KR100706026B1 - High speed submerged arc welding flux - Google Patents

Abstract

The present invention relates to a sintered flux for submerged arc welding having excellent high speed welding properties. The flux of the present invention, in weight percent

SiO ₂ : 12.0 ~ 24.0%, Al ₂ O ₃ : 24.0 ~ 38.0%, TiO ₂ : 6.0 ~ 13.0%, CaO: 2.0 ~ 9.0%, CaF ₂ : 7.0 ~ 14.0%, MnO: 12.0 ~ 23.0%, MgO: 2.0-17.0%, Na ₂ O, K ₂ O, the sum of one component or more of Li ₂ O: consisting of flux containing 1.0 to 5.0%, the basicity (B) of the following formula ranges from 2.0 to 6.5 It is characterized by consisting of,

2.0≤≤6.5

2.0≤≤6.5

The particle diameter of the flux is 5.0% by weight or less based on the total weight of the flux, the particle size of less than 1.00mm is 0.20.0mm or more 90.0% by weight or more, the particle size less than 0.20mm is characterized by consisting of 5.0% by weight or less. .

The use of the present invention is applicable to welding of steel frames, bridges, pipes, ships, offshore structures and the like that require excellent welding workability even at high speed welding.

Submerged Arc Welding, Sintered Flux, High Speed Welding, Basicity

Description

High Speed Weldable Sintered Flux for Submerged Arc Welding {HIGH SPEED SUBMERGED ARC WELDING FLUX}

The present invention relates to a sintered flux for submerged arc welding having excellent high-speed weldability, and more particularly, to submerged mild steel and 50kgf / mm class ² high tensile steel used in steel, bridges, pipes, ships, offshore structures, etc. A sintered flux for arc welding, the present invention relates to a sintered flux for submerged arc welding that ensures good arc stability, fork mark resistance, slag peeling resistance, pit resistance and bead appearance during high speed welding.

Submerged arc welding is a welding method in which powder flux is applied to a portion to be welded to a certain thickness, and arcs are generated between the wire tip and the base material while continuously feeding electrode wires therein. The generated arc heat dissolves the wire, the base material and the flux, the molten flux forms slag and the molten metal forms weld beads. Submerged arc welding is also called latent welding because welding arcs are generated inside the flux and are not exposed to the outside.

In submerged arc welding, no current flows at the beginning of the welding because the flux is not molten. Therefore, when starting welding, steel wool (steel wool) or the like is inserted between the base material and the wire to easily generate an arc, or generate an arc using a high frequency wave. When an arc is generated, molten slag and gas are generated by the arc heat, and the arc is continuously maintained.

Flux for submerged arc welding can be divided into molten flux and sintered flux according to the manufacturing method. The molten flux is pulverized to a predetermined particle size by melting and cooling raw materials in an electric furnace. Doing Melted flux has the advantages of uniform chemical composition, relatively easy slag removal, low hygroscopicity, simple storage and handling, and no change in particle size and composition during reuse.

However, there is a disadvantage in that it is not possible to add a deoxidizer or an alloying element because it goes through a manufacturing process that dissolves at a high temperature. That is, since the necessary alloying components must be supplied entirely from the wire, proper selection of the wire is very important when using the molten flux. The particle size of the molten flux affects the meltability of the flux, the state of gas evolution, the bead shape, and the like, and the finer the particles, the higher the current used.

If a high current is used for the flux of coarse particles, the arc protection is poor, the beads are rough, and defects such as pores and undercuts are likely to occur.

The sintered flux is obtained by pulverizing and mixing the raw ore and alloy components to a suitable size, granulating them into a predetermined size by adding sodium silicate as a caking agent, and drying and sintering at a temperature range where the raw material components are not decomposed. Since sintered flux has almost no loss of deoxidizer (Fe-Si, Fe-Mn) or alloys (Ni, Cr, Mo, V, etc.), deoxidation of molten metal, chemical composition of weld metal, and microstructure Relatively easy.

Therefore, sintered fluxes are frequently used in high-strength steels and low-alloy steels that require strong deoxidation of molten metals or chemical composition adjustment. The drawbacks include the fact that it is easy to absorb moisture, the chemical composition of the weld metal varies depending on the welding conditions, the chemical composition may vary for each layer in multi-layer welding, and there is a limit to reuse because it is undifferentiated during use and handling. And so on. Therefore, sintered fluxes have to be careful in their selection and much care is required during handling, storage and use.

Recently, in the manufacture of steel, bridges, pipes, ships, offshore structures, etc., where submerged arc welding is performed, productivity has been improved by increasing the welding speed. However, when the welding speed is increased, the conventional sintered type for submerged arc welding is used. Flux has poor welding workability such as arc stability, fork mark resistance, slag peeling resistance, pit resistance, and bead appearance, and thus, it is difficult to improve productivity due to an increase in welding speed.

The present invention is to solve the problems of the sintered flux for the submerged arc welding, as described above, welding operations such as arc stability, fork mark resistance, slag peeling resistance, fit resistance and bead appearance even in high-speed welding It is an object of the present invention to provide a sintered flux for submerged arc welding, which is suitable for high strength mild steel and 50kgf / mm class ² high tensile strength steel.

In order to achieve the above object, the sintered flux for submerged arc welding of the present invention is based on the total flux weight.

SiO ₂ : 12.0 ~ 24.0%, Al ₂ O ₃ : 24.0 ~ 38.0%, TiO ₂ : 6.0 ~ 13.0%, CaO: 2.0 ~ 9.0%, CaF ₂ : 7.0 ~ 14.0%, MnO: 12.0 ~ 23.0%, MgO: 2.0 to 17.0%, Na ₂ O, K ₂ O, Li ₂ O of one component or more: 1.0 to 5.0% and other components: 0.5 to 1.5%.

Preferably, the basicity (B) composed of the following formula satisfies the range of 2.0 to 6.5.

[Equation 1]

≤6.52.0≤

≤6.5

More preferably, the particle diameter of the prepared flux is 5.0 wt% or less for particles of 1.00 mm or more, less than 1.00 mm for particles of less than 0.20 mm and 90.0 wt.% Or more for particles of less than 0.20 mm, and 5.0 wt% or less of the flux. A sintered flux for submerged arc welding is provided.

The detailed description of the configuration controlled as described above is as follows, the flux for submerged arc welding described below represents the weight percentage of the total flux.

SiO ₂ : 12.0 ~ 24.0%

SiO ₂ is an acidic component, which adjusts the basicity of molten slag, adjusts viscosity and melting point to make the bead appearance uniform, and is used in quartz (Quartz, SiO ₂ ), quartz sand (SiO ₂ ), wollastonite (CaSiO _3). ) As an oxide or a complex oxide.

If the content is less than 12.0% of the total flux, the viscosity is insufficient to cause meandering beads or undercuts, the bead width becomes uneven, the spreading decreases, and convex beads are generated. When the content exceeds 24.0%, As the basicity is lowered, the oxygen in the deposited metal increases, so the toughness deteriorates, and the viscosity becomes excessive, resulting in irregular beads.

Al ₂ O ₃ : 24.0 ~ 38.0%

Al ₂ O ₃ is a neutral component necessary to form slag and adjust the basicity to improve welding workability. It adjusts the viscosity and melting point of slag and improves arc workability and stability during high current welding. .

If the content is less than 24.0% of the total flux, the viscosity and melting point is lowered, resulting in non-uniform bead width and grain, and defects such as undercuts may occur. In addition, if it exceeds 38.0%, the solidification temperature is increased to cause the bead to deteriorate, and the viscosity is increased, so that convex beads are formed or slag is mixed.

Sources of Al ₂ O ₃ include bauxite, Al ₂ O ₃ .2H ₂ O, aluminum oxide, and Al ₂ O ₃ .

TiO ₂ : 6.0 ~ 13.0%

TiO ₂ is an acidic component, and as a slag generating agent, Ti is transferred into the weld metal during welding, thereby improving the toughness of the weld metal and improving slag peelability.

If the content is less than 6.0%, slag peeling deterioration, toughness of the weld metal and undercut occur. In addition, when it exceeds 13.0%, the arc becomes unstable, the wave of the bead becomes rough, and as Ti is excessively generated in the weld metal, the strength is increased to increase the possibility of low temperature cracking.

Sources of TiO ₂ include rutile (Rutile, TiO ₂ ), ilmenite (Immenite, FeTiO ₃ ), and the like.

CaO: 2.0-9.0%

CaO is a basic component, which adjusts basicity and viscosity, and has an effect of reducing the amount of oxygen in the weld metal, which is effective for improving the toughness of the weld metal part.

However, when the content is less than 2.0%, the effect is insignificant, and when the content exceeds 9.0%, the bead mark and weld workability deteriorate, and a fork mark occurs, and the viscosity increases, resulting in uneven beads.

As the source of CaO and the like wollastonite (Wollastonite, CaSiO _3), dolomite _{(Dolomite, MgCO 3 · CaCO 3} ), lime feldspar _{(Anorthite, CaO · Al 2 O} 3 · 2SiO 2).

CaF ₂ : 7.0 ~ 14.0%

CaF ₂ is a basic component that improves the fluidity of slag and generates fluorine gas, which reduces the partial pressure of water vapor, which is effective in reducing hydrogen in the deposited metal.

If the content is less than 7.0%, the effect is not sufficient and the shielding effect of the weld metal is insufficient, and if it exceeds 14.0%, the arc becomes unstable, resulting in deterioration of the appearance of the bead. Or undercut occurs. As the source of calcium fluoride CaF ₂ and the like (Fluospar, CaF _2).

MnO: 12.0-23.0%

MnO is a basic component that improves the appearance of beads when the welding speed increases, and is a useful component for controlling the melting point and viscosity of slag.

If the content is less than 12.0%, there is little effect, and if it exceeds 23.0%, the CO reaction in the molten pool becomes severe, and the appearance of beads or slag peeling is significantly worsened. Examples of sources of MnO include ferro-manganese and manganese oxide (MnO).

MgO : 2.0 to 17.0%

MgO is a basic component and has a function to increase the basicity of molten slag, and has an effect of improving the toughness by reducing the amount of hydrogen by moving hydrogen in the slag.

If the content is less than 2.0%, the effect is not sufficient, so the slag adheres to the weld bead surface, resulting in poor peelability. If the content exceeds 17.0%, the arc becomes unstable and convex beads are formed, and the melting point of the slag is too high. The slag peelability is deteriorated.

As a source of MgO, there are magnesite (MgCO ₃ ), magnesia clinker (MgO), dolomite (MgCO ₃ · CaCO ₃ ), and the like.

Na ₂ O , K ₂ O , Li ₂ O  medium 1 ingredient  Or more: 1.0 to 5.0%

Na ₂ O, K ₂ O, Li ₂ O is an important component to secure the arc stability, in particular serves to maintain the arc stability during high-speed welding.

If the sum of one component or more of Na ₂ O, K ₂ O, and Li ₂ O is less than 1.0%, the arc stability effect is remarkably reduced, the penetration becomes shallow, the slag is mixed, and if it exceeds 5.0%, the convex beads Is formed to deteriorate the welding workability, the arc becomes significantly unstable and the hygroscopicity is deteriorated.

Na ₂ O, K ₂ O, and Li ₂ O are commonly used in the manufacture of sintered fluxes for submerged arc welding. Water glass, Cryolite, Na ₃ AlF ₆ , Potassium titanate, K ₂ TiO ₃ ), Li-Si and the like.

On the other hand, in the present invention, in addition to the flux having the composition as described above, it is preferable that the basicity (B) defined by the following formula satisfies 2.0 to 6.5. In other words,

[Equation 1]

≤6.5의 값을 충족해야 한다. 2.0≤

The value of ≤6.5 must be satisfied.

In this equation, the CaF ₂ and MnO components are low melting point chemicals and the CaO and MgO components are solid solution chemicals. That is, the ratio of the sum of the low melting point CaF ₂ and MnO components and the sum of the high melting point CaO and MgO components has a great influence on the melting point and fluidity of slag for the sintered flux for submerged arc welding of the present invention. The impact on welding workability, such as good arc stability, slag peelability, and bead appearance, required by the invention is very large. Therefore, the present invention controls the melting point and fluidity of slag through proper ratio of low melting point chemical composition to high melting point chemical composition by deciding the range of the above formula, so that good arc stability, slag peelability and Weldability such as bead appearance is secured.

Hereinafter, when the ratio between the low melting point chemical composition and the high melting point chemical composition is out of the range of the equation in the present invention, the effect on the weldability is high. If the basicity (B) is less than 2.0, the slag melting point and viscosity become too high. Deterioration of the bead appearance and slag peelability is deteriorated, the possibility of the fork mark is increased, and if the basicity exceeds 6.5, the arc stability is lowered, the slag melting point is lowered, the slag peelability is worsened.

Therefore, in order to obtain a sintered flux for submerged arc welding having good welding workability even in high speed welding required by the present invention, the basicity (B) defined in the present invention should be 2.0 to 6.5.

In order to secure welding workability such as good arc stability, fork mark resistance, slag peeling resistance, pit resistance and bead appearance required for high speed welding required in the present invention, the particle size distribution of the manufactured flux must be properly adjusted. Inadequate particle size distribution results in poor arc protection, coarse beads, and defects such as pores and undercuts.

The suitable particle size distribution of the sintered flux for submerged arc welding having the above chemical composition and basicity (B) is 5.0 wt% or less for particles having a particle diameter of at least 1.00 mm based on the total weight of the flux and less than 1.00 mm. It is preferable that 90.0 weight% or more of particles larger than 0.20 mm and 5.0 weight% or less of particles smaller than 0.20 mm are comprised.

If the particle size of the flux is greater than 5.0% by weight of 1.00 mm or more, the space between the flux and the flux becomes larger, which lowers the arc protection, the beads are rough, and the fork marks are easily formed.

In addition, when the particle size of the flux is less than 1.00 mm and less than 90.0 wt% of particles of 0.20 mm or more, the beads appear convex and the grains of the beads appear rough.

Finally, when the particle size of the flux is less than 0.20mm exceeds 5.0% by weight, the gas component generated during the submerged arc welding is not smoothly released, causing a fork mark, and a possibility of pitting is increased. In addition, slag peelability deteriorates.

Through the embodiment of the present invention will be able to understand the specific welding properties of the flux corresponding to the present invention.

Hereinafter, embodiments of the present invention will be described.

Flux having a chemical composition and basicity as shown in Table 1 was prepared. Each raw material flux was granulated with water glass, and then dried and sintered to obtain a sintered flux for submerged arc welding having the following composition.

In Table 1, the other components are the sum of ZrO ₂ , BaO and FeO, which are contained in a very small amount in each raw flux.

division Flux Components, Weight% B SiO ₂ Al ₂ O ₃ TiO ₂ CaO CaF ₂ MnO MgO Sum of at least one component of Na ₂ O, K ₂ O, Li ₂ O Other ingredients Sum Inventive Example 1 12.0 32.5 10.0 4.0 14.0 18.0 8.0 1.0 0.5 100.0 5.3 Inventive Example 2 14.5 27.0 6.0 9.0 10.0 23.0 7.5 2.5 0.5 100.0 4.0 Inventive Example 3 21.5 29.0 6.5 5.0 7.0 15.5 12.0 3.0 0.5 100.0 2.6 Inventive Example 4 13.0 24.0 8.5 7.0 13.0 16.5 14.0 3.5 0.5 100.0 2.8 Inventive Example 5 20.0 30.0 9.0 4.5 9.0 20.0 5.0 1.5 1.0 100.0 6.1 Inventive Example 6 24.0 28.5 9.5 3.0 8.5 15.0 6.0 4.0 1.5 100.0 5.2 Inventive Example 7 19.0 26.0 13.0 2.0 8.5 12.0 17.0 2.0 0.5 100.0 2.2 Inventive Example 8 17.0 38.0 8.0 8.0 7.5 13.0 2.0 5.0 1.5 100.0 4.1 Inventive Example 9 23.0 29.0 7.5 3.0 8.0 18.5 9.0 1.5 0.5 100.0 4.4 Comparative Example 1 26.0 24.0 7.0 1.0 10.0 21.5 8.0 2.0 0.5 100.0 7.0 Comparative Example 2 20.0 40.0 10.0 5.5 7.0 8.0 6.0 2.5 1.0 100.0 2.6 Comparative Example 3 13.5 25.5 15.0 3.5 11.5 19.5 10.0 0.5 1.0 100.0 4.6 Comparative Example 4 10.0 35.0 6.0 7.5 12.0 20.0 6.0 2.0 1.5 100.0 4.7 Comparative Example 5 15.0 29.5 8.0 4.0 4.5 26.0 11.5 1.0 0.5 100.0 3.9 Comparative Example 6 21.0 20.0 12.0 11.0 9.0 14.0 7.5 4.5 1.0 100.0 2.5 Comparative Example 7 12.0 26.0 8.5 4.0 8.5 15.0 24.5 1.0 0.5 100.0 1.6 Comparative Example 8 17.5 27.5 3.0 6.0 9.5 16.5 12.0 7.0 1.0 100.0 2.9 Comparative Example 9 18.0 25.0 7.0 4.5 17.0 23.0 1.0 4.0 0.5 100.0 14.5

The flux having the composition of Table 1 was used to weld with the welding wire of Table 3 to the base material shown in Table 2 below.

Welding conditions are as shown in Table 4 below, the weldability evaluation according to the summarized in Tables 5 to 7. Under the same polarity, current and voltage, Table 5 shows the welding speed of 100cm / min., Table 6 shows the welding speed of 150cm / min., And Table 7 shows the welding speed of 200cm / min. to be. In addition, the symbol shown in Tables 5-7 represents (circle): good, (triangle | delta): normal, and x: poor.

Steel grade Thickness (mm) Chemical composition of the base material, weight percent C Si Mn P S SM490 25 0.14 0.34 1.30 0.008 0.010

Wire diameter (mm) Chemical composition of the wire, weight percent C Si Mn P S 4.8 0.06 0.31 1.10 0.018 0.008

polarity Current [A] Voltage [V] Speed (cm / min) Remarks One 2 3 AC 750 34 100 150 200 Bead on plate welding

Welding condition AC 750A-34V-100cm / min. division Arc stability Fork Mark Resistance Slag peelability Fit resistance Bead appearance Inventive Example 1 ○ ○ ○ ○ ○ Inventive Example 2 ○ ○ ○ ○ ○ Inventive Example 3 ○ ○ ○ ○ ○ Inventive Example 4 ○ ○ ○ ○ ○ Inventive Example 5 ○ ○ ○ ○ ○ Inventive Example 6 ○ ○ ○ ○ ○ Inventive Example 7 ○ ○ ○ ○ ○ Inventive Example 8 ○ ○ ○ ○ ○ Inventive Example 9 ○ ○ ○ ○ ○ Comparative Example 1 △ △ △ ○ △ Comparative Example 2 ○ ○ ○ ○ △ Comparative Example 3 △ ○ ○ ○ △ Comparative Example 4 ○ ○ ○ ○ △ Comparative Example 5 ○ △ △ ○ △ Comparative Example 6 ○ △ ○ ○ △ Comparative Example 7 ○ △ △ ○ △ Comparative Example 8 △ ○ △ △ ○ Comparative Example 9 △ × △ ○ △

Welding condition AC 750A-34V-150cm / min. division Arc stability Fork Mark Resistance Slag peelability Fit resistance Bead appearance Inventive Example 1 ○ ○ ○ ○ ○ Inventive Example 2 ○ ○ ○ ○ ○ Inventive Example 3 ○ ○ ○ ○ ○ Inventive Example 4 ○ ○ ○ ○ ○ Inventive Example 5 ○ ○ ○ ○ ○ Inventive Example 6 ○ ○ ○ ○ ○ Inventive Example 7 ○ ○ ○ ○ ○ Inventive Example 8 ○ ○ ○ ○ ○ Inventive Example 9 ○ ○ ○ ○ ○ Comparative Example 1 △ × × ○ △ Comparative Example 2 ○ ○ △ ○ △ Comparative Example 3 △ ○ ○ ○ × Comparative Example 4 ○ ○ ○ ○ × Comparative Example 5 ○ △ × ○ △ Comparative Example 6 ○ × ○ ○ △ Comparative Example 7 ○ × △ ○ △ Comparative Example 8 △ ○ × △ ○ Comparative Example 9 × × △ ○ △

Welding condition AC 750A-34V-200cm / min. division Arc stability Fork Mark Resistance Slag peelability Fit resistance Bead appearance Inventive Example 1 ○ ○ ○ ○ ○ Inventive Example 2 ○ ○ ○ ○ ○ Inventive Example 3 ○ ○ ○ ○ ○ Inventive Example 4 ○ ○ ○ ○ ○ Inventive Example 5 ○ ○ ○ ○ ○ Inventive Example 6 ○ ○ ○ ○ ○ Inventive Example 7 ○ ○ ○ ○ ○ Inventive Example 8 ○ ○ ○ ○ ○ Inventive Example 9 ○ ○ ○ ○ ○ Comparative Example 1 × × × ○ △ Comparative Example 2 ○ ○ △ ○ × Comparative Example 3 × ○ ○ ○ × Comparative Example 4 ○ ○ ○ ○ × Comparative Example 5 ○ △ × ○ × Comparative Example 6 ○ × ○ ○ × Comparative Example 7 ○ × △ △ × Comparative Example 8 × ○ × △ ○ Comparative Example 9 × × × ○ △

Looking at the results of Tables 5 to 7, it was found that the welding workability is good, such as arc stability, fork mark resistance, slag peeling resistance, pit resistance, bead appearance, as the welding speed increases.

On the other hand, in the case of Comparative Example 1, the SiO ₂ component is higher than the range of the present invention, the CaO component is lower than the range of the present invention, and the basicity (B) defined in the present invention is higher than the range of the present invention, and in the case of Table 5 Did not achieve good results in arc stability, fork mark resistance, slag peelability and bead appearance. Also, in Table 6, as the welding speed increased from 100cm / min. To 150cm / min. Markability and slag peeling were poor. In the case of Table 7, the arc stability was also worsened as the welding speed was further increased (150 cm / min. → 200 cm / min.) Than Table 6.

In the case of Comparative Example 2, the Al ₂ O ₃ component was higher than the range of the present invention, and the MnO component was lower than the range of the present invention, and in the case of Table 5, good results were not obtained in the bead appearance. In addition, in Table 6, as the welding speed was increased from 100cm / min. To 150cm / min. Than in Table 5, the results of slag peelability did not show good. In Table 7, the welding speed was increased more than Table 6 ( 150 cm / min. → 200 cm / min.)

In the case of Comparative Example 3, since the TiO ₂ component is higher than the scope of the present invention, and one or more of Na ₂ O, K ₂ O, and Li ₂ O is lower than the scope of the present invention, Table 5 shows the arc stability and Bead appearance was not good. And in the case of Table 6, as the welding speed increases from 100cm / min. To 150cm / min. In the case of Table 7, the arc stability was also poor as the welding speed was further increased (150 cm / min. → 200 cm / min.) Than Table 6.

In the case of Comparative Example 4, since the SiO ₂ component was lower than the range of the present invention, in Table 5, the appearance of the beads was not good. And in Table 6, as the welding speed increased from 100cm / min. To 150cm / min. Than Table 5, the bead appearance was poor, and in Table 7, it was found that the bead appearance was poor.

In the case of Comparative Example 5, the CaF ₂ component is lower than the range of the present invention, and the MnO component is higher than the range of the present invention, so that in Table 5, the fork mark resistance, slag peelability, and bead appearance were not good. In the case of Table 6, as the welding speed was increased from 100cm / min. To 150cm / min. Than in Table 5, the slag peelability was worse than that of Table 5, and it was observed that the defect was poor. And in the case of Table 7 it can be seen that the bead appearance is poor as the welding speed is further increased (150cm / min. → 200cm / min.) Than Table 6.

In the case of Comparative Example 6, the Al ₂ O ₃ component was lower than the range of the present invention, and the CaO component was higher than the range of the present invention, and therefore, in the case of Table 5, the fork mark resistance and the appearance of beads were not good. In the case of Table 6, as the welding speed is increased from 100cm / min. To 150cm / min. Than Table 5, the fork mark resistance is poor, and in Table 7, the welding speed is further increased than Table 6 (150cm / min. min. → 200 cm / min.)

In the case of Comparative Example 7, the MgO component is higher than the range of the present invention, and the basicity (B) defined in the present invention is lower than the range of the present invention. I couldn't. In the case of Table 6, as the welding speed is increased from 100cm / min. To 150cm / min. Than Table 5, the fork mark resistance is poor, and in Table 7, the welding speed is further increased than Table 6 (150cm / min. min. → 200 cm / min.

In the case of Comparative Example 8, since the TiO ₂ component is lower than the range of the present invention, and one or more of Na ₂ O, K ₂ O, and Li ₂ O is higher than the range of the present invention, in the case of Table 5, the arc stability , Slag peelability and fit resistance were not good. And in the case of Table 6, as the welding speed is increased from 100cm / min. To 150cm / min. And in the case of Table 7 it can be seen that the arc stability is poor as the welding speed is further increased (150cm / min. → 200cm / min.) Than Table 6.

In the case of Comparative Example 9, the CaF ₂ component is higher than the scope of the present invention, the MgO component is lower than the scope of the present invention, and the basicity (B) defined in the present invention is higher than the scope of the present invention. , Slag peelability, bead appearance was not good, and fork mark resistance was poor. In the case of Table 6, as the welding speed increases from 100cm / min. To 150cm / min. And in the case of Table 7, it can be confirmed that the slag peelability is also poor as the welding speed is further increased (150cm / min. → 200cm / min.) Than Table 6.

≤6.5의 값을 만족하는 상기표 1내 발명예 1에 대하여 플럭스의 입도 분포를 총 8개로 구분하여 제조를 실시하였고, 표 8에 나타난 입도 분포를 지닌 서브머지드 아크 용접용 소결형 플럭스에 대한 용접작업성을 평가한 결과를 하기표 9에 정리하였다. 이때 용접조건은 AC 750A-34V-100cm/min.으로 실시하였다.Table 8 has a chemical composition distribution of the sintered flux for the submerged arc welding specified in the present invention, the basicity (B) is 2.0≤

For Inventive Example 1 in Table 1, which satisfies the value of ≤6.5, the fluxes were manufactured by dividing the particle size distribution of the flux into a total of eight, and for the sintered flux for the submerged arc welding having the particle size distribution shown in Table 8, The results of evaluating the weldability are summarized in Table 9 below. At this time, welding conditions were carried out at AC 750A-34V-100cm / min.

Symbols shown in Table 9 indicate ○: good, △: normal, ×: poor.

division Particle size distribution of flux, weight percent More than 1.00mm Less than 1.00mm 0.20mm or more Less than 0.20mm Sum Inventive Example 10 5.0 90.0 5.0 100.0 Inventive Example 11 1.0 95.0 4.0 100.0 Inventive Example 12 4.0 95.5 0.5 100.0 Inventive Example 13 3.0 93.0 4.0 100.0 Comparative Example 10 6.0 91.0 3.0 100.0 Comparative Example 11 2.5 90.5 7.0 100.0 Comparative Example 12 10.0 85.0 5.0 100.0 Comparative Example 13 5.0 80.0 15.0 100.0

division Arc stability Fork Mark Resistance Slag peelability Fit resistance Bead appearance Inventive Example 10 ○ ○ ○ ○ ○ Inventive Example 11 ○ ○ ○ ○ ○ Inventive Example 12 ○ ○ ○ ○ ○ Inventive Example 13 ○ ○ ○ ○ ○ Comparative Example 10 × × ○ ○ × Comparative Example 11 ○ × ○ × ○ Comparative Example 12 × × × ○ × Comparative Example 13 ○ × × × ×

Looking at the results of Tables 8 and 9, in the present invention, the particle diameter of the prepared flux is 5.0 wt% or less for particles of 1.00 mm or more, less than 1.00 mm and 90.0 wt% or more for particles of 0.20 mm or more, and less than 0.20 mm, based on the total weight of the flux. When the particles were composed of 5.0 wt% or less, it was found that they exhibited good arc stability, fork mark resistance, slag peeling resistance, pit resistance and bead appearance.

On the other hand, Comparative Example 10 in Table 8 was found that the particle size of 1.00mm or more is higher than the range of the present invention, showing a poor result in the arc stability, fork mark resistance, bead appearance in Table 9.

In Comparative Example 11 in Table 8, particles smaller than 0.20 mm were higher than the range of the present invention, thereby obtaining poor results in fork mark resistance and fit resistance in Table 9.

In Comparative Example 12 in Table 8, the particle size of 1.00 mm or more is higher than the range of the present invention, and the particle size of 0.20 mm or more is less than the range of the present invention. Showed poor results.

In Comparative Example 13 in Table 8, particles less than 1.00 mm and 0.20 mm or more were lower than the range of the present invention, and particles less than 0.20 mm were higher than the range of the present invention, and thus Table 9 showed fork mark resistance, slag peelability, and pit resistance. Poor results were observed in sex and bead appearance.

≤6.5의 값을 나타냄과 동시에 제조된 플럭스의 입경이 플럭스 전중량에 대하여 1.00mm이상의 입자가 5.0중량% 이하, 1.00mm미만 0.20mm이상의 입자가 90.0중량% 이상, 0.20mm미만의 입자가 5.0중량% 이하로 구성되었을 때 용접속도가 증가함에 따라서 아크 안정성, 내포크마크성, 슬래그 박리성, 내피트성, 비드외관 등 용접작업성이 우수한 서브머지드 아크 용접용 소결형 플럭스를 얻을 수 있었다.The chemical composition of the sintered flux for submerged arc welding specified in the present invention has a basic composition (B) of 2.0 ≦

At the same time, the particle diameter of the produced flux is 5.0% by weight or less for particles of 1.00 mm or more, 5.0% by weight or less for particles of less than 1.00 mm, 90.0% by weight or more for particles of 0.20 mm or more, and 5.0 weight of particles for flux total weight. When the welding speed was increased to less than%, the sintered flux for submerged arc welding with excellent welding workability, such as arc stability, fork mark resistance, slag peeling resistance, pit resistance, and bead appearance, was obtained.

Claims (3)

In the sintered flux for submerged arc welding, The flux is based on the total weight, SiO ₂ : 12.0 ~ 24.0%, Al ₂ O ₃ : 24.0 ~ 38.0%, TiO ₂ : 6.0 ~ 13.0%, CaO: 2.0 ~ 9.0%, CaF ₂ : 7.0 ~ 14.0%, MnO: 12.0 ~ 23.0%, MgO: Sintering for submerged arc welding, comprising from 2.0 to 17.0% and one or more of Na ₂ O, K ₂ O, LiO ₂ : 1.0 to 5.0% and other components: 0.5 to 1.5% Type flux The sintered flux for submerged arc welding according to claim 1, wherein each component of the sintered flux for submerged arc welding satisfies the basicity (B) value represented by the following equation by weight%. [Equation 1] 2.0≤

≤6.5 The particle diameter of the sintered flux for submerged arc welding is 5.0% by weight or less for particles of 1.00 mm or more, 90.0% by weight or more for particles of 0.20 mm or less for 1.00 mm or more, based on the total weight of the flux. , Sintered flux for submerged arc welding, characterized in that less than 0.20mm of particles are composed of 5.0 wt% or less