SU1508458A1 - Joint-forming device for resistance butt welding of pipe with plug - Google Patents

Description

 The invention relates to the field of contact welding and can be used to seal the fuel rods of nuclear power reactors in power engineering.

The aim of the invention is to improve the quality and stability of welding by equalizing the heating temperature of the inner contacting layers of the pipe and outer plugs, and

also increase stiffness and ienoso-. device durability, Figure 1 shows the device diagram (longitudinal section); Fig. 2 is a top view and a longitudinal section of the device with a shunt in the form of a tape from an alloy of high ohmic resistance; Fig. 3 is a top view and a longitudinal section of the device with shunts in the form of a hollow conical stud,

equal to each other. Consequently, the currents through the discharge plates, with the exception of the first, will be zero, and the currents through the pipe and shunt are distributed according to Ohm's law, i.e. inversely proportional to resistance. It was established experimentally that optimal and stable formation of welds within 1 × 2.5 (Y, when using 1 heat sink of 1 bronze plates Yar NBT as a material, is provided when the current through the shunt of the KUH sector is 0.3 -1.0 of the magnitude of the current flowing through the corresponding section of the pipe. Overheating of the shunt in the device is excluded because it is connected to all heat sinks.

ry 7 (figure 2) with the help of conical zaklek-20 plates and the current lead of the pipe.

8. Conical rivets 8 electric- Ability to change resistance

from an alloy of high ohmic resistance; Fig. 4 is a top view and section of the fixture for drilling holes and riveting the packages of the device blanks.

A device for welding pipe 1 (Fig. O with a plug 2) consists of an annular current lead 3, a heat of shkh metal plates 4 of an annular y-pole-holo DIiLnika (KUH) for heat removal from the weld zone. The heat removal plates have electrical contact with the pipe 1 and an annular current supply, as well as a shunt 5 (Fig. 2-3). The device is placed in an insulating sleeve 6. The heat sink plates 4 and the annular current lead 3 are interconnected in a sector

insulated from the connected parts with insulating conical bushings, 9. A washer GO is attached to the end of the rigidity enhancing device. Shunt 5 mokhet be made of foil (figure 2) or made in the form of a conical hollow stud (fig.Z). For example, Nichrome, Manganin, Fekral, etc. can serve as a material for 1ChUNTOV. those. alloys with high electrical resistance. Heat-removing plates are made of bronze, for example, VRNBT. The heat sinks on flat surfaces 35 are electrically insulated from each other. The insulating material can serve as plates of steel foil with a thickness of (O, 1–0.01) o, whose surfaces adjacent to the plates of 40 KUH are oxidized.

When welding pipe 1 with a plug 2, the diameter of which is larger than the internal diameter of the pipe, the pipe is clamped in the 45 device with KUH sectors until the sectors 7 are closed together. This ensures a tight electrical contact of the 4 KUH plates with the pipe 1 and an annular current lead 3. The separate KUH 4 plates are interconnected by pipe sections that have RTP resistance by shunt sections with resistance Ntsch. . , К7р.п (Фйг «О, 55

50

a R

UI, KUIJ. "R

q ,,, the potentials at the nodal points of the pipe and shunt, due to the leakage of the current Iirp through the pipe and through the current jute 1m

50

5 5

0

A shunt (by selecting the material, cross section, etc.) ensures such a welding mode, which eliminates the overheating of the materials being welded and ensures the quality of the welded joints obtained. After clamping the pipe, a pulse of welding current is supplied to the KUH and a weldable plug is deposited.

The shunt can be made in the form of a tape from an alloy with high ohmic resistance, for example steel 12X 18X10T. I iyHT in the form of a ribbon allows the resistance of the sector of the ring-cooler to be obtained in the order of 1-2 mΩ. The shunt can also be made in the form of a hollow cone stud. This shunt is convenient in the case when the resistance of sector 7 KUH should not exceed 600-800 ohms. The use of such a shunt increases the rigidity of the entire package sector, including the current lead. In addition, it is easier to fit the resistance values of the KUH shunts, which should be equal to each other, by drilling them out and being able to be replaced without disassembling the assembled sectors.

The thickness range of the foil with the oxidized surface used in the KUH to isolate the heat sink plates from each other is (0.1-0.01) {Y, due to the following. When the foil thickness is less than 0.01, electrically and electrically unstable is obtained, and when the welding current pulse is applied, the heat dissipating plates close together.

51

burrs formed in the manufacture (drilling, boring) sector.

If the foil thickness is greater than Opo j, it substantially decreases the heat dissipation of the plates of the X and the burning of the plates of the KUH to the surface of the welded pipe occurs, which is unacceptable. The use of steel insulating gaskets in KUH increases the wear resistance of the device.

The technology in the device is simple.

A package of blanks I1 (collet current supply, blackened heat sink on plate, insulated ferrule, stiffening washer) with an allowance of 6–8 mm in diameter is placed in conductor hub 12 (figure 4). It is covered with a cover with holes .53 and 14 are tightened through the holes in the cranks of the 3 B package of blanks, through holes are drilled, they are unrolled with a tapered sweep, and conical shunts and tapered insulated rivets are pressed into them and riveted riveted pack The em is removed from the conductor, cut into three parts and in special mandrels in the folded state of the collar, the front door is bored and: Shugri.This technology provides the need for fixing, processing precision and obtaining the required resistance of the device sectors (the latter is checked by micro-metron)

The procedure for obtaining an insulating oxide layer for heat-removing plates is standard. The resulting blackening phase has a thickness in the order of fractions of a micron and an electrical resistance of 20-100 ohms. Steel pads made of oxydresor foil are also in accordance with the standard technology of microfusion oxidation. Riveting technology is simpler and more reliable than bonding.

The device allows you to improve quality and stability (by

seams) of butt welded joints, and thus improve the quality and-; reliability of sealing tpalov- energy nuclear repktorov.

Claims (3)

1. Device for fprmmropaki joints in butt welding of pipe c. agl P11ko t, soldering ring annular lgG; tokppo.i pd and put nygy- in xyyyenuk (. Chёmnuga clip from .Isol1.1 of a single helmcryptl TIPS REFERING - stop-cold-to, all-year-round vice, packages that are interspersed between themselves, have been isolated. each other; zi; ryi i metal .parts ;, p.rneidnku lnny axes of the opening of the shaft of the up-cooler cooler, which is so that, in order to improve the quality and stability of welding , increasing the reliability and wear resistance of the device, it is equipped with electrically insulated rivets and an electric 1m shunt, connecting the plate plate of the cooler pack to the RING CURRENT 730DOM. 2. The alignment of the n.J, which is due to the fact that the electrical tupts of each sector of the ring cold-supports stand out in the form of a tape made of an alloy of high resistance ohmicheskogo, shirshgoy, exceeding the height of the sector of the ring stop is 1.5–2 times that of the ring between the outer shell: noBeiix of the ring stop of the refrigerator and the inner cylindrical surface of the sector of the insulating cage. 3. The device according to n.i, is of the same, because, with the goal Improving reliability, it is made on a tapered hollow bird made of high ohmic resistance, with STOM in the plates of which. tsenovy emphasis refrigerator and ring - A continuous cone through hole is made through which the shunt is pressed. 1508458 / f-X FIG. Yu A-A