SU1581519A1 - Method of electron-beam welding of welded parts of crater type - Google Patents

Abstract

The invention relates to the technology of electron beam welding and can be used in mechanical engineering to eliminate defects in welds. The purpose of the invention is to improve the quality of the welded joint and reduce the power of the electron beam while eliminating the defect by reducing the volume of metal melted per unit time. In the zone of the detected weld defect, a conical hole is made and a conical insert with an axial hole is inserted into it, its upper wider end is located with an excess relative to the surface of the weld. The welding is performed by a doubly refracted beam, the point of intersection of which with the optical axis of the electron emitter is located in the axial bore. The beam is moved along a circular path, first melted the lower end of the insert, and then sequential overlying volumes, gradually withdrawing the named point of intersection of the beam and the optical axis from the axial hole. At the initial melting of the lower end of the insert, the beam power should provide the possibility of reflowing and welding of this insert end with the base metal of the welded joint, and further this power is kept constant.

Description

The invention relates to the technology of electron beam welding and can be used in mechanical engineering to eliminate defects in welds.

The purpose of the invention is to improve the quality of the welded joint and reduce the power of the electron beam while eliminating the defect by reducing the volume of metal melted per unit time.

The drawing shows a diagram of the electron-beam welding of crater-type welding defects in the weld area.

A conical bore is made in the defective seam section formed during welding of parts 1 and 2, and a conical insert 3 with a through axial bore is placed in it. The electron beam 4 is double-deflected with the help of two deflecting systems 5 so that the trajectories of the electrons of the beam Ka are intersected with the optical axis of the electron radiator at point B,

First, this point B is placed in the axial hole of the insert, and then with the help of deflecting systems 5

bake the rotation of the double-pronged beam 4 and increase its current to the working value, gradually moving point B in the direction of the electron emitter 6. After gradual melting down the axial opening of the insert brewed into the defective weld zone, and melting it protruding above the seam parts of the beam current are smoothly reduced to zero. At the first stage of welding, the lower end of the insert is completely melted with the lowest possible melting of its upper end. The drawing shows the angle / tilt of the beam to the axis of the electron emitter, which, taking into account the usual geometric relationships, can be calculated by the formula

a / arctg (D, (+ d) / 2Ј3,

Where. DH - outer diameter of the bottom

end insert; d - diameter of the axial bore

inserts;

$ - insertion height. The initial position of the point B in the axial hole of the insert can be determined by the formula

H1 0.5d -ctgof,

where H is the depth at which point B is located in the axial hole of the insert,

During the initial melting of the lower end of the insert, the electron beam power is chosen taking into account this melting and welding of the lower end of the insert with the base metal of the welded joint. Subsequently, the selected beam power is maintained at a constant level, and the melting of the overlying insert volumes is produced by moving point B ( up the drawing). Due to this, at each time point a smaller volume of metal is melted than by a known method and less power is expended

Example. Welded in the lower position of plates made of aluminum alloy AMg 6 with a thickness of 60 mm in the mode: accelerating voltage 60 kV, electron beam current 320 mA, focusing current 15 mA, welding speed 30 m / h, distance from the electron radiator to the front surface of ylit 100 mm, the frequency of the circular movement of the beam I70 Hz, the initial depth of the point B in the insert hole H 14 mm, the final height of the point B above the plate surface H 43 mm, the speed of moving point B during the welding process 40 m / h. During welding, the OL-143 double refraction unit was used.

Defects of the weld were artificially obtained by periodically disconnecting the power source.

In the defective area to be repaired, a conical opening 40 mm deep with diameters DH 4 mm and De 6 mm was made. An insert with corresponding external dimensions was inserted into this hole, in which an axial hole with a diameter of 2 mm was previously made. Excess vtagzhi above the surface of the plates was 3 mm.

After welding, it was found that in the zone of the former defect there are no pores or non-fusions, the content of magnesium and manganese in the cast metal decreased by less than 5% in comparison with their initial content, and the strength properties of the cast metal were at least 95% of the metal strength to welding defect.

Practice has shown that the best results are achieved with the following insert sizes: 20-40 mm, d 1.5-2.5 mm, DH 3-4 mm, Hg 5-6 mm.

Thus, the application of the proposed method allows to improve the quality of the welded joint.

Claims (1)

The invention The method of electron-beam welding of welding defects of the cracker type, in which a tapered hole is made in the weld defect zone, an insert is placed in it with excess above the weld surface and irradiated with an electron beam moving along a circular path, melting it all the way due to the fact that, in order to improve the quality of the welded joint and reduce the power of the electron beam while eliminating the defect by reducing the volume of metal melted per unit time, rate previously performed axial hole and its derivatives irradiation m doubly refracted elektZonaras- m.p. Editor L. Veselovska Compiled by E, Mamutov Tehred L. Oliynyk Proofreader O. Tsiple Order 2056 Circulation 634 VNIIPI State Committee for Inventions and Discoveries at the State Committee on Science and Technology of the USSR 113035, Moscow, Zh-35, Raushsk nab., A / 5 Production and publishing plant Patent, Uzhgorod, st. Gagarin, 101 Subscription