2 Minutes to understand factors affecting welding arc stability

The stability of the welding arc refers to the extent to which the arc remains stable when welded.

Influencing factor

(1) Welding power source
The higher the no-load voltage of the welding power source, the better the field emission and field ionization, so the
stability of the arc is higher. 

(2) Welding current and arc voltage
When the welding current is large, the thermal ionization of the arc is stronger, and more charged particles can be
generated, and the arc is more stable. As the voltage increases, the arc length increases and the arc stability decreases.

(3) Polarity and type of current
If there is no magnetic partial blow, the DC arc is the most stable, the pulsed DC arc is second, and the AC arc stability is
worse. For the DC arc welding DC reverse connection, the arc stability is better than the DC positive connection. For
tungsten argon arc welding, the arc stability during DC positive connection is better than that at DC reverse connection.

(4) Electrode coating and flux
The electrode coating or flux contains more elements with low ionization energy (K Na Ca). Due to the easy ionization, the
charged particles in the arc atmosphere increase, and the arc stability is improved. When it contains more fluoride chloride
with high ionization energy, it will reduce arc stability.

(5) Magnetic partial blown
Direct current welding is prone to severe magnetic partial blow, and magnetic partial blow is much weaker when AC is used.

(6) Other factors
When there is rust，moisture and oil stain on the weldment, it will consume arc heat when it is decomposed, which will reduce
arc stability.