For the industrial application of laser-arc hybrid welding, the groove gap bridging ability of this process was investigated in detail. The results show that this process has strong groove gap bridging ability: for 4mm thick plate, the weldable gap is 18mm and that of 6mm thick plate is 2.8mm. There also exist optimal ranges of groove gap with good weld shape.
It is 0.5~1mm and0.6~1mm to the 4mm and 6mm thick plate respectively. In the laser-arc hybrid welding, arc current can synchronously determine the arc pressure, the gravity of molten pool, the quantity of melted substrate and filler wire, as well as the fusion state of substrate on the both sides of groove gap. So it is the key factor to the increase of welable gap of hybrid welding. Furthermore, with the same welding speed big arc current can enhance the weldable gap of thicker plate, while relatively smaller arc current should be used to increase that of thin plate.
