JPS62101380A - Butt welding method for thick steel plate - Google Patents

Abstract

PURPOSE:To prevent the deterioration in the quality of a thick steel plate by inserting the welding head having nonconsumable electrode and filler wire inside a groove, then by weaving the nonconsumable electrode in the horizontal direction with ascending the welding head. CONSTITUTION:A welding head 3 is inserted into the groove 2 of a thick steel plate 1 by arranging it so that the beveling face 2a becomes in the vertical direction. The head 3 is made its weaving possible in full width of the beveling face 2a by providing an nonconsumable electrode 6 and filler wire 7 inside the recessed part 5. Moreover, the wire 7 is fed by continuing inside the recessed part 5 through a feeding pipe 9. The welding of the thick plate 1 is performed by weaving the electrode 6 in the horizontal direction with ascending the welding head 3 along the beveling face 2a. Due to the bead 10 being able to be laminated with small heat input the material deterioration of the thick plate 1 at the welding time is prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a method for butt welding thick steel plates.

[Prior art and its problems]

Butt welding of thick steel plates is performed with the groove surfaces facing each other so as to extend in the vertical direction. This kind of thick steel plate welding is
Traditionally, electrogas welding or electroslab welding has been used, but neither method allows beads to be layered within the groove by forming beads with a small amount of heat input. The problem was that the material quality of the thick steel plates could not be avoided due to welding.

[Purpose of the invention]

In view of the above-mentioned current situation, an object of the present invention is to provide a method for butt welding thick steel plates, which can weld thick steel plates without causing material deterioration.

[Summary of the invention]

The butt welding method for thick steel plates according to the present invention involves welding a steel plate continuously below an electrode provided in a gas shield box in a narrow groove of a thick steel plate having groove surfaces extending vertically and facing each other. inserting a welding head having a filler wire and moving the non-consumable electrode horizontally within the groove along the groove surface while the welding head is relatively raised along the groove surface. It is characterized in that the bead F is laminated within the groove by weaving.

[Structure of the invention]

Hereinafter, the method for butt welding thick steel plates according to the present invention will be explained in detail based on the drawings.

FIG. 1 is a perspective view showing a thick steel plate bent and formed into a steel pipe to be butt welded by the method of the present invention, FIG. 2 is an explanatory diagram showing one embodiment of the welding method of the present invention, and FIG. FIG. 3 is a perspective view showing a welding head used in the welding method of FIG. 2;

In the drawings, reference numeral 1 denotes a thick steel plate bent into a steel pipe, and the thick steel plate 1 is placed vertically so that the groove surface 2a of the groove 2 extends in the vertical direction. In order to avoid welding with large heat input, the groove 2 has a narrow gap as narrow as possible, and the groove surfaces 2a are opposed to each other. For example, for a steel plate with a thickness of 30 crn, the gap is conventionally 20 to 25 cm, but in this invention, the gap is at most 12 wn or less, and on average 6
It should be about the same level as a kindergarten.

3 is a welding head, and the welding heel F″3 has a non-consumable electrode, for example, a tungsten electrode 6, and a filler wire 7 in a recess 5 provided in the gas shield number 4. Recess 5 has a width larger than the width of the groove surface 2a.The tungsten electrode 6 is held by an arm 8 made of a double tube whose tip is bent downward, and in order to avoid welding with a large heat input. 1. Bevel surface 2 by arm 8 within concave portion 5
Weaving is performed in the horizontal direction along the direction a to the full width of the groove surface 2a. Further, a shielding gas such as argon gas is guided to the arm 8, and the shielding gas flows out from the tip of the arm 8. 'The shield gasket 4 is provided with one or two filler wire supply pipes 9, and the filler wire 7 is continuously led out through the supply pipe 9 into the recess 5 below the electrode 6. It has become so.

In this invention, the welding head 3 as described above is inserted into the groove 2, and the welding head 3 is moved relatively upward along the groove surface 2a, and the electrode 6 is moved horizontally along the groove surface 2a. The thick steel plates 1 are butt-welded by stacking beads 10 in the groove 2 while weaving in the direction. In this case, since the electrode 6 is weaved, the bead 10 can be laminated to a thin thickness of 3 to 5 mm, which requires a small amount of heat input, and it is possible to prevent material deterioration due to welding of the thick steel plate 1.

Note that the bead 10 is cooled by applying a water-cooled copper plate 11 or a ceramic plate to the groove 2 from both the inner and outer surfaces of the thick steel plate 1 below the welding head 3, or by spraying cooling gas. The bead end 10a protruding from the groove 2 of the bead 10 is cut after welding.

As described above, in this invention, the groove 2 of the thick steel plate 1 is made narrow, and the electrode 6 is horizontally weaved within the groove 2, and then the bead 10 is laminated within the groove 2. Therefore, each of the 100 laminated beads can be formed with a small amount of heat input, and therefore, the thick steel plate 1 can be welded without causing material deterioration.

〔Effect of the invention〕

According to this invention, thick steel plates can be welded without causing material deterioration.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing a thick steel plate bent and formed into a steel pipe to be butt welded by the method of the present invention, FIG. 2 is an explanatory diagram showing one embodiment of the welding method of the present invention, and FIG. FIG. 3 is a perspective view showing a welding head used in the welding method of FIG. 2; In the drawings: 1... Thick steel plate, 2... Bevel, 2a...
Groove surface, 3... Welding head, 4... Gas seal F' sex, 5... Concave portion, 6... Tungsten electrode, 7... Filler wire, 8... Arm, 9
...Filler wire supply pipe, 10...Bee F, 11...Water-cooled copper plate.

Claims (1)

[Scope of Claims] A non-consumable electrode is provided in a recess provided in a gas shield box in a groove of a thick steel plate having groove surfaces extending in the vertical direction that are opposed to each other in a narrow groove, and the non-consumable electrode A welding head having a filler wire continuously led out below the groove is inserted, and while the welding head is relatively raised along the groove surface, the non-consumable electrode is inserted into the groove. A method for butt welding thick steel plates, characterized by laminating beads within the groove by weaving horizontally along the leading edge.