Effect of fluxes containing oxides on tungsten inert gas welding process

The use of an inorganic powder, termed activating flux, is a technique that can be used to improve the tungsten inert gas welding process. The activated tunsten inert gas (ATIG) process greatly increases single pass depth penetration. In the present work the activating effect of different oxides on 304L stainless steel was studied, to determine the main relationships between the oxide propertie(s) and the weld bead geometry variation and consequently to determine the mechanism(s) occurring during the ATIG welding process. The results show that oxide melting point T _m, the liquid state ( T _b– T _m), the lattice energy E _L, and the quantity of oxygen that can be liberated seem to play an important role, even though T _m is the main property. Moreover, for some oxides, the hygrometry rate is another property that can increase the activating effect.