SU1837003A1 - Method and apparatus for automatic one-sided arc welding - Google Patents

Description

The invention relates to methods od. extraneous automatic submerged arc welding with reverse weld formation and can be used in shipbuilding, chemical, oil, transport, power engineering in the manufacture of welded sheet and hull steel structures.

The purpose of the invention is to reduce the labor of bone manufacturing panels and improving the quality of welds in single-sided welding.

In FIG. 1 shows a device for the implementation of the proposed method of welding; in FIG. 2 and 3 are, respectively, sections AA and BB in FIG. 1; in FIG. 4-6, respectively, section B B, G — D, D-D in FIG. 1; in FIG. 7 - section BB in an enlarged view, explaining the operation of the feed block rollers; in FIG. 8-10, respectively, the design of the forming device with a slider, a longitudinal axial section of the forming device EE and view G in FIG. 8; in FIG. 11 - a device for welding.

In the electrode part of the welding machine, the mouthpiece 1, connected with a mechanical copier 2 with a spring-loaded conical roller 3, is rigidly with <is single with the induction sensor 4. Suspension <. g. 5, connected to the welding machine by a flat rod (knife) 6, provides for holding and pressing the forming device to the joint at the welding site. On the suspension there is a cassette 7 with filler wire, the correct mechanism 8, tracking block 35 of the rollers 9 (see Fig. 7) with knurled work surfaces, a spring-loaded guide 10 and 11 leading the filler wire 12 into the gap, the rollers.

The forming device 13 has a housing 14 (see FIGS. (8, 9, 10) with supporting surfaces 15 parallel and located above the forming surface of the slider 16. The head part of the slider is connected to the housing by a hinge 17. And the forming part has the possibility of transverse, adjustable by screws In the front of the forming groove 18 there is a groove 19 for placing the filler wire under the joint at small gaps in the joint, and the recess 20 is a flux and slag accumulator, with the surface inclined towards the tail of the slider. a slider rigidly associated with a pneumatic vibrator 21 creates transverse oscillations of the slider 16 in the housing 14. The tail end of the slider beyond the displayed body-forming unit.

In FIG. 11 shows a diagram of a process for unilateral submerged arc welding according to the proposed method.

The device operates as follows.

During welding, the flux being washed in an alternating gap between the sheets being welded 22, the flux along the inclined surface of the flux and slag accumulator 20. enters the 10 melting space of the welding arc, feeding the slag protective layer between the arc and the slider and forming the slider groove, as it accumulates and displacement of slag by an arc from 15 drives. Welding in this case is carried out along the increased slag sublayer 23. Stabilization of the gap filling with molten metal and the depth of penetration of the joined edges is done by automatically adjusting the welding speed and the pulsating arc with two energy levels, and the welding speed and frequency of the welding current are changed: I am inversely collecting. to which gap at the junction.

When the tractor moves along a variable gap, the amount of immersion in the gap of the conical spring-loaded roller 3 of the mechanical copier 2 and the distance from the cut of the sensor 4 to the surface of the sheets to be welded, i.e. h ------ f (a) (see Fig. 2). The sensor signal, through a voltage divider, is fed to the control unit of the thyristor drive for moving the cart and, through the voltage-frequency converter, to the circuit of the thyristor power source of the welding arc. ·

Improving the formation of the reverse side of the seam with maximum gaps in the joint (6-10) mm associated with too much flux to the slider is carried out in the proposed invention as follows. Before welding in the mode of technological adjustment, the end 45 of the filler wire 12 from the cassette 7, Th. cutting the right rollers 8, the block rollers 9, the spring-loaded guide 10 and the winding 11 rollers are fed into the head groove 19 of the slider before the start of the drive 20. After 50, the suspension is pressed to the welded sheets with a force P.

The forming device is pressed to the joint by a spring-screw device with an force F. Depending on the size of the gap in the joint, the block-roller feeding the filler wire either presses it against the panel or not.

. The structural dimensions of the block rollers are selected in such a way that with a gap at the joint of 6-10 mm, a reliable pressing of the wire to the panel is ensured and its supply restricts the flux to the slide at the speed (-Vcb). Additive! Shows a favorable effect on the formation of a one-sided seam (filler wire diameter is 3-4 mm, welding flux granulation is 0.5-4 mm). Depending on the size of the maximum clearances at the junction and the thickness of the metal being welded, it is possible to use a symmetrical la block roller to feed two filler wires into the gap from the sides of both pieces.

As an additive, it is possible to use a flux-cored wire containing alloying and surface-active chemical elements that can additionally affect the metallurgy of the welding process and the formation of the reverse weld bead

I With small gaps in the junction, the wire is pressed out of the assembly-welding gap and recesses the spring-loaded rails. the driving and driving roller and lies in the groove of the slider, moving together with the forming device with the welding speed and without affecting its course.

Characteristic of the process of one-sided welding on a moving slider is | slagging of the forming groove ccj of the side of the head of the slider with the formation of a slag visor 24, which prevents the flux from entering the slider (and PFI welding by an increased slag sublayer in the drive). The activation of the flux supply to the melting space of the arc and to the slider, the transportation of slag and molten metal from the arc to the forming part of the groove, and the formation of the back roll in the crystallization zone are achieved due to the transverse vibration of the slider.

The location of the pneumatic vibrator 21, the frequency and amplitude of the transverse vibrations are selected so that a directed forced movement of the flux and the weld pool is created in the c + direction opposite to the welding direction, in the tail forming part of the slider.

The amplitude of the oscillations is regulated by the winnts (see Fig. 8). Forced feed of the drive with flux and slag forming knavki is carried out by means of the slider 16 vibration. Moreover, the slag goat is 24, which is formed by burning an arc with a low energy level (duty) with a melting space 1, which worsens the flux to the slider, and accumulates at the boundary of the melting space 1 flux is remelted upon transition of the arc to a higher energy level with a melting space П (main arc), which guarantees complete penetration of the edges of joined sheets without damage shaping device 5. wa, because the pulse is short-term (0.3-1.0) s, and provides a periodic restoration of the process of supplying flux and slag to the slider during the transition to the duty arc. The receipt of slag in the forming 10 part of the slider acquires a periodic nature, improving the formation of the roll of a one-sided seam.

Slag visor 25, formed during the combustion of the main arc, further 15 the welding process does not affect the formation of the seam. At the same time, the use of a pulsating arc in one-sided welding with a variable gap in the joint allows stabilization of the penetration of 20 edges and the formation of a reverse weld bead.

The dimensions of the storage ring are selected in such a way that the melting space 1 of the arc on duty overlaps the inclined 25 area 20 approximately half its length. The frequency, duration and amplitude of the pulses of the standby and main arcs depend on the size of the gap at the junction and the thickness of the sheets being welded and are selected empirically. Changing the welding speed and the arc pulsation frequency inversely proportional to the gap significantly stabilizes the heat input into the base metal, the penetration of abutting edges, filling the groove with electrode metal and the formation of a one-sided seam.

A groove with a cylindrical surface and linearly increasing in size from the beginning and towards the end of the slider facilitates the movement of the melt into the forming tail portion of the slider and its concentration along the axis of the forming groove, the free passage of the slider along the formed back roll without burrs, squeezing the slider from the welded sheets and obtaining the optimal geometry of the reverse side of the seam. The gap between the lower plane of the sheets to be welded and the upper surface of the slider created by the protruding supporting surfaces 15 of the housing 14 provides the possibility of lateral displacements of the slider under the influence of the vibrator 21 and reduces the likelihood of undercutting from the extruded by the arc on the periphery of the groove and the slag backward roller quickly hardening.

The length of the forming part of the slider is selected so that the temperature separation of the crystallizing metal of the weld pool (ΐκρ.Μ. = 1500 ° С) and the liquid slag located below it (Tm.sh = 11001250 ° С) at the maximum allowable clearances in the joint occurs in the rear region end slice of the slider in mode 5 draining from it of excess slag. The length of the forming part of the slider is determined by the expression where S is the thickness of the sheets to be welded;

Omake - the maximum allowable gap at the junction. fifteen

When the tail part of the bath crystallizes from below, when excess slag is removed from it, under the influence of hydrostatic pressure of its upper liquid part and vibration, it settles on the slider surface forming 20. The amount of slag necessary to protect the cooling roller from atmospheric oxygen is held on its surface by adhesion forces and on top. lean tension. .25

Due to the use of vibration, the zone of temperature separation of metal and slag turns out to be wide enough, which, while observing technological discipline during welding, eliminates the failures of the weld pool 30 and the outburst of metal c. slider on large zezorekh.

When welding at small and medium gaps in the joint, the formation of the back side of the seam occurs in the middle part 35 of the forming groove using vibration,

The dimensions of the reverse roller at large gaps differ by a slightly larger width (1.5-2.5) mm, since its formation 40 occurs in the wider part of the slider groove, but does not go beyond the existing tolerances.

An example of performing one-sided welding by a variable gap in the manner described by 4.5 is given in the table.

Claims (2)

Claim 1. The method of one-way automatic submerged arc welding with forced formation of the reverse side 50 of the seam on a slider moving with the welding head with a forming groove filled with flux, under which. an excess flux is created by the arc, welding is performed by a pulsating arc at two 55 energy levels, lateral vibrations are imparted to the slider, the welding speed and arc pulsation frequency are chosen inversely proportional to the gap between the edges, and the length of the forming part of the slider is selected 7-8 times longer than the arithmetic average of the gap and the thickness of the parts, characterized in that, in order to improve the formation of the weld joint when welding sheets with a variable gap, in the welding process when the gap exceeds the maximum tolerance In winter limit value delivery of flux onto the forming groove of the slider by feeding into it the filler wire from the head portion of the slider parallel to the forming surface at a rate equal to the welding speed, while reducing the size of the gap is less than the permissible value of the filler wire supply is interrupted. 2. Device for one-sided arc automatic welding of sheets, containing a welding machine equipped with a spring-loaded conical roller for measuring the welding gap and an induction sensor, and rigidly connected with. through the suspension, a housing with parallel supporting surfaces, in which a slider is installed pivotally with lateral gaps with an inclined recess in the head part, which passes into a forming groove located below the housing supporting surfaces, and also a slider oscillation generator in a plane parallel to the supporting surfaces connected to it the tail part, characterized in that it is equipped with a feed unit mounted on the suspension of the feed block of tapered rollers with knurling on the working surfaces, one of which is located along the axis forming · grooves, slider, cassette with filler wire, the correct mechanism, a spring-loaded guide roller with a guide groove and a spring-loaded roller for introducing the wire into the gap, connected to the head of the housing by a rotation axis perpendicular to the forming groove, and a rolling surface protruding above the forming surface of the slider in which a guide groove is made, placed along the axis of the forming groove in the head of the slider, between the inclined recess and the front end. I N ΙΠΝ 40 1L O G * »40 1L ιλφ о -S 'r *, -t cm co <»ΙΛ40 M3 tn 40 1 -ΐΐΛ4θΓ \ σ> lilt cm · »1 ЛГХ in 40 n * cn I I! t CM - »tn r · * Μ \ 4θ r ^ m Illi CM <tn r * 1 s α | 1 ¢ - s t | U X 1 1 X L) I 1 'a ®> 1 f about t 1 b a 1 1 y x 1 1 f Σ 1 1 a a f | 1 Q O s ί 1 x Θ · e I 1 .. . _______________________________________1 1 · g 1 1 σ i f about 2 i 1 g CL X I 1 x f • X I g 1 u about about f 7 ι Cl t and I a 1 1 1 ί. a) 1 ABOUT ϊ 1 x X L. 1 ί z E ABOUT 1 i a ABOUT about 00 f f ι ω Q Q X 1 1 b GO 1- F t I and X X and rm η 1 o Ts about a Ts 1 1 f μ ω ae about ABOUT At 1 I οι 0 b X n FROM X 1 1 1 N> 1 t R go 1 and from 1 14 X 1 about about 7 1 1 -S t f os <a from I 1 eleven- <" a X about t 1 x about. f X b f - ( ι q f from f υ = t Φ 1 1 g E = 1 about η X 1 12 about· about f a η X " 1 < 1 FROM U X X TO <0 t 1 e · 1 | Lc. ] 1 X 1 g f X F 1 1 N and X 1 I O <0 > ·> I 1 N a P I 1 and 1O Ts 1 1 <0 X ABOUT t 1 ΣΓ (0 from . 1 t l ί 1 n 1 ί and X t 1 o £ 1 eleven Q 1 o LE -g 1 * ω 1 CJ 1 and X i i - mom m m <l "31 1 t ια t t a J g o * i l f 2 1 1 f to Σ 1 1 C <> 1 <_> Σ 1 tn C4 tn О m-z · -4 tn m о cn g- * -T -4- U> 40 Note. Welding modes are given for welding low-alloy carbon steel wire with a diameter of b mm, at direct polarity for AN-37P flux. Welding was performed by a pulsating arc with a constant feed rate of the electrode wire. The duration of the pause and pulse were set on the regulator of the welding cycle the same. Fig. /. Aa Fig.Z