Energy input and metal transfer behavior of CMT welding process

To analyze process characteristic of CMT welding method, experimental systems to photograph arc shape and molten droplet images by using high-speed charge coupled device camera and to record welding current and arc voltage in synchronism were established. The energy input characteristic and metal transfer behavior were analyzed by above-mentioned experimental systems. The results show that CMT welding process is typical direct current impulse process and has lower heat input during welding. The droplet size does not increase obviously with raising welding current. The stable droplet size is beneficial for short circuiting transfer. The spatter can be eliminated with the aid of adscititious force. A hybrid metal transfer made up of projected transfer and short circuiting transfer also can be found when welding current reaching a rather large value.