SU1303314A1 - Method of arc welding of multilayer annular seams - Google Patents

Abstract

This invention relates to arc welding of annular multi-layer welds. The purpose of the invention is to improve the quality of the welded joint by reducing the unevenness of the thickness of the multilayer annular seams. The weld joint is divided into central angles, the number of which is equal to the number of passes. Welding is carried out with overlapping and displacing each subsequent passage relative to the end of the previous one in the direction opposite to the direction of the previous passage by the circumference of the sum i-1 of the corresponding central angles, where i is the sequence number of the passage. The amount of overlap is taken equal to the circumference of the corresponding central angle. To reduce the deformation of the enriched product, the joint may be divided into equal central angles. The method allows welding of drill pipes with locks by the automatic-submerged arc welding method. 1 hp f-ly. 2 Il. i (L

Description

The invention relates to arc welding of multilayer annular welds, mainly pipe joints, and can be used in the manufacture and repair of welded products.

The purpose of the invention is to increase the quality of the welded joint by reducing the unevenness of the thickness of the multilayer annular welds.

FIG. Figure 1 shows a diagram of the welding of an annular joint divided into five central angles of various sizes; in fig. 2 - the same, equal to each other.

The method is carried out as follows.

In multi-pass welding of annular welds with overlapping, stopping and changing the welding direction after each pass, the entire joint circumference is divided into n central corners, where n is the total number of passes. The starting point of each subsequent passage is shifted relative to the end of the previous one in the direction opposite to the direction of the previous passage by the circumference of the sum i-1 Corresponding central angles, where i is the order number of the passage. The overlap value is equal to the circumference of the corresponding central angle.

When splitting a joint into five unequal; The central corners (Fig. 1) of the beginning of the first passage should be located on one of the edges of any central corner, into which the joint is pre-divided.

The beginning of the first pass coincides with the point A j, but can be in any of the tog (ek A ,,.., A.). The overlap of the first pass ends with the continuation of the radius OA. the direction opposite to the direction of the previous passage, the circumference of the sum i-1 of the respective central angles. Since the second passage is brewed, then i 2. Then i-1 2-1 1, i.e., it is necessary to shift the circumference of one central angle. the end of the first The passage is located on one side of the center angle A OA (on the side OA), it is obvious that, taking into account the direction of welding of the first pass and the direction

five

0

five

0

five.

0

five

Lenin displacement, the beginning of the second passage is located on the other side of the central angle (on the extension of the radius OA). The end of the second pass after completing the overlap is located on the extension of the radius OAj.

During the third pass, the offset from the continuation of the radius OAj is performed within two central angles, since.

Thus, the displacement is performed within the central angle, and the central angle A, OAj.

On the extension of the radius OA-j-, the beginning of the third pass is found. The end of the third pass after the overlap spacing is completed; it is on the continuation of the OA radius. .

During the fourth pass, the offset is made within the central angles,,, A, OA2. On the continuation of the radius of the OA is located the beginning of the fourth passage. The end of the fourth passage coincides with the continuation of the radius OA, and the offset of the beginning of the nth passage is made within the central angles A., OA.2: A, OA,. On the continuation of the OA radius is the beginning of the p of the passage.

When the joint is divided into equal central angles (Fig. 2), the overlap of the welded seams and the displacements are performed similarly and provide a weld with the same thickness along the entire circumference with minimal deformations.

Example, Automatic flux welding of drill pipes with locks is made in two passes on the lining ring to the slotted wire Sv-08G2S with a diameter of 2 mm under the flux AH-3 i8A in the following mode Uo 24-28 V, f, 47.7 Hz (frequency

e.pectrode vibration), 2 mm (amplitude of the electrode vibration).

IU: Icg 120-160. A, and, c 20 m / h

After each pass, the welding is stopped to cool the weld and remove the slag crust.

Performing the welding according to the proposed method allows to obtain a smooth-bore, balanced drill string (0 of the A0 lock pipe) with improved exalvatiation properties.

Claims (2)

1. The method of arc welding of multilayer annular welds with overlapping, stopping the process and changing the welding direction after each pass, characterized in that, in order to improve the quality of the weld by reducing its thickness irregularity, the joint circumference is divided into n central angles, where n is about - the number of passes, the starting point of each subsequent pass is shifted I44 relative to the end of the previous one in the direction opposite to the direction of the previous passage, the circumference of the sum i-t of the respective central angles, where i is the sequence number of the passage, and the amount of overlap is equal to the length of the corresponding central angle. 2. The method according to p. 1, differs from the fact that, in order to reduce welding deformations, the central angles are taken equal to each other. cpue.i Editor I. Rybchenko Compiled by, Tyutchenkova Tehred A. Kravchuk Proofreader L, Pilipenko Order 1251/14 Circulation 976 Subscription VNIIPI State Committee of the USSR for inventions and discoveries 113035, Moscow, 1-35, nab ,, d. 4/5 Production and printing company, Uzhgorod, st. Project, 4