Arc efficiency of Gas Tungsten Arc Welding (GTAW) was determined by calorimetric method. A water-cooled anode calorimeter was designed and manufactured to measure the arc thermal efficiency, which was determined as a function of current, arc length, polarity and gas flow rate for GTAW of mild steel. With Direct Current Electrode Negative (DCEN) polarity and 5 mm arc length, a thermal efficiency of 67±4% was obtained, which was independent of the welding current. With Direct Current Electrode Positive (DCEP) polarity and 5 mm arc length, arc thermal efficiency was determined as 52±4%. The experimental data show that the arc efficiency decreases from 67% to 58% and 51% as the arc length increases from 5 mm to 11 and 17.5 mm, respectively. The experimental results also show that the arc efficiency is not significantly affected by the shielding gas flow rate.
- Arc length
- Arc welding
- Thermal arc efficiency
- Water-cooled anode calorimeter