Filling-material-free low-alloy steel heat-exchange pipe butt-joint automatic welding technique

The invention provides a low-alloy steel heat-exchange pipe butt-joint automatic welding technique. The technique comprises the following steps that a first heat exchange pipe (1) and a second heat exchange pipe (2) are assembled; welding equipment is mounted and debugged; and welding technological parameters are arranged, and welding treatment is conducted. The low-alloy steel heat-exchange pipe butt-joint automatic welding technique is free of a filling material, a tool (7) is adopted for assembly of the heat exchange pipes, and the coaxial effect is ensured; and a welding machine head and the tool (7) are matched for clamping, and the positions of a tungsten electrode and the heat exchange pipes are controlled; and according to the welding parameters and the operating requirements of the technique, the rotation center of the welding machine head drives the tungsten electrode to rotate to conduct self-melting automatic welding, the welding process is stable, the welding seam quality and welding seam forming