Ionization-Recombination Equilibrium

The ionization-recombination equilibrium is nothing more than the ratio of charged to neutral particles in the arc. If the ratio is right, the arc burns stably and heat transfer is uniform. If it tips, the arc becomes unstable, flickers or wanders, and you get a dirty weld with lack of fusion or undercut. In practice, you usually notice it in the weld bead: irregular ripples or color changes indicate a fluctuating arc. This almost always has to do with gas coverage or too high a travel speed. So: check gas flow and torch guidance, then it'll run smoothly again.