中国精学生妹品射精久久,国产成人盗摄精品a片在线观看,天天躁日日躁AAAAXXXX,邻居漂亮的妻子5在线观看

Pure tungsten electrode is the earliest electrode that applied for argon arc welding, and it is only used as a welding electrode or a resistance welding electrode under AC conditions as this type of electrode is prone to appear the phenomenon of no arc or pilot arc instability under DC welding conditions. This problem can be greatly approved by adding rare earth oxides. Generally, the tip of pure tungsten electrode is spherical, and is used in the process of sine…

Tungsten electrode is referred to as an electrode made of tungsten. It can be classified in accordance with the color of the electrode tip. There are a variety of tungsten electrodes. Tungsten electrode is divided into various types such as pure tungsten electrode, thoriated tungsten electrode, cerium tungsten electrode, composite tungsten electrode, lanthanated tungsten electrode, and silver tungsten electrode, etc. It depends on whether rare earth additive is added or not. Some types of tungsten electrode are shown as follows:…