Calorimetric Measurement of Droplet Temperature in GMAW

Average temperature was calculated from calorimetric measurements in free-flight gas metal arc welding (GMAW) for ER70S-6 (carbon steel), ER316L (stainless steel), and ER4030 (aluminum) electrodes. Measurements were conducted using a constant-pressure water calorimeter to capture the droplets and a flow-through copper cathode/calorimeter to carry the arc. Thermocouples were used to monitor the temperature change of the water flowing through the cathode as well as in the constant pressure calorimeter. Results show a local minimum in temperature during the transition from globular to spray transfer modes.