SU1310146A1 - Method of gas-shielded two-arc welding - Google Patents

Abstract

The invention relates to methods for dual-arc welding by a direct-current melting electrode, intended primarily for welding and surfacing doped metals in argon, which require a small amount of heat input to the base metal of the compound and a relatively large amount of weld metal. The aim of the invention is to improve the performance and quality of the weld metal by reducing heat transfer to the weld metal and making jet transfer of the metal. Welding is carried out in argon at the same time by arcs of direct and indirect action from two independent power sources. In this case, the arc of indirect action is carried out between the rod electrodes (E), and the direct arc is maintained between the activated E and the product. Non-activated E and the product are connected to the positive poles, and activated E to the negative poles of the power sources. The currents in the bar E are set equal to or higher than the critical, and the arc current with direct action is 15 1, (Pyr / oipjj-l), where Ij is the arc current of direct action, 1 is the current in nonactivated E; otp, d.p are the melting coefficients of unactivated and activated E, respectively. Due to the balancing performance of the melted rod E and the additional melting of the base metal, the required dimensions of the weld pool are obtained. 1 ill., 1 tab. and (L co 4 05

Description

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The invention relates to arc welding and surfacing in argon at a direct current current and can be applied in the manufacture of metal welded structures from alloyed materials and the surfacing of parts surfaces, where a small amount of heat input to the base metal of the compound and a relatively large amount of weld metal is required.

The aim of the invention is to increase the productivity and quality of the weld metal of the weld by reducing heat input to the weld metal while ensuring jet transfer of the metal.

In argon, welding is performed simultaneously by a direct and indirect arc from two independent power sources, an indirect arc burns between rod electrodes, and a direct arc between activated electrode and product, the unactivated electrode and product are connected to the positive poles, and an activated electrode to the negative poles of the power sources; in this case, the currents in the electrodes are set to be equal to or higher than the critical, and the direct current arc is

,

 J Cip

where p is the melting coefficient

non-activated electrode j d f, - melt ratio

activated electrode I is the current in the non-activated electrode.

The rationale for the chosen dependence is the presence of a critical current when welding to the reverse polarity of almost all known metals and alloys in argon, except materials with high vapor pressure, such as brass. At this current, the large-drop metal transfer sharply transforms into a small-drop jet. Direct polarity current when the electrode is a cathode, steady jet transfer of metal is obtained by using an activated electrode. However, this metal transfer is carried out at currents higher than from the anode electrode.

five

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To obtain jet transfer simultaneously with the electrodes of the cathode and the anode current. in the cathode electrode is increased by creating a straight arc

5 actions, whereby the melting performance of the rod electrodes is balanced and simultaneously the base metal is additionally melted, as a result of which

0 the required size of the weld pool, contributing to the best formation of the seam. The use of direct and indirect arc allows one to regulate the heat input to the deposited metal and its pregreve and thereby prevents the burnout of alloyed. elements, and the jet transfer of metal helps to improve the conditions of formation and crystallization

0 weld metal.

The drawing shows a diagram of the device.

The circuit includes a melting non-activated electrode 1, an activated electrode 2, between which a welding power source 3 is installed. A second power source 5 is installed between product 4 and electrode 2.

I 0 The first power source is connected.

the positive pole to the non-activated electrode 1 and the negative pole to the activated electrode 2. The second source 5 is connected by a positive 35 pole to the product 4 and by the negative pole to the activated electrode 2.

The method is carried out as follows.

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Pre-set the feed rate of the electrodes 1 and 2, corresponding to the critical current or above it for welding at the inverse polarity. Argon is supplied to the arc burning zone. The power supplies 3 and 5 are turned on and the voltage is applied to electrodes 1 and 2 and product 4. At the same time, an arc of indirect and direct action is ignited and the activated and non-activated electrodes are fed at a constant speed. In electrode 1, an indirect arc current 1 is set to be equal to or higher than the critical one, characterized by a jet transfer of metal. The magnitude of the current Ij of the direct-acting arc is established by the value providing the jet transfer of the metal in the activated electrode 12.

31

Example. Two-arc surfacing of rollers was carried out on plates made of steel 12Х18ШОТ with an SV-06X19N9T electrode wire with a diameter of 1.6 mm in a protective atmosphere of argon. The electrode-cathode was surface activated by carbon dioxide layers of cesium and sodium in the ratio of 6: 1, the coating weight was 0.03% by weight of the wire. The arc was powered by two PSG-500 independent welding transducers. The surfacing speed is 40 m / h. The welding parameters of the welding mode were produced by electronic and switch instruments with simultaneous recording of electrical parameters by an H-115 oscilloscope. The nature of the metal transfer and the behavior of the arcs was recorded by high-speed filming. The quality of the seam was determined by visual inspection and by macro and micro sections.

Pgon was supplied to the arc burning zone. Between the electrode wires supported arc indirect action. The non-activated electrode served as an anode, and the activated cathode. The current in the non-activated electrode was set equal to 260 A, which corresponds to the critical current in argon of the CB-06X19-H9T welding wire with a diameter of 1.6 mm. A stable process with jet transfer of metal from an activated electrode to a product was provided with an arc of direct action, a current of 1,114 A was set, and a current in the activated electrode was 374 A. At the same time, the weld bead had a fine flap, and the metal structure of the fine-grained bead.

The implementation of the method under different welding conditions is given in the table, which includes the initial data and the corresponding quality indicators. The critical current for a non-activated electrode CB-06X19H9T with a diameter of 1.6 mm is 260 A, and for an activated direct polarity 320 A

As can be seen from the table, high-quality seams are obtained when maintaining pro64

The welding process at the currents corresponding to the critical currents from the electrode.

The use of the welding method ensures a reduction in the fading of the alloying elements as a result of controlled heat input, an improvement in the crystallization conditions due to the jet transfer of the metal and a reduction in the loss of the electrode metal

and splashing.

Claims (1)

Invention Formula  two-arc welding in shielded gases by direct-current arc arc of direct and reverse polarity, located along the weld axis, one of which is an activated electrode, characterized in that, in order to increase the productivity and quality of the weld metal, reducing heat input in the deposited metal and the implementation of jet transfer of metal; welding is conducted in argon at the same time as an arc of direct and indirect action from two independent power sources, while the arc of indirect action t The VIA is supported between the activated electrode and the product, the unactivated electrode and the product are connected to the positive poles, and the activated electrode to the negative poles of the power sources, the currents in the electrodes are set equal to or above the critical, and the direct arc current is selected from the ratio -ABOUT. (P2 where p is the melting coefficient of the non-activated electrode i - melt ratio of the activated electrode; -current in the non-activated electrode. P2 318 88 18.0 13.4 312 52 16,0 13.4 260 37A 114 16.0 11.6 300 A70 141 16.7 12.0 Close-drop metal transfer, large-seam seam, coarse-grained weld metal structure. Jet transfer of metal from the anode, coarse transfer from the cathode. Large-seam seam, coarse-grained weld metal structure. Inkjet transfer from both electrodes, small-flaked suture, fine-grained structure. Inkjet transfer from both electrodes, small-flaked suture, fine-grained structure. Editor A.Gulko Compiled by G. Tyutchenkova Tehred N.Glushchenko Proofreader M.Sharoshi (. Order 1851/12 Circulation 976 Subscription VNIIPI USSR State Committee for inventions and discoveries 113035, Moscow, Zh-35, Raushsk nab., 4/5 Production and printing company, Uzhgorod, Projecto st., 4