Key words: resistance welded pipe machine
Resistance welded pipe machine is 3 to 5 times more efficient than traditional TIG welding. After that, the filling and covering process of TIG welding bottom seal MIG welding changed due to imperfect penetration and shrinkage of the root. The improved welding process basically solves the problem of insufficient root penetration, but reduces the welding efficiency. Increase equipment investment and complicate operation procedures. Recently, hot pot TIG automatic pipe welding machine was introduced from abroad. The principle of hot wire TIG welding is to feed filler wire into molten pool.
Previously, power was supplied from a separate constant voltage AC power supply.  The resistance is heated to 650 - 800 C, which greatly accelerates the melting rate of the wire, and its deposition rate is close to that of the same diameter MTG welding.


In addition, the good back sealing characteristics of TIG method ensure the melting quality of backing beads. Therefore, hot wire TIG welding is the preferred welding method for butt welding of small diameter and wall thickness pipelines. However, the feasibility of using pulsed MIG welding in the butting of small diameter and wall thickness pipelines should not be totally negated. Through a large number of experiments, it is found that more than 90% of the root penetration is located in the super-arc part of thick-walled pipe MIG butt welded joints, and sagging is caused by overheating. Molten metal in molten pool during continuous multi-layer welding.  If the power of welding arc is controlled accurately, the above defects can be eliminated completely. However, due to the original welding power source of imported MIG automatic pipe welding machine, thyristor pulse power source can not realize arc power source program control, such as switching to the most advanced digital control inverter pulse welding power source or waveform control pulse welding power source (computer software control). The welding arc power can be easily controlled according to the welding process requirements to ensure the welding quality of the joints.