Plasma arc welding application

Material Types Plasma arc welding can apply for:

  • The PAW procedure is popularly applied for welding stainless steels in the various of range of thickness
  • The process can also be used with carbon and alloy steels, aluminum alloys, titanium alloys, copper and nickel alloys, and more specialized materials, such as zirconium and tantalum.
  • The thicknesses that can be welded in a single pass range from 0.025 mm (1 mil) for microplasma applications to 12.5 mm (0.5 in.) for the VPPA welding of aluminum. Direct-current pulsing can be used on most materials.
  • The PAW process is often carried out in an autogenous mode, that is, without filler wire. When edge beveling is used, a filler wire is required to complete the joint. A filler wire can also be used with the keyhole mode of operation to avoid undercut at high welding speeds. Wire composition depends on that of the parent materials in the joint. The same continuous-wound wire that is used in GTAW operations is suitable.


Plasma arc welding machine can be applied in many fields

Plasma arc welding is used in three modes:

1. Microplasma welding, with welding current from 0.1A to 20A.
2. Medium-plasma welding, with welding current from 20A to 100A.
3. Keyhole welding, above 100A, where the plasma arc penetrates the wall thickness

Industry that plasma arc welding can be used:

The industries that use the PAW process can be categorized as those that weld thin-section sheet using microplasma or medium-current plasma welding and those that weld plate using keyhole plasma welding.

  • A wide range of small devices and assemblies made from thin stainless steel sheet, including bellows assemblies and associated fittings, are welded using the microplasma operating mode.
  • The narrow weld bead that can be produced provides sheet-metal fabrications with a good cosmetic appearance.
  • Furthermore, the high welding speed that can be achieved, coupled with the good tolerance to stand-off variations resulting from the columnar nature of the arc, makes the process attractive for high-volume production work.

Microplasma, as well as medium-current plasma modes, can be used to spot weld guide wires and lamp filaments, as well as in other applications that require highly repetitive autogenous welds. This type of application allows a user to limit the number of high-frequency arc starts that would be required with tungsten-inert gas welding.

Keyhole plasma welding is extensively used to weld stainless steel pipe and tankage. The process is applied to individual strakes from plate to make stainless steel vessels in the food and chemical processing industries. Circumferential welding of strakes also can be used to create these products.

The manufacturing of stainless steel tube from strip was one of the first applications of the PAW process. Because the process can reliably produce full-penetration welds without the use of backing, it is extensively used on tube mills, because a lack of access precludes welding from the inside