English
TIG welding current types and welding polarities are as follows:
1: According to the output current type can be divided into: DC, AC, pulse three types of power supply output current.
2: According to the output current polarity can be divided into: DC reverse connection, DC reverse connection pulse, DC positive connection, DC positive connection pulse, sinusoidal wave AC, sine wave pulse, square wave AC, square wave pulse several types.
DC positive connection is suitable for welding low-carbon structural steels, alloy steels, bottom welding of pressure vessels, copper and copper alloys. The DC positive connection pulse is suitable for the welding of the above workpieces requiring precise welding and thin material.
DC reverse polarity, DC reverse pulse applications are less. It is only used for the welding of oxygen-sensitive metals such as aluminum and aluminum alloys, magnesium and magnesium alloys when there is no AC tungsten argon arc welding. DC reverse connection has a cathode crushing function. The reverse pole of the tungsten electrode is severely burned, and the arc stability is far inferior to the AC stability.
sinusoidal wave AC and Zenithal AC pulse are suitable for welding aluminum and aluminum alloys, magnesium and magnesium alloys. The latter is suitable for welding thinner workpieces than the former. However, due to the fact that the sinusoidal wave AC uses industrial frequency alternating current, the stability of the arc is poor and it is not suitable for precision parts and high quality welding.
The square wave alternating current is suitable for precision welding of aluminum and aluminum alloys, magnesium and magnesium alloys.
The square wave pulse is suitable for welding thin aluminum workpieces, and the frequency, duty cycle, base current, peak current, etc. can be adjusted respectively. It is currently the best way to weld aluminum and aluminum alloys, magnesium and magnesium alloys in tungsten argon arc welding.
