Chemical Reactions during Submerged Arc Welding with FeO-MnO(2) Fluxes

摘要

Measurements have been made of the compositional changes of fluxes and weld metal during submerged arc flux welding with a series of synthetic MnO-FeO-SiO2 model fluxes containing 40 wt pct SiO2 and different ratios of Mn0 to Fe0. Mechanisms for the transfer of Mn, O, Si, C, S, and P are discussed in terms of thermodynamic driving forces and kinetic factors such as diffusion, nucleation, and segregation. One unique deduction is that interfacial, not bulk activities of components (such as FeO) govern transfer into (or out of) the metal phase. The concentrations of C, P, S, and possibly Si tend to be larger in the molten weld metal than in the base plate.