CS260103B1 - Method of simultaneous multi-electrode surfacing,especially for fittings' sealing surfaces - Google Patents

Abstract

The purpose of speaking is to increase productivity work to obtain a high quality weld and reducing the possibility of deformation, especially small works and minimal burns elements. This purpose is achieved by turning the arc between the main tubular electrode and base material is added at least one additional an electrode that is a tubular electrode.

Description

The invention relates to a method of simultaneous welding with multiple electrodes, in particular sealing surfaces of fittings.

It is known that tubular electrodes are also used for welding the sealing surfaces of fittings, anti-seize layers, anti-corrosion coatings. Various technologies are used, such as an argon shielded electrode, or argon-carbon dioxide mixed gases, an electrode fed into an arc burning between a tungsten electrode and a base material using argon, a plasma electrode fed into a flame arc, and a flux tube electrode. The disadvantage of most of the above technologies is the relatively high heat input into the weld deposit, which is directly related to the depth of the weld and the percentage of misalignment with the base material. For these reasons two or more weld deposit layers must be selected to achieve required properties of the overlay layer.

Essentially, the present invention, which is a method of simultaneously welding multiple electrodes, in particular the sealing surfaces of fittings, wherein at least one additional electrode is added to the arc burning between the main tubular electrode and the base material, removes the disadvantages. tube electrode ·

The solution according to the invention achieves a higher effect by introducing less heat into the weld deposit, the depth of penetration decreases, even one layer of weld deposit is sufficient, the burn-off of individual alloying elements is reduced, the possibility of deformation is reduced reduces susceptibility to hot cracking and susceptibility to intercrystalline corrosion. Further, the welding speed is increased by 80-100% and by a possible combination of two or more tubular electrodes, the surfacing can be achieved over a wide range of desired properties.

An example of a specific embodiment of the method of simultaneous surfacing with multiple electrodes, in particular the sealing surfaces of the fittings according to the invention, is schematically shown in the drawing representing a surfacing device.

1, main contact tube 2, tubular electrodes 8 and contactless line 2 of additional tubular electrodes 6. The output of the power supply 1 is provided with a negative terminal 6 and a positive contact line 2 of the main tubular electrode 8 and a negative terminal 6 with the base material 11. The contact line 2 of the main tubular electrode 8 is provided with a feeding device 6. The contactless guide of the additional tubular electrode is provided with an independent feeding device 6.

After ignition of the arc 12 between the main tubular electrode 8 and the base material 11, the main tubular electrode 8 is fed by means of a feed device 8 and is melted by the arc 12. An additional tubular electrode (j) is supplied to the arc 12 burning between the main tubular electrode 8 and the base material 11 by means of an independent feeder. These additional tubular electrode 2 to be fed to the burning bblouku 12 main tubular electrode 8 side, front and rear direction of movement of the ^four main tubular electrode 8 which forms a welded material 10th

The invention can be used in gas shielded arc welding or in automatic submerged arc welding. When welding, it is also possible to use a swing or pulsation arc. Neither the use of different diameters of the electrode tubes to be fed, nor their different chemical composition, to achieve a weld deposit of the chemical composition is excluded.

Examples of tube electrode composition:

1. For valves for conventional IrfX power plant the following guideline:

C

Mn

Cr

W

1.2% 0.3%

27,5% 4,3%

,,, 61.7% and »0 5.0%

- 5 2, For artiBtury for nuclear power plants the following guideline composition:

C max ............ 0.11% σ>

/ 0

Mn ........... 4,6

Cr ............. 18.0

Si .......... 4.5

Ni ............. 8.0

Mo ............. 5.5%

Nb ............. 1.15%

B max · 2.0 · 2.0%

Fe ............. 56.54%

Example of welding parameters:

Arc voltage 52 «rff 59 V Arc current 560 or 450 V Tube electrode diameter 2.8 5.0 mm

Welding speed 22 sts 52 M / h.

In both examples of tubular electrode composition, the weld penetration by two electrodes was reduced to about 17% at real welding parameters. This percentage can be further reduced to 10% to 12% with perfectly optimized parameters. There is therefore not only a reduction in penetration, but also mixing with the base material and subsequent equal change and increase the quality of the weld metal.

The composition of the tubular electrode according to the example showed the degree of mixing of the weld deposit at the height of 5 mm from the base material. The simultaneous welding with two electrodes increased the percentage ratios of some elements against conventional welding as follows: .00%, W + 0.50%, Co + 1.00%.

Claims (1)

SUBJECT OF THE INVENTION Method of simultaneous welding with more electrodes, in particular sealing surfaces of fittings, where at least one additional electrode is added to the arc burning between the main tube electrode and the base material, characterized in that the additional electrode is a tube electrode.