Estudio de la influencia de la incorporación de arenas ferrosas como parte del fundente utilizado en el proceso de soldadura por arco sumergido sobre las propiedades mecánicas y microestructura de juntas soldadas de acero ASTM A572

Abstract

This experimental study establishes the influence of replacing part of the flux used in SAW process with ferruginous sand, over, the mechanical properties and microstructure of the weld metal. The aim of this study is to determine the feasibility of incorporating raw ferruginous sand to obtain a welded joint of ASTM A572 steel with comparable properties to one obtained using commercial flux. Weld beads (along the joints) were made using neutral flux, incorporating sand in weight ratios between 0,1 and 0,3. Ultimate tensile strength, toughness, and bending behavior of the welded joints was characterized. Additionally, micrographic analysis and measurements of microhardness on weld metal were performed. The chemical composition of the weld metal samples was analyzed using optical emission spectrometry to verify the variation of alloying elements. The results show that the amount of manganese and silicon is reduced, leading to the formation of nucleate structures different to acicular ferrite. The bending behavior of welded joints obtained when the weight ratio is 0,1 remains unchanged, however, the tensile strength, yielding point, and the percentage of elongation decreases due to the presence of porosity, as a result of the oxygen released from the minerals contained in sand during the process.