JPH10128572A - Welding method of super-thin metallic sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a welding method capable of stably and easily performing the welding of a super-thin metallic sheet. SOLUTION: A joining line is formed by the close bending on each of two super-thin metallic sheets 1-1, 1-2 to be joined with each other, the joining line is butted to each other and the welding is performed along the butt line. Or, a joining line by the close bending is formed on one super-thin metallic sheet, and a joining line and a return part 6 are formed by the triple close bending in the other super-thin metallic sheet, one super-thin metallic sheet is loaded on the return part 6 of the other super-thin metallic sheet, parts 2-1, 2-2 to be joined are butted to each other, and the welding 3 is performed along the butt lines. This welding method can be applied to a case where no backing is used in a covering work of a structure.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for stably and easily welding an extremely thin metal plate.

[0002]

2. Description of the Related Art In order to perform sound welding by arc welding, it is necessary for a base material to have a heat capacity to hold molten metal melted by arc heat and to promote solidification of a molten pool. If the heat capacity of the molten metal is insufficient, the molten metal is melted down and a bead cannot be formed.

On the other hand, as a method for controlling the amount of penetration of the base material, a method of adjusting the welding heat, the arc voltage, and the welding speed to adjust the heat input to the base material appropriately is usually adopted. I have.

Further, the molten metal is forcibly solidified or held in a molten pool using a backing material of Cu or a flux or a common metal. Alternatively, a weld bead is formed by forcing cooling from the front and back with a Cu sheet metal and forcibly cooling the sheet.

However, even if the welding conditions are selected and a method using a Cu cooling plate is employed, if the plate thickness is further reduced, the molten metal at the end of the plate thickness melted by the arc heat becomes “surface like spilled mercury on the floor”. It is shrunk round by the tension, and it becomes difficult to form a molten pool stably by bridging between butt plates. The minimum thickness of a plate capable of forming a sound weld bead is approximately 0.6 to 0.8 mm.

[0006]

For example, in a steel pipe pile of an offshore structure, a layer of a rust inhibitor, for example, a layer of petrolatum is formed on the surface of the steel pipe pile in the splash zone and the tidal zone, and the outer surface is further formed. Coated with an ultra-thin sheet of 0.4 mm titanium metal.
Conventionally, ultra-thin plates with a thickness of 0.4 mm cannot be welded,
For joining the ultrathin plates to each other at the time of coating, an outward bending is formed at each joint of the ultrathin plates to be joined, and the two joints are abutted with each other using a joining member of a tubular body having a vertical slit. A mechanical joining method has been used in which a vertical slit of a connecting member is inserted into a butt portion of two ultrathin plates, and both folds are stored inside a tubular body of the connecting member.

However, this mechanical joining is very complicated and has a problem that seawater enters. The present invention has been made to solve these problems, and an object of the present invention is to provide a method for stably and easily joining ultrathin metal sheets having a thickness of 0.6 mm or less. Also, in the above-mentioned welding and coating work of an ultra-thin metal titanium plate, it is difficult to provide a backing material at the joint.
Accordingly, another object of the present invention is to provide a method for joining ultrathin metal plates to each other without using a backing material.

[0008]

According to the present invention, there is provided (1) a joining line formed on each of two metal ultra-thin plates to be joined by close contact bending, and joining the joining lines to each other, and along the joining line; A method for welding ultra-thin metal sheets, characterized in that they are welded together.

(2) A joining line is formed on one of the two ultrathin metal sheets to be joined by close contact bending, and the other end of the ultrathin sheet is joined in a triple contact bending manner, and the joining line and the tip are formed by close contact bending. A folded part protruding from the joining line is formed, one ultra-thin plate is placed on the folded part of the other ultra-thin plate, the joining lines are butted against each other, and welded along the butt line. It is a method of welding an extremely thin metal plate.

[0010] (3) In the work of coating a structure whose surface is covered with an ultrathin metal plate, the ultrathin metal plates are joined to each other without using a backing material. Or a method for welding an extremely thin metal plate according to (2).

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is an explanatory view of an example of the method of the present invention, and 1-1 and 1-2 are vertical cross sections of two ultrathin metal sheets to be joined. In the present invention, bonding lines 2-1 and 2-2 are formed on each of the two ultrathin metal plates 1-1 and 1-2 to be bonded in FIG. Then, the joining lines 1-1 and 1-2 are butted against each other, and welding 3 is performed along the butting line in FIG.

In welding a very thin plate having a plate thickness of 0.6 mm or less, the penetration depth in welding becomes larger than the plate thickness. In the present invention, the joint is formed by a double plate by close contact bending. Therefore, the thickness of the joint is extremely thin
It is twice the thickness of 1, 1-2. For this reason, penetration in welding is prevented from becoming larger than the thickness of the joint, and therefore, burn-through is prevented. As a result, the sheet thickness was 0.
Welding can be easily performed even on an extremely thin metal plate of 6 mm or less. According to the findings of the present inventors, the welding metal 3 of metal titanium having a thickness of, for example, 0.4 mm formed by this method is welded when metal titanium having a thickness of 0.8 mm is joined by a conventional method. It was as healthy as metal.

In FIG. 1, reference numeral 7 denotes a steel pipe pile in a construction material for an offshore structure, which is a structure in which a Cu backing material (cooling plate), a flux-based backing material, and the like cannot be used. Reference numeral 4 denotes a rust inhibitor layer formed on the surface of the steel pipe pile 7, for example, a petrolatum layer. In the present invention, since the joint has a thickness twice as large as the plate thickness, the penetration during welding is prevented from reaching the petrolatum layer even when there is no backing material. A good weld bead is obtained. Therefore, according to the present invention, the coating work of the marine structure is easy and there is no damage to the rust preventive layer.

FIG. 2 is an explanatory view of another example of the method of the present invention.
5-1 and 5-2 are vertical cross sections of two ultrathin metal plates to be joined. In this method, in FIG. 2 (A), one of the two metal ultra-thin plates 5-1 to be joined is bonded to the joining line 2 by tight bending.
-1 is formed, and the other 5-2 is a bonding line 2-2 formed by tightly bending an ultra-thin plate in triple contact, and a bonding line 2-2 is formed at the tip.
A folded portion 6 protruding more than 2 is formed. FIG. 2 (B)
, One of the ultra-thin plates 5-1 is placed on the folded portion 6 of the other ultra-thin plate 5-2, and each of the joining lines 2-1 and 2-2.
-2, butted against each other, and welded along the butt line in FIG. 2 (C).

In the method of FIG. 2, the thickness of the weld is
It becomes three times the plate thickness of -1 or 5-2. Therefore, the penetration depth by welding can be further prevented from becoming larger than the thickness of the joint, and the molten metal is also solidified smoothly. As a result, welding can be performed more stably and easily even in an extremely thin metal plate having a thickness of 0.6 mm or less. In addition, since the folded portion 6 also serves as a backing material and receives the molten metal to prevent burnout, the range of appropriate welding conditions is further widened. Even without a backing material, welding can be performed without damaging the rust preventive layer.

[0016]

According to the present invention, welding of an extremely thin metal plate can be performed stably and easily. Even if there is no backing material, stable welding is possible, and it is possible to prevent the structure to be covered from being damaged in the covering work.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of an example of the method of the present invention.

FIG. 2 is an explanatory diagram of an example of another method of the present invention.

[Explanation of symbols]

1-1 (1-2): extremely thin metal plate, 2-1 (2-
2): joint, 3: welding, 4: rust inhibitor layer, 5-
1 (5-2): metal ultra-thin plate, 6: folded portion, 7:
Steel.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Morihiro Wada 2-chome Iwamotocho, Chiyoda-ku, Tokyo Nippon Steel Corrosion Protection Co., Ltd. (72) Inventor Hideo Sakurai 2-1-1, Iwamotocho, Chiyoda-ku, Tokyo No. 9 Nippon Steel Corrosion Protection Co., Ltd. (72) Inventor Toyo Ando 2-chome Iwamotocho 2-chome, Chiyoda-ku, Tokyo (72) Inventor Masahiro Endo 2-chome Iwamotocho, Chiyoda-ku, Tokyo 10th Ichiban Nippon Steel Corrosion Protection Co., Ltd.

Claims (3)

[Claims] 1. A metal, wherein a joining line is formed by tightly bending each of two ultrathin sheets of metal to be joined, the joining lines are butted against each other, and welded along the butting line. Method of welding ultra-thin plate. 2. A joining line is formed on one of two metal ultra-thin plates to be joined by close contact bending, and the other end of the ultra thin plate is adhered and bent by triple adhesion to form a joining line by the contact bending. And forming a folded portion that is more protruding than the other, and placing one ultrathin plate on the folded portion of the other ultrathin plate, butt each joining line to each other, and welding along the butt line. , Metal ultra-thin plate welding method. 3. The method according to claim 1, wherein, in the work of coating a structure whose surface is covered with a metal ultra-thin plate, the metal ultra-thin plates are joined to each other without using a backing material. A method for welding an ultrathin metal sheet as described above.