SU1540989A1 - Method of arc welding of butt welds of thin-sheet elements - Google Patents

Abstract

The invention relates to arc welding of butt joints of thin-sheet structures in protective gas with a non-consumable electrode, mainly automatic, and can be applied in various fields of engineering for welding sheet structures. The purpose of the invention is to improve the quality of welded joints and the stability of the welding process. In the process of welding, the elements to be welded are assembled on the lining so that the flanged edge of the first element is located in the forming groove of the lining, and the edge of the second element is joined to it on the outer side of the flange directed towards the electrode. The angle of inclination is 30 - 60 °, and the amount of flanging is (1 - 2) S, where S is the thickness of the material. As a result, a welded joint of a nominal geometric shape with smooth transitions from the weld to the base metal is obtained, the process of initiation and burning of the arc stabilizes, which improves the quality of the joint. 1 dw., 2 tab.

Description

The invention relates to arc welding of butt joints of thin-sheet structures in the environment of protective gases with a non-consumable electrode, mainly automatic.

The purpose of the invention is to improve the quality of the welded joint and process stability.

The drawing shows the welding scheme for the proposed method.

The welded elements 1 and 2 are assembled on the lining 3 so that the flanged edge of the element 2 is located in the forming groove of the gasket 3, and the edge of the element 1 is joined to it along the outer side of the flange directed towards the electrode 4. The assembled joint of the elements is fixed by pressing keys 5 Welding is carried out with a non-consumable electrode without filing the filler metal with complete melting of the flanged edges. Strengthening and melting of the weld are formed by smoothing the flanged edges. The amount of flanging edges (/) and their angle of inclination (a) determine the geometrical dimensions of the weld and are within the following limits: the amount of flanging / (1-2) 5, where S is the thickness of the parts to be welded, and the angle of inclination of flanging wasps 30-60 °

When flared to less than 15, there is not enough metal in the junction to form a seam of nominal cross section and undercuts are formed. When flanging more than 25 in the joint, there is an excess of metal to form a seam, incomplete melting of the lower edge and distortion of the cross-sectional shape of the weld occurs. When flared with an angle of less than 30 °, the flanging edges extend into the peripheral portion of the seam, and non-fusions or undercuts are formed. When flanging with an angle of more than 60 °, the lower edge melts incompletely and distorts the shape of the weld.

Example 1. Welded sheets of aluminum alloy AM-2M with a thickness of 2 mm

O1

4i

ABOUT

co oo co

by flanging the edges at an angle; the amount of flanging (t) was 1, 2, 4 and 5 mm. Welding was performed on the installation of automatic argon arc welding with tungsten electrode without filing the filler wire. Weld samples were assembled on a lining with a forming groove. Welding modes are listed in Table. one.

Table 1

140 150

18 18

The quality of welded joints was assessed by external inspection. When the flanging is less than IS, an uneven seam is obtained, due to a lack of metal, the seam is weakened in the upper part. When the flanging is more than 2S of the sheets to be welded, incomplete melting of the lower edge is observed; as a result of an excess of metal, the seam is formed with an influx.

Example 2. Welded sheets of aluminum alloy AMG-2M with a thickness of 2 mm with flanging the edges at an angle of (a) 25, 30, 45, 60 and 65 °, the amount of flanging in mm. Welding was performed on the installation of automatic argon arc welding with tungsten electrode without filing the filler wire. Weld samples were assembled on a lining with a forming groove. Welding modes are listed in Table. 2

Experiments have shown that good quality welded joints were obtained.

25

150

4 3

3 3 2

150 150

140 140 140

140

effort at the top Good seam formation

Incomplete melting of the lower edge, non-fusion in the root of the seam

with flared edges at an angle a 30-60 °. When the flanging angle was less than 30 °, an incorrect formation of a seam was observed in the form of non-fusion of edges along the edges of the seam. When the angle is more than 60 °, a distortion of the seam shape was observed, the seam is formed unevenly with a large gain.

The quality of welded joints was assessed by external examination, X-ray control and microsection studies.

Control results show that the weld is formed without internal defects with a normal macrostructure. The use of the method allows to obtain high quality welded joints of a nominal geometric shape with smooth transitions from the weld to the base metal, significantly stabilizing the processes of welding arc initiation and burning, as a result of which the amount of scrap decreases.

and increases the life of the structures.

table 2

10-12

10-12 10-12

10-12 10-12 10-12

10-12

The fusion of the lower edge, the distortion of the seam shape

Satisfied form stitch The seam is formed the correct form

P

Satisfied formation

seam

Seam shape distortion

Claims (1)

Claims The method of arc welding of butt welds of thin-sheet elements, in which the abutting edges are flanged and assembled on a lining with a forming groove, characterized in that, in order to improve the quality of the welded joint and stabilize the process, the flanging is made at an angle of 30-60 °, the edges they join along the outer side of the flanging with the exit of one edge into the forming groove, and the other towards the electrode, while the length of the flanging is 1 - 2 thickness of the sheets being welded.