Study On The Rotating Gmaw Technology With Narrow Groove

The welding structures become bigger and bigger as well as the thickness of the welding steel. the advantages of NG-GMAW such as improved mechanical properties and welding efficiency are limited because of the bad sidewall fusion. High rotating arc can improve sidewall fusion and droplet transfer.10Ni5CrMoV steel and JS80 welding wire are researched in this paper. Rotating speed is the most important factor to have effect on the arc and droplet transfer. High-speed photography is used to monitor the different situations from the different welding conditions. The rotating arc is caused by the rotating current contact nozzle. Two methods are used to measure the diameter of the droplet at different rotating speeds, which shows that the increased speeding can promote droplet transfer. More over, the mechanical model of droplet transfer is simplified to one sphere with a certain speed and two certain stresses. Matlab is used to simulate the tract motion of the droplet, and we found that the motion distance from the central positions is increased with the higher rotating speed, which is the reason for the rotating arc to improve the sidewall fusion. This research provide the tech support for the use of the steel with big thickness in shipbuilding and submarine.