The method of welding with non-consumable electrode shielding gas

 

(57) Abstract:

The method can be used when welding thin materials. Legumineuses material is fed directly into the area before welding arc to stabilize at welding speeds of more than 70 m/H. the Invention improves the performance of the welding due to the stabilization of the arc at high welding speeds. 1 Il.

The invention relates to a welding method, mainly for welding thin materials.

Known welding method [1] non-consumable electrode shielding gas, wherein the gas ow occurs through the gas-permeable ceramic-forming substrate with the aim of improving the uniformity of gas flow in the weld zone before the arc.

The disadvantage of this method is that it does not provide stabilization of the arc at high welding speeds, which leads to poor welding performance.

Known welding method [2] non-consumable electrode shielding gas when the blanks are assembled with a large gap, in which is placed a metal having a lower evaporation temperature compared with welded metalloelastase is, that it is applicable primarily for welding thick materials, and also the introduction in the welding zone of foreign material modifies the chemical composition of the weld breaking the homogeneity of the welded connection. The metal having a lower evaporation temperature and has a lower strength properties, which does not allow for ravnopravnosti connection.

Known welding method [3] non-consumable electrode shielding gas with the introduction of oxygen in the weld zone.

The disadvantage of this method is that it eliminates wandering anode spots only for cases pre-oxidation of the edges or filler wire, which is virtually unacceptable in most cases. When welding thin materials (i.e., when the arc length of 1.0 - 2.0 mm) the introduction of oxygen in the weld zone, especially in a certain place, it is impossible.

In addition, it is known [4] that the plasma arc has a swirling motion in a closed circuit, the cathode-anode-cathode, and the outer casing of the arc with a temperature of 6000 - 8000oC is a direction from the anode to the cathode and, consequently, the oxygen inevitably falls on the cathode (tungsten) and leads to its fast the gases, when legumineuses substance fed into the combustion zone of the arc through a nozzle to stabilize the position of the welding arc and productivity of welding.

The disadvantage of the prototype is that this method does not allow to stabilize the welding arc at high speed welding. This is explained in the following. With increasing welding speed due to the fact that the metal directly under the cathode does not have time to melt, the anode spot starts to lag, and the curvature of the arc column. Because this method legumineuses substance surrounds the arc from all sides, the arc continues to stabilize around the anode spot. At the further delay of the anode spot is arc break and a new anode spot on the shortest distance from the electrode.

The task, which is aimed by the invention, is to increase the productivity of welding due to the stabilization of the arc at high welding speeds.

The solution of this problem is achieved in that in the method of welding with a consumable electrode in inert gases with the introduction of legumineuses substances in the welding zone unlike promotee welding speeds of more than 70 m/h

The essence of the method is illustrated in the drawing, which shows a diagram of the way.

Products for welding is collected as follows. For the lining 1 install gas-permeable porous ceramic-metal strip 2, between them there is a clearance section 2 x 1 mm for feeding a mixture of Ar and legumineuses substances. Then on the gasket set svarivaemost product 3. Down the welding torch 4 with the electrode 5. After ignition of the arc 6 is a welding process with the formation of a welded seam 7.

A specific example of implementation of the method.

During welding legumineuses substance enters the combustion zone of the arc across the gap between the welded edges. But due to the fact that in the process of melting metal, this gap disappears, legumineuses substance will flow only in the area in front of the welding arc. Part legumineuses substances will be carried away by a stream of plasma at the leading edge of the arc, and the rest to deflate protective gas coming from the burner, as shown in the drawing. The part legumineuses substance, which is supplied to the welding arc to ionize the space in front of it, thereby to seduce her in the direction of the Leno next. At speeds less than 70 m/s welding can be performed without the use of legumineuses substances. And when welding speeds over 70 km/h because of the lag the anode spot welding arc will be interrupted and will continue to experience poor penetration and other defects. Therefore, without the use of legumineuses substances welding would be difficult.

Thus, the claimed invention improves the stability of the welding arc during a welding speeds over 70 km/h and, therefore, to provide a higher welding productivity.

Sources of information

1. Japan's bid 61-46393, MKI4B 23 K 9/16, 1986.

2. Japan's bid 60-174267, MKI4B 23 K 9/16, 1985.

3. A. C. the USSR 284214, MKI B 23 K 9/16, 1968.

4. The magazine "Welding production", N 7, 1982, "a Mathematical model of the free surface of the welding arc S. 4 - 6.

5. Patent GDR 40155, MKI3B 23 K 9/16, 1982.

The method of welding with a consumable electrode in inert gases, including the introduction legumineuses substances in the welding zone, characterized in that legumineuses material is fed in the area immediately before the welding arc to stabilize at welding speeds of more than 70 m/H.

 

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