JPS63295061A - Method for preventing welding defect by ultrasonic excitation - Google Patents

Abstract

PURPOSE:To form weld bead without defect of blowhole, etc., by fitting ultrasonic exciting tip to a material to be welded at the time of arc-welding the metal material and exciting the ultrasonic vibration to the molten metal for weld bead. CONSTITUTION:At the time of welding the work 22 for welding material with arc welding, etc., the ultrasonic exciting tips 23, 24, 25, 26 are brought into contact with the surface of the work 22 near the weld bead 27 as inserting the bead 27 and the work 22 is welded with the welding torch 21 while applying the ultrasonic vibration from an ultrasonic exciting source 29. A weld metal pool 28 is forcedly vibrated and the weld bead 27 is uniformly solidified and cooled to depth direction and the uniformly fine weld bead depth direction and the uniformly fine weld bead 27 without defect of blowhole, weld crack, etc., is formed.

Description

[Detailed description of the invention] [Industrial application field] The present invention is arc welding and laser welding (LBW).

The present invention relates to a method for preventing welding defects using ultrasonic vibration, which is applied to improving the quality of welded joints such as electron beam welding (EBW) and castings.

[Conventional technology]

A conventional example is shown in FIG. If defect prevention measures are not taken in FIG. 2, the weld tip 2 will often have a narrow and deep penetration peak when arc welding is performed using the welding torch 1, as shown in FIG. 2(a). In this case, blowholes 4 are particularly noticeable at the tip 2, and the solidification line is as shown in 6, and impurities (e.g., Sn, P, S) are segregated in the center near the final solidification line 7. It is easy to break and can cause high temperature cracking.

Therefore, the case of the conventional countermeasure technique is shown in FIG. 2(b). Oscillate electrode 1 as shown by the arrow to create weld bead shape 2
A wide pitch is used to facilitate the removal of blowholes that occur. As a result, segregation in the molten metal was reduced, and a uniform microstructure 6 was obtained.

[Problem that the invention seeks to solve]

In the case of the conventional technology, it is expected that welding defects can be reduced by widening the bead width, but there is a drawback that welding defects and segregation cannot be completely prevented when the plate thickness becomes large.

In addition, in the conventional technology, the amount of heat input increases by widening the welding pead width, which causes weld cracking and cold cracking (H
AZ cracking). In addition, the amount of welding deformation increases due to the increase in heat input, which is a disadvantage in terms of welding quality.

[Failure to solve the problem]

In order to solve the above-mentioned problems, the present invention grounds an excitation tip that serves as an ultrasonic excitation source on the surface of the workpiece itself or on its side,
This method vibrates the molten metal pool during welding to ensure uniform solidification and cooling. In other words, an ultrasonic excitation tip that applies electricity to vibrate the molten metal that will become the weld bead pinches the weld bead of the workpiece, or is grounded to the side of the workpiece and ultrasonically vibrates the molten metal part that is being welded. The present invention provides a method for preventing welding defects by ultrasonic excitation, which is characterized in that welding is performed while the welding is performed.

[Effect]

The method for preventing welding defects using ultrasonic vibration of the present invention is as described above, so that the molten metal in the molten metal pool is uniformly solidified and cooled by generating ultrasonic vibrations in the molten metal pool, and the blowing This is a method for preventing welding defects that makes it possible to obtain uniform weld metal by preventing holes and segregation of impurities.

〔Example〕

Hereinafter, two embodiments of the present invention will be specifically described based on embodiments shown in the drawings.

FIG. 1 is a perspective view showing an application state of a method for preventing welding defects using ultrasonic excitation according to an embodiment of the present invention. A detailed explanation will be given below. In FIG. 1, 21 is a welding torch, and 22 is a workpiece.

28.24,25. 26 is an excitation chip, 27 is a welding bead, 28 is a molten metal pool, and 29 is an ultrasonic excitation power source. When performing welding by generating an arc between the welding torch 21 and the workpiece 22 of the present invention, several sets of ultrasonic excitation tips 2B, 24, 25, and 26 are welded to the surface of the workpiece 22 depending on the excitation state. The bead 27 is placed close to the ground so as to sandwich it, and welding is performed in the direction of the arrow while vibrating from both sides. As a result, the molten metal pool 28 is forcibly oscillated, uniformly solidified and cooled in the depth direction of the weld bead, and has a uniform structure.

Therefore, high-quality welding without blowholes, weld cracks, and segregation of impurities is possible. In addition, the excitation power source 29
The excitation chips 23, 24, 25, and 26 are connected in parallel.

Furthermore, the excitation frequency and sound pressure can be controlled manually or automatically.

〔Effect of the invention〕

As specifically explained above, the present invention uses arc welding and electron beam welding (EBW).

Blowholes and hot cracks in laser welding (LBW) welds can be easily prevented, and a wide range of welding conditions can be used, which is advantageous in welding work.

[Brief explanation of the drawing]

Fig. 1 is a perspective view showing the applied state of the method for preventing welding defects using ultrasonic excitation according to an embodiment of the present invention, Fig. 2 shows the conventional welding method, and the same figure (,) shows the application state of the method for preventing welding defects using ultrasonic excitation according to an embodiment of the present invention. Figure (b) is a sectional view of the welded part showing a welded state in which the welding torch is oscillated to prevent welding defects. 21... Welding torch, 22... Workpiece, 2B,
24.25. 26... Vibrating chip, 27... Welding bead, 28...
... Molten metal pool, 29... Ultrasonic excitation power source.

Claims (1)

[Claims] An ultrasonic excitation tip that applies electricity to vibrate the molten metal that will become the welding bead pinches the welding bead of the workpiece, or is grounded to the side of the workpiece and welds while exciting the molten metal being welded with ultrasonic waves. A method for preventing welding defects by using ultrasonic vibration.