SU1466888A1 - Method of submerged arc welding of horizontal butt joint in the vertical plane - Google Patents

Abstract

The invention relates to submerged-arc welding of horizontal butt joints on the vertical plane of sheet steel structures and can be used in construction, shipbuilding, power plant engineering, etc. The purpose of the invention is to increase the productivity and quality of welding. On the automatic welding machine, two bunkers are placed — with a low-melting flux 3 in front of the electrode and with a refractory flux 4 in the area of the electrode. The bunkers are installed in the joint zone of the sheets, and the flux is held on the product by the plane 6. To prevent mixing of the fluxes, the bunker is equipped with a nozzle 7, feeding the flux 3 into the joint gap. After filling the gap with the flux 3, flux 4 is supplied with simultaneous excitation of the arc 10 and movement of the automaton along the junction. The low melting flux 13 melts in the gap in front of the welding arc, and the molten slag flows under the weld pool 11, creating a protective layer of slag in the root of the seam, which prevents air from flowing from the back of the joint. The refractory flux 4, having melted, forms a layer of viscous slag on the surface of the bath 11, ensuring the formation of the surface of the weld 14 without undercuts and sagging. The method provides high performance due to the exclusion of manual preparation, installation of forming pads or supply of protective gas from the back side of the joint. Welding of the joint is performed on both sides. The first pass is performed using two fluxes, and the second pass, on the reverse side, using only the refractory flux. The quality of the weld is ensured by the formation of a protective layer of flowable slag on the back side of the joint during the first pass. 5 il. S CL: O5 O5 QO CX5 00

Description

 The invention relates to arc welding; Under the flux of horizontal butt joints on the vertical plane of sheet steel structures and can be used in construction, shipbuilding, power plant engineering and other equipment sectors.

The aim of the invention is to increase: productivity and quality of welding. I FIG. 1 shows a diagram of the process I welding; in fig. 2 is a section A-A in FIG. ; I in FIG. 3 shows a section BB in FIG. one; in fig. 4 - i section BB of FIG. one; in fig. 5 - section; YY in FIG. one.

; Welding is performed as follows. ; On the welding machine set; two hoppers 1 and 2 with flux. The first: during welding, the bunker 1 is filled with light-: melting flux 3 of fine granulation,: forming flowable slag, and the bunker; The refractory flux 4 of the average granule: a, forming a viscous slag. Bunkers: 1 and 2 are installed in the joint zone of the sheets to be welded 5. The flux is kept in the zone: the joint in plane 6. Flux bunker 1; it is equipped with a wedge-shaped nozzle 7, which provides the flux 3 to the joint gap when the machine moves. After filling up: the gap with fine flux 3 to a certain depth, flux 4 is fed from the hopper 2 to the front surface of the welded sheets 5, creating a protective layer of the required height. The welding wire 8 is fed through the mouthpiece 9 to the joint to create the welding arc 10 and weld the welded edges of the sheets 5. In welding, the low-melting flux 3 melts in front of the gap; arc, and the resulting molten slag flows under the weld pool 11 of liquid metal, creating a protective layer 12 of slag: at the root of the seam, preventing air from flowing from the back of the joint. At the same time, the flux 4 melts on the front surface of the sheets 5, forming a layer of viscous scrap 13 on the surface of the weld pool and maintaining the liquid metal on the vertical surface with simultaneous formation of the seam 14 without undercuts and sagging.

The above method performs welding of horizontal joints placed on the vertical cylindrical surface of the air heater with a diameter of 9 m from steel grade 09G2S with a wall thickness of 20 mm. Butt joint is assembled with a gap of 3 mm. The first bunker of the welding machine, placed in front of the mouthpiece with wire, is filled with low-melting flux of the brand АN-8 of fine granulation with mp. 1,100 ° C and a viscosity of slag 0.1 P. Second bunker.

placed in the area of the mouthpiece with the electrode, is filled with a refractory flux FT-22 with a pl. 1450 ° C and a slag viscosity of 0.8 P. Welding is carried out with J-Sv-08GA wire with a diameter of 2 mm on the mode: 430-450 A welding current; 30-32 V arc voltage; 20 m / h welding speed; 15-20 mm overhang of the electrode.

The first pass is performed using two types of fluxes simultaneously (AN-8

0 and FTs-22). The second pass is performed on the back side of the joint using one flux of FC-22 grade.

As refractory fluxes, you can use fluxes of the types F1D-16, FTs-22,

g; AN-29, FVT-1, etc., and as low-melting fluxes - fluxes of the grades AN-22, AN-8, AN-348A, and others. It is recommended to use the following combinations of low-melting and refractory fluxes: AN-8--FC- 22; AN-22-FWT-1; AN-348-

0 -A-AN-25, etc.

The welding method involves the use of flux feeding means that prevent their displacement during welding. To do this, an outlet funnel in the form of a truncated cone is placed in a bunker with low-melting fluxes with the placement of an outlet opening on the surface of the sheets being welded.

The welding method provides high performance by eliminating the need for manual welding of the seam, installing shaping gaskets or supplying protective gas from the back side of the joint, and also allows you to perform joints without bevel edges along the gap in a horizontal position, which greatly reduces the weight

5 weld metal in welded joints. The required quality of the weld metal and the weld as a whole is ensured by the formation of a protective layer of slag at the end of the weld that isolates the molten metal of the weld pool from air and a layer of slag

0 on the surface of the weld pool, which ensures the retention of the liquid metal and the formation of the schv without surface defects.

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Claims (1)

Invention Formula The method of submerged-arc welding of a horizontal butt joint on a vertical plane along an open gap, characterized in that, in order to increase 50 of the productivity and quality of welding, the product is simultaneously supplied with low-melting and refractory fluxes, while the low-melting flux is fed into the joint gap in front of the electrode, and the refractory flux is ng the surface of the product to be welded in the area of the electrode offset. AA Fi.g.3 FIG L Fiz. Yr