flux-filled wire formed by filling a flux in a mild steel outer shell, the total flux% is large. Fe powder: 60 ~ 85% C: 0.5% or less Ti: 0.5 ~ 3.0% One or two or more sums of the Cs compound and the Rb compound, or any one of the compounds (Cs and Rb, or any element conversion value): 0.01 to 0.3% Flux containing 10% to 30% by weight of the total weight of the wire in the soft steel shell, and {C / (Cs + Rb)} + Ti = 3 or more (where Cs and Rb is a Cs compound and A gas shielded arc welded metal-based flux-filled wire, which is an Rb compound or a Cs and an Rb element conversion value (vs. total flux%) in any one of the compounds. The method of claim 10, wherein the mild steel jacket C: 0.01% or less Ti: 0.01 ~ 0.20% A gas shielded arc welded metal-based flux filling wire comprising a. In the gas-sealed arc-welded titania-based flux-filled wire formed by filling a flux in a mild steel shell, with a large flux total weight, TiO ₂ : 8 ~ 60% Compound of Cs (Cs element conversion value): 0.01 to 1.0% (However, the ratio of TiO ₂ / Cs compound (Cs element conversion value): 20 to 2000) C: 0.5% A gas seal arc-welded titania-based flux-filled wire, comprising a flux containing 5 to 30% by weight of a total weight of wire in a mild steel shell. The method according to claim 12, wherein the chemical composition of the mild steel jacket is in proportion to the total weight of the jacket, C: 0.02% or less Ti: 0.20% or less A gas shielded arc-welded titania-based flux-filled wire, characterized in that. The method according to claim 1 or 2, wherein the flux is the total weight of the wire, One or two or more sums of the Cs compound and the Rb compound, or any one of the compounds (Cs and Rb, or any element conversion value): 0.005 to 0.3% Flux filling wire for gas seal arc welding, characterized in that the flux containing. The method according to claim 10, wherein the soft steel outer sheath, in proportion to the total weight of the sheath, C: 0.01% Ti: 0.01 ~ 0.10% Al: 0.01 ~ 0.05% Containing, and Ti / C 3.0 Al / C 2.0 Flux filling wire for gas seal arc welding, characterized in that the steel of the composition satisfying the. In the gas-sealed arc-welded metal-based flux filling wire formed by filling a flux in a mild steel shell, ① Mild steel outer sheath, in proportion to the total weight of the outer shell, C: 0.02% Ti: 0.01 to 0.20% Al: 0.01 ~ 0.10% Containing, and Ti / C 1.0 Al / C 1.5 Made of steel of composition to satisfy the ② flux is in proportion to wire total weight, One or more of oxides and fluorides of alkali metals excluding Cs and Rb (Alkali metal element conversion value): 0.01 to 0.30% Fe powder: 5 ~ 28% Metal powder: 94% (vs. flux total weight) One or two or more sums of the Cs compound and the Rb compound, or any one of the compounds (Cs and Rb, or any element conversion value): 0.001 to 0.10% Containing, and Mn (total amount of Mn in the skin): 0.50 to 3.60% Si (total amount of Si in the shell): 0.10 to 1.80% A gas sealed arc welded metal-based flux filling wire, characterized in that the metal-based flux containing. In the gas seal arc welded titania-based flux filling wire formed by filling a flux in a mild steel shell, ① Mild steel outer sheath, in proportion to the total weight of the outer shell, C: 0.02% Ti: 0.01 to 0.20% Al: 0.01 to 0.15% Containing, and Ti / C 1.0 Al / C 1.5 Made of steel of composition to satisfy the ② flux is in proportion to wire total weight, TiO ₂ : 1.00 ~ 8.50% Alkali metal oxide (alkali metal element conversion value) except Cs: 0.01 to 1.50% Compound of Cs (Cs equivalent): 0.0005 to 0.3% (However, the ratio of TiO ₂ / Cs compound (Cs element conversion value): 20 to 2000) C: 0.06% Mn (total amount of Mn in the skin): 0.50 to 3.60% Si (total amount of Si in the shell): 0.10 to 1.50% A gas sealed arc-welded titania-based flux filling wire, characterized in that it is a flux containing. 18. The method of claim 17, wherein the flux is further proportional to the total weight of the wire, Mg and MgO, or either (Mg element conversion value): 0.01 to 1.00% A gas sealed arc-welded titania-based flux filling wire, characterized in that it is a flux containing. The method of claim 4, wherein the flux is further, in proportion to the total weight of the wire, C: 0.07% (However, Ti / C 1.0) A gas-sealed arc-welded metal flux-filled wire, comprising: The method of claim 19 wherein the flux is Ti / C 3.0 Gas shielded arc welded metal-based flux filling wire, characterized in that to satisfy. The method of claim 8, wherein the flux is further, in proportion to the total weight of the wire, C: 0.06% or less A gas sealed arc-welded titania-based flux filled wire, characterized in that it contains a. The method according to claim 12, wherein the soft steel outer sheath, in proportion to the total weight of the sheath, C: 0.01% Ti: 0.01 ~ 0.10% Al: 0.01 ~ 0.05% Containing, and Ti / C 3.0 Al / C 2.0 Flux filling wire for gas seal arc welding, characterized in that the steel of the composition satisfying the.