Electroslag welding (ESW)
A welding process that produces coalescence of metals with molten slag that melts the filler metal and the surface of the workpieces. The weld pool is shielded by this slag which moves along the full cross section of the joints as welding progresses. The process is initiated by an arc that heats up the slag. The arc is then extinguished by the conductive slag which is kept molten by its resistance to electric current passing between the electrode and the workpieces.