JPH0195874A - One-side welding method for al material - Google Patents

Abstract

PURPOSE:To perform welding with high efficiency and to form a satisfactory Uranami bead and to obtain a welded joint with high strength by forming projections to project on the rear sides of the end faces of Al materials to abut these against each other and forming a Y or V groove to perform welding and subsequently, removing said projections. CONSTITUTION:The facing end faces of a couple of Al materials 1 and 2 to be welded are extruded and the projections 3 and 4 to project are formed respectively on the rear sides thereof. Further, these projections are removed so that the Y or V groove is formed when the upper parts of the respective end faces are abutted against each other. Both materials 1 and 2 to be welded are abutted against each other on the end faces and the Y or V groove 5 having the above- mentioned projections 3 and 4 is formed on the rears 1a and 2a. Afterward, said groove 5 is subjected to MIG or TIG welding. At that time the weld penetration is deepened than the rears of the materials 1 and 2 to be welded. After welding, the above-mentioned projections 3 and 4 are removed along the rears 1a and 2a.

Description

DETAILED DESCRIPTION OF THE INVENTION <Object of the Invention> Industrial Application Field The present invention is an Al or Al alloy material C hereinafter simply referred to as an Al material. ), in detail, it is a single-sided welding method for structures such as ships, pressure vessels, bridges, etc. in which Al materials, especially Al alloys, are used, and backing materials etc. are set during this welding. This relates to a single-sided welding method that allows for highly efficient welding without any problems.

BACKGROUND OF THE INVENTION Conventionally, as a single-sided welding method for Al material, for example, as described in Japanese Patent Application Laid-Open No. 61-219484, welding is performed using a backing material such as stainless steel, copper, or ceramic, which has a higher melting point than the Al material to be welded. The method of attaching this material to the back side of the material to be welded and butt welding from the surface,
As described in Japanese Patent No. 2, a method has been proposed in which an insert metal is inserted into the bottom of a butt groove and then butt welded.

However, with the former method of using a backing material, it is extremely difficult to set the groove for producing the uranami bead of the backing material in line with the welding line. Unavoidably, there will be places where the conditions are poor, and you will not be able to get a normal Uranami bead. In addition, in the latter method of using an insert, the use of the insert itself is extremely complicated, and it is difficult to obtain a uniform Tanami bead compared to the case of using a backing material.

That is, Al shown in Japanese Patent Application Laid-Open No. 61-219484
In the single-sided welding method for materials, a layered backing material made of a thin plate of a high melting point material such as stainless steel and an Alt material is attached to the surface of the weld groove, and butt welding is performed from the surface using, for example, MIG or TIG. In this welding method, the backing material is used to form a uranami bead, and in order to form the uranami bead normally and well, the backing material is layered and the contact area of the weld metal is It is purposely constructed from high melting point stainless steel. Therefore, according to the former welding method, the weld metal does not weld to a high-melting point material such as stainless steel, so there is an advantage that an uranami bead can be formed in a desired shape. However, regardless of the structure, using a backing material is a complicated welding method. Further, a groove is provided on the surface of the backing material in correspondence with the backing bead, and when the backing material is set, the weld line or groove line must be precisely aligned with this groove over the entire length. However, this work is extremely difficult and if the weld line or groove line becomes long,
In practice, it is almost impossible to match exactly.

Furthermore, in the single-sided welding method for Al materials disclosed in JP-A-56-131082, an insert metal is inserted into the bottom of the butt groove, and this insert metal is brazed by external heating to form an interpolated weld. Then, weld metal is overlaid on top of this initial weld and butt welded. However, with this welding method, it takes time and effort to insert and braze the insert metal, and because it does not form an underwave bead, a high-strength joint cannot be obtained. Further, in brazing, it is possible to form a uranami bead by eliminating the parts, but because there is no separate backing material, it is not possible to obtain a uranami bead that is uniform and has a good shape.

Problems to be Solved by the Invention The present invention aims to solve the above-mentioned drawbacks, and specifically takes into consideration the excellent properties of Al material, such as the malleability, of the material to be welded, and makes effective use of this. However, we propose a method of welding by groove processing the material to be welded and also by performing sufficient penetration.

To explain in more detail, the end faces of a pair of materials to be welded are beveled by, for example, stamping so that a protrusion protrudes from the back side, and then these end faces are abutted against each other, and a backing material is applied to the bevel. without inserting materials or inserts.
We propose a method for welding with sufficient penetration.

Therefore, according to the method of the present invention, since there is no setting of backing material or insertion of insert material, no preparation time is required, and even if post-welding processing takes some time, welding can be performed with extremely high efficiency. Can be done. In addition, although no backing material is used, a good uranami bead can be formed and a welded joint with high strength can be obtained.

<Structure of the Invention> Means for solving the problem and its operation, that is, the method of the present invention involves processing the end faces of a material to be welded made of AI or Al alloy so that protrusions protrude from the back side, and then processing these end faces. are butted together to form a Y or V groove with the protrusion on the back surface, and then this groove is welded so that the penetration is deeper than the back surface of the welded material, and then,
At least a portion of the protrusion is cut out from the back surface of the material to be welded.

Therefore, the structure of these means and their operation will be specifically explained with reference to the drawings as follows.

Note that FIGS. 1(a), (b), (c), (d), and (e) are explanatory diagrams showing each process of welding by the method of the present invention.

First, prior to welding, the end surfaces, that is, the opposing end surfaces of a pair of materials to be welded 1.2 made of a pair of Al materials are processed, for example, by embossing, as shown in FIG. 1(a). That is, the end face of each workpiece 1.2 is processed into a shape in which projections 3.4 protrude from the back sides 1a and 2a, respectively. Each protrusion 3.4 may be formed into an angular shape as shown in FIG. 1(a), or may be formed into a round shape or other shape instead of a angular shape.

Regardless of the shape, it is necessary that each protrusion 3.4 protrudes from the back side, and that it can be sufficiently melted into the protrusion as described later.

Therefore, as described above, the protrusion 3.4 is protruded from the back side of the end face of each workpiece 1.2, and when a part of each end face is butted together, a ν groove or a Y groove is formed. , excise. That is, the dotted line portion in FIG. 1(il) is cut out.

Next, the respective welding materials 1.2 whose end surfaces have been processed as described above are butted against each other to form a V groove or a Y groove 5 as shown in FIG. 5 is welded by MIG or TIG. In this welding,
As shown in , the penetration depth is the back surface 1a of each workpiece 1.2.
, 2a. In other words, in Figure 1 (in
Welding is continued until the penetration reaches a part of each protrusion 3.4, as shown in FIG.

Finally, after welding, each protrusion 3.4 is removed along the back surfaces 1a, 2a of the welded material 1.2, as shown in FIG.

When welding is carried out through each process as described above, the penetration reaches the back sides 1a and 2a of the welded material 1.2, and the weld metal R6 forms a back wave a as shown in Fig. 1 (el). Since the shape is adjusted at the time of removal as described above, it is good and uniform, and a predetermined joint strength is provided.

Furthermore, as described above, the groove 5 is formed by utilizing the properties of the material to be welded 1.2 as an Al material.
(see Figure 1(a)) is up to 10m.

Dimension b (see Figure 1(a)) is at most 10@, and further,
The dimension C (see FIG. 1 rb) is preferably in the range of +2 to -2111 m. That is, the dimension a may be any value as long as a certain degree of penetration can be ensured. However, Al
For example, when stamping a material, if the dimension a becomes too large, processing becomes difficult, but if it is within 10 mm, processing is easy.

Furthermore, if the dimensions are small, burn-through may occur depending on the welding conditions. In order to prevent this, it must be large to some extent, about 10 mm at most. Furthermore, if the dimension C is within the above range, sufficient penetration can be ensured.

Further, welding is usually performed by TIG or MUG, and any welding conditions may be used as long as penetration reaches the back side of the material to be welded. For example, 1. When welding A3083 material to be welded using an A3183 wire with a diameter of approximately C1 mm, it is preferable to use a current of 250 to 350 A, a voltage of 20 to 35 V, and a welding speed of 10 to 60 C1llI'.

Example First, a pair of A3083-based Al materials with a thickness of 15 mm were used as the materials to be welded. After assembling as shown, the groove lines are MIG welded under the conditions shown in Table 1.
Thereafter, as shown in Figure 1 (re), the protrusion on the back side was removed.

At this time, first, the end face of each material to be welded is
), the dimension a was 7111 m and the dimension was 7 mm, and was processed by embossing. After that, Fig. 1 (b'+
As shown, the dotted line portion Cθ is 30°) is cut out, and the dimension C
is -2 mm, that is, the dimension d shown in Figure 1 (C'l)
5Ill111, the end surfaces of a pair of materials to be welded were butted together to form a ν or Y groove.

For comparison, the above-mentioned materials to be welded were subjected to MIG welding (9'1) under the same conditions using a backing material according to a conventional example.

Therefore, when the welding time required for a welding length of 1 m was compared between the method of the present invention and the conventional method, the results were as shown in Table 2.

Table 1 MIG welding conditions Table 2 Time required for welding length 1 m As is clear from Table 2, according to the method of the present invention, it takes a little longer to remove the protrusion after welding than in the conventional method, but the preparation before welding There is no need for welding, and the welding time is 20-
It was possible to shorten the time by 30%.

<Effects of the Invention> As explained in detail above, the method of the present invention can reduce the AJ of the material to be welded.
By effectively utilizing the properties of the material such as its malleability, the end surface of the material can be
After processing the back side so that the protrusion protrudes, they are butted together, and this groove is welded so that the penetration reaches a part of the protrusion on the back side.
After that, the protrusion is removed. Therefore, there is no need to set backing materials, insert materials, etc. prior to welding, and the materials to be welded can be butt-welded with high efficiency.

Further, even though no backing material is used, penetration is performed to the back side of the welded material, so a good back wave bead can be formed and a welded joint with high strength can be obtained.

[Brief explanation of the drawing]

Figure 1 (a), (b), (0), (d) and (e)
FIG. 2 is an explanatory diagram showing each process in welding according to the method of the present invention. Code 1.2... Material to be welded 1a, 2a...
...Front surface 3.4...Protrusion 5...V or V groove 6...Weld metal

Claims (1)

[Claims] The end faces of the Al or Al alloy material to be welded are processed so that the protrusions protrude from the back side, and then these end faces are butted to form a Y or V groove with the protrusions on the back side. A characterized in that the tip is welded so that penetration is deeper than the back surface of the material to be welded, and then at least a part of the protrusion is cut off from the back surface of the material to be welded.
Single-sided welding method for l materials.