The experimental material was a 25 mm thick low-carbon mild steel plate corresponding to ASTM A283, and its major alloying elements were C-0.17, Si-0.19, Mn-0.51, S-0.020 and P-0.040. Plate samples measuring 350x220x25 mm were flame-cut from a single large plate, and surfaces were cleaned to remove dirt and oxides.
The welding consumables use in the investigation were those that are commonly use for the ASTM A283. Thus, an ESAB OK AUTOROD-12.0 (conforming to AWS A5.17-89 EL 12) electrode wire 3.0 mm in diameter was used in conjunction with ESAB OK Grain 21.85 (C-0.14%C, MN-1.8% and Si-0.40%). The submerged welding are unit used was LINCOLN IDEALARC DC-1500 transformer/rectifier along with an NA-5 control unit and feeding head. For all samples, reverse polarity or direct current electrode positive (DCEP) was used, and the power source was set to constant voltage (CV) mode. Powder addition was chosen for the current work, because of the simplicity of setting the forward feed method. The amount of powder dispensed was determined from the digital meter on the powder feeder control unit.