METHOD AND EQUIPMENT FOR WELDING FIXED PIPINGS

PURPOSE:To obtain the uniform depth of penetration, deposited metal thickness and bead shape over the whole periphery of pipes 1 by detecting the temperature at the time of a peak current of a pulse, changing the supply speed of filler metal and controlling the molten pool temperature. CONSTITUTION:A pulse welding current is impressed between the pipes 1 and an electrode 2 of a welding head 3 to generate an arc 4 and a molten pool 5 is formed. The surface temperature thereof is detected by a temperature detector 6. The welding current is not changed so that the same set temperature is obtained for the respective welding positions of all position welding at the time of the peak current and the supply speed of the filler metal (welding wire) 20 is changed by using a welding controller 13, a wire feed control circuit 22, etc., so that the set temperature is obtained for the respective welding positions of all position welding at the time of a base current. Consequently, sagging of a bead is prevented, simultaneously, the deposited metal thickness is maintained and a satisfactory penetration bead can be obtained.