Bead-on-plate welds were produced using twenty four fused reagent grade submerged arc welding fluxes, selected from three flux systems, SiO2-MnO-FeO, MnO-CaF2 and SiO2-CaO-CaF2. The welds were processed using AISI 1010 steel coupons, and a Lincoln L-50 AWS type A5.17) welding wire with a constant heat input of 3.0 kJ mm−1. The three flux systems were selected because of their different oxygen potentials and their ability to produce welds with a wide oxygen range (70 to 1400 p.p.m.). Qualitative and quantitative metallography and chemical analysis were performed on the welds. Inclusion morphology and volume fraction are observed to be affected by flux composition Inclusions of 1 μm in size and greater are associated with grain boundary and blocky proeutectoid ferrites, while inclusions 0.64 μm and smaller are linked with the presence of acicular ferrite.