Specifities of application of activating fluxes in electrical welding in protective atmosphere

Abstract

Without the increase in welding current, activating fluxes for arc welding with a non-consumable electrode (ATIG) and for welding with a consumable electrode (AMIG) allow for the increase in depth of penetration 2-4 times. These two procedures are essentially different in terms of their implementation. In AMIG welding, the problems in the creation of a welding joint stem from the influence of the critical value of the metal bath surface. The critical value of the surface is achieved by using welding current of 280-300 A and, according to the experimental results, its value is 160-190 mm². By achieving the critical surface value, the positive influence of the activating fluxes on the penetration ability of the electric arc is lost. Optimum interval of welding current for AMIG is 200-500 A, which significantly exceeds the permissible threshold. In ATIG welding, the effect of the critical surface of the bath is not observed, because it requires welding current that exceeds the optimal value interval (max. 250 A), which is conditioned by the stability of the non-consumable electrode. By increasing welding current over 250-300 A, the working tip of the electrode is rapidly consumed and the stability of the welding process is disturbed.

Keywords

• welding
• activating flux
• penetration depth
• metal bath
• critical value surface
• heat input