JP2003290979A - Agent for preventing adhesion of spatter and method for preventing adhesion of spatter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an agent for preventing adhesion of spatters capable of sustaining an effect of preventing the adhesion of the spatters. <P>SOLUTION: The agent for preventing the adhesion of the spatters formed by mixing inorganic oxide particles 4 and joining agents 5 into a solvent forms coating films 3 covering the surfaces of weld zones and the members near these zones. The ruggedness by inorganic oxide particles is then formed on the surfaces of the films and air layers 7 are formed between the spatters 6 and the surfaces 3a of the coating films by the ruggedness, and gaps 8 are formed in the coating films 3 and therefore the heat retained by the spatters is no longer easily transferred to the coating films and the welding members and the spatters are rapidly cooled and solidified by the ambient air, by which the easy melt sticking thereof to the welding members 1 can be prevented. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a spatter adhesion preventing agent and a spatter adhesion preventing method for preventing spatter scattered during welding from adhering to a member to be welded (hereinafter referred to as a welding member).

[0002]

2. Description of the Related Art In general, melted metal particles (spatter) during arc welding or gas welding scatter and adhere to the surface of a welded member. If spatter adheres, the welded product may fail the visual inspection. Therefore, a post-treatment process for removing spatter is required for shipping as a product.
In particular, if the spatter adheres to the mechanical parts, the fitting may be poor and the assembly may not be possible. If you force it,
Assembling accuracy may deteriorate and distortion may occur. Further, when the UT inspection is performed, the sensor slips badly, which becomes an obstacle to the inspection. Further, the attached spatter may injure a hand or the like, and the spatter may fall off later to cause corrosion.

The spatter thus deposited on the surface of the welded member is generally removed by knocking it down with a chisel or polishing it with a grinder. However, there is a problem in that the removing work requires time and labor, and the productivity is lowered. .

Therefore, conventionally, a welding machine having a low spattering property,
It has been practiced to use welding materials such as flux wires with low spattering properties. According to these, spatter adhesion can be reduced, but it cannot be completely prevented. In addition, the adhesion of spatter is prevented by applying a spatter adhesion preventive agent to the surface of the welded member (Magazine: Welding Technology, 20001, 2).
Monthly issue, pages 100-101).

[0005]

However, the conventional spatter adhesion preventive agent cannot completely eliminate spatter adhesion. In particular, when performing multi-layer welding, there is a problem that the first layer welding is effective, but the effect becomes weaker toward the second layer and the third layer.

It is an object of the present invention to realize a spatter adhesion preventing agent and a spatter adhesion preventing method capable of maintaining a spatter adhesion preventing effect.

[0007]

The present invention solves the above problems by the means described below.

The sputter adhesion preventive agent of the present invention is prepared by mixing inorganic oxide particles and a binder in a solvent.

Here, an embodiment of the present invention will be described.
This will be described with reference to FIGS. As shown in the cross-sectional view of FIG. 1, the surface of the welded portion 2 of the welded member 1 and the vicinity thereof is coated with the spatter adhesion preventing agent of the present invention to form a coating film 3. As a result, as shown in the enlarged cross-sectional view of FIG. 2, the inorganic oxide particles 4 dispersed in the binder 5 form irregularities on the surface of the coating film 3. Due to this unevenness, an air layer 7 is formed between the sputter 6 and the coating film surface 3a. Moreover, in the coating film 3, 8 voids are formed between the inorganic oxide particles 4. As a result, the heat retained by the sputter 6 is reduced by the coating film 3
Also, it is difficult for the spatter 6 to be transmitted to the welding member 1, and the spatter 6 is quickly cooled and solidified by the ambient air and is not welded to the coating film 3 and the welding member 1. That is, the coating film functions as a heat-resistant heat insulating film, and it is possible to prevent the spatter from solidifying before adhering to the coating film and the welding member and from adhering to the welding member.

In this case, as the inorganic oxide particles, at least one kind of powder or granules of silica, alumina, titanium oxide, iron oxide, etc. can be used, and it is desirable that they have heat resistance. As the binder, a resin such as a silicone resin can be used, and it is essential only that it has a property of holding the inorganic oxide particles on the surface of the welding member for a predetermined period.

In particular, the inorganic oxide particles are preferably porous particles. The average particle size is in the range of 2 nm to 500 μm, preferably 20 nm to 50 μm.
As a result, a heat resistant heat insulating film (air layer) can be effectively formed on the surface of the welding member. That is, if the average particle size is less than 20 nm, the size of the space that can hold air is too small, and the distance between the spatter that scatters and collides with the welding member and the welding member becomes small.
If it exceeds m, the interval between the convex portions becomes large, and small spatters that scatter enter the concave portion, and an air layer cannot be formed between the spatter and the welding member, which may adhere to the welding member.

The heat insulating film formed by the air layer is retained even when spatter of molten metal comes in, that is,
Even if the molten metal scatters on the surface of the member, the heat insulating layer for air is formed between the molten metal and the member, so the molten metal rolls like mercury on the surface without directly contacting the member. Since it is cooled and solidified, it is possible to prevent spatter from adhering to the surface of the welding member.

The inorganic oxide particles are preferably surface-treated with a treating agent having a hydrophobic group. According to this, by increasing the water repellency of the coating film and, for example, setting the contact angle with water to 90 degrees or more, the effect of preventing spatter adhesion can be further enhanced. In addition, when a member having a coating film is poured into water, it is preferable that the film surface has water repellency capable of holding an air layer. As a result, the effect of preventing spatter adhesion can be further enhanced.

On the other hand, the spatter adhesion preventing method of the present invention is
This is to perform welding after the heat insulating film is coated on the surface of the welded portion of the welded member and the vicinity thereof. According to this
As described above, even if the spatters are scattered, the spatters are solidified before being welded to the heat insulating film and the welding member, so that the spatter adhesion can be prevented.

Here, the heat insulating film is preferably formed by coating the above-mentioned sputter adhesion preventing agent.
As a coating method, for example, a conventional coating method such as spraying a spatter adhesion preventive agent prepared by mixing and dispersing inorganic oxide particles and a binder in a solvent into a slurry to the surface of a welding member, brush coating, dipping, etc. Applicable.

After the welding is completed, it is necessary to remove the coating film for inspection and painting. According to the present invention, the coating film and the scattered metal remaining on the surface of the member can be easily removed by a brush, a brush, a broom, a spray of an ear, suction with a vacuum cleaner, washing with water or the like. That is,
The coating film can be firmly adhered to the member by the resin of the binder, but it is preferable that the coating film can be easily removed because the work of removing it after welding increases. Therefore, in the present invention, it is preferable that voids are formed between the oxide particles by increasing the volume ratio of the oxide particles to the resin of the binder. That is,
It is preferable to increase the porosity of the coating film.
As a result, the contact area between the resin and the welding member is reduced, the adhesive strength is reduced, and the strength of the coating film itself is also reduced, whereby peeling and removal can be facilitated. Further, when the porosity of the coating film is large, the above-mentioned thermal insulation property is also improved.

Incidentally, the volume ratio of the resin in the coating film after curing is preferably 1 to 50 vol%, more preferably 3 to 30 vol%. In this case, the volume ratio of the oxide particles is preferably 50 vol% to 99 vol%. When the amount of the resin is less than this ratio, there is a problem that the adhesion between the particles and the welding member is reduced, the coating film becomes too brittle, and peels off during welding. On the other hand, when the amount of resin is large, the adhesion is strong, but the work required for peeling after welding increases. In addition, the heat insulating effect is slightly reduced.

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below. The composition of the spatter adhesion preventing agent of Examples 1 and 2 is
As shown in Table 1.

[0019]

[Table 1] (Example 1) A coating liquid (slurry) consisting of the spatter adhesion preventive agent having the composition of Example 1 shown in Table 1 was applied along a welding line with a brush for a width of 30 cm, and then dried at room temperature for 2 hours. After that, manual arc welding (LB52
As a result of performing T, 200 A, 3 layers), no spatter adhered. A photograph of this process is shown in FIG. FIG. 3 shows the result of an experiment comparing the cases where the coating liquids of Examples 1 and 2 were applied and the cases where the coating liquid was not applied.

In FIG. 3A, the left half is the first embodiment.
And the right half corresponds to the second embodiment. Then, the coating liquid of Example 1 is applied to the right half of the plate surface of the welding member on the left half, and the remaining left half shows the case where the coating liquid is not applied for comparison. Figure 3 (b)
Fig. 3 shows the state of the surface after welding, and Fig. 3 (d) shows the state where the surface has been cleaned with a wire brush after welding. As can be seen from FIG. 3D, spatters are not attached at all to the right side region to which the coating liquid of Example 1 is applied, but sputters are attached to the left side region to which the coating liquid is not applied. . (Example 2) A coating liquid containing a spatter adhesion preventive agent having the composition of Example 2 shown in Table 1 was sprayed along the welding line with a width of 30 cm, and then dried at room temperature for 2 hours.

After drying, the apparent contact angle of the coating film surface with water was measured and found to be 160 degrees. Also, as a result of observing the coating film surface while placing a transparent cylinder on the coating film and holding water so that water does not leak from the bottom, a uniform air film is formed on the entire film surface. confirmed. After that, as a result of manual arc welding (LB52T, 200A, 3 layers), no spatter adhered. That is, FIG.
As can be seen from the state of the surface after welding shown in (c) and the state where the surface was cleaned with a wire brush after welding shown in (e) of the figure, spatter was completely absent in the right region to which the coating liquid of Example 2 was applied. Although not attached, spatter is attached to the left side area where the coating liquid is not applied.

In Examples 1 and 2, the coating film remaining on the surface of the welded member and the spattered particles scattered after welding were easily removed by brushing, brushing, broom, yer blow, suction with a vacuum cleaner, or washing with water. Can be removed.

According to Examples 1 and 2, it was found that the following effects can be obtained. (1) When the surface of the welded member is coated with the spatter adhesion preventing agent of the present invention composed of inorganic oxide particles and a binder, a coating film having fine irregularities is formed on the surface. Even if the welding spatter collides with the coating film, the air layer held on the fine irregularities of the coating film prevents direct contact between the spatter and the surface of the welding member, and also provides thermal insulation between them. Is planned. That is, the coating film functions as a heat insulating film. As a result, the spatter is cooled and solidified before being welded to the surface of the welding member, and the spatter does not adhere to the surface of the welding member. (2) The coating film formed on the surface of the welded member has fine irregularities on the surface thereof, so that the surface has high water repellency. For example, according to the second embodiment, an air film is formed on the surface when submerged in water. Is retained. In other words, since the coating film of this example has an affinity for air, the welding spatter is repelled by the surface of the coating film,
Difficult to attach spatter. (3) According to the first and second embodiments, since the spatter does not adhere, the work of removing the spatter after welding becomes unnecessary and the work efficiency of welding is improved. Further, there is no risk of damaging the welded member when removing spatter. (4) Adhesion of spatter can be prevented even in the case of multi-layer welding.

Although silica is used as the inorganic oxide in the above embodiments, the present invention is not limited to this, and alumina, titanium oxide, iron oxide or the like can be used. Further, the binder is not limited to polyvinyl alcohol and silicone resin, and other resins can be used. Also, the solvent may be appropriately changed instead of water or isopropyl alcohol. Further, as a method for coating the surface of the member with a substrata adhesion inhibitor in which inorganic oxide particles and a resin are mixed in a solvent, well-known coating methods such as brushing, spraying, dipping and the like can be adopted.

In Example 2, the inorganic oxide particles were subjected to a hydrophobizing treatment (or water repellent treatment) using trimethylmethoxysilane having a hydrophobic group as a surface treating agent. The surface treatment agent can be used.

Here, as the surface treating agent having a hydrophobic group, a so-called silane compound such as silane having an alkyl group or a fluorine-substituted hydrophobic group, chlorosilane, silazane, dimethylpolysiloxane, a titanate coupling agent having an alkyl group. An aluminum-based coupling agent can be used.

As the silane compound having an alkyl group,
Having a methyl group, for example, methylmethoxysilane
CH_ThreeSi (OCH_Three)_Three, Dimethyldimethoxysilane
(CH _Three)_TwoSi (OCH_Three)_Two, Trimethyl methoxy
Run (CH_Three)_ThreeSi (OCH _Three), Methyltriethoxy
Silane CH_ThreeSi (OC_TwoH₅)_Three, Dimethyl diet
Sisilane (CH_Three)_TwoSi (OC_TwoH₅)_Two, Trimethyl
Ethoxysilane (CH _Three)_ThreeSi (OC_TwoH₅), Hexa
Such as methyldisilazane.

Also, a silane compound having an alkyl group
Then, in the case of having an ethyl group, ethyl trimethoxy
Silane C_TwoH₅Si (OCH_Three)_Three, Diethyl dimetho
Sisilane (C_TwoH₅)_TwoSi (OCH_Three)_Two, Triethyl
Methoxysilane (C_TwoH₅) _ThreeSi (OCH_Three), Ethyl
Liethoxysilane C_TwoH₅Si (OC_TwoH₅)_Three, Jie
Cyldiethoxysilane (C_TwoH₅)_TwoSi (OC_TwoH₅)
_Two, Triethylethoxysilane (C_TwoH₅)_ThreeSi (O
C_TwoH₅)and so on.

Further, a silane compound having an alkyl group
And having a propyl group,
Sisilane C_ThreeH₇Si (OCH_Three)_Three, Dipropyl dime
Toxysilane (C_ThreeH₇)_TwoSi (OCH_Three)_Two, Trip
Ropylmethoxysilane (C_ThreeH₇)_ThreeSi (OCH_Three),
Propyltriethoxysilane C_ThreeH₇Si (OC_TwoH ₅)
_Three, Dipropyldiethoxysilane (C_ThreeH₇)_TwoSi
(OC_TwoH₅)_TwoTripropylethoxysilane (C_ThreeH₇)
_ThreeSi (OC_TwoH₅)and so on.

Examples of long-chain alkylsilanes include n-octadecyltrimethoxysilane and n-dodecyltriethoxysilane.

The alkoxysilane having 1 to 3 alkyl groups having 1 to 20 carbon atoms as described above can be used alone or in combination of plural kinds of chlorosilane or silazane.

Silane compound having fluorine-substituted hydrophobic group
Is, for example, perfluorooctylethyltriethoxy
Run CF_Three(CF_Two)₇(CH_Two)_TwoSi (OC_TwoH₅)
_Three, Perfluoroisopropylethyltriethoxy
Run (CF_Three)_TwoCF (CH_Two) _TwoSi (OC_TwoH₅)_ThreeNa
Besides, perfluoromethylethyltrimethoxy
Orchid, perfluorobutylethyltrimethoxysilane,
Perfluorooctylethyltrimethoxysilane, per
Such as fluorooctylethylmethyldimethoxysilane
Perfluoro having 1 to 20 carbon atoms, preferably 1 to 10 carbon atoms
Alkoxy silanes having alkyl groups, etc.
It

As titanate coupling agents, isopropyl triisostearoyl titanate, isopropyl tris (dioctyl pyrophosphate) titanate,
Examples thereof include tetraisopropyl bis (dioctyl phosphite) titanate and tetraoctyl bis (ditridecyl phosphite) titanate.

Examples of the aluminum-based coupling agent include acetoalkoxyaluminum diisopropylate.

However, the surface treating agent is not limited to the above-mentioned surface treating agents as long as it is a hydrophobic surface treating agent having the same performance as the above surface treating agent. That is, the welded member of the present invention coated with the spatter adhesion preventive agent, which is obtained by mixing and dispersing the hydrophobic inorganic oxide particles and the binder in the solvent, has a property of not being wetted by the molten metal such as spatter. This property can be easily confirmed by submerging the welding member coated with the spatter adhesion preventing agent of the present invention in water. That is, since the coating film of the present invention has excellent water repellency, when immersed in water, a thin air film is formed on the surface and is retained.
This air film reflects silver when exposed to light, so it can be easily confirmed visually. Then, by this air film, even if the scattered molten metal particles collide with the coating film surface, the air film does not directly contact the member surface, but rolls on the surface in a spherical shape like mercury,
During that time, the material is cooled and solidified, so that spatter does not adhere to the surface of the member. That is, even if the spatter adheres to the surface of the coating film, it is removed from the surface of the member when a slight force such as gravity, inertia, or a slight wind acts.

Here, the property of holding the air film on the surface of the coating film according to the present invention when it is submerged in water will be described with reference to FIGS. As shown in FIG. 4, when the coating film 12 is formed on a part of the surface of the member 11 and the member 11 is submerged in the water 13 from the air, the air contacting the surface of the coating film 12 is retained. It is brought into water 13 and an air film 14 is formed on the surface. For example, when a small amount of air 16 is sent into the air film 14 through the thin tube 15, the air film 14 takes in the air 16 and expands as shown by a dotted line 17. That is, the coating layer 12 according to the present invention has the property of retaining a thin air film on the surface in water and the unique property of taking in air supplied from the outside into the air film.

Further, the property of taking in air will be described with reference to FIG. First, as shown in FIG.
The plate-shaped member 11 having the coating layer 12 formed on the entire surface is held in the water 13 while being inclined. And thin tube 1
When the air 16 is intermittently supplied to the plate surface through 5, the air 16 rises in the air film 12 formed on the surface of the coating layer 12, and bubbles 17 are formed from the upper end of the air film 12 into the water 13. It is released as a result and comes to surface in the water 13. 5B is a perspective view of FIG. 5A, in which the air 16 rises while spreading along the slope of the flat plate-shaped member 11, and an air pool is formed at the upper edge of the member 11. After the formation, the air bubbles 17 form the surface of the air bubbles 17. FIG. 6 is a comparative example when the coating film 11 is not provided. As shown in the figure, when the flat plate-like member 11 is slightly tilted and immersed in water, and air 16 is sent into the surface of the member 11 through a thin tube 15, the air 16 immediately separates from the plate surface and becomes air bubbles 17 to form an underwater 13 To surface.

[0038]

As described above, according to the present invention, it is possible to realize the spatter adhesion preventing agent which can maintain the spatter adhesion preventing effect and the spatter adhesion preventing method using the prevention agent.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a state in which a surface of a welding member is coated with a spatter adhesion preventing agent according to an embodiment of the present invention.

FIG. 2 is an enlarged sectional view illustrating that the coating film of the present invention prevents spatter from adhering.

FIG. 3 shows the state of the surface after welding in the case where the coating liquid of Examples 1 and 2 of the present invention was applied and the case where the coating liquid was not applied for comparison, and the surface was cleaned with a wire brush after welding. It is a substitute photograph which shows a state.

FIG. 4 is a diagram for explaining the property that an air film is retained on the surface of a coating film according to the present invention when it is submerged in water.

FIG. 5 is a view for explaining the property that an air film is retained on the surface of a coating film according to the present invention when it is submerged in water.

FIG. 6 is a view for explaining the behavior of air on the surface of the member when the member having no coating film according to the present invention is submerged in water for comparison with FIGS. 5 and 6.

[Explanation of symbols]

3 coating film 4 Inorganic oxide particles 5 binder 6 spatter 7 Air layer

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Yutaka Ono             Mitsui Shipbuilding No. 1 Hachiman Kaigan Dori, Ichihara City, Chiba Prefecture             Chiba office

Claims (9)

[Claims] 1. A spatter adhesion preventive agent comprising inorganic oxide particles and a binder mixed in a solvent. 2. The inorganic oxide particles have an average particle size of 2n.
m to 500 μm, preferably 20 nm to 50 μm
The spatter adhesion preventive agent according to claim 1, wherein 3. The sputter adhesion preventing agent according to claim 1, wherein the inorganic oxide particles are surface-treated with a treating agent having a hydrophobic group. 4. A method for preventing spatter adhesion in which welding is performed after a heat insulating film is coated on the surface of a welded portion of a member to be welded and in the vicinity thereof. 5. The method for preventing spatter adhesion according to claim 4, wherein the thermal insulation film comprises inorganic oxide particles and a binder. 6. A heat insulating film is formed by coating a spatter adhesion preventive agent, which is obtained by mixing inorganic oxide particles and a binder with a solvent, on the surface of a welded portion of a member to be welded and the vicinity thereof, and then performing welding. Spatter adhesion prevention method to be performed. 7. The spatter adhesion preventing method according to claim 5, wherein the heat insulating film has an uneven surface formed by the oxide particles on at least a surface thereof. 8. The spatter adhesion preventing method according to claim 7, wherein the heat insulating film has water repellency such that an air film is formed on the surface of the film when the film is submerged in water and is retained. 9. The thermal insulating film has a contact angle with water of 90 °.
The spatter adhesion prevention method according to claim 7, which has the above-mentioned hydrophobicity.