Plasma cutting machine nozzle is exposed to a mechanical pressure, thermal and magnetic constriction of plasma arch through splattering plasma gas, so as to increase energy thickness and impacting strength to accomplish the cut process. Plasma nozzle arch functions as an arch guide. During the operation electrodes serve as cathode, the nozzles as anodes. As a result of electrical area plasma gas ionized products guide the arch within the field of electrode and nozzle. Flame flowing brings about arch connection with the work piece. In the aftermath of flame flow, nozzle is replaced by the work piece serving as anode and a cut plasma arch forms within the electrode and nozzle field. Among CNC plasma cut equipment properties nozzle is the most consumable one. Replacing it while operating is not weird for it appears a wear element of the CNC cut equipment torch. The reflection may differ to some extent like too frequent nozzle change and highly defective nozzle.
- Mixed gas intersects the area of high frequency arch. Gas might consist of air or a mix of hydrogen, argon, azote. High frequency arch ionizes gas into main atomic particles generating plasma. Arch passes to stainless steel blank, plasma gets blown out of the gas –jet by high-pressure gas at exiting rate of 800-1000 mm/s. The generated energy when the plasma gas comes to a regular condition produces heat of 2700 degrees, which is twice as much as stainless steel melt temperature. Stainless steel melts swiftly and high-pressure gas flow blows melted metal off. It needs smoke purification and deslag mechanism.
- In case of improper use of the cut equipment, faults may occur. For instance, cutting jet appears too close to steel plates while operating (it should be at least 3-8 mm for 100 A plasma cutter), the outer inlet voltage is excessively big or unsteady and the like.
- The work piece material, density and cut procedure influence serving life of the nozzle. While cutting stainless steel or regular iron nozzle expenditure is not so high. In case of cutting 10 mm thick plates, nozzle will be spared, but thicker plates up to 16 mm require frequent nozzle replacement. Plate puncturing requires nozzle replacement twice as much as edge arch cut process.