In Part 2 of the plasma cutting terminology series, we will be looking at more commonly used plasma cutting terms.
Conventional Plasma Cutting: In this process of conventional plasma cutting, usually a single gas, i.e. nitrogen or shop air is used for the purpose of cooling and also producing the plasma. Most traditional cutting systems are usually rated below 100 amps and are used for cutting materials that are 5”to 8” thick.
Arc Lag: Arc lag is the angle at which the plasma arc lags the plasma torch with respect to the vertical direction. This angle increases with the power or speed at which the torch is cutting. The optimal setting is usually at around 5 degrees.
Bevel: Also known as the kerf angle, it is the angle formed on the surface which is being cut caused by the flow of the plasma gas when it is released from the nozzle. The angle depends on the torch height, air pressure, power, quality of the air, cutting direction and speed, and the condition of the consumables.
Dross: During the process of plasma cutting, waste material that is produced, builds up and sticks to the bottom of the material being cut. This is called dross.
Electrode: An electrode is the component that starts the plasma arc in a plasma cutter. An electric current of high frequency is passed between the nozzle and the electrode and a pilot arc is formed. The electrode has an element of hafnium, tungsten, or zirconium at the centre. Every time a pilot arc is produced, a tiny amount of the element evaporates. At this stage, no pilot arc will be produced and the electrode must be replaced.
Duty Cycle: This is the amount of time a plasma cutter can cut in a timeframe of 10 minutes at a particular amperage. Usually, the duty cycle for most mechanised plasma cutters is 100 percent.
Kerf: Also referred to as kerf width, it is the slot that is created by the plasma cutting process.
Swirl Ring: It a ring which is made of a tough material such as ceramic. The swirl ring has tiny holes which swirls the plasma gases. This swirling action accelerates the gases and constricts the plasma arc. With prolonged usage, the swirl ring can turn brittle and must be replaced.
In this article, we have looked at more of the terms and definitions commonly used in the plasma cutting scenario. In the third and concluding part of the series we will look at more terminology that will add to your plasma cutting dictionary.