JPS5937156B2 - Tatemukijiyoushin Gas Shield Door - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an upward gas shielded arc welding method, and more particularly to an upward gas shielded arc welding method using a composite strip electrode.

Conventional automatic welding methods include electroslag welding, consumable nozzle electroslag welding, electrogas arc welding, carbon dioxide arc welding, or inert gas arc welding in combination with weaving. In the former type of welding, the root gap of the groove needs to be large, so the groove cross-sectional area is large, and since this wide groove cross-sectional area is welded, the welding speed is slow, efficiency is low, and welding input is slow. Currently, it is not used for butt welding of ship side shell plating in shipbuilding due to the large amount of heat that causes many problems such as embrittlement of the heat-affected zone of the base metal.

In addition, in carbon dioxide arc welding and inert gas arc welding, which use weaving for the latter welding, it is common to draw a triangular or trapezoidal pattern along the groove shape.
Since welding is performed using a small diameter solid wire, it is not possible to increase the welding current, and if the welding current is too high, the bead will droop, resulting in an extremely slow welding speed (for example, about 1/3 of electrogas welding). .

), in shipbuilding, it is applied to welding high-grade steel such as round gunwales and welding relatively short objects. Another method is to weave the tip of the consumable electrode in the thickness direction of the base material using a sliding water-cooled copper plate, but this also requires a certain amount of groove root gap, and the welding current cannot be increased too much, so the Compared to gas arc welding, it does not have many advantages, and on the contrary, it has the disadvantage that the tolerance range for groove accuracy is narrow. Such welding in combination with weaving requires a device with a complicated mechanism, is prone to failure, and is extremely complicated to adjust, making it impractical. In order to eliminate the drawbacks of the conventional upward welding method described above, we previously proposed a upward welding method using a strip electrode (Japanese Patent Application No. 49-71377, Japanese Patent Publication No. 53-1
(See No. 7089). To explain this below, the first
As shown in the figure, the base material 1 is butted with a suitable groove, and is slidable with a backing material 4 made of a suitable material such as fibrous, solid, rigid, glass, metal, etc. Welding is carried out while holding the molten metal by a water-cooled copper plate 2, a strip electrode 3 (solid) is fed into the groove by a feeding roller 8 through an energizing tip 5, and shielding gas is supplied from a shielding gas supply port 7. It passes through the gas shield sozzle 6 to shield the molten pool and arc. This strip electrode 3 is fed so that the surface including the wide direction of the electrode intersects the welding line, that is, the second
As shown in the figure, the base material is deeply deflected by the strip electrode 3 to form a deflection portion 9. The wide groove formed by deep melting by the strip electrode 3 is filled with molten metal from the strip electrode 3 and the base metal, and this molten pool 1
0 is held by the sliding water-cooled copper plate 2 and the backing material 4 while welding progresses. According to this method, it is possible to weld even a groove with a narrow groove cross-sectional area compared to the conventional vertical advancement welding method, so the welding speed is extremely high and the welding heat input can be reduced. It is.

However, since a sliding water-cooled copper plate is used, when the bead is formed, the surface of the copper plate and the surface of the bead that is still solidifying rub against each other, which may cause scratches on the surface.
Furthermore, since the weld bead is exposed to the outside air while it is still red-hot, the surface is oxidized and the appearance deteriorates. In this case, if glass tape is used as the backing material, the glass tape will melt during welding, and its main component, SiO2, will become slag and enter the gap between the bead surface and the sliding water-cooled copper plate, acting as a kind of lubricant. This makes it difficult to get scratches on the surface, and since the bead surface is covered as slag, the bead metal surface is shielded from the outside air, and when the slag is removed, a bead with a beautiful appearance can be obtained.

However, the slag from the glass tape is not evenly distributed over the surface, and the amount of backing material melted by the arc or molten pool is not constant, making it difficult to substantially completely cover the bead surface. Therefore, when flux was supplied from the outside during melting, for example, when flux was supplied from the upper side of the strip electrode 3 in Fig. 2, the strip electrode transitioned to a sbrae arc state, but this arc was disturbed and welding was difficult. It is not good, and from below the strip electrode 3, that is, the copper plate 2 and the strip electrode 3
If flux is supplied between the two, the flux will not be melted by the arc but will be melted only by the heat of the molten pool, so good results will not be obtained and this is not practical. The present invention
This method solves many of the drawbacks and problems of the conventional vertical advancement welding method and the previously proposed vertical advancement welding method using a strip electrode, as explained above, and is suitable for welding when the groove cross-sectional area is narrow. The welding speed can be increased by using a large current, and the groove can be sufficiently melted without using a complicated weeping mechanism, thereby preventing welding defects such as poor fusion and slag entrainment. This is a vertical upward gas-shielded arc welding method that can prevent brittle fracture in the heat-affected zone because it forms a type weld metal. The metal is fed towards the narrow groove in such a way that an arc is generated between the electrode and the base metal to melt the groove surface and expand the space between the groove surfaces, and the molten metal is placed on the front and back sides. In the vertically advancing gas-shielded arc welding method in which welding is performed by flowing down into a molten pool held by a molten material, a sliding material is arranged at least on the front side of the vertical narrow groove, and the strip-shaped electrode is A composite strip-shaped electrode filled with at least one kind of deoxidizing agent or slag agent is used, and while the slag generated as the strip-shaped electrode melts covers the upper surface of the molten pool and the bead surface, the arc and molten Welding is performed while shielding the pool with shielding gas. Used in the present invention? The composite band-shaped electrode 11, which is filled with at least one kind of deoxidizing agent or slag agent, is made by folding a metal plate into a hoop shape and filling the inside with at least one type of deoxidizing agent or slag agent. It is filled with flux, etc., and flux can be continuously supplied during welding.

With this composite strip electrode, flux is supplied directly to the point where the arc occurs, completely melting it and forming slag that covers the bead surface, causing scratches and oxidation of the metal surface. This eliminates the drawbacks of vertical welding using solid strip electrodes as previously proposed. The ratio of the flux to the entire electrode is preferably 3 to 70%, and the deoxidizing agent may be contained in the hood in advance. In addition, when an arc stabilizer, TiO2SiO2, etc. is added to the flux, the arc becomes spray-like and the occurrence of spatter is suppressed.In addition, using a composite strip-shaped electrode with flux rather than a solid strip-shaped electrode has a higher impact value due to the slag reaction. This is the effect of flux.

In addition, regarding the manufacturing method for strip electrodes, solid strip electrodes already contain alloy components and are therefore extremely hard, and rolling them with rollers requires several annealing steps. The band-shaped electrode can be manufactured by simply forming a normal soft mild steel hoop as shown in FIG. 3 and filling it with a flux containing an alloying element, and can be manufactured without any complicated process, and is advantageous in terms of cost. Also, to explain the deoxidizing agent, slag agent, etc. that are filled in this composite strip electrode, first, as the deoxidizing agent, Mn. Si. ．． Ti
etc. are preferred, and A1, Mg. Ca, etc. can also be used, and metal Mn, metal Sil, metal Ti. ．． Fe-Mn.
．． Fe-Si. ．． It is filled in the form of Fe-Ti, etc.

These deoxidizers have the effect of reacting with CO, which causes proholes, to remove it in the form of oxides, and combine with CO to reduce the amount of O in the weld metal. Then, MnO which became an oxide. Since SiO2, TiO2, etc. float as slag and precipitate on the bead surface, the deoxidizing agent also functions as a slag forming agent. Next, as a slag agent, SlO2, TiO2, MgOlzrO, . Al2
O3, CaO. ．． MnO. ．． K2O. ．． Na2OlFe
Oxides such as O, carbonates such as CacO3, MgCO3, JaCO3, CaF2, NaF. BaF2, LiF, MgF
2. Metal fluorides such as TiF4, AlF3, Na3AlF6 are used. In addition to the above-mentioned deoxidizing agent and slag agent, various alloying agents or iron powders are added to the flux as appropriate.In particular, the alloying agent powder guarantees the mechanical properties depending on the intended use of the welded joint. It is added for MO
、． Ti. ．． Zr. ．． B. Ni. Metal powder such as Cr is used. In addition, iron powder is filled in for adjustment as the remainder of the above flux component, but it has the effect of softening the arc and increasing the melting rate, and also makes the flow of flux smooth when filling the composite strip electrode. It also has the effect of

In the present invention, an arc is created between the electrode and the base metal by feeding a composite strip-shaped electrode filled with one or more types of deoxidizing agent or slag agent so that its width direction intersects the welding line. The groove surface of the base metal is melted to expand the groove space, and the molten metal is deposited in a lower molten pool held by the metal. The state where the electrode intersects with the base material refers to the state shown in A, b, and c in Fig. 4, and when welding is performed by feeding a composite strip electrode in such a state, the base material and the electrode An arc is generated between the base metal and the base metal, and the arc force excavates the groove in the base metal and deposits molten metal in the molten pool held in the base metal. 5
The figure shows one side of the base metal cut out so that the arc point can be easily seen. There is.

That is, the molten metal of the strip electrode 11 and the molten metal of the base metal 1 flow into the molten pool 10 below the wide groove formed by deep melting by the composite strip electrode 11, and are deposited therein, resulting in welding. Form metal. This molten pool 10 is held by the sliding water-cooled copper plate 2 and the backing material 4 and is rapidly cooled, so that the molten metal rapidly solidifies, and the slag agent filled in the strip electrode 11 is melted. Because it covers the bead surface, beautiful beads can be obtained. Further, the angle at which the width direction of the composite strip electrode intersects the weld line is preferably in the range of approximately 10 to 900, and may be determined based on various conditions.

The method of the present invention will be explained with reference to FIG. 6. Specifically, the composite strip electrode 11 is fed into the groove through the current-carrying tip 5 by the feed roller 8. The base material 1 is a sliding water-cooled copper plate 2 and a backing material 4
The molten pool is held in the gap between the two. The shielding gas is supplied from the shielding gas supply port 7 and passes through the gas shielding nozzle 6 to shield the molten pool and the arc. In this case, the composite strip electrode 11 is fed so as to intersect the weld line. Next, to explain the melting rates of the composite strip electrode filled with one or more deoxidizers or slag agents used in the present invention and the previously proposed solid strip electrode, Table 1 shows As shown, under the same welding conditions, the composite strip electrode of the present invention has a higher welding speed, extremely high efficiency, and reduced welding heat input.

The welding conditions in Table 1 are as follows: shielding gas Ar8
O%+CO22O%, wire protrusion length 25m7! It is L. Next, examples of the method of the present invention will be described.

Strip-shaped electrodes filled with various flux components shown in Table 2 (
Using a base material having a flux rate of 20%) and the composition shown in Table 3, vertical advancement welding was performed under the following welding conditions. Tables 4 and 5 show welding results regarding the composition, mechanical properties, and workability of weld metals obtained by welding under the above conditions.

As explained above, according to the method according to the present invention, a composite strip electrode filled with one or more types of deoxidizing agent or slag agent is fed so that its width direction intersects the weld line. Therefore, since welding is performed while melting the groove, the cross-sectional area of the groove can be reduced due to the large penetration depth brought about by the concentration of the arc, and the welding heat input is also small, resulting in a welding process. The efficiency is improved, the toughness of the heat-affected zone is also improved, and the slag agent from the strip electrode makes it possible to obtain a bead with a good appearance.

[Brief explanation of the drawing]

Figure 1 is a schematic diagram showing the previously proposed vertical welding method using a solid strip electrode, Figure 2 is an enlarged perspective view of the vicinity of the arc in Figure 1, and Figure 3 is a welding method used in the method of the present invention. FIG. 4 is a schematic diagram showing a state in which the width direction of the composite strip electrode intersects the welding line in the method of the present invention, and FIG. 5 is a partial cross-sectional perspective view of the composite strip electrode. FIG. 6 is an enlarged perspective view of the vicinity of the arc when it is carried out, and is a schematic diagram showing the method of the present invention. 1...Base material, 2...Sliding water-cooled copper plate,
3... Solid strip electrode, 4... Backing material, 5... Current carrying tip, 6... Gas shield sozzle, 7...・Shield gas supply port, 8
. . . Strip electrode feeding roller, 9 . . . Relief portion, 10 . . . Melt pool, 11 .・・Metal hoop, 13・・
...Flux, W...Welding line.

Claims (1)

[Claims] 1. Feed the strip electrode toward the narrow groove so that its width direction intersects the weld line, generate an arc between the electrode and the base metal, melt the groove surface, and spread the gap between the groove surfaces. In the vertical upward gas-shielded arc welding method, in which the molten metal is deposited by flowing down into the molten pool held by the material placed on the front and back sides of the material, a sliding type is used at least on the front side of the narrow vertical groove. A composite strip electrode is used in which the material is arranged and the strip electrode is filled with at least one kind of deoxidizing agent or slag agent, and the slag generated as the strip electrode melts causes the molten pool to melt. A vertically advancing gas shielded arc welding method characterized by welding while shielding the arc and molten pool with shielding gas while covering the upper surface and bead surface.