Atomic Hydrogen Welding
In this process, an arc is struck between two tungsten electrodes using AC power supply.The Streams of hydrogen gas are passed from orifices around the electrodes into the arc. Here the molecules of hydrogen dissociate into atoms at a point a few millimetres away from the arc and liberate intense heat, which melts the base metal. The hydrogen gas acts as a heat carrier. Filler metal may or may not be used. Till date this process is obsolete.