NARROW GROOVE CO2 GAS SHIELDED WELDING METHOD

摘要

PURPOSE:To readily execute narrow groove welding in the state free from flowing down of molten metal and penetration defect by setting welding current and arc voltage between the respective lower and upper limit values in compliance with the change in the groove spacing of the rotating butt pipes. CONSTITUTION:In the narrow groove CO2 gas shielded arc welding method, the welding current I and arc voltage V are set between the respective lower limit values Ia, Va and upper limit values as shown in formulas in compliance with the change in the groove spacing X of the both side groove faces 1a, 1b of the pipes to be welded 4. In this case, it is desirable that a torch 5 be deviated in the welding direction from the position right above the pipes 4 and welding be done by setting the angle of inclination theta of the torch at 10-20 deg.. Namely, by setting the welding current and arc voltage like above, the narrow groove welding may be readily executed in a good state simply in terms of the execution of welding method without using any intricate device. Here, 3 in the figure denotes beads and 2 the low melting point liquid phase of the final period of solidification, respectively.