JPS62183966A - One side welding method for extremely thick plate - Google Patents

Abstract

PURPOSE:To execute one side welding with a high efficiency by inclining both base metals to a crest type centering around a groove part, prior to a start of welding, and ending the welding by dissolving an inclination of the base metal in accordance with a welding distortion as the welding advances. CONSTITUTION:Base metals 2, 2 are formed to a butt groove of I type, and a raised bottom part of a weld zone on which a backing metal 4 has been placed is set to a prescribed size. The base materials 2, 2 which have been set to a welding position are welded by one layer one pass by TIG automatic welding. As welding advances, a welding distortion collects in an object to be welded, but in order to eliminate an inclination of the object to the welded, but in order to eliminate an inclination of the object to be welded, by the welding distortion when welding has been ended, hydraulic pressure for fixation is released in the course of welding. After the hydraulic pressure has been released, an inclination of both the base metals is dissolved gradually as the welding distortion of both the base metals is generated, and when welding has been ended, both the base metals form roughly a flat surface.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a one-sided welding method for extremely thick plates, in particular a welding method for one-sided welding of extremely thick plates.
− Concerning a one-sided welding method for extremely thick plates.

(Prior Art) Even in the past, extremely thick plates have often been welded, as seen in, for example, slab welding during hot rolling.

However, in the past, in many cases, prior to welding, a U-shaped groove was prepared in advance and TIG welding was performed from both sides of the plate, which required a large number of welding steps. Moreover, in the past, most of the welding was done by hand, and the time required for welding was long. Therefore, in the conventional method, the number of steps is large, the working time is long, the amount of gas used during welding is also large, and the cost is inevitably high.

In the past, there have been attempts to improve the above-mentioned drawbacks by introducing automatic welding, but it takes time to process the groove, and welding needs to be done from both sides due to the problem of welding distortion. It took time to perform tasks such as reversing the welding base material, making it impossible to take advantage of the excellent features of automatic welding.

(Problems to be Solved by the Invention) Thus, the object of the present invention is to
An object of the present invention is to provide a welding method that enables automatic welding from one side of an extremely thick plate such as No. 1. Another object of the present invention is to provide a method for welding extremely thick plates that does not require special bevel processing and only requires cutting or electric discharge cutting to level the welding surface. be.

Furthermore, another object of the present invention is to provide a welding method that makes it possible to significantly reduce the number of steps and reduce costs by reducing the amount of work by creating a narrow gap and automating welding. .

(Means for solving the problem) Here, the gist of the present invention is that 100 to 200
When welding an A+M extra-thick plate as the base material from one side with an I-type butt groove, before starting welding,
Both members are set at the welding position with their grooves tilted in a chevron shape as the center, and as welding progresses, welding is completed while the inclination of both members is resolved according to the welding distortion of both members. This is a one-sided welding method for extremely thick plates.

According to aspect 1a of the present invention, the inclination is adjusted in advance so that both the members become flat surfaces upon completion of welding.

Furthermore, in a preferred embodiment of the present invention, the above-mentioned welding is performed by:
TIG automatic welding is performed in one pass for each layer.

Note that titanium slabs are a typical example of extremely thick plates, but other slab materials such as ordinary steel, alloy steel, and stainless steel are also included.

This is the angle of inclination of both members at the initial welding position, that is, the opening angle of the butt end faces of both members, and this is determined by the plate thickness,
Although it varies depending on the groove width etc., generally 2~10°
It would be sufficient if the upper surfaces of both base materials are adjusted in advance so that they become flat surfaces upon completion of welding of both base materials.

As described above, according to the present invention, in order to facilitate welding, the base metal plates, which are both thick plates, are tilted and set at the welding position, and during welding, the base metal itself is gradually tilted due to the welding strain. This eliminates the inclination and creates a flat finish when welding is completed.

Therefore, the present invention can be said to be an excellent welding method that can be expected to have the following excellent effects.

First, ■ extremely thick plates up to 200w+s can be welded from one side, and further up to 02001m111, preferably 10
Extremely thick plates from 0 to 200+m can be welded on one side with high efficiency in a single pass using a narrow gap TIG automatic welding machine, and there is no need to process a U-shaped groove from both sides, and the weld groove can be welded in the summer. A butting groove of a mold may be used, and it is sufficient that the groove surface is also formed by an appropriate means such as a machine cutting surface or an electric discharge cutting surface.

(Operation) Next, the present invention will be described in more detail with reference to the accompanying drawings.

1 to 3 are conceptual diagrams showing the order of implementation of the welding method according to the present invention.

First, as shown in Figure 1, at the start, the thickness is 17 mm.
A titanium slab 2.2 which is a base material of 0mm+ is made into a type 1 butt groove, for example, the groove width is 9ma+ and the tip width is 17mm.
Set the titanium slab in the welding position as shown in the figure. In that case, it is sufficient that the lift of the bottom of the welded portion to which the backing metal 4 is applied is 50-1. This corresponds to 2.7° in terms of the opening angle (θ) of the groove.

The method for fixing the welding base material is to grasp and fix both parts using an appropriate hydraulic device (not shown) and fix them at the welding position.
To prevent the groove width from becoming excessively narrow due to welding distortion during welding.

The base material 2.2 thus placed at the welding position is automatically welded one layer at a time by TIG automatic welding, as shown in FIG. 2, as indicated by reference numeral 6. The welding torch is not shown in the figure. Since the groove portion is opened by the above-mentioned opening angle, the welding torch can reach the bottom of the welded portion even if the groove is narrow in an extremely thick plate.

As welding progresses as described above, welding distortion accumulates on the welded object, but at the end of welding, in order to eliminate the inclination of the welded object due to such welding distortion, welding is carried out at an appropriate time during welding. Release the aforementioned fixing hydraulic pressure. Refer to Figure 3. The timing for releasing the hydraulic pressure is not uniform as it varies depending on the size of the workpiece, steel type, etc., but as a rough guide, welding of 1/2 of the thickness of the workpiece is completed. At that point, it is preferable to release the hydraulic pressure to the locking device. After the hydraulic pressure is released, the inclination of both companies' materials gradually disappears as welding distortion occurs in both companies' materials, and when welding is completed, both companies' materials almost form a flat surface. Also, adjust the opening angles of the materials from both companies in advance so that this happens.

In order to complete the welding on the start and end sides of welding, a backing metal 4 is used between the base metals 2.2 and 2.2, as shown in FIG. The tab plate 8 may be attached to the object to be welded, in which case the start and end of welding should be within the range of the tab plate.

Here, in the case of using the welding method according to the present invention described above, and in the case of using the same slab material by the conventional method, a 0-shaped groove (groove width of 35II
A comparison with the case of forming II11) and manual welding revealed the following results.

The number of processes was reduced from 8 to 3 at once, the total gas consumption for sealing was reduced from 215 ca3 to 72 m3, almost 1/3, and the welding groove processing loss was reduced from 2% to 0.5%.
/4.

(Effects of the Invention) As described above, the present invention has great practical benefits, and since its configuration is 1MTJn, it is considered to make a great contribution in this field.

[Brief explanation of drawings]

1 to 3 are conceptual diagrams showing the process order of the welding method according to the present invention; and FIG. 4 is an explanatory diagram showing another modification example when setting the welding position. 2: Titanium slab 4: 'JJ1 padding 8: Tab plate applicant Nippon Stainless Co., Ltd. agent Patent attorney Akira Hirose - Qin 7 Zuo 21! l (during welding) 3 concave holes (end concave) 1.4 'ryJ

Claims (3)

[Claims] (1) When using extremely thick plates of 100 to 200 mm as base materials and welding them from one side with an I-type butt groove, before starting welding, both base materials are tilted in a chevron shape with the grooves in the center. Set it at the welding position, and as welding progresses, while eliminating the inclination of both base materials according to the welding distortion of both base materials,
A one-sided welding method for extremely thick plates, characterized by finishing the welding. (2) The inclination is adjusted so that both base materials become flat surfaces upon completion of welding.
The method described in section. (3) The method according to claim 1 or 2, wherein each layer is welded in one pass by TIG automatic welding.