Abstract:

The droplet transfer in the twin-wire co-pool gas-shielded metal arc welding （TCGMAW） process greatly affects the welding seam appearance and the welding quality. In this paper, the transfer trajectory of the droplet in TCGMAW process is explored according to the high-speed photographing results, and the characteristics of the droplet transfer are theoretically analyzed. Then, some mathematical models are set up in the body-fitted coordinates based on the analytical results to describe the heat and momentum inputs caused by the droplets entering the molten pool, and the boundary conditions of momentum and energy on each surface of the molten pool are investigated. Moreover, a numerical simulation is performed for the welding seam appearance. The results are finally com- pared with the experimental ones. It is found that the simulation results accord well with the experimental ones and that the proposed model is of excellent feasibility .

Key words: twin-wire co-pool, gas-shielded metal arc welding, droplet transfer, welding seam appearance, numerical simulation