scope:

Hot Wire welding and surfacing techniques are the result of the combination of a heat source with a separately added resistance heated (PR) and melted wire. The welding or surfacing heat may be provided by any one of the welding or surfacing arc processes, as well as flames, induction heating, radiant heating, etc. The 12R heating power source is completely independent of the welding heat source, and may provide either direct current (dc) or alternating current (ac) power for melting the wire filler. The 12R melted wire is added to the welding or cladding zone by conventional wire feeding equipment. Correlation of the Hot Wire feed rate and melting current is required to avoid intermittant arcing or sparking of the wire due to a local "fuse action." When practiced in the preferred way the Hot Wire is deposited in a completely arcless manner. The Hot Wire addition process has at times been referred to as an arcless deposition process. Several versions of the Hot Wire process are used commercially and have been described in the literature. These include:

1. Gas Tungsten Arc (GTA) plus Hot Wire

2. Plasma Arc plus Hot Wire

3. Submerged Arc plus Hot Wire Other heat source combinations have been used but are not sold commercially.