DE2708618A1 - Multiple arc plasma welding using different polarities - permits exceptionally high speeds in welding steels, aluminium or copper - Google Patents

Abstract

Multiple arc plasma welding is effected using continuously burning d.c. arcs of different properties where adjacent arcs have opposed polarity, using protective media (I) and a plasma-forming gas (II). All arcs are ignited between nonconsumable electrodes (e.g. three electrodes) and the workpiece; or some arcs are formed between electrodes and the workpiece while another arc is created between a consumable electrode and the workpiece. The ratio: prod. of the current of two adjacent arcs:distance between these arcs, is >=6.103 A2/cm. (I) is pref. CO2, Ar, a gas mixture, and/or a welding powder. (II) is pref. a molecular gas, esp. CO2, for normal polarity; inert gas, esp. Ar; or their mixt. Used partic. for the welding of low alloy- and stainless steels-, Al and Cu. The entire thickness of joints can be welded at speed previously unobtainable.

Description

Process for plasma multiple arc welding by means of

continuously burning direct current arcs of different polarity The invention relates to the field of plasma processing of electrically conductive Materials and refers to a process for plasma multiple arc welding by means of continuously burning direct current arcs of different polarity Use of plasma-forming gas and protective agents and with arcs arranged in this way, that adjacent arcs have opposite polarity.

The invention is predominantly in the field of industry for welding of ferrous and non-ferrous metals applicable where maximum high speed for the whole Range of thicknesses using the known processes of arc fusion welding cannot be realized. In addition, the invention can be applied to various industrial fields in the manufacture of metal structures, as well as, in some cases, in heating and melting of fast moving Instructions for use reach.

It is well known that the single arc processes are proportionate marked low welding speeds, this results in a direct increase of the working tester on the electrode no proportional increase in the welding speed, There is considerable overheating of the material to be melted, resulting in losses the arc power increase, the night design disturbed and the quality of the Suture is deteriorated.

An increase in welding speeds with the activation of a Sufficient seam shaping and quality can be achieved by using multiple arc systems can be obtained from consumable and non-consumable electrodes.

Known: 'is a process for multiple arc welding with Using multiple consumable electrodes (Japanese Patent No. 7456, El. 123112). It is about the interaction of two arcs of light burning next to each other to close, these have different polarity and are on such at a distance from each other so that no common weld pool is formed.

Also known is a method for multiple arc welding means consumable electrodes in which a sol-.

chor distance between electrodes is set that is through Combine pain baths formed by individual arcs into a common sweat pool (see Uttrachi 60 MXessina JE. Thu-wire submerged arc welding of line pipe, weld. J. 19C'C 47, No. 6 475-481). This multiple arc welding process will applied when using welding powder as a protective agent.

For multiple arc welding processes using a melting electrodes fundamental disadvantages are characteristic: it is impossible to measure the amount of regulate the introduced heat output and the filler metal to be melted separately, what the implementation of the welding process for large thicknesses starting with 14-16 mm required and it does not allow to control the geometry of the seam.

It is a process for multiple arcing, tearing by means of non-melting Electrodes with arcs of the same polarity are known, which only in the case of a special arc stabilization is implemented.

At low currents, the arcs are stabilized by means of gas flows, whereas with large currents magnetic stabilization is necessary (copyright No. 238046, class 21 30/10, 21 30/14 of July 9, 1969. Publication. Glue Wolfram, Lehnert Güther, Liemek Gerhard, increasing the welding speed in the WiG process Electrode burner. "Welding and Cutting", 1970, 22, No. 10, 427-431).

The increase in the distance between the non-consumable electrodes in order to avoid the interaction of the arcs leads to the separation of the entire bath, which is why this welding process is not very effective.

For the known multiple arc welding processes using non-consumable Electrodes have the following disadvantage characteristic: 1. As a result, that in all known processes arcs of the same polarity are used, the working currents and the range of the thicknesses to be welded are limited.

2. Only inert gases can be used as protective agents, according to the nomenclature which restricts welding materials.

3. It is necessary to have additional equipments for magnesia tables Stable to use arcs.

The aim of the present invention is to eliminate the above enumerated disadvantages of the method for multiple arc welding by means of melting and non-consumable electrodes. The main aim of the invention is to create of such a method of plasma multiple arc welding, at the maximum Speeds in comparison with well-known arc welding processes, a maximum range of the thicknesses to be welded without edge preparation, a minimum Effort for every 1 running meter of seam, the applicability of the process for all metals and alloys, which are welded with the help of the heat of an electric arc. " can be welded are guaranteed.

The invention is based on the object of a method for Plasma multiple arc welding using direct current arcs of different polarity using consumable and non-consumable electrodes with such Specify parameters with which a stable implementation of the welding process in an unlimited range of work flows. Speeds, composition of the plasma-forming and preservatives by creating burning conditions and regime for arcs of different polarity is guaranteed.

The problem posed is achieved in that in the method for plasma multiple arc welding, by means of continuously: burning direct current arcs of different polarity under Use of plasma-stable gas and protective agents according to the invention, the welding material with electric arcs ignited between non-melting electrodes and welding piece is heated, or part of the arc between the non-consumable electrodes and the weldment and the other part between consumable electrodes and the weld piece is ignited, the currents of all arcs and dc spacing between the arcs can be adjusted in such a way that the behavior of the product from the streams of two side by side. located arcs to the distance between their axes are equal to # 6.10³A² cm-1.

With multiple arc welding by means of continuously burning Direct current arcs of different polarity can be molecular as a plasma stable gas and inert gases and their mixtures can be used. As molecular gases, the Use of CO2, H2, N2, O2 preferred.

The use of Ar and He is preferred as inert gases.

The use of Ar + He, CO2 as plasma-forming gas mixtures + Ar, Ar + N2, Ar + He, Ar + O2 are preferred.

The composition of the plasma-forming gas is determined by the Composition of the welding material and the polarity of the non-melting point Electrode determined. If the non-consumable electrode then reverse direct current rolarita - @@@ works, so is the use of molecular gas or mixture the same with the inert gas as the plasma-stable gas is not recommended.

In the case of plasma reversible light boep welding by means of con-polarity using molecular and inert continuously burning direct current arcs different gases or mixtures thereof as plasma-forming gases are used for protection of the common bath with the help of a gas atmosphere or a welding powder layer.

As a protective gas atmosphere, molecular and inert gas can se as well mixtures of which are used.

The preferred molecular gases are C02, H2, N2 and ° 2.

The use of Ar and He is preferred as inert gases.

The use of C02 + 02, CO, + Ar, Ar + He, Ar + 62 preferred.

The composition of the protective gas atmosphere is determined by the composition determined by welding material and filler metal.

All standardized welding fluxes and pastes can be used as protective agents are used, which under the 3 conditions of submerged arc welding by means of melting Electrode, the weld on the powder layer by means of consumable and non-consumable Electrode as well as in the protective gas atmosphere by means of non-melting Electrode is designed and applied. It is best to go for welding high-silicon long welding powder made of carbon and low-alloy steels, for welding high-alloy steels and copper silicon-arine welding powder and for welding aluminum welding fluxes and pastes based on chlorides and Use fluorides.

In individual cases, the use of a combined one is recommended Protection of the seam by welding powder and gas atmosphere.

The proposed method for multiple arc plasma I welding guarantees the highest performance compared to all other arc welding processes, a better seam formation and quality, stability and reliability in the whole Range of work flows.

The process performance in the proposed plasma welding process is through the possibility of independent regulation of individual and common Xrårme flows, due to the optimal distance between the adjacent arcs of different polarity guaranteed under conditions of a common weld pool.

The stability and reliability of the welding process throughout The range of the working flows is determined by the ratio of the product of the flows of two adjacent arcs to the distance between them, which is within the limits A 6-10 A2 cm 1 is maintained.

The electromagnetic interaction of the arcs is compensated one by changing their polarity and the Use of plasma imaging devices and protective agents.

In those cases when out and the conditions of training the joint no additional material or a small amount of the same If necessary, it is advisable to use the plasma arc welding process using non-consumable electrodes of different polarity. For example, when welding on the flanging of the edges.

In the cases when onjr'und the conditions of the GCSTA-1 "'doC the welded joint requires a 'considerable amount of filler metal, It is recommended to use the procedure for plasma multiple arc welding part of the non-consumable electrodes and part of the meltable electrodes To apply electrodes. For example in welding with edge preparation.

The filler material can be identical to in the first and in the second ball the base material or different from it z. The composition of the additional material is determined by the technological and operating characteristics of the seam.

To better understand the essence of the invention are the following Embodiments of the same given with reference to the accompanying drawings; In the drawings: FIG. 1 shows a method for plasma multiple arc welding using only non-consumable electrodes using the example of triple arc welding of steels, according to the invention; Fi. 2 Process for plasma multiple light welding using melting zones and non-melting electrodes on the 3eiQ'oiel the triple arc welding of steels and copper, according to the invention; Fig. 3 Process for plasma multiple light welding using only non-consumable Electrodes using the example of triple arc welding of Al and its alloys, according to the invention; Fig. 4 Process for plasma multiple light welding below Use of consumable and non-consumable electrodes using the example of the three-faced arc weld of Al and its alloys, according to the invention.

The process for plasma multiple light welding using of only non-consumable electrodes using the example of triple arc welding of steels consists of the following.

As can be seen from Figure 1, the negative poles of direct current sources 1 and 2 connected to non-consumable electrodes 3 and 4, respectively. The positive pole a direct current source 5 is connected to a non-shedding ßleXtrode 6. The non-melting electrodes 3, 4 and 5 are insulated from one another. The positive pole the power sources 1,2 and the ninuspole of the power source 5 are connected to a welding piece 7 connected.

Plasma-forming nozzles 8, 9 and 10 with central ICanai 11 serve as Means for stabilizing arcs 12, 13, 14. The plasma-forming nozzles 8, 9 and 10 are one below the other isolated. To the non-melting ones Electrodes 3, 4, 6 and the plasma-forming nozzles 8, 9, 10 are for contactless Ignition of welding arcs 12, 13, 14 high-frequency discharger 15 connected. The leading arc 12, the middle arc 13 and the rear arc 14 each have individual channels 16, 17, 18 for the supply of a plasma-forming Gas from gas bottles 19, 20, 21. A protective gas is supplied from a common protective nozzle 22 fixes and flows in a channel 23 from a gas cylinder 24.

If a welding powder is used as a protective agent, it gets out a bunker 25 directly on the welding piece 7. If necessary, with To weld filler metal, one makes of a feed device 26 for the Feeding of filler metal 27 Use.

The start of welding occurs in a specific sequence. First, arcs of normal polarity 12 and 14 from the electrodes 3 and 4 ignited to the welding piece 7. The original current value on the arc 12 and the arc 14 is based on the condition of stable running thereof and the absence of such electromagnetic interaction is chosen that one Deviation of the ele - ': fresh arcs from the electrode axis by more than .70 may result. The arc is then ignited at the same current value 13 reversed polarity, and the triple arc system becomes electromagnetic Balance. The currents at all arcs 12, 13, 14 brought on the same side. At the same time or with a certain Time delay sets its displacement relative to the workpiece 7 with the welding speed in cntgcgengeeotztor direction that is in Si. 1 is indicated by an arrow.

It is a variant of the simultaneous ignition of all welding arcs possible. However, in this case, it increases. electromagnetic interaction between the arcs and the permissible ignition current value at each arc must compared to the variant of the ignition of the welding arcs after an intermediate one are reduced, which the stability of the burning of the plasma arcs at low Currents worsened.

Welding using only non-consumable electrodes is depending on the requirements placed on the welded joint with feed or recorded without the addition of additional hydrogen. The filler metal does not carry current. The melting of the filler material takes place directly in the combustion zone of any one the welding arcs 12, 13, 14 take place. A protective gas is used to protect the weld pool, a welding flux or a combined protection against gas and welding flux at the same time applied.

The process of using plasma multiple arc welding of melting and non-melting electrodes using the example of triple arc welding of steels and copper consists in the following.

The negative poles of the DC power sources 1 and 2 (Fig. 2) are respectively connected to electrodes 3 and 4. Of the Positive pole of the direct current source 5 is connected to a consumable electrode 29 via a conduit 28, which is fed to the 'Gasamtbad with the help of a Mechanicmus 30. The non-melting ones Electrodes 3, 4 and the consumable electrode 29 are insulated from one another. The positive poles of the power sources 1 and 2 and the negative pole of the power source 5 become connected to a welding piece 31.

The plasma-forming nozzles 8 and 10 with the central channels 11 are used as a flittel for stabilizing the arcs 12 and 14. A protective nozzle 32 is used for the supply of a protective gas, which according to its composition of the protective gas for the arcs 12 and 14 is different, immediately to the burning zone of an arc 33. The plasma-forming nozzles 8, 10 and the protective nozzle 32 are isolated from one another. The high-frequency dischargers 15 become the non-consumable electrodes 3, 4 and the nozzles 8, 10, to the consumable electrode 29 and the welding piece 31 for contactless Ignition of the arcs 12, 14 and 33 connected.

The plasma arcs 12 and 14 have individual channels 16 or 18 for the supply of a plasma-forming gas from the gas bottles 21, 19. The Protective gas is fixed by the common protective nozzle * 22 and flows through the duct 23 from the gas bottle 24. That immediately to the, introduction zone of the melt-off probes Protective gas fed to electrode 29 flows through a channel 34 from a gas cylinder 35 a. When using a welding powder as a protective agent, the welding powder comes from the bunker 25, and gets directly to the Weldment 31.

The start of welding takes place in a specific sequence. First Line, the arcs of normal polarity 12 and 14 are ignited by the non-consumable Burn the electrode 3, 4 towards the welding piece 31. The original current value at the arcs 12 and 14 is based on the condition of stable burning the same and the absence of such electromagnetic interaction, which leads to a deviation of the welding arcs from the electrode axis by more than 70 leads. Then the arc 33 is discharged with the help of a high frequency the peeling-off electrode: 29 ignited towards the welding piece 31, and the forward pusher mechanism 30 for the supply of the melting electrode 29 is switched on. The arc ignition through a connection between the electrode and the welding piece is only possible under the condition if devices limiting the short-circuit current are used. After ignition The multiple light entry system turns all light into the electromagnetic Equilibrium, and at the same time the current at all light arches 12, 14, 33 allf brought the labor value. At the same time or with a certain time delay sets its displacement relative to the workpiece 31 with the welding speed for example, in the opposite direction, indicated in FIG. 2 by an arrow It is a variant of the simultaneous ignition of all welding arcs 12, 11S, 33 possible with the aid of the high-frequency discharger 15. Igniting the arc 33 between the melting electrode 29 and the weld 31 by closing between the electrode and the welding piece is only under the both sides possible if devices limiting the short-circuit current are used. However In this variant, the electromagnetic interaction between the two increases the arcs and the permissible ignition current value at each arc must be compared to the above retained variant of the ignition of the welding arcs after an intermediate one be decreased, which increases the stability of the arc burning at low Currents worsened.

The variant with r initial ignition of the lightbocenc between the consumable electrode and the welding piece can ignite the welding arc Help the short circuit too, however, requires the use of facility for Prograr control of the welding process, which ensures a stable burning of the welding arc guaranteed at low ignition current values at the moment of starting welding.

The process for plasma multiple light welding using of only non-melting electrodes using the example of triple-strand welding of Al and its alloys is shown according to a scheme shown in FIG out, which is similar to that of Fig. 1 and has the only difference that in this case the positive poles of the direct current sources 1 and 2 each to the non-melting Electrodes 3 and 4 are connected, the negative pole of the direct current source 5 to the non-consumable electrode 6 is placed and the negative poles cr sources; 1,: '2 and the positive pole of the Source 5 connected to welding piece 7 will.

Dns process for plasma multiple light welding using of melting and non-melting electrodes using the example of triple light welding from Al un.1 whose lieings are after a; in Fic. 4 shown scheme carried out, which is similar to that of FIG. In this case the polarity is the consumable and non-consumable electrodes have also been changed to the reverse.

For the realization of the plasma multiple light welding by means of electric arcs of different polarity in accordance with the examples described above the indispensable condition is the formation of a continuous weld pool.

To meet this condition, the arcs must be sufficient closely spaced from each other.

Here, the size of the ratio of the product of currents of arcs burning next to one another to the distance between them- amount, that is, it will be the relationship complied with, where I1 and I2 mean the current values of the arcs burning next to one another and 1 the distance between the axes of the same arcs.

The size 6.103 A2 cm 1 is minimally permissible and is due to special features the welding of small thicknesses.

@@ Example 1.

Welding of a beam with a rectangular cross-section nus two U-beams. The process is implemented according to the scheme shown in FIG. Depending on the working conditions of the wearer, one of the butt joints must be imperative have a seam reinforcement. The second butt joint is without seam reinforcement authorized. The connections represent one-sided intended for a passage Connections without bevelled edges. The welding material has the following composition, %: @ C # 0.12; Si = 0.17-0.37; Mn = 1.4-1.80; Cr # 0.30; Ni # 0.30; Cu # 0.30; S = 0.04; O = 0.035; the rest is Fe.

The thickness of the welding edges is 8 mm.

Welding without reinforcement is carried out according to that shown in FIG Scheme realized and carried out under the conditions when arcs of different The polarity between the non-consumable electrodes and the welding piece can be ignited. The number of the non-consumable electrodes is three. ve.

leading and rear arcs have normal polarity.

The middle arc has reverse polarity.

The plasma-forming gas of the leading and rearward light encounters normal polarity is carbon dioxide gas (CO2) which is the middle arc Argon (Ar). The consumption of the plasma-forming gas CO2 in the leading and the backward arc is 260 l / h.

The consumption of the plci-forming gas Ar in the medium arc is equal to l / h.

Carbon dioxide gas CO2 is used as a protective agent.

The consumption of the protective gas is 2,000 l / h.

As a protective means, the use of a welding powder is as follows or a similar composition in% possible: SiO2 = 41.0-44.0; EnO = 34.0-38.0; CaOZ 6.5; D'gO = 5, C-7.5; A2O3 # 4.5; CaF2 = 4.0-5.5, Fe2O3 <2.0; S <0.15; P <0.12.

Using the welding powder will improve the high-quality seam appearance achieved.

The working current of the lead arc of normal polarity is equal to 1150 A, the working current of the backward arc, is equal to 980 A, the The working current of the middle arc is equal to 780 A.

The distance between the axes of the arcs normal and reverse Polarity is 37 mm. The smaller ratio of the product of the two streams of adjacent arcs to the distance between the axes is 20.7.103 A2 cm 1.

The welding speed is equal to 390 m / h. When using the Mixture of C02 + Ö2 as plasma-forming gas in the leading and the rear arc normal polarity will detach the slag: and improve the appearance of the seam.

The other welding parameters remain unchanged.

The welded joint is formed by melting the Welding material. To compensate for the burn-up and other losses of Metal is supplied with a filler material of the following composition, in 5t: C = 0.05-0.11; Mn = 1.80-2.10; Si = 0.7-0.95; Cr # 0.20; Ni # 0.25; S <0.025; P <0.030; the rest is Fe.

Welding a butt joint with absolutely necessary reinforcement is according to the Sch @ given in Fig. 2 ma realized and under the conditions performed when the arcs of different polarity between Non-consumable electrodes and welded piece (carrier) as well as consumable electrode and workpiece $ and consumption values. The number of non-consumable electrodes is between the melting electrodes is one. The arcs between the non-consumable electrodes and the weldment have normal polarity. Of the The arc between the consumable electrode and the weldment has reversed Polarity. The compositions and consumption values of the plasmabilder.den Gascs, the compositions and consumption values of the protective agents are the same as well in the case of welding a butt joint without seam reinforcement.

The diameter of the consumable electrode is 3 mm.

The composition of the consumable electrode in ° J: C # 0.10; Mn = 1.4 ° -1.70; Si = 0.65-0.85; Cr # 0.20; Ni # 0.25; S <0.025; P <0.030; the rest is Fe.

The working current of the leading arc of normal polarity is equals 1150 A, the work current of the reverse light crossing normal polarity is equal to 30 A and the working current of the mean arc, 'that between the consumable electrode and the welding piece (carrier) burns is equal to 850 A.

The distance between the axes of the arcs normal and reverse Polarity is 37 mm.

The smaller ratio of the product of the two neighboring currents Arcs to the distance between the axis is 2 ^, 5,103 A2 cm 1.

The welding speed is 440 m / h.

When welding in the conditions when part of the arcing between non-melting electrodes and Switzerland piece (carrier) and the other Part of the arcing between the melting electrodes and the welding piece (carrier) is ignited, a gap between the welding edges within a range of 1-1.5 mm is permitted.

3eisniel 2.

Welding of vessels made of corrosion-resistant steel before 20 mm Thickness. Due to the manufacturing technology, one-sided welding of butt joints Provided in a single pass without bevel and with beveled edges. At the Welding without bevelling edges is not permitted to reinforce the seam.

The composition of the welding material in%: C # 0.08; Cr "17.0-19.0; Ni 3 9.0-11.0; Si C 0.8Q, Mn # 1.20; S # 0.020; P # 0.035. The rest is Fe.

Welding a butt joint without beveling edges is used according to realized the scheme shown in Fig. 1 and carried out under the conditions, when arcs of different polarity between non-consumable electrodes and weld piece (vessel) are ignited. The number of non-consumable electrodes is three. The leading and back arcs have normal polarity. Of the middle arc has reverse polarity. '' As the plasma-forming gas of the electric arcs normal and vice versa Polarity is used by argon. The consumption of the plasma-forming gas in each arc is equal to 180 l / h.

The protective agent is argon. The consumption of argon for protection purposes is 1 200 Ilh, the working current of the leading arc of normal polarity is equal to 1 100 A, the operating current of the reverse arc of normal polarity is the same 950 A, the operating current of the middle arc of reversed polarity is equal to 730 A.

The distance between the axes of the arcs normal and reverse Polarity is 37 mm. The smaller ratio of the product of the two streams adjacent arc to the distance between the axes is 18.7 # 10³ A² cm-¹.

The welding speed is 55 m / h.

When using the mixture 95% Ar + 5% H2 as plasma-forming gas in arcs of normal polarity the welding speed can be increased by 50-60% will. The other parameters of the process remain unchanged.

When using carbon dioxide gas C02 as a plasma-forming gas in Arcs of normal polarity can increase the welding speed by 1.5-2 times increase. The other parameters of the process remain unchanged.

The use of carbon dioxide gas for arcing of normal polarity as a plasma-forming gas and as a protective agent increases the welding speed by 2-2.5 times, but worsens the quality of the seam. That Carbon dioxide gas as a plasma-forming agent for arcs of normal polarity and as a protective agent is expedient to use in the event that the seam appearance does not have any strict requirements are imposed.

The protection of the seam material when using carbon dioxide gas as a plasma-forming agent for arcs of normal polarity leads to the improvement the seam appearance. In this case it is possible to reduce the consumption of the plasma-forming C02 gas on the leading and back arcs of normal polarity to increase and the melt depth up to 20% without changing the other parameters of the process. The acceptable composition of the Welding flux. in%: SiO2 = 19.0-24.0; MnO # 0.5; @@@. CaO = 3O-9.0; MgO w 9.0-13.0; Al203 - 27.0-52.0; Na2Q and K20 s 2.0-3.0; CaF2 = 25.0-33.0; Fe 2 O 3 <1.0; S # 0.08; P <0.05.

The welded joint is only formed by melting out of the welding material.

The welding of a butt joint with beveled edges is carried out according to realized according to the scheme shown in Fig. 2 and is carried out under the conditions when arcs of different polarity between non-consumable electrodes and welded piece (vessel) as well as consumable electrode and welded piece (vessel) be ignited. The number of non-consumable electrodes is two and that of consumable electrodes Elcktroden one.

The arcs between the non-consumable electrodes and the welding piece (vessel) have normal polarity. The arc between the consumable Electrode: and the welding piece have reversed polarity.

The compositions and consumption values of the plasma-forming gas, the compositions and consumption values of the protective agents are the same as also in the case of welding a butt joint without beveled edges.

The diameter of the consumable electrode is 5 mm.

The composition of the consumable electrode in%: C # 0.08; Mn = 1.0-2.0; Si = 0.3-0.8; Cr = 18.0-20.0; Ni = 9.0-11.0; Ti = 0.5-0.8; S # 0.018; P # 0.025; Mo = 2.0-3.0; the rest is Fe.

The working current of the leading arc of normal polarity 1 100 A, the working current of the reverse arc of normal polarity 950 A and the Working current of the middle arc 790-A.

The, distance between the axes of the arcs normal and reverse Polarity is 37 mm.

The smaller ratio of the product of the two neighboring currents Arcs to the distance between the axes is 20.3.103 A2 cm-¹.

The welding speed is 67 m / h.

The welding speed can be reduced when using molecular gases or gas mixtures of inert and molecular gases as a plasma-forming agent as well when using welding flux as a protective agent.

There is a 4-6 fold increase in speed achieved.

Beisnicl 3.

Welding of molds for vacuum arc and electrical slag remelting. According to the working conditions, the molds are used for vacuum arc remelting made of chrome bronze and made of copper for electro-slag remelting. The thickness of the welding edges 40 mm.

Welding the butt joint of a mold for vacuum arc remelting is implemented according to the scheme shown in Fig. 1 and under the conditions performed when arcs of different polarity between non-consumable Electrodes and welding piece (mold ') are ignited. The: number of non-melting Electrodes is three. The leading and the backward arc have normal polarity, the middle arc has the opposite polarity. The welding is carried out without beveling the edges. The welding material has the following composition in%: Cr = 0.4-0.7; Fe # 0.06; Pb # 0.005; Zn # 0.015; Mn # 0.002; Si # 0.05; P # 0.01; the rest is Cu.

As a plasma-forming gas for arcs of normal and reverse polarity serves argon. The consumption of the plasma-forming gas in each arc is 260 l / h. The protective agent is argon. The consumption of argon for protective purposes is 900 l / h. "The working current of the leading arc of normal polarity is the same 1 100 A, the working current of the reverse arc of normal polarity is pale 950 A, the working current of the middle arc is reversed Polarity is equal to 730 A.

The distance between the axes of the arcs normal and reverse Polarity is 37 mm. The lesser ratio of the product of the two streams adjacent arcs to the distance between the axes is 18.7.103 A? cm1.

The welding speed is equal to 11.0 m / h. As a plas ma-forming Means for arcing arcs of normal polarity and as a means of protection is use of nitrogen (N2). possible.

This increases the welding speed by a factor of two possible without changing the other welding data.

As a plasma-generating agent for arcing normal and reverse Polarity is wakeful while using the mixture 305'3 Ar + 70% He the seam protection is expediently carried out with argon. This is a high welding speed maintained and the quality of the connections improved Hold the highest vacuum seams, whose welding using the mixture 30% Ar + 70% He as plasmabildez of the means for arcing arcs of normal and reverse polarity and a welding flux is carried out as a protective agent of the following composition, in%: SiO2 - 30.0-32.0; Al203 = 20.0-22.0; MnO = 2.5-3.5; CaF2 = 20.0-24.0; ngO w 16.0-18.0; CaO = 5.0-6.5; FeO2 + Fe2O3 # 1.0; S # 0.015; P # 0.1.

The formation of the seam is due to the base material (visual welding material) and the additional material.

Consumption of the filler material with regard to burn-off losses and splash is minimal. The composition of the filler material corresponds the base material (SchwseisszerX-stoff).

The beveled edge welding of molds for electroslag remelting from copper containing up to 0.069 oxygen is shown according to FIG Scheme realized and carried out under the conditions when arcs of different Polarity between non-consumable electrodes and welding piece (mold) as well as Melting electrode de and welding piece (mold) are ignited. The number of non-consumable electrodes is two. The number of electrodes to be consumed is one.

The arcs between the non-consumable electrode den and the weldment have normal polarity, and the arc between the consumable Electrode and the welding piece has reverse polarity.

The compositions and consumption values of the plasma-forming gas as well as those of the protective means are the same as in the case of welding with three non-consumable electrodes.

The diameter of the consumable electrode is 5mm.

The composition of the consumable electrode in degrees; Si = 3.5; Mn = 1.5; Zn # 1.0; Fe # 0.03; Ph # 0.03; P # 0.05; Ni # 0.1; Bi # 0.002; the rest is Cu.

The working current of the leading arc of normal pole rity 1 100 A, the working trigger of the reverse arc of normal polarity 950 A, the working current of the middle lich arc 790 A.

The distance between the axes of the arcs normal and reverse Polarity is 37 mm. The smaller ratio of the product of the two streams of adjacent arcs to the distance between the axes is 20.3.103 A2 cx 1. The welding speed is equal to 15 m / h. The welding speed is at Application of plasma-forming and protective agents from molecular gases, for example N2, a mixture of inert gases, for example Ar + He as well as common Use of molecular, oxygenated gases and their mixtures in combination with Welding powder increased. A 4-6-fold increase in speed can be achieved here will.

Example 4.

Welding of low temperature equipment with a thickness of the welded edges of 30 mm. The process is carried out according to the one shown in Fig.

3 implemented scheme. The composition of the welding material is the following, in%: Cu # 0.02; Mg # 0.05; Mn # 0.025; Fe # 0.3; Zn # 0.3; Ti # 0.1; the The rest is Al.

Welding is carried out under conditions when arcing of different polarity between non-consumable electrodes and weldment be ignited. The number of the non-consumable electrodes is three. The leading c and reverse arcs have reversed polarity, and the medium arc has normal polarity.

The mixture of Argon with helium (Ar + He). The consumption of argon in a mixture 45 l / h, the consumption of helix in a mixture of 135 l / h. Argon is used as a protective agent. The consumption of argon for the protection of the bath is equal to 1,800 l / h.

The working current of the leading arc of reverse polarity is equal to 820 A, the working current of the reverse arc of reverse polarity is equal to 710 A, the working current of the middle arc of normal polarity is equal to 430 A.

The distance between the axes of the arcs normal and reverse Polarity is 32 mm. The smaller ratio of the product of the two streams adjacent arcs to the distance between the axes is 9.5 # 10³ A² cm-¹.

The welding speed is 20 m / h.

The welded joint is made by melting the base material shaped. Burn-off and spatter losses are caused by a wire of the following Composition compensated, in a,: Al P 99.97; Fe = 0.015; Si = 0.010; Cu = 0.005.

The welding speed can be increased by 15-2C% if in the plasma-generating agent of an arc of normal polarity is a molecular gas is introduced in a mixture with argon (Ar + O2). The other parameters remain unchanged.

Under the conditions when arcing as a plasma-forming agent normal and under-polarity the genic Ar + He serves, the protection of the Seam material brought about by a welding flux cr of the following composition are, in%: C1 P 50; NaCl = 28; LiCl = 14; NaF - 8.

In this case, the welding powder loosens the oxide skins and is refined the metal, however, is an additional operation to remove the welding flux residues in warm water required.

When conducting a welding process in which the plsma-forming Means of arcing of normal and reverse polarity consisting of argon alone, while the seam by welding powder of the composition given above is protected, the use of protective gas is also used for better protection Argon recommended. Here, the welding flux layer can be reduced, or they can be applied as a paste of the same composition.

Welding the cryogenic equipments under 3c conditions, when arcs of different polarity between non-consumable electrodes and welding piece as well as ignited between melting electrodes and smoldering piece is realized according to the scheme shown in Fig. 4 and with beveled Edges carried out. The composition and the thickness of the material are those similar when welding with non-consumable electrodes.

The number of the non-consumable electrodes is two.

The number of melting electrodes is one.

The non-consumable electrodes have reverse rolarity while the consumable electrode has normal polarity.

Serves as the plasma-forming gas in the arcs of reverse polarity Argon. The consumption of argon 220 l / h. - The protective agent is inert and exists made of argon. The consumption of argon 1,800 l / h. The working current of the leading arc 820 A, the working current of the rear arc 760 A, A, the working current of the middle arc 520 A.

The distance between the axes of the arcs normal and reverse Polarity is 32 mm.

The smaller ratio of the product of the two neighboring currents Arcs to the distance between the axles is 12.3.103 A2 cm 1 The welding speed is 38 m / h. The welded joint is made by melting the base material and the consumable electrode of identical composition.

The use of the mixture ar + Iic as a plasma-forming gas is effective to increase the welding speed by 30% with the other changed parameters of the process.

The protective agent is the gas mixture Ar + 02 or a welding powder applicable, the composition of which has been given above. The use of Ar as a plasma-forming gas on the arcs of reverse polarity and from Ar + C2 for the protection leads to an increase in the speed of silence and to beam transmission in the arc between melting Electrode and welding piece.

The use as a plasma-forming gas of argon or the mixture Ar + He in combination with a welding powder enables oxide-free welded joints to manufacture.

This involves an additional operation for removing the powder residues introduced by washing the products in warm water.

Claims (38)

Method for multiple plasma arc welding by means of continuously burning direct current arcs of different polarity Use of plasma-forming gas and protective agents and with arcs arranged in this way, that adjacent arcs have opposite polarity, characterized in that all arcs (12,13,14) between non-melting Electrodes (3,4,6) and the welding piece (7) are ignited, or part of the Arcs (12, 14) between the non-consumable electrodes (3, 4) and the welding piece (31) and the other part (33) between consumable electrodes (29) and the welding piece (31) are ignited with the currents of all arcs and the distance between the arcs are adjusted so that the ratio of the product from the Flow of two adjacent arcs to the distance between them> - 6.103A2 cm -1. 2. The method according to claim g, characterized in that as a protective agent a molecular gas, preferably carbon dioxide gas (CO2) is used. 3. The method according to claim 1, characterized in that as a protective agent an inert gas, preferably argon (Ar), is used. 4. The method according to claim 1, characterized in that as a protective agent a mixture of a molecular and an inert gas is used. 5. The method of claim 1, d a d u r c h G c X e r nz e i c h n c t that a welding powder is used as a protective agent. 6. The method according to claims 1, 2 or 1, 3 or 1,4, d a d u r c h g e k c n n n z e i c h n e t that a welding powder is used as a protective agent is used. 7. The method according to claims 1,2 or 1,3 or 1,4 or 1,5, d a it is noted that as a plasma-forming gas: £ for arcs normal polarity a molecular gas, preferably carbon dioxide gas (CO2) is used will. 8. The method according to claims 1, 2 or 1, 3 or 1, 4 or 1.5, d a d u r c h g c k e n n n z e i c h n c t that the plasma-forming gas is an inert Gas, preferably argon (Ar), is used. 9. The method according to claims 1,2 or 1,3, or 1,4 or 1,5, d a d u r c h e k c n n z e i c h n e t that the plasma-forming gas is a mixture a molecular and an inert gas is used. 10. The method according to claims 1, 2 or 1, 3 or 1, 4 or 1.5, wherein the consumable electrodes have a composition that is that of the composition of the welding material is similar. 11. The method according to claims 1, 2 or 1, 3 or 1, 4 or 1.5, wherein the decay electrodes have a composition different from the composition of the workpiece is different. 12. Procedure for. Welding of low-alloy steels according to requirements 1, d a d u r c h g c k e n n n z e i c h n c t. that when only non-melting electrodes are used as plasma-forming ones Gas and as a protective gas on the arcs with normal polarity carbon dioxide gas and on the arcs with reversed polarity is used as the plasma-forming gas argon. 13. A method for welding low-alloy steels according to claim 1, d a d u r c h e k e n n-z e i c h n e that when using only non-melting Electrodes as palsma-forming gas on the arcs of normal polarity form the mixture C02 + 02, in protective material C02 and on the arcs the polarity Ar is used will. 14. A method for welding stainless steels according to claim 1, d a d u r c h e k e n n n z e i c h n e t that when using only non-melting Electrodes as plasma-forming gas on the arcs of normal polarity, the other way round Polarity and argon is used in the protective agent. 15. A method for welding stainless steels according to claim 1, d a d u r c h e k e n n n z e i c h n e t that when only non-melting ones are used Electrodes as a plasma-forming gas on the arcs of normal polarity form the mixture Ar + R2, on the arcs the polarity is reversed and Ar is used in protective equipment will. 16. A method for welding stainless steels according to claim 1, d a d u r c h g e k c n n z e i c h n e t. the b use of only non-melting electrodes as; 'ësmåbildendes Gas on the arcs of normal polarity C02, on the arcs ur. reversed polarity Ar and in the protection means CG. 17. Ancestors of welding low-alloy and stainless steel Steels according to claim 1, d u r c h g k c n n z e i c h n e t, dald in use of non-melters the electrodes as plasma-forming gas on the arcs more normal Polarity C02, on the arcs with reversed polarity Ar and as a protective agent welding powder be used. 18. A method for welding copper according to claim 1, d a d u r c h g k k e n n n z e i c h n e t that when only non-consumable electrodes are used as plasma-forming gas on the arcs of normal polarity, reversed polarity and Ar is used in the protective agent. 19. A method for welding copper according to claim 1, d a d u r c h e k e k e n n n z e i c h n c t that with winsatz only non-melting electrodes at the arcs of normal polarity as a plasma-forming gas as well as in protective means N2 and Ar on the arcs of reversed polarity. 20. A method for welding copper and aluminum according to claim 1, d u r c h e k e n n n z e i c h n e t that when using only non-melting Electrodes on the arcs of normal polarity and reverse polarity as plasma-forming Gas the mixture Ar + Ile and Ar can be used in the protective agent. 21. A method for welding copper and aluminum according to claim 1, d a d u r c h g e k e n n n n z e i c h n e t, that using only non-melting elc '<trode as plas: "forming gas on the arcs normal and reverse polarity the mixture Ar + He and one for the protective agent Welding powder can be used. 22. A method for welding aluminum according to claim 1, d a d u r c h e k e n n n z e i c h n e t that when using only non-melting Electrodes as a plasma-forming gas on the arcs of normal polarity form the mixture Ar + 02, Ar on reversed polarity arcs and Ar in the protective device will. 23. A method for welding aluminum according to claim 1, d a d u r c h e k e nn n n n z e i n e t that when using only non-melting Electrodes as plasma-forming gas on the arcs of normal and reverse polarity Argon and as a protective agent argon and welding powder can be used. 24. A method for welding low-alloy steels according to claim 1, d a d u r c h e k e n n n z e i c h n e t that when using consumable and non-melting electrodes of normal polarity as plasma-forming gas the arcs of normal polarity and in the protective agent C02. 25. A method for welding low-alloy steels according to claim 1, d a d u r c h e k e n n n z e i c h n e t that when using consumable Reverse polarity electrodes and normal from non-slimming electrodes Polarity as a plasma-forming gas at the arcs is more normal polarity the mixture C02 + O2 2 and in the protective agent CO2 can be used. 26. A method for welding stainless steels according to claim 1, d a d u r c h g c k e n n n z c i c h n e t that with the use of skimmers Reverse polarity electrodes and normal electrodes for non-consumable electrodes Polarity as plasma-forming gas on the arcs of normal polarity and in the protective device Argon is used. 27. Method for the appearance of stainless steels according to claim 1, d a d u r c h E e k e n n n z e i c h n c t that when using consumable Reverse polarity electrodes and normal electrodes for non-consumable electrodes Polarity as a plasma-forming gas at the arcs of normal polarity the mixture Ar + 112 and in the protective agent Ar can be used. 28. A method for welding stainless steels according to claim 1, because d u r c h g c k e n n n z e i c h n e 1 that when using melting electrodes of reverse polarity and non-consumable electrodes of normal Polarity as plasma-forming gas on the arcs of normal polarity and in the protective device CO2 is used. 29. Process for welding stainless and low alloyed Steels according to claim 1, d u r c h e n n n n e i c h n e t that during use of decaying electrodes of reversed polarity and of non-consumable electrodes Electrodes of normal polarity as plasma-forming gas to the arc more normal Polarity C02 and for the cleaning agent ci @ welding powder can be used. 30. A method for welding i: upfer according to claim 4, d a e u R e k e k e k e n n n e i n e t that when using consumable electrodes reversed polarity and non-disruptive electrodes of normal polarity as. plas :: depicting Gns on the light gusts of normal polarity and in the protective agent Argon is used. 31. Ancestors for welding copper according to claim 1, d a du r c h g o k e n n z e i c h n c t that when using consumable electrodes reversed polarity and non-consumable electrodes of normal polarity read plasma-forming gas on the arcs of normal polarity and in protective equipment N2 is used. 32. A method for welding copper according to claim 1, d a d u r c h e k e k e n n n n e i c h n e t that when using consumable electrodes reverse polarity and normal polarity non-consumable electrodes as a plasma-forming gas at the arcs of normal polarity the mixture Ar + He and used in the protective agent Ar. 33. A method for welding copper according to claim 1, d a d u r c h e k e n n n z e i c h n e t, t that when using consumable electrodes reverse polarity and normal polarity non-consumable electrodes al plasma-forming gas at the arcs of normal polarity the mixture Ar + Re and a welding powder can be used for the protective agent. 34. A method for welding aluminum according to claim 1. d n d u r c h e a k e n n n z e i c h n e t that in use from fusing elelstrodes of normal polarity and non-fusing electrodes reverse polarity las plasma-forming gas on the arcs of reverse polarity and argon is used in protective agents. 35. A method for welding aluminum according to claim 1, d a d u r c h e k e k e nn n n e i c h n e t that with ir the substitution of consumable electrodes normal polarity and reverse polarity of non-consumable electrodes the mixture Ar as the gas that forms the gas in the arcs of reversed polarity + He and in the protective agent Ar can be used. 36. A method for welding aluminum according to claim 1 d a d u notices that when using melting electrodes normal polarity and reverse polarity of non-fusible electrodes as a plasma-forming gas on the arc of reversed polarity Ar and in the protective means the mixture Ar + 0 can be used. 37. A method for welding aluminum also claim 1 d a d u Notices that when using consumable electrodes normal polarity and reverse polarity non-consumable electrodes As a plasma-forming gas on the arcs of reversed polarity, the mixture Ar + He and a welding powder is used for the protective agent. 38. A method for welding aluminum according to claim 1, d a d u r c h e k e n n z c i c h n e t that when using consumable electrodes normal polarity and reverse polarity non-consumable electrodes as Plasma-forming gas on the arcs of reversed polarity Ar and Ar and welding powder can be used as a protective agent.