What are the applications of tungsten electrodes

Tungsten electrodes are used for TIG welding. These are tungsten alloy strips made by doping tungsten matrix with about 0.3%-5% of rare earth elements such as cerium, thorium, lanthanum, zirconium, yttrium, etc., through powder metallurgy, and then pressure-processed. The diameters of tungsten alloys range from 0.25 to 6.4 mm, and standard lengths are from 75 to 600, with the most commonly used sizes being 1.0, 1.6, 2.4, and 3.2 diameters. The shape of the electrode end is an important factor for TIG, when using DCSP, the electrode end needs to be ground into a pointed shape, and the tip angle changes with the range of applications, electrode diameter, and welding current, narrow joints require a smaller tip angle, when welding very thin materials, the need for low-current, needle-like minimum electrode for stabilizing the arc, and the proper ground electrode ensures that it is easy to arc, good arc stability, and the proper ground electrode is suitable for welding. The proper grounding electrode ensures easy arc initiation, good arc stability and proper weld path width. When welding with AC power, there is no need to grind the electrode tip, because when using the proper welding current, the electrode tip will form half a sphere, and if the welding current is increased, the electrode tip will become bulb-shaped and may melt and contaminate the molten gold.

With the development of tungsten electrode inert gas shielded welding and expand the application of tungsten electrode research is more and more in-depth. In the plasma arc welding, cutting and non-fusion pole tig welding, the past are used thorium tungsten electrode, but due to the radioactive effects of thorium (the dose of its ray up to 3.60 × 105 curies / kg), will damage human health and pollution of the environment, so that the cerium tungsten electrode with cerium oxide content of 2 to 4% instead of thorium tungsten electrode. In DC positive connection tig welding, cerium tungsten electrode is easy to start the arc, electrode burnout is less, the allowable welding current density than thorium tungsten; and in AC tig welding, cerium tungsten electrode burnout than thorium tungsten electrode, cerium tungsten electrode selection of the allowable range of welding current is smaller than thorium tungsten electrode.

Thoriated tungsten electrodes are easy to operate and work well even at overloaded currents, and there is still a lot of use for this material, which is seen as part of quality welding. Despite this, people are gradually turning their attention to other types of tungsten electrodes, such as cerium tungsten and lanthanum tungsten. The trace amount of radiation produced by the thorium oxide in tungsten thorium electrodes has made some welders reluctant to go near them.