Control of back weld pool shape in MIG welding by using switch back method

This paper deals with the problem concerning the sensing and controlling of weld pool shape in the MIG welding of plates. In the robotic one side MIG welding process without a backing plate, in order to obtain a good quality of weld, it is important to control the weld pool shape so as to prevent the melting metal from burning through the plate. The method of controlling the weld pool shape is discussed. The moving torch is repeatedly switch changed, known as the switch back method. Primary welding experimental results have proved that the switch back method is effective and satisfactory for controlling the back weld pool shape in one side MIG welding processes without a backing plate.