Effect of TiO2-containing fluxes on the mechanical properties and microstructure in submerged-arc weld steels

This work presents a study of the effect of TiO₂ additions in fluxes on the mechanical properties and microstructure of the weld metal formed during Submerged-Arc Welding (SAW) of ASTM A-36 steel plates. Four fluxes with about 9, 12, 15 and 18% Ti were used with a low-carbon electrode. The welding conditions were kept constant. The microstructure of the weld metal for each flux consisted mainly of equiaxed ferrite and acicular ferrite. The increase in the percentage of acicular ferrite and a decrease in its length were observed with an increase in titanium content. The increase in titanium content in fluxes also improved the toughness and ductility of the welds.