And the allowable current range is reduced.

Thorium tungsten electrode is the earliest rare earth tungsten electrode used, and it is also the tungsten electrode with the best welding performance so far, so it occupies the highest market share in the world.

However, the production of thorium tungsten electrode is restricted by European and American countries because of radioactive pollution in powder metallurgy and calendering, but its use is not restricted because of its excellent welding performance.

Thorium-tungsten electrode contains thorium oxide (Th02 or thorium oxide), which is the most commonly used tungsten electrode in the United States and has become the standard to judge the quality of other tungsten electrodes. However, many users have turned to other options because of the low-level radioactive hazard of this tungsten electrode.

Generally speaking, 2% thorium tungsten electrode is a good tungsten electrode with the lowest work function, which works well even under overload voltage. The performance of thorium tungsten electrode is superior to that of pure tungsten electrode in many aspects. Thorium oxide provides about 20% higher current carrying capacity than pure tungsten, and generally has a longer service life, which is more helpful to prevent pollution during welding.

Using thorium tungsten electrode, it is easier to start the arc, and the arc is more stable than pure tungsten electrode or zirconium tungsten electrode. Thorium tungsten electrode 1%(EWTh _ 1) and thorium tungsten electrode 2%(EWTh _ 2) can be used for DCEN.

They keep their tips sharp during welding, so they can be used to weld steel pipes, and usually do not need direct current, because it is difficult to keep the tips spherical without cracking during welding, which is necessary for direct current.

Refer to the above content: Baidu Encyclopedia-Thorium tungsten electrode description is incorrect.