FORMATION OF MOLTEN DROPLETS AT A CONSUMABLE ANODE IN AN ELECTRIC WELDING ARC

A theoretical dynamic model has been developed to predict the formatio n of molten droplets on a moving wire electrode in a gas metal welding are. Calculations have been made of the droplet shape and size as a f unction of the welding current by accounting for the electromagnetic p inch effect, surface tension, gravitation and momentum transfer due to motion of the solid wire electrode. Our calculations start with an ar tificial cylindrical liquid column which, for low currents, develops i nto a droplet which is dose to spherical. However, for currents above about 250 A, the magnetic pinch constricts the column such that a smal ler elongated droplet is formed.