Influence of Flux Basicity on Weld Bead Geometry and HAZ in Submerged Arc Welding

Abstract

Weld bead geometry and heat affected zone which are generally dependent on the welding parameters may also be influenced by the chemical composition of flux i.e. the flux base and its basicity in submerged arc welding. The different flux constituents which impart different physical/chemical properties to the flux may also affect the weld bead geometry and heat affected zone. Investigation have been carried out to study the combined effect of welding parameters and flux basicity which is one of the measure for chemical nature of the flux on weld bead geometry and heat affected zone in the case of mild steel. It has been found that the welding parameters and flux basicity appreciably influence the depth of penetration and the weld bead width. The reinforcement is also influenced by the welding parameters, however, flux basicity does not seem to affect reinforcement appreciably. The widths of heat affected zones at the centre line of the weld bead and at the toe of the weld are appreciably influenced by the welding parameters. Higher basicity fluxes generally give rise to lower width of heat affected zones as compared to low basicity fluxes.