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In the arc welding, the tungsten electrode in arc discharge has great influence on the loss of electrode material, the stability of welding arc and the quality of welding, so the electrodes need to have the following properties. ① arc ignition is easy and reliable, the arc is produced at the front of the electrode and does not appear on the top of the cathode spots. The melting deformation and wear in the ② work do not make a big impact on the arc characteristics. The stability of ③ arc is good.Pure Tungsten Electrode
In the metal because tungsten has a very high melting point, can withstand very high temperature, in the larger current range fully equipped with the ability to transmit electrons, so TIG welding and plasma arc welding Select Tungsten as an electrode. such as Ng arc, plasma arc of the cathode current density, its operating temperature at the electrical extremes usually reach 3 $number K. At such a high temperature, the tungsten electrode itself will produce a burning loss. Therefore, it is very important to maintain the stability of tungsten electrode shape and reduce the burn loss of tungsten electrode.
The burning loss and shape change of tungsten electrode will bring the following problems. The change of ① shape will bring about the change of arc shape, affect the arc force and heat input to the base material. ② the welding of the important components will bring about the problem of the weld clamping tungsten. ③ affect the electrode life, need to change the electrode frequently, in addition, also involves the arc performance.Pure Tungsten Electrode
Tungsten Argon arc welding electrode materials used are pure tungsten, cerium tungsten and thorium tungsten pole, melting point is 3 400 ℃ above, and escape power is low, therefore has a strong electronic emission capacity, in recent years, better performance of new materials electrode is also in development. In order to ensure good arc-ignition performance and stable welding process, the electrode has lower escaping power, larger permissible current and smaller ignition voltage.Pure Tungsten Electrode
