The process is operated using the ‘transferred arc’ mode, in which the arc is maintained between the electrode and the material to be cut; a pilot arc is maintained between the electrode and the constricting orifice. The cutting process uses high plasma gas
flows and active gases.
Properties of Plasma Cutting:
- A high energy density heat source allows melting and ejection of molten material in the high velocity plasma jet
- It can be used for a wide range of ferrous and non-ferrous alloys and is particularly suited to cutting of aluminium alloys and stainless steels
- Plasma gases may be argon/hydrogen mixtures, nitrogen, air or even oxygen, and water-cooled electrodes with tantalum tips are often used.
- Secondary gases may be CO2, N2 or air
- Welding fume is generally high, but some modern equipment is capable of maintaining low fume levels
- The process tends to be noisy and generates high levels of radiation.