About Plasma Cutting

Plasma cutting, also known as plasma-arc cutting, is a technology that evolved from the WWII era plasma-arc welding technique. The process involves using a tungsten electrode and high pressure plasma (which is gas in an ionized state) to generate and carry an electrical arc between a copper nozzle and workpiece. It is the electrical arc that performs the cutting, but the pressurized plasma helps to keep the cut cleared by removing the dross (metal impurities generated by the cutting).

Temperatures

The plasma used in plasma cutting is under such intense pressure that it can reach temperatures of over 36,000 degrees F during the cutting process.

Plasma Gases

Plasma cutting employs a number of gases to produce plasma, including argon, nitrogen, oxygen and regular air.

Electrodes

While tungsten electrodes are the standard, plasma cutting that uses regular air for plasma creation require the use of copper mounted hafnium or zirconium electrodes.

Electricity

Plasma cutting is a high-voltage process that can require up to 400 volts during initialization of the arc.

Calibration

Calibration of the plasma torch is extremely important. An improperly calibrated plasma torch may generate a double arc, which can melt the torch nozzle.

References

• Cutting processes -- plasma arc cutting -- process and equipment considerations
• Plasma-arc Cutting Technology