KR19980048222A - How to calibrate the deformation of aluminum welded structures - Google Patents

Abstract

The present invention relates to a method for correcting the distortion deformation portion of the aluminum welded structure, the line is drawn to the back side of the deformed portion by welding and heated while moving the Tig torch according to the drawn line to solve the strain stress caused by the welding However, the heating process is divided into the initial and the middle, and the initial heating is relatively weak so that the aluminum plate is not heated rapidly, the medium is strongly heated and then naturally cooled to relieve the stress of the welding site to correct.

Description

How to calibrate the deformation of aluminum welded structures

The present invention is to provide a method for straightening deformation of an aluminum welded structure, which is effective for correcting the deformation of the welded portion generated in manufacturing a non-ferrous structure, in particular, a structure formed of an aluminum plate, such as a deck house of a high-speed ship. .

In high speed ships, the weight of the hull acts as a major obstacle to the increase in speed, so it is necessary to reduce the weight. The weight reduction of the hull is conventionally solved by employing a structure made of aluminum. In this case, the aluminum structure has a large number of parts connected and connected depending on the welding. As is well known, aluminum is welded by continuously supplying electrode wires while generating an arc between a metal rod, which is a solvent, and a base metal. In this case, the aluminum to be welded is deformed due to the extreme temperature difference between the heating center and its surroundings.

In the case of the aluminum plate 2 including the T-shaped member 1 as shown in FIG. 1A, the deformation caused the deformation to form a curved surface under the influence of high heat applied to the welding site as shown in FIG. 2B. Form. This can be seen in webs and the like where fillet welding is required.

Such modifications are not limited to the form depicted in FIG. 1. When viewed from another angle, the correct shape before welding as shown in FIG. 2A is deformed as shown in FIG. 2B after welding, and appears as a complex deformation with the modified form of FIG. 1.

Therefore, in the case of the aluminum plate 2 including a plurality of the T-shaped member (1) as shown in the example of Figure 3 in the correct form as shown in Figure 3a after the form of a cross-sectional shape as shown in Figure 3b after welding It is often found in sidewall members, decks and the like.

In addition, as shown in FIG. 4 to connect two side wall members, butt welding of two or more aluminum structures also appears in the butt welding part 4 as shown in FIG. Resulting in a transformation.

Due to this deformation problem, in the construction of a ship including an aluminum structure, such as a high-speed vessel, correction work of the deformed portion is always performed after welding of the aluminum structure.

As a calibration method, the method of releasing the stress in a deformation | transformation site | part by heating by the MIG welding method in the position opposite to the heating direction at the time of welding is mainly used.

In this MIG welding method, an arc is generated when the electrode wire is brought close to an aluminum plate serving as a base material, and the electrode wire is welded to the aluminum plate to form beads unnecessarily. There is a problem that the id must be removed, and furthermore, unnecessary waste of the electrode wire and poor appearance of the bead removal site are caused.

For this reason, in recent years, attempts have been made to apply Tungsten Insert Gas arc welding, in which arcs are generated by bringing a tungsten electrode close to a base material, to a calibration operation.

As an example, the present applicant has proposed a method for correcting a TIG of an aluminum plate welding deformation in Korean Patent Application No. 89-6746, which corrects the deformation area by heating the welding deformation part with a TIG torch in the opposite direction. It is. However, since the deformation part which appears by welding of an aluminum plate in ship building is represented in a complex as actually described with reference to FIGS. 1-4, it is not corrected by a simple heating furnace.

On the other hand, as another example of a method for correcting the deformation of the welded portion, an arc is generated while cooling the TIG torch, and the arc generated at this time is focused toward the center to perform local heating for a short time on the outer plate, and then the heating portion is Tig torch heating methods are also known which are forced to cool by force, but this method also cannot correct complex deformation.

According to the present invention, a guide line of a vertical or horizontal straight line or a zigzag line is drawn to the back surface of the deformation part by welding, and the welding deformation part is heated with a TIG torch according to the guide line, but the aluminum plate is relatively deformed by rapid heating at the initial stage of heating. It is characterized in that it is heated by weak heating, strong heating in the middle stage, and then naturally cooled to correct the stress at the deformation site due to the welding.

In the above method, the temperature control of the heating can be performed by setting a high and low replacement interval or current value between the TIG torch and the aluminum plate.

The present invention as described above is very simple even in the case of complex deformation because it is weakly heated at the beginning of heating in the calibration process so that rapid thermal expansion does not occur, and in the middle, it is more strongly heated to release the stress concentrated at the deformation site. It can be easily and easily calibrated, and thus there is an advantage that even a beginner can work efficiently, and after the calibration, the bead removal work is omitted, thereby eliminating unnecessary waste and hassle.

1A is a view showing a form before welding as an example of an aluminum welding structure including a general T-shaped member.

1B is a diagram showing a deformation after welding.

FIG. 2A is a view showing the form before welding of FIG. 1 at another angle; FIG.

FIG. 2b shows the deformation after welding of FIG. 1 at different angles. FIG.

3A is an example of an aluminum structure including a large number of T-shaped members, illustrating a form before welding;

Figure 3b is a view showing a deformation of the aluminum structure including a plurality of T-shaped members after welding.

4A is an example of butt welding two or more aluminum structures, illustrating a state before welding;

Fig. 4B is a diagram showing the deformation of butt welding two or more aluminum structures after welding.

5 is a view for explaining a heating portion of the aluminum structure according to the calibration method of the present invention.

Fig. 6A is a diagram showing an example of vertical alignment of curved deformation portions.

6B is a diagram showing an example of horizontal lateral alignment of curved deformation portions.

It is a figure which shows the example of the zigzag line drawing of a curved deformation | transformation site | part.

Explanation of symbols for the main parts of the drawings

1: Aluminum plate 2: T-shaped member 3: Welding part

4: Butt welding spot 5: Tig torch

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to FIGS. 5 and 6.

Referring to FIG. 5, in the aluminum plate 2 including the T-shaped member 1, the tag torch 5 is positioned on the opposite side of the welding portion 3 to start heating for calibration.

As shown in the figure, the position of the tag torch 5 is set to two, a position A deviating from the welding portion 3 and a position B within the range.

The position A is a place where the contraction action of the curved deformation portion by heating occurs relatively weakly, so it is preferable to start from this position at the beginning of heating. In addition, since position B is a place where a strong contraction action takes place, it is good to set it as the starting point in the intermediate process of heating.

Before starting heating, the oxide film of the heating part of the back surface side of the aluminum plate 1 is first peeled off, and a line drawing is performed. Drawing is made with the longitudinal direction as (a), the horizontal direction like (b), or the zigzag direction like (c) according to the deployment direction of a welding site with reference to FIG.

The pitch of the line drawing is selected according to the degree of deformation, and when the line drawing is completed, the TIG torch 5 is heated while moving at a constant speed along the line drawn. At this time, the movement of the tag torch 5 can be automatically performed, and the current value required for heating can be set to 300 A class or 500 A class.

During heating, the tungsten electrode may be cooled with water or other antifreeze, but such cooling should not result in temperature unevenness of the heating.

The calibration of the aluminum plate by heating is determined by the time at which the stresses in it are released. Since most of the stress relief takes 30-40 minutes, there is no calibration effect at the beginning of heating. However, the calibration is completed by heating the entire object according to the drawn line.

In addition, the movement of the TIG torch should be moved from the severely deformed portion to the weaker portion, and consequently, the heat should be evenly applied to the entire deformed portion.

In the initial stage of heating, the gap between the object and the tag torch is heated to a low current or away from the target, and in the middle of the heating, the tag torch is heated to be close to the object or the current value is heated to deform the site. To be corrected.

In the case of the aluminum plate 2 including two or more T-shaped members 1, since the heating lasts for a long time, locally excessive heating proceeds, which may cause secondary deformation. The secondary deformation appears in the form of struck. If the struck part is a slight degree, the entire surface can be corrected by applying heat on the back side, and in the order of the weak parts in the severe part, the entire heating is solved.

Example 1

(Correction of side wall members and decks)

The deck is made of aluminum plate with many T-shaped members. Therefore, the deformation is shown in the form as shown in Figure 3b.

In order to correct this, first, the oxide film was stripped, and the places where the deformation amount was severe and small were selected, and then the lines where the severe areas were zigzag-lined and the places where the areas were low were straight-lined.

The TIG torch was directed from the center of the deformation to the place where the deformation amount was severe, but moved laterally from the center of deformation to perform the primary heating.

In the primary heating, the distance between the TIG torch and the aluminum plate was maintained at 4-5 mm, and the current was moved at a speed of 60-70 cm / min with 100-120 A.

The starting point of the TIG torch was position A in FIG. 5.

After completion of the primary heating, the current was raised to 280-290 A and the TIG torch was heated to the starting point B of FIG. 5, and the deformation site was corrected after 35 minutes of natural cooling.

In addition, the site heated for a long time by the TIG torch showed a night bead phenomenon, but it was easily removed with a brush.

Example 2

(Correction of web)

Deformation caused by fillet welding is shown in the form illustrated in FIGS. 1 and 2.

The back side oxide film of the deformation | transformation site | part was peeled off, and the drawing operation was performed.

The scribing was made into a straight line along the deformation site, and then heated while running the Tig torch along the drawn line.

At the beginning of the heating, the distance between the tungsten electrode and the aluminum plate was 4-5 mm, the moving speed was 30-40 m / min, the current was 100-120 A, the starting point was A of FIG. 5, and the middle value of the heating was 260. It was carried out in the range of 270A, the starting point at this time was set to position B of FIG.

When the heating was finished and 40 minutes had elapsed into the natural cooling, the calibration of the deformation site was completed.

As described above, the present invention is performed by dividing the process of heating the aluminum plate with a TIG torch into the initial and the middle, but initially heated to a weak heat and a strong heat in the middle, so that the heated object does not cause a sudden thermal deformation, but also a complex deformation. Since it is possible to calibrate in a variety of variables, even if you are a beginner can be easily and easily correct the deformation of the aluminum welding site, which requires a high level of skill in practice, the method using the conventional MIG welding method after the calibration work Unlike the welding of the beads does not occur, the additional work is omitted, and since the TIG torch does not cause the consumption of the electrode wire, there is an advantage that no waste of material occurs.

In addition, it is an invention that the appearance of the back of the calibration is completed beautifully and can also be expected to improve the reliability and product quality.

Claims (2)

In the aluminum welded structure, the method for straightening the deformed portion of the aluminum welded structure by applying heat to the back side of the deformed portion by welding, Draw a horizontal or vertical straight or zigzag guide line on the back surface of the deformation part by welding, and heat the welding deformation part with a TIG torch according to the guide line, but heat relatively weakly so that the aluminum plate is not deformed by rapid heating at the initial stage of heating. And, in the middle of the heating method is strongly heated and then naturally cooled to deform the deformation portion of the aluminum welded structure, characterized in that the stress of the deformation by the welding is lost. The method of claim 1, Adjusting the heating temperature by the tag torch is performed by setting the replacement interval or the current value between the tag torch and the aluminum plate high and low, the deformation portion calibration method of the aluminum welded structure.