SU1199526A1 - Method of welding u-joints - Google Patents

Abstract

A METHOD FOR WELDING TIRE COMPOUNDS of aluminum alloys with a three-phase arc with non-constricting electrodes in a protective gas medium with a wall thickness of 3-8 mm, in which the wall is made at an angle of 45 ° C; technological ledges to the surface of the shelf, install a wall on the shelf and melt the projections, positioning the welding torch electrodes obliquely to the surface. one after another in the direction of the welding speed vector, characterized in that, in order to improve the quality of welded I joints by improving the weld formation conditions, the first electrode (L is tilted at an angle of 25-30, followed by angle of 60 - 70 ° 0 N5 O)

Description

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The invention relates to electric arc welding by three-phase arc with non-emitting electrodes in a protective gas environment B can be used mainly for automatic welding on technological protrusions of T-joints of alkaline alloys with a wall thickness of 3-8 mm.

The purpose of the invention is to improve the quality of welded joints by the best; the conditions of the formation of the weld reduce the cost of their manufacture.

The drawing shows a diagram explaining the method.

For the implementation of the method, there are the first electrode I of the welding torch, shelf 2, technological ledge 3, wall 4, the second electrode 5 of the welding torch.

The angle of inclination / 3 of the first electrode of the welding torch determines the intensive destruction of the oxide film from the surface of the shelf 2 and the protrusion 3 by the plasma flow, as well as the forced displacement of the molten metal droplets of the protrusion onto the wall 4 ..

The angle of inclination / 3 of the second electrode 5 ensures, by overcoming the surface tension forces, the forced flow of the molten metal from the wall to the shelf and the formation of fillets of the fillet weld. This can be explained as follows: the protrusion metal, melted by the arc from the first electrode, moves as a continuous stream of droplets onto the wall, where it is further heated by the arc burning between the first and second electrodes. Under the action of the arc from the second electrode, the metal flows from the wall, forming a fillet of an fillet weld.

Three-phase arc welding of tungsten electrodes in argon medium of samples of T-joints from Amg61 alloy with a wall thickness of 3 mm is carried out. Shelf thickness 6 mm, sample length 1m. Welding mode: current in electrodes 320 A, current in parts 550 A, welding speed 0.973 cm / s, argon consumption 0.25. Tilt angles first

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the electrode / and the second electrode / Zoo are equal to the boundary values of the proposed intervals, the middle of these intervals and the values are larger and 5 less than the boundary ones. After the end of welding, the amount of incomplete welding is measured at the point of contact between the butt and the wall (H), the deflection arrows (f), the angular deformation of the flange (f) fO and the presence of weld formation defects is determined. The results are shown in the table.

When the first electrode is tilted

15 at an angle of ft less than 25 °, the flow of plasma1 1 is displaced to the wall, increasing the amount of metal melted on it, which, under the second electrode per stack, causes

20 formation of undercut on the wall (example l). If / 5 is greater than 30, then the conditions for destruction of the oxide film from the surfaces of the protrusion and the shelf deteriorate (for a given angle of inclination

25 protrusion) and sharply increases the amount of lack of penetration (examples 5 and 7). In the case of the inclination of the second electrode at an angle of / b less than 60 force, the arc takes such a direction

3Q that the molten metal remains on the wall in the form of flows (example 6).

If 2 is greater than 70, then the force effect of the arc does not move in such a way that the molten metal of the protrusion moving from the wall does not fill the cavity resulting from the intersection of the planes of the protrusion and the shelf and the vertical plane of the wall, which increases v penetration and breaks the continuity of the seam. At the same time, an influx is formed at the point of transition from the weld to the metal of the shelf (example 5).

Based on the analysis of the results presented in the table, it can be concluded that high-quality compounds are obtained only when implementing the proposed method. The use of the proposed method of welding torch joints provides, in comparison with the existing ones, an increase in the quality of welded joints and a reduction in the cost of their manufacture. 0,60,710,05 0,80,730,052 0,850,740,055 0,90,760,056 2,11,250,085 0,80,70,05 31,20,08 Undercuts on the wall No No No | Undercut on the wall, (our paws on the shelf Sink on the wall No

Claims (1)

METHOD FOR WELDING T-BOARDS from aluminum alloys with a three-phase arc by non-quenching electrodes in a shielding gas medium with a wall thickness of 3-8 mm, at which technological protrusions are performed on the wall at an angle of 45 ° to the surface of the shelf, the wall is mounted on the shelf and the projections are melted by placing welding electrodes burners inclined to the surface. one shelf in the direction of the welding speed vector, characterized in that, in order to improve the quality of the welded joints by improving the conditions for the formation of the weld, the first electrode is tilted at an angle of 25-30 °, and the next one at an angle of 60 - 70 ° 92966 P '’P8