Influencia de la cantidad de O2 adicionado al CO2 en el gas de protecci?3n sobre la microestructura del metal depositado en uniones soldadas de bordes rectos en aceros de bajo contenido de carbono con el proceso GMAW

摘要

The presence of acicular ferrite (AF) in the microstructure of weld bead, in a specified range of values, increase considerably the toughness of welded joints. The present paper, for that reason, study the relationship between the acicular ferrite quantity in the deposited metal and the oxygen present in the active gas mixture of CO2+O2, during the execution of butt welded joints with straight edges, in low carbon steels with consumable electrode and gas protection (GMAW) in invariable conditions of process parameters (welding current, arc voltage, welding speed, electrode extension, and gas flow). The graphic relation between the acicular ferrite and the oxygen content was established, as result of the research work.