SU1708556A1 - Multipass two-sided welding technique - Google Patents

Abstract

The invention relates to the welding of high-strength alloy steels prone to magnetization, and can be used in mechanical engineering. The goal is to improve the quality of welding and reduce the cost of auxiliary operations. In two-way multipass welding with a non-consumable electrode of longitudinal welds of the shells, the first pass is welded in the overhead position with the formation of a weld on the copper slider and using a magnetic shunt. A magnetic shunt is placed on the MEDI slider and ensures the contact of the shunt with both edges being welded. In the process of welding, the magnetic shunt is moved together with the copper slider synchronously with the movement of the welding arc. The method allows welding with a node of magnetic materials without demagnetization. 2 il. - ^ 'her

Description

The invention relates to welding and can be used in the welding of magnetic metals to eliminate the negative influence of magnetic fields.

The purpose of the invention is to improve the quality of welding and reduce the cost of auxiliary operations.

In figure 1, 2 presents the scheme for implementing the method.

Welding of high-strength alloy steels is carried out in three products) (ode. Welding is carried out with a non-consumable electrode in an inert gas medium without filler wire. The first pass in welding of longitudinal welds is carried out from the inside in the ceiling position, using a pulsating 50 Hz constant guaranteed welding penetration current. Before welding, shell 1 is put on console 2 and the required clearance is set

S between the edges Ki and K2 (figure 2). and also provide a permissible displacement of the edges in height and ensure that the edges are pressed to the console 2 by means of the clamps 3. Then a magnetic shunt 4 is installed. The shunt 4 is placed on the copper slider 5. The magnetic shunt 4 is filled with a U-shaped cross-section and made of a magnet material. The shunt is made up of separate sections. A current lead 6 is placed on the magnetic shunt, the fixing point of which is placed above the welding bath 7. After the welded joint and the magnetic shunt are prepared for welding, the first pass is welded from inside by the burner 8. During the first pass welding, the weld edges are completely penetrated, while the burner moves 8 perform synchronous movement.

magnetic shunt 4 together with a copper slider 5 and an additional current lead. The conductors are also fastened at the ends of T.

The welding method allows you to eliminate the closure of the magnetic field lines 9 in the gap S and transfer the closure of the field lines through the shunt 4 through the line 10. This eliminates the effect of the magnetic field on the welding arc. Moving the magnetic shunt synchronously to the welding torch allows in the welding zone to close the magnetic field lines through the shunt by constantly contacting the welded edges directly in the welding zone. The additional arrangement of the electric contact of the electric wire with a shunt excludes a change in the direction of the current and its uneven dispersion in the welded part. When welding by the first pass, the influence of the magnetic field on the welding arc is excluded. Improved welding quality and reduced costs for auxiliary operations. After the first pass from the inside, an additional two passes are welded from the weld metal of the first pass to the base metal: one from the side of the first pass from the first pass, the other from the front side, i.e. re at the first pass. Welding is performed on modes that ensure the overlap of the seam of the first pass in width.

The second and third passes are welded at a constant current. The second pass is welded autonomously with a self-contained torch.

Example. The shells were made of steel SP-28Sh with weld edges 5 mM thick. The first pass was welded using a pulsating current with a frequency of 50 Hz, a working pulse duration of 16.6 MS, and the magnetic shunt was moved at a speed equal to the welding speed. Welding modes: ICB 270-315 A; Punch 10-12 V: VCB 14-18 m / h. Second pass welding was performed in direct current in the lower position: ICB 190-200 A; Ufl 10-12 V: VCB 9 m / h. Third welding

the passage was made at a constant current: ICB 190-200 A: 10-5-12 V; VCB 9 m / h.

During the work it was found that the influence of the magnetic field is eliminated

with respect to the arrangement and movement of the magnetic shunt with the copper slider synchronously with the movement of the welding torch, in this case the contact of the magnetic shunt with both

weld edges.

Non-observance of technological methods leads to the induction of magnetic fields in the gap: the gap of the welded joint. As a result, under the influence of magnetic

the floor on the welding arc reduces the quality of the welded joints, eliminating guaranteed penetration. To eliminate the effect of the magnetic field, the need arises of the costs associated with demagnetization of the shells.

The proposed welding method allows welding the shells without demagnetization. Welding can be done in both directions.

thus eliminating idle passes. Eliminates the need to make technological hatches. Welding can be performed without process allowances in length. Excluded marriage caused

burn-throughs. Simplified welding equipment.

Claims (1)

The invention The method of two-way multipass welding with a non-consumable electrode, mainly longitudinal welds of shells made of steels prone to magnetization, in which the first pass welding is carried out in the overhead position with through penetration with the formation of a weld copper slider and the use of a magnetic shunt, characterized in that, in order to improve the quality of welding and reduce the cost of auxiliary operations, a magnetic shunt is placed on the copper slider and provide contact of the magnetic shunt with both edges being welded, and during the welding process the magnetic shunt is moved together with the copper slider synchronously with the movement Arc arc; Shg / 9 YU five Y //////////. Fig 2