Weld penetration sensing in pulsed gas tungsten arc welding based on arc voltage

An alternative to the conventional weld penetration sensing methods in pulsed gas tungsten arc welding is proposed for implementation at manufacturing sites. The fluctuation amplitude of arc voltage in the peak duration (Delta U-k) reflects the weld penetration status in a single-weld spot; a fully penetrated weld spot is obtained in the step-by-step welding process when the abrupt change of Delta U-k (denoted as Delta U'(k)) is above the threshold (1.50V herein). A full penetration control system that employs Delta U'(k) as the feature signal for step-by-step pulsed gas tungsten arc welding can be easily installed at the manufacturing sites. (C) 2015 Elsevier B.V. All rights reserved.