Plasma Cutting Systems
FAST, ACCURATE AND HIGH QUALITY
Plasma cutting was originally developed for the thermal cutting of materials which were unsuitable for flame cutting, such as high alloy steels or Aluminum. Today, the process is also used for the economical cutting of thin, low alloyed steels.
WHAT IS PLASMA? THE FOURTH STATE OF MATTER
One common definition of plasma is to describe it as the fourth state of matter. We normally think of the three states of matter as solid, liquid, and gas. For a common element, water, these three states are ice, water, and steam. The difference between these states relates to their energy levels. When we add energy in the form of heat to ice, the ice melts and forms water. When we add more energy, into the water it vaporizes into hydrogen and oxygen, in the form of steam. By adding more energy to steam these gases become ionized. This ionization process causes the gas to become electrically conductive. This electrically conductive, ionized gas is called a plasma.
HOW PLASMA CUTS THROUGH METAL
The plasma cutting process, as used in the cutting of electrically conductive metals, utilizes this electrically conductive gas to transfer energy from an electrical power source through a plasma cutter torch to the material being cut.
The basic plasma arc cutting system consists of a power supply, an arc starting circuit and a torch. These system components provide the electrical energy, ionization capability, and process control that is necessary to produce high quality, highly productive cuts on a variety of different materials.
The power supply is a constant current DC power source. The open circuit voltage is typically in the range of 240 to 400 VDC. The output current (amperage) of the power supply determines the speed and cut thickness capability of the system. The main function of the power supply is to provide the correct energy to maintain the plasma arc after ionization.
The arc starting circuit is a high frequency generator circuit that produces an AC voltage of 5,000 to 10,000 volts at approximately two megahertz. This voltage is used to create a high intensity arc inside the torch to ionize the gas, thereby producing the plasma.
The Torch serves as the holder for the consumables especially nozzle and electrode, and provides cooling (either gas or water) to these parts. The nozzle and electrode constrict and maintain the plasma jet.
PLASMA CUTTING CHARACTERISTICS:
- Plate thickness: 1/32 inch (0,8 mm) up to 6 inches (150 mm)
- Typical: 1/8 inch (3 mm) up to 3 inches (75 mm)
PLASMA CUTTING KEY FEATURES:
- Low to high cut quality
- Smooth, edge surface
- Metallurgical perfect surfaces for welding
- Medium heat input
- Excellent cutting speed
- Hardening within the area of the HAZ
- Wide range of material