Influence of the chemical composition of flux on the microstructure and tensile properties of submerged-arc welds

A study was conducted on the effect of flux composition for the microstructure and tensile properties of a submerged-arc welded AISI 1025 steel. Three flux compositions were used with a low-carbon electrode. A commercial flux composition was used for comparison. The welding conditions were kept the same. Tension tests were pursued at room temperature. Microstructure and macrostructure of welds were observed with light and scanning electron microscopes (SEM). The presence of acicular ferrite was detected for welds of fluxes with the highest content of titanium oxide. The yield and ultimate tensile strengths seem to be influenced by the presence of acicular ferrite. The elongation and area reduction percentages are affected by the inclusion volume percentage. Tensile properties and microstructure were compared with the values predicted by the computer programs.