Plasma cutting: technology and flow chart
Plasma cutting is a method of cutting the metal by plasma stream. This method allows cutting any metal that has electrical conductivity. Comparing to other cutting methods, plasma cutting allows treating the metal faster, better, without enormous gas cylinders, and special additives.
It is possible to process various rolled metal products – metal sheets, pipes of various diameters, shaped and sorted products.
Scheme
Plasma cutting provides high quality cut and allows to remove various defects from the metal surface, such as protrusions, seams and unevenness, and prepare for welding, drilling and etc.
Quality of plasma cutting
Air-plasma cutting technology
Air-plasma cutting is performed by the special equipment that has sizes of a regular welding machine. Originally, this equipment had large dimensions but gradually they became smaller. The household versions of the equipment are connected to the power supply of 220V and the industrial ones – to the power supply of 380V.
CNC guided machines can perform actions on the embedded program, which greatly simplifies the work in the case of cutting the same metal sheets.
To create a plasma stream the system should be connected to the compressor or air supply line. The compressed air supplied to the machine should be cleaned of dirt, dust and moisture droplets. For this purpose, air filters and a dehumidifier are included in the system. Without such devices, wear of electrodes and other elements will occur faster. Plasma torches with liquid cooling also require a water supply unit.
The air-plasma technology allows achieving a good cut quality and avoiding the strains. Therefore, it’s possible to perform welding the cut metal without preliminary machining.
The essence of plasma cutting sheet metal
Plasma cutting of steel is carried out by the equipment including the hoses of up to 12 m in length. Hand-held devices have air cooling system, as it is simpler in design and does not require an additional cooling unit. Water cooling is used for the equipment of industrial use, it is more efficient, but the price is higher.
Oxy-plasma cutting technology
Oxy-plasma cutting requires special electrodes and nozzle withstanding a significant temperature exposure. First, an auxiliary arc gets ignited from the discharge created by the unit oscillator. Then the arc creates a plasma torch of 20-40 mm in length. When the torch touches the metal, the working arc arises and the auxiliary arc disappears. Thus, the plasma acts as a conductor between the machine and the workpiece. The working arc is self-sustaining, it creates a plasma by ionizing the air molecules. The working temperature of plasma cutting is up to 25 000 °C.
Plasma cutting of big diameter pipes
The plasma cutting can be performed both at the industrial facility and outdoors. However, this method is not as efficient as the plasma cutting at the facility. Nevertheless, it can be useful when you need to treat the workpieces of different size and shape.
The plasma cutting of the parts of large diameter is easily performed manually or by self-propelled machine. The self-propelled machine makes a turn on the outside of the pipe with a fixed burner. The self-propelled machine provides accurate and even cut. Cutting shaped and rolled products can also be automated, especially in industrial conditions/
The advantages of Sibir equipment:
- Versatility (any metal including nonferrous and refractory metals can be used);
- High cut speed;
- High quality of the surface after cutting;
- Efficiency (due the use of compressed air);
- No thermal deformations on the part being cut;
- Mobile and light (in case of air cooling);
- Ease of operation.