Prediction of Element Transfer Behaviour in SAW Process Using SiO2-CaO-TiO2 & Al2O3-SiO2-CaO Silica Based Flux Systems

Weld mechanical as well as metallurgical properties are widely affected by the flux composition. Selection of flux composition play an important role in determining the good bead quality and mechanical properties of the welded joint. By using laboratory developed agglomerated rutile basic fluxes a study has been carried out to predict the element transfer behaviour in submerged arc welding process (SAW). With the application of mathematical experiments of mixture design approach different statistical model were developed in terms of flux constituents. Using twenty one rutile basic submerged arc welding fluxes a series of bead on plate weld deposits were made at constant welding parameters. Twenty one submerged arc welding fluxes were prepared as per mixture design approach for SiO2-CaO-TiO2 & Al2O3-SiO2-CaO flux system. Regression models were developed in terms of individual, binary and ternary mixture flux constituents for different ∆ quantities. Mathematical regression models have been checked for 95% significance level by using F-test. Results indicates that there was predominant effect on weld metal carbon, silicon, manganese, sulphur, phosphorous, molybdenum and chromium contents. Individual flux ingredients CaO and SiO2, has synergistic effect on ∆C and increases its weld bead carbon content while TiO2 and Al2O3 shows antisynergistic effect on ∆C and decreases the delta carbon content in weld region.