oxyfuel cutting and plasma cutting

oxyfuel cutting systems, plasma cutting systems, laser cutting systems

Thermal cutting (oxyfuel cutting, plasma cutting and laser cutting) is used in industry for economical cutting of a wide range of sheet metal, steel profiles and pipes.

Nenok as a specialized used machinery dealer has different used thermal cutting systems available - either as pure oxyfuel cutting machine, as plasma cutting machine or as a combination of both thermal cutting processes.

Oxyfuel cutting

Autogenous cutting is a reliable and cost-effective thermal cutting process. Wear parts such as nozzles and torches are less expensive compared to plasma and laser cutting. In oxyfuel flame cutting, a flame from a gas mixture heats the workpiece to be cut (steel plate or steel profile, etc.). The gas combination of oxygen and the process gas (propane, acetylene, natural gas, mapp) heats the material to be cut up to the ignition temperature of approx. 1200 degrees C (for low-alloy steel). When the workpiece has reached this temperature, the actual burning process is initiated. Almost pure oxygen is now fed into the hot cutting joint and thus heats up the deeper layers of material, transforming the material to be cut into molten slag. The oxygen pressure transports the slag from the cutting joint into the extraction table. The respective cutting torches are moved over the workpiece according to a cutting pattern specified by the CNC control.

Oxyfuel cutting systems

The oxyfuel cutting machines are suitable for flame cutting of thicker steel sheets and steel plates in steel construction, steel trade, mechanical engineering and shipbuilding. Usually 1 to 12 oxy-fuel torches or a combination of oxy-fuel torches and 1 to 2 plasma torches are used. The oxy-fuel cutting systems or the combination of an oxy-fuel and plasma cutting system are the basis of every steel construction company and are used economically from a material thickness of 3 mm to 300 mm. Due to the availability of ever cheaper and more efficient plasma cutting systems or combinations, the use of a pure oxyfuel cutting system is often only worthwhile from a material thickness of 30 mm.

Plasma cutting systems

Plasma cutting is a fast thermal cutting process that is becoming increasingly important in the steel industry and is replacing oxyfuel cutting. Plasma cutting with modern plasma sources achieves much higher cutting speeds. Up to a material thickness of 50 mm (soon to be 60 mm), a higher cutting speed is achieved with mild steel (and other conductive materials) than with oxyfuel cutting. When buying a new machine, most steel constructors increasingly rely on plasma technology. This fast cutting technology is therefore used on gantry cutting machines, sheet metal processing centers, drilling flame cutting systems, notching systems and pipe cutting machines.

By using modern plasma cutting sources from manufacturers such as Kjellberg® with the HiFocus system and Hypertherm® with the HyDefinition system, significantly better cutting qualities are achieved even with thicker material thicknesses. Plasma cutting systems from 100 amp. to 400 amp. are available. power. If the plasma cutting systems are additionally equipped with True Hole or Contour Cut technology, the course of the plasma cut is only slight. The hole quality and the angle accuracy have been improved many times over.

The choice of the respective gas depends on the component material to be processed. When processing mild steel, aluminum and stainless steel, it is possible to use favorable compressed air as plasma gas. In order to achieve a higher cutting quality, the gases nitrogen or a mixture of argon and hydrogen are also used for plasma cutting of aluminium or stainless steel.

In steel construction, however, the use of oxygen is widespread, even if the service life of wearing parts such as cutting nozzles is reduced. However, the cutting speed is increased and the quality of the plasma cut is improved. The slag burr is reduced and thus the costly deburring process.

Plasma cutting machine or plasma cutting system

If the majority of the material thickness to be cut is greater than 3 mm and less than 60 mm sheet thickness, a plasma cut is used, depending on the availability of the machine equipment. The plasma cutting machines are considerably faster and with modern cutting sources from Kjellberg® and Hypertherm® they are accurate up to 60 mm sheet thickness and economical for many flame cutting companies. However, an accurate plasma cut can only be achieved if the equipment also has precise guidance of the gantry and torch unit. Also very important is a stable machine cutting table in combination with a suitable extraction table and a powerful filter system.

The plasma cutting systems are supplied by manufacturers such as Kjellberg® and Hypertherm® to the internationally renowned machine manufacturers, who integrate them into the flame cutting systems.

The following manufacturers offer with their machining centers or portal flame cutting systems different system solutions for steel construction, plant engineering, metal construction, steel trade and shipyards.

ESAB, Ficep, Kaltenbach, Messer Cutting Systems, MicroStep, MGM, Sato, Vernet-Behringer, Voortman and Zinser.

Due to the rapid technical development of plasma sources and machine concepts in the field of flame cutting, ever thicker plates / sheets are produced with higher cutting accuracy and higher cutting speed at the same time.

Pipe cutting machines / 3D profile cutting machines

Thermal cutting of round tubes is either possible with an additional unit on a portal cutting machine or tube cutting machines from manufacturers such as ESAB, HGG, Müller Opladen, Ficep, Voortman, Messer Cutting Systems, MicroStep, Sato, Vernet-Behringer and Zinser are used. Pipe cutting machines are also optionally equipped with oxy-fuel or plasma cutting technology.