SU948588A1 - Method of welding cross butts of shapes - Google Patents

Description

(54) METHOD OF WELDING BOWL JOINTS OF SHAPED PROFILES

one

The invention relates to the field of welding, and in particular to methods of welding transverse joints of shaped profiles having vertical sections and overlapping their horizontal with thickenings in places of interface of sections, for example, Tauri, I-beams, and can be used in various fields of mechanical engineering.

There is a known method of automatic bath welding of parts of massive section, mainly rails, using cooled copper molds 1 to form a seam,

In this method of welding, the abutting rails are installed with a gap (12-15 mm) and welding starts from the base of the rails with two converging side electrodes. By the end of the weld welding, the sole feathers include a third, middle electrode (melting mouthpiece). Three arcs form a common weld pool, ensuring the penetration of the thickened middle part of the sole.

After welding the sole, the side electrodes are turned off, and welding of the butt of the neck and rail head continues with a mouthpiece. The welding process from the arc goes into electroslag.

This method is impractical for welding shaped profiles having thin (8–12 mm) vertical sections (walls).

The closest in technical essence and the achieved effect to the invention is a method of welding transverse joints of shaped profiles, mainly of T-section, including butt-butt assembly,

10 the implementation of the holes in the wall of the profile, the melting of the holes and welding first of the butt of the shelves, and then the joint of the walls 2.

The technologists of this method consist in the fact that profiles (I-beams) collect

15 without a gap, blind holes are drilled along the axis of the junction of the walls from the outer surface of the shelves to the wall, which are molded by the electroslag method. Then, the joints of the shelves and vertical walls with periodic turning of the product are successively made.

The disadvantage of this method, which guarantees the quality of the welded joint, is the lack of productivity associated with the operation of drilling a blind hole and their melting operation, which includes installing a head above the hole, filling flux, welding the hole, beating and slagging. The method is suitable for individual production. The aim of the invention is to increase productivity while ensuring welding quality. The goal is achieved by the fact that in the method of welding transverse joints of shaped profiles, mainly of T-section, including butt-end assembly, making holes in the wall of the profile, melting the holes and welding first the butt of the shelves and then the walls, after assembling, the butt of the shelves is welded simultaneously to two electrodes in the direction from their ends to the wall, then holes are made by stopping the closed electrodes at the wall and holding the process until a through hole is formed in the wall and the hole is sealed ti during subsequent weld junction wall. FIG. 1 shows profiles assembled for welding; in fig. 2 - profiles with welded seams of the shelves; in fig. 3 - section A-A of FIG. 2 in FIG. 4 (a, b, c, d) is the sequence diagram of the welding of the transverse joint of the profiles; in fig. 5 is a photograph of the macrosection of a two-sided welded seam of the shelf welded without forming a technological hole in the wall; in fig. 6 is a photograph of the macrosection of a two-sided welded seam of the shelf welded to form a technological hole in the wall. Technological way is sledstom. Weldable profiles 1 and 2 with pre-cut ends are joined with a gap

Welding upper single- 55-

850 shelf seams, alternately, 2-60 angles (on a flux-coated electronic gasket) with trodes, bypassing the mission to the wall

Welding Bottom One

800 of them seams electropolis (home weight) 94

42

35

thirty

20x12

25

42

Claims (2)

35 4 (3-5 mm), clamp and weld the lead-ins 3 at the beginning of ir and at the end of the junction of the shelves of profiles, for example, Tauri. Then, automatic welding is carried out in the lower position of the upper seam of the shelves with two electrodes 4 (Fig. 2, 3) starting from the lead-ins 3. During the welding process, the electrodes 4 are mixed simultaneously and at the same speed and stopped at the vertical wall at the interface with the shelf . After stopping the movement of the electrodes, the welding process is continued with a time delay sufficient to form a through-hole in the vertical wall. The width and height of the technological hole 5 should be such that the upper seam of one shelf is transferred to the upper seam by a single seam with the formation of one common seam with a cross section coefficient of the seam along the axis of the vertical wall eliminating the occurrence of crystallization cracks in the upper seam of the shelves. Partially welded profiles (Fig. 4a) turn over 180 and automatically weld the lower seam of the shelves (Fig. 46). The junction of the vertical walls is made by one of the methods of arc welding with turning the product for welding in the lower position (Fig. 4c, d). Example. Automatic welding was carried out of the butt of the half-beams of I-shaped profile No. 45M; welding without cutting edges; gap in the junction of 3-4 mm; welding wire 08GA diameter 3 mm; flux AN-348A. Current type is constant, polarity is reverse. Welding modes are presented in the table. Welding the upper seams of the shelf was performed on a special experimental 2-arc installation using 2 power sources VDU-1001. Welding of the lower seams of the shelf and two-sided welding of the vertical walls was carried out on the A-1401 serial automatic welding machine using the VDU-100 power source. Compared with the known method, specifying the welding technology allows, without reducing the quality of the welded joint, to increase welding productivity by 2.0. times by eliminating the operation of drilling a blind hole and the operation of melting it, introduced to eliminate incomplete penetration in the zones of interface between the wall and the shelves. In this method, complete penetration of the thickened zone of the profile is provided by the simultaneous thermal effect of two arcs when the welding heads are stopped at the vertical wall and the use of a two-sided shelf welding scheme. The need to create a technological hole is explained by the quality requirements of welded П1ва — the absence of crystalline cracks. Since the welded joint consists of a vertical section and a horizontal overlapping it with thickenings in the places of their conjugation during welding without forming a technological hole in the wall, the shape of the upper welded bore of the shelves (Fig. 5) is axially sectioned, wall (vertical section) perpendicular to the axis of the schva has an unfavorable 0-shape, contributing to the formation of crystallization cracks. When welding with the formation of a technological hole in a vertical wall, the shape of the upper welded groove of the shelf in the same cross section improves - there are no crystallization cracks (Fig. 6). This method makes it possible to create complex-automated production lines for the assembly and welding of transverse joints of shaped profiles such as a brand, an I-beam, for example, for the production of lightweight support beams of single-beam electric cranes. As a base object, we took the technology of welding cross-section of lightweight supporting beams of single-block electric cranes at the Zabaikalsky plant of lifting-transport equipment, which includes the following operations: trimming the ends of profiles, milling chamfers on the joined ends of profiles, semi-automatic welding of the joint in CO2 with periodic beams welding in the lower position, the installation of reinforcing plates on the transverse joint from the side of the shelves profile. The method has the following advantages compared with the base object: automate the welding process; eliminates chamfer milling at the ends of the joined profiles; eliminates installation and welding of the reinforcement plates. These advantages provide: improvement of the quality of the welded joint; reducing the labor intensity of manufacturing beams; saving metal and electrode materials. The expected economic effect from the use of the method at the Trans-Baikal PTO plant will be 92 thousand rubles. in year. Claims The method of welding cross-sectional joints of shaped profiles, mainly of T-section, including butt-assembling profiles, making holes in the profile wall, making holes and welding first the shelves and then the walls, characterized in that, in order to improve performance while ensuring welding quality, after assembly, the butt flange is welded simultaneously with two electrodes in the direction from their ends to the walls, then the hole is filled by stopping said electrodes against the wall and pulling out ki welding process to form the through hole in the wall of the hole and zaplavl dissolved during subsequent weld junction wall. Sources of information taken into account in the examination 1. USSR author's certificate number 197048, l. 23 K 31/02, 1967. 2. USSR author's certificate number 74043-CH l. In 23 K 9/18, 1980 (Protopsh). 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