Weld penetration control of wire-filled pulsed gas tungsten arc welding of pipe in the horizontal position

Wire-filled pulsed gas tungsten arc welding (GTAW-P) is usually used to join pipes in the horizontal position, in which uniform full penetration is required to guarantee a high weld quality. Based on the characteristic signals reflecting the penetration degree, the penetration control strategy of step welding is designed, and the dynamic modeling of backside molten pool width using the characteristic signals is conducted by back propagation (BP) neural network. The influence of step distance on the characteristic signals is explored. The weld is well shaped when the step distance is 3 mm. The backside weld width in the horizontal position can be controlled to be around the preset value with the control strategy of step welding and real-time feedback from the prediction of BP neural network. The control system is robust, which can work well under the fit-up condition of variable gap or variable heat dissipation in the horizontal welding of pipe.

Automated summary

Wire-filled pulsed gas tungsten arc welding (GTAW-P) is commonly used for horizontal position welding of pipes, requiring uniform full penetration for high weld quality. A penetration control strategy of step welding is designed using characteristic signals, and the dynamic modeling of backside molten pool width is conducted with back propagation (BP) neural network. The influence of step distance on characteristic signals is explored, with well-shaped welds achieved at a step distance of 3 mm. The control system, utilizing the step welding strategy and real-time feedback from BP neural network prediction, effectively controls the backside weld width in the horizontal position, even under variable gap or heat dissipation conditions.