JP2003112287A - Flux cored wire for welding seashore weather resistant steel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a flux cored wire for welding seashore weather resistant steel having the excellent strength, toughness and seashore weather resistance of weld metal and having the high welding performance and productivity of a solid wire, a low amount of slag production and deep penetration performance and the excellent welding workability of the flux cored wire in combination. SOLUTION: The wire for arc welding formed by filling a flux into a sheath made of steel contains, by the total mass% of the wire, 0.05 to 1.8% arc stabilizer and contains 0.02 to 0.15% C, 0.30 to 1.8% Si, 0.8 to 3.0% Mn, 0.02 to 0.3% Ti, 1.0 to 5.0% Ni, 0.3 to 0.65% Cu, and <=0.03% P, in which <=0.05% Cr and <=0.01% S and the flux filling rate is 3 to 10%. The stabilizer of the flux cored wire for the welding seashore weather resistant steel consists of one or >=2 kinds among <=1.8% synthetic matter containing Na2 O and TiO2 , <=0.6% NaS2 O in the value in terms of Na2 O and <=1.8% TiO2 in the value in terms of TiO2 .

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is used in the fields of construction and bridges in an environment where salt damage is feared due to the presence of high concentrations of incoming sea salt particles, such as in beach areas or areas where snow melting agents are sprayed. Regarding the flux-cored wire for welding beach weather-resistant steel used for welding beach weather-resistant steel used in various structures, the arc state is extremely good, the amount of spatter is small, and the excellent weld metal performance is stable. The present invention relates to a flux-cored wire for welding beach weather-resistant steel.

[0002]

2. Description of the Related Art Weather-resistant steel has a property of forming a protective rust layer on the surface of a steel sheet to suppress corrosion of the steel sheet, and has excellent corrosion resistance. Widely used in the field of goods.

However, in areas with high concentrations of flying sea salt particles, such as beach areas and areas where snow melting salts are sprayed, a stable rust layer is not formed on the surface of the steel sheet and corrosion is not suppressed, so it is sufficient. Can not ensure good corrosion resistance.

Therefore, when the weather resistant steel sheet is used in the beach area and the area where the snow melting agent is sprayed, the steel sheet whose surface is coated is used. However, there is a problem that it takes a great deal of time and labor to coat the entire surface of the steel sheet, and the cost becomes enormous.

A steel sheet excellent in weather resistance in such a beach area is currently under development, and Ni is 1.0
Cu-containing up to 5.5% and limiting the amount of Cu, Ti, etc.
There are Ni-Ti steels and the like.

On the other hand, the welding wires used for the weather resistant steel plate (hereinafter referred to as beach weather resistant steel) that can be used in these beach areas and areas where the snow melting agent is sprayed are Ni and Cu.
A wire with a limited number is being considered.

As an example thereof, Japanese Patent Laid-Open No. 2000-288878.
No. 1, in the wire, C, Si, Mn, Ni, C
There is disclosed a TiO ₂ -based flux-cored wire that contains u and P and that limits the contents of Cr and S to ensure weather resistance in the beach area and has excellent low temperature toughness.

According to this method, it is possible to prevent deterioration of weather resistance due to flying sea salt particles and to secure excellent mechanical properties, but the arc state during welding is rather unstable, and the amount of spatter generated is small. Many have problems in terms of welding workability.

Further, a major characteristic of the conventional flux-cored wire is that it has excellent welding workability such as a stable arc state as compared with a solid wire, but on the other hand, the amount of slag covering the bead is large and fumes are generated during welding. There is a problem in welding work such as a large amount. Furthermore, the flux-cored wire has a problem that the penetration is shallower than that of the solid wire, and welding defects such as slag entrainment and fusion failure are likely to occur.

As described above, in order to secure the weather resistance and improve the welding workability in the beach area, the advantages of the flux-cored wire are maintained, the amount of slag is reduced, the deep penetration property and the poor fusion are maintained. There is a demand for improved thin wire for gas shielded arc welding.

For the purpose of improving the slag, the fume, and the deep penetration depth of such a flux-cored wire, technical disclosure of a low-filling-rate flux-cored wire having a flux filling rate of 5% has been scattered. However, the conventional flux component systems have problems such as excessive welding slag and excessive fume generation, and such a low filling rate wire has not been put into practical use.

For example, a wire containing a flux having a cross-sectional area ratio of 5 to 25% is disclosed in JP-B-51-1.
There is a 659 publication. Although an example in which the wire cross-sectional area ratio of the filling flux of the present invention is as low as 5% is disclosed, the filling flux contains graphite as an arc stabilizer as an essential component and is composed of Ti, Al, Mg, etc. Is a wire which contains 2 to 10% and further contains 20 to 90% of a deoxidizer and which is filled with a flux containing substantially no metal component. However, the arc stabilizer containing graphite contains a factor of arc destabilization due to a CO reaction between the graphite and oxygen in the wire or oxygen adhering to the wire surface, and the arc becomes rough and welding workability deteriorates to cause spattering. Increase the amount generated. Further, the yield of C in the weld metal becomes excessive, and the performance of the weld metal cannot be adjusted.

Further, in Japanese Patent Laid-Open No. 6-218577, a flux containing a flux having a flux filling rate of 5 to 30%, a content of Mn and S, and a Mn / S ratio of 40 to 60% is contained. Wires are disclosed. This is a wire belonging to a metal-based flux-cored wire, and in a wire having a flux filling rate of 5% and 10%, a sufficiently stable arc cannot be obtained with the filling flux made of such metal powder. As a result, excellent welding workability and good welding results cannot be obtained.

Further, in Japanese Patent Laid-Open No. 3-180298, TiO is used to prevent pits and gas grooves during fillet welding of a steel plate coated with a primer which is a primary rust preventive agent.
₂ contains Na ₂ O as a base, discloses a wire to be essential metal fluoride and water. This is a flux-cored wire which contains TiO ₂ and Na ₂ O with a low wire filling ratio in a wire mass ratio of%. It also requires metal fluoride and water, and its water content and gas release can be easily adjusted. However, the fluidity of the slag is high, and the bead forming property and the weld metal properties are problematic.

These welding materials contain alloy elements such as Cu, Ni, and P contained in the filling flux to limit the amount of Cr and S added, thereby ensuring weather resistance and improving mechanical properties in beach areas. There is no disclosure about the addition of, and it is difficult to apply it to the welding of beach weather resistant steel sheets.

[0016]

DISCLOSURE OF THE INVENTION The present invention ensures a high beach weather resistance even in an environment of flying sea salt particles such as beach areas and areas where snow-melting agents are sprayed, while the arc state is extremely good and spatter is generated. An object of the present invention is to provide a flux-cored wire for welding beach weather resistant steel, which has a small amount and can stably obtain excellent weld metal performance.

[0017]

According to the present invention, a flux-cored wire contains an arc stabilizer and C, Si, Mn, Ti, Ni, Cu, P limited to a specific range, and has a flux filling ratio of 3 to. It is a flux-cored wire for beach weathering steel with a low filling rate of 10%, and is a new type of flux-cored wire with excellent welding workability and mechanical performance.

That is, the gist of the present invention is, in the flux-cored wire for welding beach weather resistant steel, the total mass% of the arc welding wire filled with the steel shell flux, and the arc stabilizer of 0.05 to 1.8. %, C: 0.02-0.1
5%, Si: 0.3 to 1.8%, Mn: 0.8 to 3.0
%, Ti: 0.02 to 0.3%, Ni: 1.0 to 5.0
%, Cu: 0.3 to 0.65%, P: 0.03% or less, Cr: 0.05% or less, S: 0.03%, and the flux filling rate is 3 to 10%. It is characterized by

The arc stabilizers are Na ₂ O and Ti.
Composition comprising an O _2: 1.8% or less, the Na ₂ O 0.6% or less in terms of Na ₂ O values, the TiO ₂ in terms of TiO ₂ value 1.8
It is also characterized in that it is one or more than 2% or less.

[0020]

BEST MODE FOR CARRYING OUT THE INVENTION The inventors of the present invention have developed a composition containing Na ₂ O, a deoxidizing agent containing Ni, Cu and P in an appropriate amount, a deoxidizing agent consisting of Si and Mn, Na ₂ O and TiO ₂ in order to ensure beach weather resistance. , T
Incorporating an arc stabilizer containing io ₂ alone or in combination, promotes the separation of the droplets during welding, increases the droplet size and the number of transitions, and stabilizes the arc for flux filling. It is a completely new flux-cored wire for welding beach weather-resistant steel, which has been found to increase the deposition rate, reduce fume, reduce slag, and deep penetration by reducing the rate to 3 to 10%.

The reasons for limiting the components and the like of the flux-cored wire for welding beach weather resistant steel of the present invention will be described below.

C: 0.02 to 0.15% by mass (hereinafter,%
Say. ), C is one of the most important elements for adjusting the strength of the weld metal by solid solution strengthening, and is greatly related to toughness. Therefore, if the addition amount of C is less than 0.02%, the required strength cannot be secured, and if it exceeds 0.15%, the weld metal structure becomes martensite, the strength becomes excessively high, and the toughness deteriorates, Further, spatter frequently occurs, which adversely affects welding workability.

Si: About 0.3 to 1.8%, Si is used as a deoxidizer and has an effect of reducing the amount of oxygen in the weld metal. However, if it is less than 0.3%, the deoxidizing power is insufficient and blowholes are generated in the weld metal, and if it exceeds 1.8%, the yield of Si in the weld metal becomes excessive and the crystals become coarse. , The toughness deteriorates.

Regarding Mn: 0.8 to 3.0%, Mn promotes deoxidation of the weld metal, enhances the fluidity of the molten metal, and improves the weld bead shape. In addition, yielding the weld metal has the effect of adjusting the weld metal performance and increasing its strength. 0.8% to obtain these effects
The above additions are necessary, but if it exceeds 3.0%, the droplets become large, the effect of reducing spatter is lost, the yield to the weld metal becomes excessive, and the strength of the weld metal increases.

Ti: About 0.02 to 0.3%, Ti
Has the function of refining the structure of the weld metal and is an element necessary for ensuring the strength and toughness of the weld metal. However, if it is less than 0.02%, the structure is not refined and the required toughness is not secured, and if it exceeds 0.3%, the toughness decreases due to the increase in hardness and the strength becomes higher than necessary.

Ni: About 1.0 to 5.0%, Ni is the most important element for improving the corrosion resistance in the environment of high concentration flying sea salt particles. This element has a function of suppressing Cl ions contained in the flying sea salt particles from entering the rust layer and suppressing the Cl concentration inside the rust layer. As a result, in order to suppress crystallization and coarsening of the rust layer formed on the surface of the steel sheet, the rust layer is kept fine and the corrosion resistance under the environment of flying sea salt particles is improved. Therefore, the added amount of Ni is 1.0%
If it is less than the above, sufficient corrosion resistance cannot be secured. On the other hand, if the addition amount exceeds 5.0%, the corrosion resistance becomes saturated and hot cracking easily occurs, resulting in excessive strength. Also, N
Since i is an extremely expensive element, it is set to 5.0% or less in consideration of cost performance.

Cu: About 0.3 to 0.65%, Cu
Like Ni, it is an essential element for ensuring the corrosion resistance under the environment of flying sea salt particles. This element is also C like Ni
It has the function of suppressing the penetration of l-ion into the stable rust layer, suppressing the crystallization and coarsening of the rust layer on the surface of the steel sheet, and improving the weather resistance under the environment of flying sea salt particles. Therefore, if the addition amount of Cu is less than 0.3%, it is not possible to prevent Cl ions from entering the rust layer, and it is not possible to secure sufficient corrosion resistance. Moreover, when the addition amount exceeds 0.65%,
Although the weather resistance does not deteriorate, high temperature cracking is likely to occur and mechanical properties such as toughness also deteriorate.
It was set to 65% or less. The Cu addition amount limited here includes the Cu amount when the wire surface is Cu-plated.

P: If it is 0.03% or less, P is an element that improves the weather resistance, but if added in excess of 0.03%, hot cracking tends to occur. Moreover, since the toughness of the weld metal part is deteriorated, the addition amount is set to 0.03% or less.

Cr: About 0.05% or less, Cr has a function of forming a stable rust layer on the surface of a steel sheet and improving corrosion resistance by adding an appropriate amount of Cr, and therefore it is used as an alloy component of weather resistant steel. It is an element that is sometimes changed. However, in a high-concentration flying sea salt particle environment, the presence of Cr in the weld metal impairs the weather resistance, so it is desirable that the Cr content be as low as possible. If the added amount of Cr is 0.05% or less, the inhibition of the beach weather resistance can be almost ignored, so the Cr amount was set to 0.05% or less.

S: 0.01% or less, S is an element that deteriorates the weather resistance of the weld metal portion under the environment of flying sea salt particles and further deteriorates the toughness, so is suppressed to 0.01% or less. There is a need.

Arc stabilizer: About 0.05 to 1.8%, if the arc stabilizer is less than 0.05%, the arc breakage that occurs at the moment when the droplets migrate can be prevented as in the welding of solid wire. Moreover, since the arc state is not improved and the spatter generation amount is not reduced, improvement over the solid wire cannot be achieved. On the other hand, if it exceeds 1.8%, the arc break can be prevented, but the arc length becomes longer than necessary, and as a result, the spatter generation amount and the fume generation amount also increase. Therefore, the addition amount of the arc stabilizer is 0.05 to 1.
At 8%, the arc state during welding is very good, the droplets are small, and the spatter generation is extremely small.

Arc stabilizers include Na ₂ O and TiO ₂
Composition comprising, Na ₂ O conversion value of Na ₂ O source and TiO
One or two or more of TiO ₂ converted values of _two sources.

Composite containing Na ₂ O and TiO ₂ :
When the content of the compound containing Na ₂ O and TiO ₂ exceeds 8% with respect to 8% or less, the arc break can be prevented, but the arc length becomes longer than necessary, and as a result, the spatter generation amount increases, The amount of fume generated also increases.

Na₂O and TiO₂The compound containing
iO₂Ternary compound containing Na, Na₂O and TiO₂of
Similar effects can be obtained even with various ratios of synthetic products.
And is included in the technical idea of the present invention. Na₂O and TiO₂
The compound containing is sodium titanate, for example,
High temperature treatment by mixing sodium and rutile in the desired ratio
Can be obtained by₂O is 10
TiO at 50%₂Of the ratio within the range of 50 to 90%
It is desirable to use a synthetic product. For example, 13Na ₂O-
80 TiO₂, 20Na₂O-73TiO₂, 42Na₂O
-53TiO₂, Or 13Na₂O-25SiO₂−
58 TiO₂Examples include synthetic products containing
However, it is not limited thereto.

When the Na ₂ O source is added in an amount of 0.6% or less in terms of Na ₂ O, the Na ₂ O source is Na ₂ O and TiO _2.
It is an additive component other than the compound containing ₂ or SiO ₂ to reduce the arc length fluctuation during welding, increase the number of droplet transfer,
That is, it has the effect of promoting atomization of the droplets. However, if it exceeds 0.6%, the number of times of droplet transfer tends to decrease and only the arc length tends to increase, resulting in an increase in the amount of spatter generation. Sources of Na ₂ O include sodium carbonate and soda glass.

For addition of 1.8% or less of TiO ₂ source in terms of TiO ₂ , the TiO ₂ source is Na ₂ O and TiO _2.
It is an additive component other than the compound containing ₂ or SiO ₂ and has the effect of promoting the downward electromagnetic pinch effect that stabilizes droplet transfer by expanding the arc generation area generated at the droplet tip as an arc stabilizer. Have. However, if it exceeds 1.8%, the downward electromagnetic pinch force becomes excessive, which makes the droplet transfer unstable and increases the spatter generation amount. Further, the amount of Ti reduced to the weld metal becomes excessive, the strength of the weld metal increases and the toughness also decreases. T
Sources of iO ₂ include titanium oxide, rutile, titanium slag, illuminite and the like.

The flux filling rate is 3-10%. If the flux filling rate is less than 3%, it becomes difficult to fill and mold the flux, resulting in poor productivity. Further, when the flux filling rate exceeds 10%, the amount of slag and the amount of spatter increase, the penetration depth becomes shallower, the performance of the wire cannot be improved, and the wire drawability at the time of wire production is inferior and the wire breakage occurs. Cause a decrease in productivity. However, in consideration of higher productivity, low slag generation amount, low spatter, and deep penetration, the flux filling rate is preferably 3.5 to 8%.

The cross-sectional shape of the flux-cored wire of the present invention is shown in FIGS. 1 (a) and 1 (b). FIG. 1 (a) shows that a steel shell 1 of a mild steel pipe is filled with a filling flux 2 and then a drawn wire or a strip steel is flux filled, formed into an O shape in a forming step, welded, and drawn. It is a schematic diagram of the cross section of the drawn wire. The wire seamless to the steel outer shell does not absorb moisture in the atmosphere and can obtain better weld metal performance.

The flux cored wire shown in FIG. 1 (b) having a seam in the steel shell 1 is a schematic cross-sectional view of a wire obtained by flux-filling a band steel in a forming step, forming it into an O-shape, and then drawing it. is there. Also in this wire, since the filling rate is low, the contact portion of the outer seam becomes wide, the effect of blocking the filling flux from the atmosphere is large, and the moisture absorption of atmospheric moisture is extremely small. Further, the joint shape of the steel outer cover is not limited to that shown in the drawing, and may be a diagonal joint, so that the effect of blocking the outside air is further improved.

The components and the wire structure constituting the present invention have been described above. The components which can be added to the filling flux are:
A deoxidizing agent such as Al, Mg, or Zr is used to prevent blowholes due to insufficient deoxidation of the weld metal, and / or the same as in a flux-cored wire for normal gas shielded arc welding, and / or
Included for adjusting mechanical properties. However, if these are excessively contained, the slag removability due to slag baking, the bead appearance defect, or the strength of the weld metal becomes excessive and the crack resistance deteriorates. In addition, the deoxidizer acts as a slag in the weld metal in addition to acting as a yield alloying agent, and also affects the composition and production amount of molten slag, which may impair the intended effects of the present invention, so the type and content are It is desirable to limit it appropriately.

In the present invention, as a component for improving the slag releasability, Bi or the like can be appropriately added within a range that does not affect the basic technical idea of the present invention.

Further, the metal component contained in the filling flux is adjusted within each limited range in consideration of the component of the steel shell and its content.

The diameter of the flux-cored wire for welding beach weather resistant steel of the present invention is small, and the diameter is preferably 0.8 to 2.0 mm in order to increase the current density during welding and obtain a high welding rate.

The shielding gas during arc welding using the flux-cored wire for beach weathering steel welding of the present invention is C
A sufficient welding workability can be obtained by using O ₂ gas, but the amount of fumes generated is further reduced from the viewpoint of the welding work environment.
It may be used r-CO ₂ mixed gas.

[0045]

The effects of the present invention will be described in detail with reference to the following examples.

The mild steel pipes shown in Table 1 (P1, P2, P
3) and strip steel for seamed wires (H1, H2,
H3) was used, and after being filled with the flux having the composition shown in Table 2, intermediate annealing was performed as rolling and die wire drawing, softening and dehydrogenation treatment, and wire symbols S1, S3, S6 and S1 were used.
The plating treatment was performed except for 2, S14 and S15 to produce a flux-cored wire having a wire diameter of 1.2 mm.

[0047]

[Table 1]

[0048]

[Table 2]

Wire symbols S1 to S10 shown in Table 2 are examples of the present invention, and wire symbols S11 to S22 are comparative examples.

Using a plate thickness of 20 mm of the steel sheet for beach weather resistant steel (B1) shown in Table 3, welding was performed under the welding conditions shown in Table 4 in a groove shape based on JIS Z3111, and a weld metal performance test and corrosion resistance were obtained. An exposure test was conducted to investigate. Further, the amount of spatter generated, the number of times droplets were transferred, the amount of slag generated, and the depth of penetration were measured using the plate thickness 20 of the steel plate (B2) having the components shown in Table 3.
Welding was performed under the welding conditions shown in Table 4 using a test piece having a size of 60 mm, a width of 60 mm, and a length of 400 mm.

[0051]

[Table 3]

[0052]

[Table 4]

The amount of spatter generated was obtained by performing continuous welding for 1 minute, collecting the spatter generated during the welding three times for one wire, and averaging the collected amount (g / min). It was evaluated by. The amount of spatter generated is 1.0g
/ Min or less was considered good. The number of droplets transferred was measured by photographing the arc phenomenon during welding with a high-speed video camera, measuring the number of droplets transferred for 1 second, performed 3 times for one wire, and evaluated as the average value. Droplet transfer frequency is 35 times / s
A value of ec or higher was considered good.

For the amount of slag produced, the amount of slag produced on the weld bead after welding was visually inspected.

The penetration depth is downward bead-on-plate welding, the weld bead is cut in the vertical direction, the cross section is polished and corroded, and the penetration state is observed. From the steel plate upper surface to the penetration bottom. Was measured, and the average value of the results of three measurements was evaluated as the penetration depth. A penetration depth of 6 mm or more was considered good.

Mechanical properties of weld metal are defined in JIS Z 31.
Tensile test pieces (JIS Z 2201 A1
No.) and impact test piece (JIS Z 2224 4)
Was created and tested. Tensile strength is 520-680N / m
The m ² was good, the impact value was good or 70J absorption energy at -5 ° C..

Weather resistance under environment of flying sea salt particles in high concentration
After welding, the excess is ground and the weld bead is lengthened.
Thickness of 20mm, width of 100mm, length of 200m
A strip of m is used as a test piece and the seaside is in Futtsu City, Chiba Prefecture.
Exposure test was conducted for 3 years. The exposure point is on the shore.
Distance 5m (Flying sea salt particles average: 1.3mg / dm ²
/ Day). The evaluation is made on one side of the weld metal
The uniform plate thickness reduction amount was measured. Average weight loss is 0.2
A value of mm or less was considered good. The results are summarized in Table 5.
Show. The test results and welding workability evaluation results are shown.

[0058]

[Table 5]

Wire symbols S1 to S10 which are examples of the present invention
Can perform stable welding with a large number of droplet transfers, and as a result, the amount of spatter generated is small. In addition, a small amount of slag was formed on the bead surface, and it was formed thinly and uniformly on the entire bead surface. Further, the penetration depth was as high as that of the solid wire, and there were no welding defects, which was a very good result. In addition, the tensile strength and toughness were good, and the result was that there was little reduction in plate thickness in the exposure test, which was a very satisfactory result.

On the other hand, the wire symbol S1 which is a comparative example.
1 to S22 had the following problems as compared with the examples of the present invention.

Since the wire symbol S11 contains a large amount of Si, the absorbed energy was low. Further, since Mn is large, the amount of spatter generated is slightly large and the tensile strength is also slightly high.

The wire symbol S12 had a low flux filling rate and thus had poor productivity. In addition, since the TiO ₂ conversion value of the TiO ₂ source which is the arc stabilizer is low, the amount of spatter generated was large, the number of droplet transfer times was small, and the arc was unstable. Further, since the amount of Si was small, blowholes were generated and the elongation was low in the tensile test, and since Mn was low, the bead shape during welding was poor and the tensile strength was also low.

Since the wire symbol S13 has a large Na ₂ O conversion value of the Na ₂ O source which is an arc stabilizer, the amount of spatter and fume generated increased as the arc extended. Further, since Ti is low, the absorbed energy is low.

Since the wire symbol S14 has a large TiO ₂ conversion value of the TiO ₂ source which is the arc stabilizer, the arc was elongated and the spatter generation amount and the fume generation amount were increased. Further, since the amount of Ti was large, the tensile strength was high and the absorbed energy was low.

The wire symbol S15 is a mixture containing Na ₂ O and TiO ₂ which are arc stabilizers, and Ti which is a TiO ₂ source.
Since the total amount of terms of Na ₂ O values of the O ₂ conversion value and Na ₂ O source is large, the arc became much spatter generation rate and amount of fume generation extends. Moreover, since the amount of Ni was small, the reduction in plate thickness in the exposure test was large.

Since the wire symbol S16 contains many compatible materials containing Na ₂ O and TiO ₂ which are arc stabilizers, the arc was elongated and the spatter generation amount and the fume generation amount were increased. Further, since there was a large amount of Ni, high temperature cracking occurred in the crater portion and the tensile strength also increased.

Since the wire symbol S17 contains less Cu,
The plate thickness loss in the exposure test increased.

Since the wire symbol S18 has a large flux filling rate, it has a large amount of slag and spatter.
The penetration depth became shallow. Further, since a large amount of Cu was generated, high temperature cracking occurred in the crater portion, and the absorbed energy became low.

Since the wire symbol S19 had a small amount of C, the tensile strength was low.

Since the wire symbol S20 had a high C, the tensile strength was high and the absorbed energy was low. Also, Cr
As a result, the weight loss in the exposure test was large.
Since the wire symbol S21 has a high P, high temperature cracking occurred in the crater portion and the absorbed energy was also low.

Since the wire symbol S22 had a high S, the absorbed energy was low and the reduction in plate thickness in the exposure test was large.

[0072]

As described above, according to the flux-cored wire for beach weather resistance welding of the present invention, it is possible to use the flux-cored wire for beach weather resistance welding in the environment of flying sea salt particles at a high concentration such as beach areas and areas where snow-melting salt is sprayed. While maintaining beach weather resistance, it has stable and good strength and toughness of the weld metal, the arc is extremely stable, the droplets are small and the migration is stable, and the amount of spatter generated is small and the penetration is deep. By further improving the good points of the conventional solid wire and flux-cored wire, the welding workability and welding bead shape are good, and the addition and adjustment of alloy components are easy, so the quality of the welded part and the welding work are improved. It can contribute to efficiency improvement.

[Brief description of drawings]

FIG. 1 shows a cross section of a flux-cored wire for gas shielded arc welding of the present invention, in which (a) is a seamless wire,
(B) is a schematic cross-sectional view of a wire with a joint.

[Explanation of symbols]

1 steel outer skin 2 flux

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Sasaki Saint             7-6-1, Higashi Narashino, Narashino, Chiba Prefecture             Nittetsu Welding Industry Co., Ltd. F-term (reference) 4E084 AA02 AA09 BA22 CA08 CA24                       CA25 GA02 HA03

Claims (2)

[Claims] 1. A flux-cored wire for welding beach weather-resistant steel, comprising: a steel outer shell filled with flux, wherein the total mass% of the wire is an arc stabilizer: 0.05 to 1.8.
%, C: 0.02 to 0.15%, Si: 0.3 to 1.8
%, Mn: 0.8 to 3.0%, Ti: 0.02 to 0.3
%, Ni: 1.0 to 5.0%, Cu: 0.3 to 0.65
%, P: 0.03% or less, Cr: 0.05% or less, S: 0.01% or less, and the flux filling rate is 3-1.
Flux-cored wire for welding beach weather resistant steel, which is characterized by 0%. 2. The arc stabilizer is a compound containing Na ₂ O and TiO ₂ of 1.8% or less, and a Na ₂ O source is a Na ₂ O conversion value separately from the compound containing Na ₂ O and TiO _2. 0.6% or less,
The flux-cored wire for welding beach weather resistant steel according to claim 1, wherein the TiO ₂ source is 1.8% or less in terms of TiO ₂ and 1 or 2 or more.