Bead characterization of FCAW of a rutilic fluxed core wire

摘要

This paper studies the effect of operational conditions on bead shape characteristics in fluxed core arc welding with a Brazilian-made wire with rutilic flux (ASME SFA-5.20: E71T-1/E71T-9/E7U-9M) of 1.2mm in diameter. Bead-on-plate downhand welding trails were performed on 12mm-thick low-carbon steel plates with a constant voltage power supply. A digital data logging system was used to measure the welding current and voltage, and wire feed rate. While the shielding gas composition (75% Ar-25% CO_2 and 100% CO_2), wire polarity, and feed rate (7 and 9 m/min) were varied during the trials, the electrode voltage (16 mm) and arc length (3.5 mm) were not changed. Weld bead characteristics (penetration depth, width, and fused and deposited areas), the presence of discontinuities, bead microstructure, and hardness were evaluated. Welding conditions of high productivity (high deposition rate) associated with adequate bead characteristics were determined for the wire.