SU1224127A1 - Nonconsumable electrode - Google Patents

Description

2. Electrode according to claim 1, about tl and - due to the fact that, in order to increase the resistance of the electrode when operating on currents, a voltage of 300 A; The invention relates to gas-shielded (predominantly inert) welding 5 and specifically to non-consumable electrodes, and can be used in areas of engineering in which this welding method is used.

The aim of the invention is to create a non-consumable electrode design that has technological versatility and allows to increase the penetration depth of the welded edges by stabilizing the power of the welding arc in a wide range of current loads.

FIG. 1 shows an adjacent electrode, general view; FIG. 2 is a section A-A in FIG. 1; Fig. 3 is the same for electrode5 used as a cathode in gas-thermal coating.

A non-consumable electrode consists of a tube 1 and a refractory insert 2p pressed into it, made, for example, of tungsten, zirconium or hafnium. In order to increase the electrical contact, an external surface of the insert 2 is applied 5, for example, by using a gas-thermal spraying thin film layer of an electrically conductive coating. The tube is made primarily of copper. On the tube from the bottom end, at the place of insertion of the refractory insert 2, the grooves 3 are uniformly arranged in the longitudinal direction of the tube, the tube under the insert 2 is flared / and the outer surface is ribbed (wavy) in the area of the insert. An increase in the diameter by flaring at the place of installation of the insert is produced by an amount not exceeding two wall thicknesses, and the angle of transition from the small diameter of the gas supply tube is filled in the wall of the tube from the direction of insertion of the refractory insert.

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The diameter of the insert should be no more than 30 °. If the angle oL is more than 30 °, the flow of protective gas through the grooves 3 is insufficient to cool the refractory insert 2 ”

The refractory insert 2 contains in the center along its own axis a cone-shaped channel 4, the diameters of the openings of which are at the outlet d 0.1-0.3, and at the exit d 0.4-0.6 and diameter D of the refractory insert. The ratio of the cross-sectional area of the grooves 3 to the cross-sectional area of the orifice d at the exit of the insert is 2: 1–8: 1, and the ratio of the diameter of the outlet orifice and the length of the cone-shaped channel to provide the thermal inset insert is set to 15. The loads on the refractory insert are proportional. The value of the ratio is determined experimentally and depends on the value of the required value of the injection created by the flow of protective gas exiting through the cone-shaped channel. In the process of exit of protective gas (stream 5) through the channel under the influence of injection forces, external threads 6 compress the welding arc, thereby making it possible to increase the concentration of its thermal power in the welding zone. To further stabilize the arc on the tube, from the side of the insert 2, a visor 7 with a height h equal to 0.4 of the diameter D of the insert and with an inclination not exceeding 15G at the same time diameter D must be specified in the ratio Q ,, 5 d, t. e. depending on the diameter of the outlet hole 51 of the cone-shaped channel. When working with current loads above 300 A tube 1 from the side of the insert 2

may contain grooves 3 inside the wall (Fig. 3). This increases the contact area between the insert and the tube. For more intensive cooling, a cooling jacket 8 is carried out. During operation, the ratio of the diameters d and d is changed by changing the diameter d, depending on the material being welded and its thickness. For this purpose, a funnel 9 is installed inside the channel 4, which in the upper part contains bulges made at the entrance in the form of a half ring (a torus protruding from the insert 2 into the inside of the tube 1 by an amount equal to the radius of the funnel in the zone of thickening. The radius of rounding is half the thickness of the funnel.

The electrode works as follows.

Install it with a tube 1 in the welding torch of the standard type and clamp using collet. Set the welding mode. For example, for steel grade SP 28 W with a thickness of 5 mm, the insert diameter D is set to 6 mm, d 1.2 mm, d, 3.0 mm, the welding current is 220-250 A, the voltage across the arc is Ug 11-12 V. during the welding process, a complete protrusion of the edges to be welded is obtained, as compared with solid bar electrodes, during welding with which the melting of the edges is not more than 80% of their thickness. When welding, the flow of protective gas in

the torch is set as in conventional welding with electrodes w. For a specific example, the argon consumption in the burner is 10–12 l / min, the argon flow into the tube is 2–4 l / min (it should not exceed 30% of the flow rate in the burner). When stability is exceeded, the arc is disturbed.

The proposed electrodes can be used in gas-thermal deposition, while sputtering is carried out using standard plasma torches. A distinctive feature of the e-tc is that the powder and the carrier gas are fed into the plasma jet through a cone-shaped channel.

The use of the proposed electrode in production allows increasing labor productivity by 1.5–2 times by increasing the penetration depth and reducing the number of welding passes and reducing power consumption by more than 20% due to an increase in the utilization rate of thermal power. . In addition, when gas-thermal spraying with the introduction of refractory materials directly into the central part of the plasma arc, powders with a melting point of more than 2700 ° C are achieved, with single-vapor gases rather than mixtures being used as plasma-forming agents.

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Claims (2)

1. NON-MELTABLE ELECTRODE for welding in a shielding gas medium, consisting of a tube cooled by shielding gases, in which holes are made for supplying gas and a refractory insert pressed from the end of the tube, characterized in that, in order to increase the penetration depth of the welded edges and stabilize the arc power in a wide range of current loads by simultaneously directing concentrated shielding gas flows along the axis and along the outer surface of the refractory insert, gas supply openings are made according to the internal the surface of the tube at the insertion point of the refractory insert and are evenly distributed in the longitudinal direction along its lateral surface, and a cone-shaped channel is made in the center along the axis in the refractory insert, the diameter of the opening of which at the outlet of the insert is (0.1-0.3) d _fe , and ^ at the inlet (0.4-0.6) d _b , where Д _b is the insertion diameter ®, while the cross-sectional area of the holes made on the inner surface of the tube is 2-8 times larger than the area of the hole at the outlet of the channel, and the diameter of the outlet 15 and more times the length of the cone channel. SU n „1224127> 2. The electrode according to Claim. Characterized in that, in order to increase the resistance of the electrode when operating at currents of more than 300 A, openings for supplying gas are made in the wall of the tube from the side of the insert of the refractory insert. ί