JPH0239355B2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to an electron beam welding method, and in particular, during electron beam welding, a wire feeding device is used to add similar or different types of metal to the base metal to be welded. The present invention relates to an electron beam welding method that simultaneously melts metals.

[Prior art]

Electron beam welding is a welding method in which a highly focused electron beam is irradiated onto the welding area, melting and solidifying the metals in the welding area. Overlay repair of welding defects such as surface dents is sometimes performed to improve the metallurgical properties of metals. There are two ways to add the metal: one is to supply the additive metal in the form of a wire to the electron beam welding part, and the other is to attach it to the welding part in advance.

A conventional electron beam welding method involving wire feeding will be described with reference to FIG. The figure shows a cross section in the welding direction, and arrow A indicates the moving direction of the welded material 1.
By irradiating the electron beam 2, the material to be welded 1 is melted to form a molten part (feeding pond) 3, and further, a solidified part 4 is formed by cooling the material to be welded 1 by heat diffusion. The wire-shaped additive metal 5 is called a filler wire and is fed in the direction of arrow B. 6 is a wire feeding device for feeding filler wire, and a pinch roller or the like is used.

The filler wire 5 is supplied to the molten pool 3, melted by the heat of the molten metal, and mixed with the material to be welded 1 to form weld metal.

As described above, the filler wire 5 is connected to the material to be welded 1 during welding. This state continues until the end of welding, and when the electron beam irradiation is stopped, the filler wire 5 is also welded.

Therefore, after welding is completed, it is necessary to cut the filler wire 5, which hinders the attitude change of the material to be welded 1 to the next welding location, which poses a problem in that the automation of welding is hindered.

[Summary of the invention]

This invention was made to overcome the problems of the conventional method as described above, and it controls the timing of stopping electron beam irradiation and stopping wire feeding, and separates the filler wire from the material to be welded at the end of welding. The purpose is to provide an electron beam welding method that allows for

[Embodiments of the invention]

FIG. 2 shows the irradiation of the electron beam at the welding end, the feeding of the wire, and the welding direction cross section of the material to be welded.

FIG. 2A shows the vicinity of the welding end of the electron beam energy supply control. Point (a) indicates the end of welding,
Up to this point, the electron beam energy (mostly replaced by electron beam current) necessary for welding is supplied, and after that the current is gradually reduced until it reaches zero at point (b). This is a control to eliminate the remaining keyhole at the welding end, and is commonly called slope-down control.

Figure 2 (b) shows wire feeding drive control.
3 shows a control operation of the present invention. The wire is fed in conjunction with the electron beam irradiation, and a predetermined supply amount (feeding speed) is supplied up to point (a), but the supply drive is stopped at point (a).

FIG. 2C shows a cross section of the material to be welded in the welding direction. (a)
Up to that point the wire is molten in the weld pool. Welding is completed and the electron beam energy supply starts slope-down control from point (a), but since the electron beam energy is supplied to the material to be welded, the molten pool remains although its depth is reduced.

When the wire feeding is stopped at point (a), the filler wire 5 that has been connected to the molten pool up to point (a) is
As shown, the melting point of the filler wire 5 gradually shifts to the surface of the welded material 1 while being melted in the remaining molten pool, and eventually only the surface melts at point (d). During this time, the material to be welded is being moved in the direction of arrow A, so the filler wire 5 is separated from the material to be welded 1.

As described above, when wire feeding is stopped at the end of welding and electron beam energy supply is stopped at the start of slope down, the filler wire is melted and cut by the molten metal during slope down, and when electron beam energy supply is stopped, the welded material is The material to be welded will be separated more easily and will not interfere with the next change in attitude of the material to be welded.

〔Effect of the invention〕

In this invention, since the wire feeding is controlled to be stopped before the electron beam irradiation is stopped, there is no need to cut the filler wire at the end of welding, thereby making it possible to perform automatic welding.

[Brief explanation of drawings]

Figure 1 is a schematic cross-sectional view in the welding direction in the conventional method.
FIG. 2 is a diagram for explaining one embodiment of the present invention, showing aspects of electron beam energy supply control and wire feeding drive control corresponding to a cross section in the welding direction. 1... Material to be welded, 5... Filler wire. In addition,
In each figure, the same reference numerals indicate the same or corresponding parts.

Claims (1)

[Claims] 1 During electron beam welding, in an electron beam welding method in which a filler wire is fed to a welding part of a material to be welded and the filler wire is melted by the melting heat of the material to be welded, the point at which electron beam downslope control starts at the welding end portion An electron beam welding method characterized in that feeding of the filler wire is stopped at .