Sol-Gel Fluxes for Flux Cored Welding Consumables

摘要

The feasibility of producing high purity homogeneous welding fluxes by the sol-gel process and the effects that these fluxes have on the welding process were determined. Reagent grade sol-gel welding fluxes were produced by making systematic variations of the Si02-Ca0-Ti02-1% Na20 flux system. The resulting fluxes were made into flux cored wires and used to make bead on plate welds on a niobium microalloyed HSLA steel. Sol-gel fluxes were shown to have excellent homogeneity, low residual hydrogen content and no apparent water adsorption. The welding behavior of the sol-gel fluxes were shown to have superior arc stability compared to a commercial flux cored wire and very low weld metal hydrogen content. The chemical behavior of this flux system was characterized with respect to elemental transfer. The weldments exhibited a primarily acicular ferrite microstructure. Analysis of non-metallic inclusion size distributions was compared to previous investigations and found to be consistent with the formation of high toughness weld metal microstructure.