SU1703325A1 - Aluminium alloy arc-welding method - Google Patents

Abstract

The invention relates to welding production and can be used for arc welding with a non-consumable electrode in a protective gas environment of aluminum alloy parts. The purpose of the invention is to improve the quality of welded joints from aluminum alloys by destroying and eliminating oxide inclusions. In the method of welding with a non-consumable electrode with alternating current, the arc and the metal of the weld pool are affected by a longitudinal alternating electromagnetic field. The control magnetic field is supplied at the time of the direct polarity of the half periods of the welding current. The magnitude of the magnetic induction is determined from the expression B 0.0005 sin "to 0.007 sin and where B is the magnitude of the magnetic induction, T; a- the current value of the sinusoid angle of the welding current, deg. The method provides effective melt mixing in the weld pool and allows to obtain vacuum-log welded joints due to the destruction of oxide inclusions. 1 tab., 1 Il. ate with

Description

The invention relates to electric arc welding of metals with electromagnetic stirring of the weld pool melt and can be used in various industries in the manufacture of welded structures from aluminum alloys.

The purpose of the invention is to improve the quality of welded joints from aluminum alloys by destroying and eliminating oxide inclusions.

The drawing shows a diagram of the change in welding current and magnetic field inductance over time.

The proposed method consists in exposing the welding arc and the metal of the weld pool to a longitudinal alternating electromagnetic field generated by an alternating current at the moments of the direct polarity of the half periods of the welding current. In the first period of time Ti, the inductance of the magnetic field B is generated by the current of direct polarity, and in the period of time Tr the polarity of the generating current is reversed (see the drawing).

The magnitude of the magnetic induction is determined from the expression B 0.005 to 0.007 sin l where B is the magnitude of the magnetic induction. T;

a - the current value of the sinusoid angle of the welding current.grad.

Due to the fact that the growth of the thickness of the oxide film occurs in proportion to the increase in the magnitude of the welding current in the half period

Vj

About WITH

WITH

Yu

(I

direct polarity, the change in the magnitude of the magnetic induction is proportional to the sine of the current sinusoid angle of the welding current.

Example, Automatic argon-arc welding of aluminum alloy AMgb plates with a thickness of 4.5 mm by tungsten electrode was carried out. The plates were assembled end-to-end with a technological gap between the edges of 1.0 mm. The presence of a technological gap in the joint of 1.0 mm promotes the formation of oxide captivity in the seam, which facilitates their detection by x-ray control. For the implementation of the method, a nozzle-solenoid and a thyristor synchronous current interrupter were used for supplying the solenoid windings.

The influence of welding modes on the quality of joints is presented in the table.

The total extent of oxide films and dispersion of oxide inclusions were determined on all welds of the welded plates.

The total length of oxide captivity per unit length of the weld was determined by x-ray control. The dispersion of oxide films was determined by fracture of the cr / p-sutures using a binocular microscope.

Evaluation of the tightness of welded joints was carried out using the probe method according to OST 92-1527-89; pressure of air-helium mixture of 0.1 MPa with a helium content of less than 40%. The leak detector PTI-7A recorded leaks up to 1.3 10 W.

For this purpose, automatic argon-arc welding of aluminum alloy AMGB plates with the size of a tungsten electrode was additionally carried out.

-

mm and a thickness of 4.5 mm with the minimum possible gap in the joint (80.2 mm).

Welding was performed in mode: Ice 210 A; VCB 12 m / h; Bi 5 B2 4-10 3; Bur 8

.

ten

15

20

25

thirty

35

40

After welding by milling, the reinforcement and weld melting were removed, after which a leak test was performed.

In the welds made by the proposed method, there were no leaks at Bi and occurred at Ba (1-2 leaks) and Vz (3-4 leaks). When the seam is formed unevenly, the number of defects exceeds their number as compared to Вг.

The proposed method is simple to implement and allows effective action on oxide inclusions, leading to their destruction during welding of aluminum alloys. The method allows to obtain welded joint welded joints and improves the quality of manufactured products.

Claims (1)

Invention Formula The method of arc welding of aluminum alloys with a non-consumable alternating current electrode, in which the arc and the metal of the weld pool are affected by a longitudinal alternating electromagnetic field, characterized in that, in order to improve the quality of the welded joints, the alternating magnetic field is supplied at times of direct polarity of the welding current with the frequency and duration of the pulses of the direct polarity of the half periods of the welding current, and the magnitude of the magnetic induction is determined from the expression B 0.005 to 0.007 sin a where B is the value of magnetic induction, T; a - the current value of the sinusoid angle of the welding current, deg. I I hail /14 Ti #w 7i "